ALBERT

Description: On the Qinghai-Tibetan Plateau, the ecological crisis appears in every physical and social aspect, and typically affects the rangelands on which most local people depend for their livelihood. Until today, however, changes in land use and vegetation cover on this Plateau have not yet been adequately and practically treated in studying the framework of sustainability. This thesis deals first with the basic ecological influences and interactions before reviewing their implications for development. The limitations of an ecological perspective is recognized, but this stems mainly from the misapplication of perspective and should not detract from its value. Ecology is undoubtedly the most basic and pervasive of the many determinants of the pastoral production systems of the high-frigid land. To ignore ecology or to fail to take it into account is to court disaster. The amount of literature reflects the importance of the subject but is not reviewed here in any detail; rather the aim is simply to set the scene for later discussions.

Description: thesis

Description: DFG, SUB Göttingen

Description: Der vorliegende Band 52 der Abhandlungen „Anthropogeographie“ des Instituts für Geographische Wissenschaften der Freien Universität Berlin erfasst mit 54 Beiträgen den wissenschaftlichen Forschungsstand der IGU-Kommission “Urban Development and Urban Life”. Die vorgelegten Fassungen stellen die diskutierte und revidierte Form der Beiträge dar, die während der Jahrestagung der Kommission vom 15. bis 20. August 1994 in Berlin gehalten wurden. Die Tagung selbst stand unter dem Thema “Urban Transition and Quality of Life” und forderte damit in den jeweils zwei Einführungs- und zahlreichen weiterführenden Referaten der drei Arbeitsthemen 1) “Restructuring Urban Systems in Central and Eastern Europe“, 2) “Unemployment and Informal Economy in Cities” und 3) “Urban Identity, City Image and Urban Marketing” zu Bewertungen des Forschungsstandes bzw. kritischen Stellungnahmen durch aktuelle Forschungen heraus.

Description: 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0004.pdf"〉Titelseite〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0005.pdf"〉Titelseite〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0006.pdf"〉Vorwort〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0007.pdf"〉Foreword〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0008.pdf"〉Inhaltsverzeichnis〈/a〉〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0009.pdf"〉I. Introduction〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0010.pdf"〉Reflections Between Urban and University Structures and Planning〈/a〉〈br〉(Dietz, K., Braun, G. O.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0011.pdf"〉Berlin - Metropolis in Transition: The State of Urban Development in 1994〈/a〉〈br〉(Ellger, C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0014.pdf"〉Planning for the Future of Berlin〈/a〉〈br〉(Branoner, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0016.pdf"〉Strategic Planning in Berlin〈/a〉〈br〉(Braun, G. O.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0019.pdf"〉Change in the Urban Structure in the Five New Länder: The Example of Eisenach〈/a〉〈br〉(Cassel, M., Schwaderer, G.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0021.pdf"〉II. Restructuring of Inter- and Intra-Urban Systems〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0022.pdf"〉Questions on Hierarchical Change in Urban Systems in Eastern and Central Europe〈/a〉〈br〉(Rey, V.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0026.pdf"〉Urban and Urban System Development in Central and Eastern Europe〈/a〉〈br〉(Grimm, F.-D., Taege, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0030.pdf"〉The Impact of Recent Socio-Political and Economic Changes on the Development of Slovenian Towns〈/a〉〈br〉(Pak, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0033.pdf"〉An Urban Evolution Model Applied to Romania's Towns〈/a〉〈br〉(Ianos, I.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0038.pdf"〉Warsaw: Development Problems and Strategies〈/a〉〈br〉(Korcelli, P., Potrykowska, A., Weclawowicz, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0039.pdf"〉The Urban System and Emerging Structure: An Application of Gibb's Measure to the Case of India〈/a〉〈br〉(Mookherjee, D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0041.pdf"〉Reorganisation of the Urban System in Sri Lanka〈/a〉〈br〉(Wanasinghe, D. S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0046.pdf"〉The Formation of an European Urban System〈/a〉〈br〉(Rozenblat, C., Pumain, D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0051.pdf"〉On the Impact of Internationalization Process on the Finnish Settlement System〈/a〉〈br〉(Palomäki, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0055.pdf"〉Global Perspective of Seoul as a World City in the Region of Pacific Rims〈/a〉〈br〉(Kim, I.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0057.pdf"〉Urban Systems Dynamics: Evidence for the Toronto Urban System: 1930-1991〈/a〉〈br〉(Preston, R. E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0060.pdf"〉The Growth of Toronto: A Market-Share Approach〈/a〉〈br〉(Simmons, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0064.pdf"〉Industrial Restructuring and Urban Development: An Examination in Metropolitan Detroit〈/a〉〈br〉(Sinclair, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0067.pdf"〉Counter-Urbanization in Perspective: Images and Reality in Settlement System Change〈/a〉〈br〉(Davies, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0069.pdf"〉Urban Region as a Geoeconomic and Geopolitical Unit in "A Europe of Regions"〈/a〉〈br〉(Vartiainen, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0070.pdf"〉The Ethnic and Social Division of a World City: The Case of London〈/a〉〈br〉(Petsimeris, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0075.pdf"〉Transformation in the South African Apartheid City – Residential Desegregation in Pietersburg: A Case Study〈/a〉〈br〉(Donaldson, S. E., Kotze, N. J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0078.pdf"〉Intra-Urban Distribution of Ethnic Minorities in Munich and Duisburg〈/a〉〈br〉(Yamamoto, K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0083.pdf"〉New Urban Poverty in the Basque Country and Navarra〈/a〉〈br〉(Ferrer, M., d’Entremont, A., Ciscar, I., Saracibar, M. A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0085.pdf"〉Polarization and the Dutch Welfare State. The Case of Amsterdam〈/a〉〈br〉(Ostendorf, W., Musterd, S.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0088.pdf"〉III. Informal Economy〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0089.pdf"〉The Labour Market and the Role of Informality in Urban Mexico〈/a〉〈br〉(Aguilar, A. G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0092.pdf"〉The Informal Economy in Chinese Cities〈/a〉〈br〉(Qi, S. D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0093.pdf"〉The Urban Informal Sector: A Third World Experience〈/a〉〈br〉(Geeta Reddy, A., Rajkumar, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0094.pdf"〉Informal Urban Economy in the Lake Chad Basin〈/a〉〈br〉(Simeu-Kamdem, M.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0095.pdf"〉IV. Recent Urban Processes〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0096.pdf"〉City Challenge: Involving the Community in UK Urban Policy? 〈/a〉〈br〉(Lewis, J. R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0098.pdf"〉Intra-Metropolitan Relocation of Work Places: The Case of Stockholm〈/a〉〈br〉(Mahieu, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0102.pdf"〉Problems of Mobility and Traffic in the Ruhr〈/a〉〈br〉(Lötscher, L., Fleisgarten, S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0103.pdf"〉Moscow 1993: The Emergence of Housing Market and the Problems of Intra-Urban Segregation〈/a〉〈br〉(Vendina, O. I.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0107.pdf"〉V. Urban Marketing, City Management, Urban Identity〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0108.pdf"〉Urban Marketing: A Review〈/a〉〈br〉(Borchert, J. G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0109.pdf"〉Urban Identity, City Image and Urban Marketing〈/a〉〈br〉(Dematteis, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0110.pdf"〉The Hidden Faces of the City〈/a〉〈br〉(Racine, J.-B.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0111.pdf"〉The City of Bergen. Image and Marketing〈/a〉〈br〉(Sjøholt, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0113.pdf"〉Structural Underpinnings of an Olympic City Bid〈/a〉〈br〉(Davies, R. J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0116.pdf"〉Double Cities: Identity and Marketing of a New Urban Product〈/a〉〈br〉(Buursink, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0118.pdf"〉Corporate Space and Emerging Spatial Order in Japan〈/a〉〈br〉(Fujita, N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0125.pdf"〉The Development of International Tourism in Tallinn, Estonia〈/a〉〈br〉(Kuus, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0126.pdf"〉Conflict, Consent, Cooperation: Comprehensive Planning in Germany Beyond Market and State〈/a〉〈br〉(Helbrecht, I.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0127.pdf"〉Urban Strategies: Mega Events. A Copenhagen Perspective〈/a〉〈br〉(Thor Andersen, H., Wichmann Matthiessen, C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0129.pdf"〉From Spaces of Planning to Places of Resistance〈/a〉〈br〉(Haarni, T.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0132.pdf"〉VI. Re-Cycling Urban Landscape〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0133.pdf"〉The Role of Gentrification in the Changing Ecology of Income: Evidence From Canadian Cities and Implications for Further Research〈/a〉〈br〉(Bourne, L. S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0134.pdf"〉Gentrification and the Youth Movements of the 1960s〈/a〉〈br〉(Ley, D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0135.pdf"〉Recycling Urban Landscapes - Beyond the Power〈/a〉〈br〉(Andersson, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0136.pdf"〉Why was the Central City Population Stabilized? The Case of Copenhagen〈/a〉〈br〉(Illeris, S.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0138.pdf"〉Toronto's Underground City: Excavating the Terms of Access〈/a〉〈br〉(Hopkins, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0140.pdf"〉The Interpretation of Sea in Urban Planning and Everyday Life: The Case of Helsinki〈/a〉〈br〉(Karvinen, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0141.pdf"〉Urban Destinies - What are the Trends?〈/a〉〈br〉(Wärneryd, O.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0142.pdf"〉VII. Urban Modelling〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0143.pdf"〉DUVA – A Concept for a Metadata Driven Statistical Production and Information System〈/a〉〈br〉(Kopp, N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0145.pdf"〉A New Era for Urban Modelling?〈/a〉〈br〉(Pumain, D.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0146.pdf"〉Competing Order Parameters in a Self-Organizing City〈/a〉〈br〉(Portugali, J., Benenson, I.)〈/li〉 〈/body〉 〈/html〉 〈br〉 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0150.pdf"〉Authors and Addresses〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN1030505985/LOG_0151.pdf"〉[Werbung]〈/a〉〈/li〉 〈/body〉 〈/html〉

Description: conference

Description: DFG, SUB Göttingen

Description: Since the 14th century, moderate seismic activity with 14 earthquakes of magnitude MW≥5.0 occurred in Western Europe in a region extending from the Lower Rhine Graben (LRG) to the southern North Sea. In this paper, we investigate how well this seismic activity could reflect that of the future. The observed earthquake activity in the LRG is continuous and concentrates on the Quaternary normal faults delimiting the LRG, which are also the source of large surface rupturing Holocene and Late Pleistocene earthquakes. The estimated magnitudes of these past earthquakes range from 6.3±0.3 to 7.0±0.3 while their average recurrence on individual faults varies from ten thousand to a few ten thousand years, which makes foreseeing future activity over the long-term possible. Three of the largest historical earthquakes with MW≥5.5 occurred outside the LRG. Late Quaternary activity along the fault zones suspected to be the source of two of these earthquakes, i.e. the 1580 Strait of Dover and 1692 northern Belgian Ardennes earthquakes, is very elusive if it exists. Hence, similar earthquakes would be very infrequent at these locations suggesting that the seismicity outside of the LRG would be episodic and clustered on some faults during periods of a few hundreds of years interrupted by long periods of inactivity typically lasting for some tens to hundreds of thousand years. Seismic moment release estimation and its comparison between recent geological and historical seismicity periods lead us to suggest that the high seismicity level observed between AD 1350 and AD 1700 west of the LRG would be uncommon.

Description: research

Description: In the weekly newspaper of Osnabrück (Germany) of November 3, 1770, a report about a local earthquake was published. Pastor Buck described ground motion effects in the manor ‘Haus Horst’, 1.5 km away from the village of Alfhausen: ‘roof tiles rattled, a chimney fell down, inside the house the top of a stove was overturned, abraded chalk trickled down in all rooms; in the nearby villages, people felt the shaking, and especially the churches suffered noticeably’. The epicentral intensity was estimated to VII (MSK) by Ahorner et al. (1970), but later modified to VI (EMS) by Meier & Grünthal (1992) considering Buck’s report in detail. Since this event is the only documented earthquake in this region, a reliable characterization of its parameters is important. Our re-examination reveals that some reported effects are quite contradictory. Contrary to Buck’s statement, no documents of damages on churches or costs of repairs could be found in the parish registers. As a result, the event appears to be a tectonic earthquake with an epicenter at Alfhausen / Haus Horst. Applying intensity-attenuation relationships, a revised value of the epicentral intensity of I_0≤V (EMS-98) with a focal depth of z≥2 km was derived. A cavity collapse due to leaching processes as a cause of the effects can be ruled out here. However, several details given in the primary source turned out to be unrealistic or at least exaggerated. The tectonic earthquake on September 3, 1770 near Alfhausen should be classified therefore as uncertain or even doubtful.

Description: research

Description: Central Europe is an intraplate domain which is characterized by low to moderate seismicity with records of larger seismic events occurring in historical and recent times. These records of seismicity are restricted to just over one thousand years. This does not reflect the long seismic cycles in Central Europe which are expected to be in the order of tens of thousands of years. Therefore, we have developed a paleoseismic database (PalSeisDB) that documents the records of paleoseismic evidence (trenches, soft-sediment deformation, mass movements, etc.) and extends the earthquake record to at least one seismic cycle. It is intended to serve as one important basis for future seismic hazard assessments. In the compilation of PalSeisDB, paleoseismic evidence features are documented at 129 different locations in the area of Germany and adjacent regions.

Description: research

Description: Current procedures to collect macroseismic data in Germany are diverse and scattered. At least 10 institutions collect macroseismic data by internet. Several institutes have a long tradition in seismology and have collected macroseismic data using paper forms for many decades. In addition, the responsibilities for geoscientific issues in Germany are a matter of the federal states and several of them have a state earthquake service. The only institution that automatically calculates and maps intensities online in near real time is Erdbebenstation Bensberg in cooperation with the Royal Observatory of Belgium. Baden-Württemberg uses a short form internet questionnaire at the moment. 5 state earthquake services (Bayern, Hessen, Niedersachsen, Rheinland-Pfalz, Sachsen) have implemented the standard German earthquake questionnaire (Kaiser 2014) which is adapted from the standard questionnaire developed by the ESC Working Group on Internet Macroseismology published by Musson & Cecić (2012). Most institutions express their strong need to implement standard procedures for automatic intensity assignment and a standard format for the exchange of questionnaire responses. References Kaiser, D. (2014): Der neue einheitliche Erdbeben-Fragebogen. Mitteilungen / Deutsche Geophysikalische Gesellschaft, 2/2014, 29-33. Musson, R. M. W. & Cecić, I. (2012): Intensity and Intensity Scales. In: New Manual of Seismological Observatory Practice 2 (NMSOP-2).- Deutsches GeoForschungsZentrum GFZ, 1-41; Potsdam. doi:10.2312/GFZ.NMSOP-2_ch12

Description: lecture

Description: We develop empirical relationships between the surface wave magnitude MS and macroseismic data, i.e. the epicentral intensity I0, isoseismal radii R(I) of different intensities I and the focal depth h. The basis of this study is formed by carefully selected instrumental parts (since 1900) of 2 earthquake catalogues: Kárník 1996 (Europe and the Mediterranean), and Shebalin et al. 1998 (Central and Eastern Europe). We use the orthogonal regression because we presume that all parameters are in error and because it has the advantage to provide a reversible regression equation. From Shebalin et al.1998 catalogue we obtain MS = 0.65 I0 + 1.90 log(h) – 1.62 with equivalent error δMS = ±0.21. In order to establish a relationship between MS and isoseismal radii we apply a theoretically based model which takes into account both exponential decay and geometrical spreading. From Shebalin et al. 1998catalogue we find MS = 0.673 I + 2.44 log (S(I)) + 0.00163 S(I) – 2.48 with δMS = ±0.28. Here I is the macroseismic intensity (I = 3…9) of the isoseismal in the focal distance S(I) [km]. Kárník 1996 gives isoseismal radii for I = 3 and 5. We obtain: MS = 0.808 I + 2.84 log (S(I)) + 0.00190 S(I) – 3.71 with δMS = ±0.65. These equations make possible reliably estimates of MS . We recommend them for application. The use of high quality data only as input in the regression analysis provides reliable relationships to estimate magnitudes. The magnitude estimation of a historical earthquake from the epicentral intensity gives reliable results only if the focal depth is known well enough. The relationship using isoseismal radii is of greater practical importance as it allows more reliable magnitude estimations of historical earthquakes. We observe regional variations in the relationships which need further investigation.

Description: poster

Description: The earthquake catalogue of southwestern Germany for the last millennium now contains about 30,000 digital macroseismic intensity data points (IDPs). Intensity assessments are based mainly on primary sources using the European Macroseismic Scale 1998 (EMS). The article describes a guideline for best practice of conventional macroseismic evaluation in application to historical and modern-time earthquakes in SW-Germany. Suitability of various diagnostics for intensity assessment is discussed. Assumptions to estimate damage grades and vulnerability classes of buildings are presented. Data restrictions and treatment of special cases are outlined. Further topics are quantification of uncertainties and IDP quality as well as substitutes for intensity. An essential task is to bridge the gap between information from historical sources and seismological needs for use in the earthquake catalogue, thus all issues have a focus on historical earthquakes. Questions of completeness, subjectivity, transparency, and interdisciplinary work are addressed also. Special emphasis is given to a well balanced use of the EMS scale throughout all time periods leading to consistent assessments in the catalogue.

Description: research

Description: Geometric 3D models are a very efficient tool to visualize geological units and structural features that have been presented before just in two dimensions on maps or cross-sections. Most of the information of 3D models is presented as 3D views, virtual wells or horizontal or vertical cross-sections. However, are there further options to transfer as much as possible of the complex information of a 3D model in an adequate way to the user? Is it useful and promising to analyse 3D objects like surfaces or volumes in GIS software? In our investigation we performed a GIS based analysis of an existing geotechnical-geological 3D model of periglacial sediments. The two steps were multiple raster calculations to create geotechnical maps and a digital analysis of surface parameters based on geomorphological techniques and statistics. The investigation area is located in southern Lower Saxony and covers the city of Goettingen and surrounding regions within the valley of the river Leine. The valley is filled by unconsolidated, periglacial sediments of Quaternary age with a variable thickness ranging from 1 to 70 m. The analysed 3D model was constructed with GoCAD in a former project (Nix et al. 2009). The model is based on a heterogenous dataset comprising well data, thematic maps, and outcrop descriptions. Finally, the surfaces and volumes of the following units were modelled, with a special focus on their different geotechnical properties: (1) anthropogenic material, (2) floodplain and slope deposits, (3) freshwater limestone, peat and organic clay, (4) loess, displaced loess, and loess loam, (5) fluvial gravel, (6) outwash fan material, (7) solifluction material, (8) mixed, hetereougenous fillings of subrosion sinks and (9) the surface of the underlying hardrocks. Each top and bottom surface of the Gocad volumes was exported as raster file with additional information stored in an associated attribute table. In ArcGIS various geoprocessing tools were used to calculate and analyse these rasters and to develope thematic geotechnical and geological maps. The geomorphological analysis was subdivided in several steps. Firstly, the surfaces were described visually, concerning their outline, shape and distribution, as well as superficial structures like distinct edges, holes, channels. Secondarily, descriptive statistic parameters of thickness, area and elevation of each surface were calculated. Thirdly, geoprocessing tools of the Spatial Analyst were performed on each surface. Finally, several surfaces were combined to analyse them together, calculating ratios and overlay combinations. Seven thematical geoengineering and geological maps were created, each of them presenting one portion of the three-dimensional dataset: Map of the stratigraphy and depth of the Quaternary base, Map of the thickness of the Quaternary sediments, Distribution map of model units 1 m below ground level, Distribution map of model units 2 m below ground level, Maps of types of different foundation soils, Distribution map of sediments with low loading capacity and Map of distribution and quality of the wells. While the map creation focused on the geotechnical aspects of the model, the applied geomorphological analysis revealed various parameters and values that are related to the geological formation of the model units. Despite the complex dataset represented by the analysed 3D model, thematical information could be transfered into 2D as thematic maps. Some geological characteristics and parameters of the model units were extracted by the descriptive and GIS-based analysis. References Nix, T., Wagner, B., Lange, T. , Fritz, J., Sauter, M. (2009): 3D-Baugrundmodell der quartären Sedimente des Leinetals bei Göttingen. – 17. Tagung für Ingenieurgeologie, S. 223-227, Zittau

Description: poster

Description: The mineralogy, chemical composition, and physical properties of cratonic mantle eclogites with oceanic crustal protoliths can be modified by secondary processes involving interaction with fluids and melts, generated in various slab lithologies upon subduction (auto‐metasomatism) or mantle metasomatism after emplacement into the cratonic lithosphere. Here we combine new and published data to isolate these signatures and evaluate their effects on the chemical and physical properties of eclogite. Mantle metasomatism involving kimberlite‐like, ultramafic carbonated melts (UM carbonated melts) is ubiquitous though not pervasive, and affected between ~20% and 40% of the eclogite population at the various localities investigated here, predominantly at ~60–150 km depth, overlapping cratonic midlithospheric seismic discontinuities. Its hallmarks include lower jadeite component in clinopyroxene and grossular component in garnet, an increase in bulk‐rock MgO ± SiO2, and decrease in FeO and Al2O3 contents, and LREE‐enrichment accompanied by higher Sr, Pb, Th, U, and in part Zr and Nb, as well as lower Li, Cu ± Zn. This is mediated by addition of a high‐temperature pyroxene from a UM carbonated melt, followed by redistribution of this component into garnet and clinopyroxene. As clinopyroxene‐garnet trace‐element distribution coefficients increase with decreasing garnet grossular component, clinopyroxene is the main carrier of the metasomatic signatures. UM carbonated melt‐metasomatism at 〉130–150 km has destroyed the diamond inventory at some localities. These mineralogical and chemical changes contribute to low densities, with implications for eclogite gravitational stability, but negligible changes in shear‐wave velocities, and, if accompanied by H2O‐enrichment, will enhance electrical conductivities compared to unenriched eclogites.

Description: Plain Language Summary: Oceanic crust formed at spreading ridges is recycled in subduction zones and undergoes metamorphism to eclogite. Some of this material is captured in the overlying lithospheric mantle, where it is exhumed by passing magmas. Having formed in spreading ridges, these eclogites have proven invaluable archives for the onset of plate tectonics, for the construction of cratons during subduction/collision, as probes of the convecting mantle from which their precursors formed, and as generators of heterogeneity upon recycling into Earth's convecting mantle. During subduction and until exhumation, interaction with fluids and melts (called metasomatism) can change the mineralogy, chemical composition, and physical properties of mantle eclogites, complicating their interpretation, but a comprehensive study of these effects is lacking so far. We investigated mantle eclogites from ancient continents (cratons) around the globe in order to define hallmarks of metasomatism by subduction‐related fluids and small‐volume ultramafic carbonated mantle melts. We find that the latter is pervasive and occurs predominantly at midlithospheric depths where seismic discontinuities are detected, typically causing diamond destruction and a reduction in density. This has consequences for their gravitational stability and for the interpretation of shearwave velocities in cratons.

Description: Key Points: Exploration of metasomatic effects during subduction of ancient oceanic crust and after its emplacement into cratonic lithospheric mantle. Metasomatism by kimberlite‐like ultramafic melt affected between 20% and 40% of mantle eclogite suites worldwide, mostly at 2–5 GPa. Metasomatism lowers FeO, hence density in eclogite; no significant effect on shearwave velocities.

Description: German Research Foundation http://dx.doi.org/10.13039/501100001659

Description: National Research Foundation (NRF) http://dx.doi.org/10.13039/501100001321

Description: Wilhelm and Else Heraeus Foundation http://dx.doi.org/10.13039/501100011618

Description: Deutsche Forschungsgemeinschaft (DFG, INST

Description: research

Description: Considering the importance of migration research and the dearth in literature on migration, the following study has been done, with the intention of examining the complex interrelation between internal migration and the development process in Bangladesh. Thereby, emphasis has been given to the investigation and analysis of the causes of rural-urban migration and its spatial as well as socioeconomic consequences, with examples from Dhaka. To construct a framework for the present study, some consideration has been given to both theoretical as well as empirical studies on internal migration. The discussion of general theories which follows in the next section, has mainly been done to assess the validity of these in the analysis of internal migration in the Third World countries.

Description: research

Description: DFG, SUB Göttingen

Description: Pyrroloquinoline quinone (PQQ) is an important cofactor of calcium‐ and lanthanide‐dependent alcohol dehydrogenases, and has been known for over 30 years. Crystal structures of Ca–MDH enzymes (MDH is methanol dehydrogenase) have been known for some time; however, crystal structures of PQQ with biorelevant metal ions have been lacking in the literature for decades. We report here the first crystal structure analysis of a Ca–PQQ complex outside the protein environment, namely, poly[[undecaaquabis(μ‐4,5‐dioxo‐4,5‐dihydro‐1H‐pyrrolo[2,3‐f]quinoline‐2,7,9‐tricarboxylato)tricalcium(II)] dihydrate], {[Ca3(C14H3N2O8)2(H2O)11]·2H2O}n. The complex crystallized as Ca3PQQ2·13H2O with Ca2+ in three different positions and PQQ3−, including an extensive hydrogen‐bond network. Similarities and differences to the recently reported structure with biorelevant europium (Eu2PQQ2) are discussed.

Description: Pyrroloquinoline quinone (PQQ) is an important cofactor of calcium‐ and lanthanide‐dependent alcohol dehydrogenases. The crystal structure of a Ca–PQQ complex (Ca3PQQ2·13H2O) is reported for the first time outside a protein environment. image

Description: research

Description: Induced earthquakes are of public concern and of legal significance if they are felt or if they cause damage. Models to describe the relation between macroseismic intensities, magnitude, and distance from the epicenter or hypocenter are therefore of fundamental importance. With the aim of developing such models for induced earthquakes in Germany, the following data were analyzed: The earthquake database for Germany GERSEIS contains parameters for ~180 induced seismic events with information on magnitude M and intensity I, of which 47 include information on mean isoseismal radii. In addition, the published macroseismic maps of seismic events in mining areas in Germany were evaluated. In Germany, earthquakes caused by mining with moderate to severe building damage (intensity 7 and 8) have so far only occurred in potash and salt mining. Slight building damage (intensity 6) has also been caused by seismic events in coal mining. Over the past 20 years, the frequency of felt earthquakes has increased in regions with natural gas production and in recent years also in regions of deep geothermal energy production. Focal depths show a large influence on the relationship between M and I. Intensity 5 has been observed for shallow (~1 km depth) events with magnitudes as small as ML=1.8. Simple models of the form I = a + b M + c log R, with R = hypocentral distance, can be fitted to the observations. Models for tectonic earthquakes do not fit for induced earthquakes; for induced earthquakes I is smaller for a given M and R. Major differences were found between different mining areas: In natural gas production areas intensity 5 effects were observed at greater hypocentral distances for a given magnitude, compared to coal and potash mining areas. Since macroseismic data (especially intensity data points) in Germany are available almost exclusively in analog form and are often difficult to access, it is necessary to establish a database for induced earthquakes with macroseismic data.

Description: research

Description: In Structural Geology, many projects start with intensive field-based data acquisition campaigns, which might be performed in quite different types of natural or artificial outcrops. For some years, this field work has been substantially influenced and transformed by various close-range sensing techniques that allow the field geologist to create a digital outcrop model (DOM) and to take along plenty of geometrical and spectral information about the outcropping rocks. In general, DOMs can be utilized for outcrop visualization, documentation, manual outcrop analysis (“point-picking”), extraction of spectral data and/or semi-automatic extraction of geometric data. Within a structural investigation DOMs might be deployed for fold analysis, fault analysis, extraction of fracture networks, fracture roughness estimation, detection of neotectonic activities or digitization of geological features for 3D-models of various scales resulting in a large number of analyzing techniques. Latter might be carried out on point clouds or meshes (with or without spectral information) and may differ in pre-processing and processing steps as well as in software solution. Therefore, the analyzing structural geologist faces various tools, data formats, file types, operations and outcomes. Our investigation focus on the compilation of useful, transparent, sustainable and comparable workflows or “pipelines”, which can be executed by open-source/open-access solutions.

Description: poster

Description: Apart from the traditional contribution of geographers to the study of population, this particular thesis attempts to divert the emphasis of geographical enquiry towards the examination of how particular innovations affect the population distribution and the organization of human society. It deals specifically with questions concerning the demographic, social and economic impact of population mobility on both sending in receiving areas. It attempts to shed light on the different variables that work to produce a selective type of population mobility within a particular socio—economic set-up. Although various aspects of population mobility have been studied in some detail during the present decade, no attempt has been made, however, towards a concrete presentation of its multiple causes and its socio-economic impact on the areas and people that are left behind. Far from assuming complete coverage of all interrelated fields of study we attempt here to draw attention t0 the expected socio-economic repercussions of population mobility as induced by a particular factor, namely agricultural mechanization. Certain limitations‚ however, have made it difficult to deal with every aspect of population mobility in the Sudan.

Description: thesis

Description: DFG, SUB Göttingen

Description: Jede Gesellschaft (und jede Stadtregion) muss auf die Auswirkungen dieser Transformation (erhöhte Wohnraumnachfrage, schnelles Wirtschaftswachstum, starkes Dezentralisierungspotential neuer Technologien, drohender Bedeutungsverlust der Kernstadt) reagieren. Wir betrachten im Rahmen dieser Arbeit räumliche Entwicklungen als "kulturelle“ Antwort auf solche Veränderungen. Denn während der ökonomische und technologische Wandel ein eher universelles Phänomen darstellt, unterscheiden sich doch die Strategien zur räumlichen Handhabung und Gestaltung von Wachstum von Land zu Land enorm. So gesehen ist die uns umgebende Realität von Suburbanisierung und Dezentralisierung eben auch das Resultat von Entscheidungen, die unter spezifischen politischen und ideologischen Bedingungen getroffen worden sind. Für die Analyse der Wachstumsideologien haben wir drei westliche Industriestaaten ausgewählt: Kanada, die USA und die Bundesrepublik Deutschland. Dabei wurden sowohl die lokale bzw. regionale als auch die Ländern Provinz- bzw. Bundesebene untersucht. Für die lokale Ebene wurden Flächennutzungsmaßnahmen und statistische Wachstumsindikatoren von sechs "Fallbeispielen" analysiert und verglichen: Frankfurt/M.‚ München, Toronto, Vancouver, San Francisco und Los Angeles/San Diego. Für die überregionale Ebene ergänzt ein Vergleich staatlicher Steuerungsmaßnahmen die Analyse und Interpretation lokaler Trends.

Description: thesis

Description: DFG, SUB Göttingen

Description: This publication developed from the 5th International Colloquium on “Historical Earthquakes, Paleoseismology, Neotectonics and Seismic Hazard” which was held from 11 to 13 October 2017 at the Federal Institute for Geosciences and Natural Resources (BGR) in Hannover, Germany. It comprises four contributions: Brüstle, W., Braumann, U., Hock, S. & Rodler, F.-A. (2020). Best practice of macroseismic intensity assessment applied to the earthquake catalogue of southwestern Germany. In: Kaiser, D. (Ed.). Historical Earthquakes, Paleoseismology, Neotectonics, and Seismic Hazard: New Insights and Suggested Procedures, DGEB-Publikation 18, Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik. doi: 10.23689/fidgeo-3864 Camelbeeck, T., Vanneste, K., Verbeeck, K., Garcia-Moreno, D., Van Noten, K. & Lecocq, T. (2020). How well does known seismicity between the Lower Rhine Graben and southern North Sea reflect future earthquake activity? In: Kaiser, D. (Ed.). Historical Earthquakes, Paleoseismology, Neotectonics, and Seismic Hazard: New Insights and Suggested Procedures, DGEB-Publikation 18, Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik. doi: 10.23689/fidgeo-3866 Hürtgen, J., Reicherter, K., Spies, T., Geisler, C. & Schlittenhardt, J. (2020). The Paleoseismic Database of Germany and Adjacent Regions PalSeisDB v1.0. In: Kaiser, D. (Ed.). Historical Earthquakes, Paleoseismology, Neotectonics, and Seismic Hazard: New Insights and Suggested Procedures, DGEB-Publikation 18, Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik. doi: 10.23689/fidgeo-3867 Leydecker, G. & Lehmann, K. (2020). The earthquake of September 3, 1770 near Alfhausen (Lower Saxony, Germany): a real, doubtful, or a fake event? In: Kaiser, D. (Ed.). Historical Earthquakes, Paleoseismology, Neotectonics, and Seismic Hazard: New Insights and Suggested Procedures, DGEB-Publikation 18, Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik. doi: 10.23689/fidgeo-3865

Description: Introduction to DGEB-Publikation Nr. 18 Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik (DGEB)

Description: editorial

Description: Quantitative fold structure analyses at different scales are essential for deducing deformation mechanisms and the reconstruction of the deformation history of orogens. However, not only the field surveying of fold structures, especially in view of their quantification in three dimensions with the classical tools as measuring tape, grid mapping with measuring tapes, geological compass, field book and camera is a time consuming and laborious job, but also the construction of a georeferenced 3D-model of fold structures based on classical data. Another crucial aspect of the classical field surveying of folds is the limitation by poor outcrop conditions. Reasons might be restricted or no accessibility due to high outcrop walls, water or fences, limited visibility because of vegetation, difficult measurability due to very smooth walls or complexity as a result of irregular outcrop walls or distant outcrops. Furthermore, inappropriate oriented outcrop surfaces in respect to the fold geometry can make a survey even worse. Over the past years modern 3D surveying techniques like terrestrial Lidar and digital photogrammetry became progressively affordable for geological field work and now start to complement or replace traditional methods. We started to utilize these techniques on fold structure surveying and to apply quantitative fold structure analysis on different outcrop settings in Central Germany. Different workflows were developed and tested to optimize data conversion, handling and representation. We applied a laser scanner and a single lens reflex camera, complemented by a differential GPS device and laser tachymeter. Data conversion, correction and analysis were done by means of different free as well as commercial software packages. To test different outcrop situations, different quarries, salt mines and steep cliffs, exposing from single fold to complex folds in limestone, greywacke, cherts, rock salt or potassium salt, were selected. As a result, exact 3D point clouds of all exposed folds could be generated by the use of both techniques. The resultant point clouds are suited as excellent visualisation objects as well as base for accurate geometrical measurements in the range of mm or cm of single and complex folds. In addition, the point clouds serve as input dataset for the construction of detailed geological 3D models comprising punctual, linear and plane fold elements. In summary, terrestrial Lidar and digital photogrammetry are excellent field techniques to survey and document exposed folds in the range of few meters to tens of meters, especially under poor outcrop conditions. Different fold sections can now easily be correlated in 3D space to construct complete fold structures with their 3D-fold geometry. Certain fold elements, e.g. axial planes, can be reconstructed much faster and much more accurate compared to the classical approach. The only limiting factor are the very large datasets and the processing power. As next steps, we seek (1) to involve drones for completing data sets from inaccessible areas and perspectives and (2) to incorporate 3D-microfabric analysis data in the fold models as e.g. grain shape an crystallographic preferred orientations to better understand stain paths and deformation mechanisms.

Description: poster

Description: Under certain conditions, ocean surface gravity waves (SGW) interact with the seafloor underneath to trigger relatively faint but measurable seismic waves known as ocean microseisms. Cyclonic storms (e.g. hurricanes, typhoons) wandering over the ocean are major (non-stationary) sources of the former, thus opening the possibility of tracking and studying cyclones by means of their corresponding microseims. For this purpose, we identified storm-related microseisms hidden in the ambient seismic wavefield via array processing. Polarization beamforming, a robust and well-known technique is implemented. The analyses hinge on surface waves (Love and Rayleigh) which, in contrast to P-waves, are stronger but only constrain direction of arrival (without source remoteness). We use a few land-based virtual seismic arrays surrounding the North Atlantic to investigate the signatures of major hurricanes in the microseismic band (0.05-0.16 Hz), in a joint attempt to continuously triangulate their tracks. Our findings show that storm microseisms are intermittently excited with modulated amplitude at localized oceanic regions, particularly over the shallow continental shelves and slopes, having maximum amplitudes virtually independent of storm category. In most cases no detection was possible over deep oceanic regions, nor at distant arrays. Additionally, the rear quadrants and trailing swells of the cyclone provide the optimum SGW spectrum for the generation of microseisms, often shifted more than 500 km off the "eye". As a result of the aforementioned and added to the strong attenuation of storm microseisms, the inversion of tracks or physical properties of storms using a few far-field arrays is discontinuous in most cases, being reliable only if benchmark atmospheric and/or oceanic data is available for comparison. Even if challenging due to the complexity of the coupled phenomena responsible for microseisms, the inversion of site properties, such as bathymetric parameters (e.g. depth, seabed geomorphology), near- bottom geology or SGW spectrum might be possible if storms are treated as natural sources in time-lapse ambient noise investigations. This will likely require near-field (land and underwater) observations using optimal arrays or dense, widespread sensor networks. Improved detection and understanding of ocean microseisms carries a great potential to contribute to mechanically coupled atmosphere-ocean-earth models.

Description: Universität Hamburg

Description: poster

Description: The transient climate response (TCR) is 20% higher in the Alfred Wegener Institute Climate Model (AWI‐CM) compared to the Max Planck Institute Earth System Model (MPI‐ESM) whereas the equilibrium climate sensitivity (ECS) is by up to 10% higher in AWI‐CM. These results are largely independent of the two considered model resolutions for each model. The two coupled CMIP6 models share the same atmosphere‐land component ECHAM6.3 developed at the Max Planck Institute for Meteorology (MPI‐M). However, ECHAM6.3 is coupled to two different ocean models, namely the MPIOM sea ice‐ocean model developed at MPI‐M and the FESOM sea ice‐ocean model developed at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). A reason for the different TCR is related to ocean heat uptake in response to greenhouse gas forcing. Specifically, AWI‐CM simulations show stronger surface heating than MPI‐ESM simulations while the latter accumulate more heat in the deeper ocean. The vertically integrated ocean heat content is increasing slower in AWI‐CM model configurations compared to MPI‐ESM model configurations in the high latitudes. Weaker vertical mixing in AWI‐CM model configurations compared to MPI‐ESM model configurations seems to be key for these differences. The strongest difference in vertical ocean mixing occurs inside the Weddell and Ross Gyres and the northern North Atlantic. Over the North Atlantic, these differences materialize in a lack of a warming hole in AWI‐CM model configurations and the presence of a warming hole in MPI‐ESM model configurations. All these differences occur largely independent of the considered model resolutions.

Description: Plain Language Summary: The transient climate response (TCR) describes how strongly near‐surface temperatures warm in response to gradually increasing greenhouse‐gas levels. Here we investigate the role of the ocean which takes up heat and thereby delays the surface warming. Two models of the Coupled Model Intercomparison Project Phase 6 (CMIP6), the Alfred Wegener Institute Climate Model (AWI‐CM) and the Max Planck Institute Earth System Model (MPI‐ESM), which use the same atmosphere model but different ocean models are selected for this study. In AWI‐CM the upper ocean layers heat faster than in MPI‐ESM, while the opposite is true for the deep ocean. As a consequence, the TCR is 20% stronger in AWI‐CM compared to MPI‐ESM. We find that weaker vertical ocean mixing in AWI‐CM compared to MPI‐ESM, especially over the northern North Atlantic and the Weddell and Ross Gyres, is key for these differences. Our findings corroborate the importance of realistic ocean mixing in climate models when it comes to getting the strength and timing of climate change right.

Description: Key Points: The transient climate response in two coupled models with the same atmosphere but different ocean components differs by 20%. The upper (deeper) ocean heats faster (slower) in AWI‐CM compared to MPI‐ESM, independent of model resolution. Vertical mixing in the northern North Atlantic and the Weddell and Ross Gyres appears to be key for these differences.

Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347

Description: German Climate Computing Centre (DKRZ)

Description: Federal Ministry of Education and Research of Germany

Description: Helmholtz Association http://dx.doi.org/10.13039/501100009318

Description: https://esgf-data.dkrz.de/projects/cmip6-dkrz/

Description: In the hyperarid Atacama Desert in northern Chile, rare precipitation events can leave long‐lasting geomorphological traces and have strong impacts on biota. While moisture conveyor belts (MCBs) and atmospheric rivers (ARs) have been associated with extreme precipitation in semiarid regions, their role for the Atacama Desert has not been previously investigated. This study reveals that about four MCBs per year make landfall in the Atacama Desert. According to simulated precipitation, 40–80% of the total precipitation between the coast and the Andean foothills is associated with MCBs. A case study reveals an elevated moisture transport decoupled from the maritime boundary layer, which is generalized by a composite analysis. Back trajectories reveal the Amazon Basin as the main source of moisture. MCB landfall times are derived from the AR catalog by Guan and Waliser (2015), https://doi.org/10.1002/2015jd024257. Implications of the results on paleoclimate reconstructions are discussed.

Description: Plain Language Summary: In the extremely dry Atacama Desert in northern Chile, rare rain events can trigger landscape alterations and have strong impacts on various life forms. Traces of such events are conserved within the desert soil over long time periods throughout the enduring dryness. Such traces constitute climate archives, which can be excavated and explored. Understanding particular conditions, which lead to extreme precipitation events is necessary to interpret such archives, reconstruct climate history, and explore thresholds of life at the dry limit. In this study, the role of a weather phenomenon called moisture conveyor belt (MCB) is quantified for the first time for the Atacama Desert. It is demonstrated that depending on region, 40–80% of the total rainfall is associated with these phenomena. In contrast to atmospheric river characteristics reported for midlatitudes, a unique vertical structure with an elevated moisture transport independent of the near‐surface layer is discovered here. Even though the identified MCBs approach the Atacama Desert from northwesterly directions across the Pacific Ocean, the associated moisture mostly originates from the Amazon Basin.

Description: Key Points: For most parts of the Atacama Desert, more than half of the total precipitation is related to moisture conveyor belts (MCBs). In contrast to midlatitudes, main moisture transport takes place in mid‐tropospheric layers decoupled from the maritime boundary layer. The main origin of the MCB‐related moisture is found to be the Amazon Basin.

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: https://www.crc1211db.uni-koeln.de/search/view.php?dataID=38

Description: http://www.cr2.cl/datos-de-precipitacion/

Description: http://explorador.cr2.cl/

Description: Large artificial lakes and reservoirs affect the meteorological regime of the shore area and the local climate takes on a number of new features that were previously absent. This work focuses on the weather impact of the Alqueva reservoir, the largest artificial lake in Western Europe. An extensive set of numerical simulations using Meso‐NH mesoscale atmospheric model coupled with FLake (Freshwater Lake) scheme was carried out. The simulations covered a 12‐month period that was chosen to compose a so‐called Typical Meteorological Year. This artificial time period is meant to represent the typical meteorological conditions in the region and the model results are used to assess the changes in the local climate. To evaluate the raw impact of the reservoir, two different scenarios of simulations were compared: (A) with the reservoir as it exists nowadays and (B) without the reservoir using the older surface dataset. The results show decrease of air temperature during daytime (10–9°C) and nighttime increase (up to 10°C). In nearest towns, daily maximum temperature decreased and daily minimum temperature increased, which refers to milder weather conditions. Alqueva mainly showed suppression in fog formation in the nearby area. Local breeze regime was studied and monthly lake/land breezes were described.

Description: Large lakes and artificial reservoirs can affect the meteorological regime of their coastal areas and impact the local climate. This work focuses on the weather impact of the Alqueva reservoir, the largest artificial lake in Western Europe, studied on the basis of mesoscale atmospheric modelling data over the 12‐month period composed in a typical meteorological year for the region of interest.

Description: ALOP project

Description: COMPETE 2020 ICT project

Description: Fundação para a Ciência e a Tecnologia http://dx.doi.org/10.13039/501100001871

Description: TOMAQAPA

Description: http://mesonh.aero.obs-mip.fr/mesonh54/Download

Description: With increasing resolution of numerical weather prediction (NWP) models, classical subgrid‐scale processes become increasingly resolved on the model grid. In particular, turbulence in the planetary boundary layer (PBL) is vertically already partially resolved in contemporary models. For classical local PBL schemes, resulting up‐gradient heat transports cannot be treated correctly. Thus, nonlocal turbulence schemes have been developed in the past. As the horizontal grid sizes of NWP models become smaller than a few kilometers, the large turbulence eddies in the PBL will also start to become partially resolved in the horizontal direction. A very flexible way to formulate nonlocal turbulent exchange is the transilient matrix method, which is used here to develop a new turbulence parameterization. The resulting NLT3D scheme applies transilient mixing matrices to subgrid‐scale transports in all three dimensions. We compare results of WRF real‐case simulations including our scheme, a classical local turbulence scheme (MYNN), and an existing nonlocal one‐dimensional scheme (ACM2) with observations from field campaigns over homogeneous terrain (CASES‐99) and complex terrain (CAPTEX). Over homogeneous terrain, all three schemes similarly well capture the observed surface fluxes and radiosonde profiles, whereas over complex terrain more differences become obvious. During a tracer release experiment (CAPTEX) over the Appalachian mountain region, the mixing and vertical extent of the PBL turn out to be decisive to reproduce the observed advection speed of the tracer‐marked air mass. Deeper mixing not only accelerates surface winds but also enables tracer to travel faster at higher altitudes and then mix back to the ground. As results from a version of NLT3D with only standard horizontal Smagorinsky diffusion (NLT1D) demonstrate, simulating three‐dimensional turbulence can be beneficial already at horizontal grid sizes of a few kilometers.

Description: Decreasing grid sizes in numerical weather prediction models demand the inclusion of nonlocal effects and horizontal turbulence in turbulence parameterizations. This is the motivation for the development of the nonlocal three‐dimensional turbulence (NLT3D) scheme. Vertical nonlocal mixing accelerates the horizontal transport of near‐surface tracers by fast advection at higher altitudes (see figure), and horizontal turbulence enhances tracer dispersion. As validated by observations, both effects are beneficial to the forecast quality already at grid sizes of a few kilometers.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Compound weather and climate events are combinations of climate drivers and/or hazards that contribute to societal or environmental risk. Studying compound events often requires a multidisciplinary approach combining domain knowledge of the underlying processes with, for example, statistical methods and climate model outputs. Recently, to aid the development of research on compound events, four compound event types were introduced, namely (a) preconditioned, (b) multivariate, (c) temporally compounding, and (d) spatially compounding events. However, guidelines on how to study these types of events are still lacking. Here, we consider four case studies, each associated with a specific event type and a research question, to illustrate how the key elements of compound events (e.g., analytical tools and relevant physical effects) can be identified. These case studies show that (a) impacts on crops from hot and dry summers can be exacerbated by preconditioning effects of dry and bright springs. (b) Assessing compound coastal flooding in Perth (Australia) requires considering the dynamics of a non‐stationary multivariate process. For instance, future mean sea‐level rise will lead to the emergence of concurrent coastal and fluvial extremes, enhancing compound flooding risk. (c) In Portugal, deep‐landslides are often caused by temporal clusters of moderate precipitation events. Finally, (d) crop yield failures in France and Germany are strongly correlated, threatening European food security through spatially compounding effects. These analyses allow for identifying general recommendations for studying compound events. Overall, our insights can serve as a blueprint for compound event analysis across disciplines and sectors.

Description: Plain Language Summary: Many societal and environmental impacts from events such as droughts and storms arise from a combination of weather and climate factors referred to as a compound event. Considering the complex nature of these high‐impact events is crucial for an accurate assessment of climate‐related risk, for example to develop adaptation and emergency preparedness strategies. However, compound event research has emerged only recently, therefore our ability to analyze these events is still limited. In practice, studying compound events is a challenging task, which often requires interaction between experts across multiple disciplines. Recently, compound events were divided into four types to aid the framing of research on this topic, but guidelines on how to study these four types are missing. Here, we take a pragmatic approach and—focusing on case studies of different compound event types—illustrate how to address specific research questions that could be of interest to users. The results allow identifying recommendations for compound event analyses. Furthermore, through the case studies, we highlight the relevance that compounding effects have for the occurrence of landslides, flooding, vegetation impacts, and crop failures. The guidelines emerged from this work will assist the development of compound event analysis across disciplines and sectors.

Description: Key Points: Using case studies representative of four main compound event types we show how compound event‐related research questions can be tackled. We present user‐friendly guidelines for compound event analysis applicable to different compound event types. We demonstrate that compound events cause vegetation impacts, coastal flooding, landslides, and continental‐scale crop yield failures.

Description: European COST action DAMOCLES

Description: NERC

Description: Swiss National Science Foundation

Description: Helmholtz Initiative and Networking Fund

Description: Netherlands Organisation for Scientific Research (NWO)

Description: Fundação para a Ciência e a Tecnologia

Description: Scientific Employment Stimulus 2017

Description: Italian Ministry of University and Research

Description: European Union's Horizon 2020 research and innovation programme

Description: AXA Research Fund for support

Description: Portuguese Foundation for Science and Technology

Description: Twenty‐first‐century climate change projections are uncertain, especially on regional scales. An important source of uncertainty is that climate models exhibit biases, which limits their ability to predict climate. One of the largest biases is the too warm sea surface temperature (SST) in the eastern tropical Atlantic (TA), reflecting deficient atmospheric and oceanic circulation. Here, we show that CO2‐forced TA‐sector climate changes simulated by state‐of‐the‐art climate models exhibit a strong mean‐state dependence. In particular, models simulating largest SST warming in the eastern TA, consistent with the warming observed since the mid‐20th century, typically exhibit a more realistic mean state than models simulating largest warming in the western TA. The former models exhibit a larger climate sensitivity, and predict stronger and in part qualitatively different climate changes over the TA sector, for example in precipitation. These findings may help to reducing uncertainty in TA‐climate change projections.

Description: Plain Language Summary: Twenty‐first‐century climate change projections are uncertain, especially on regional scales. An important source of uncertainty is that climate models exhibit biases, which limits their ability to predict climate. One of the largest biases is the too warm sea surface temperature in the eastern tropical Atlantic (TA), reflecting deficient atmospheric and oceanic circulation. Here, we show that CO2‐forced TA‐sector climate changes simulated by state‐of‐the‐art climate models exhibit a strong relationship to the quality of simulating the mean state. These findings may help to reducing uncertainty in climate change projections over the TA sector.

Description: Key Points: Climate projections for the tropical Atlantic sector depend on the quality of simulating present‐day conditions. Less biased climate models provide more reliable projections. Spread in CO2‐forced climate changes over the Tropical Atlantic region.

Description: Helmholtz Society

Description: JPI Climate and JPI Ocean

Description: German Ministry of Education and Research

Description: https://www.dkrz.de/up/services/data-management/cmip-data-pool

Description: https://www.metoffice.gov.uk/hadobs/hadisst/

Description: https://psl.noaa.gov/data/gridded/data.noaa.ersst.v5.html

Description: https://psl.noaa.gov/data/gridded/data.cobe2.html

Description: https://rda.ucar.edu/datasets/ds090.2/

Description: https://psl.noaa.gov/data/gridded/data.hadslp2.html

Description: http://www.esrl.noaa.gov/psd/data/gridded/data.coads.2deg.html

Description: Cold-pool-driven convective initiation is investigated in high-resolution, convection-permitting simulations with a focus on the diurnal cycle and organization of convection and the sensitivity to grid size. Simulations of four different days over Germany were performed using the ICON-LEM model with grid sizes from 156 to 625 m. In these simulations, we identify cold pools, cold-pool boundaries and initiated convection. Convection is triggered much more efficiently in the vicinity of cold pools than in other regions and can provide as much as 50% of total convective initiation, in particular in the late afternoon. By comparing different model resolutions, we find that cold pools are more frequent, smaller and less intense in lower-resolution simulations. Furthermore, their gust fronts are weaker and less likely to trigger new convection. To identify how model resolution affects this triggering probability, we use a linear causal graph analysis. In doing so, we postulate a graph structure with potential causal pathways and then apply multi-linear regression accordingly. We find a dominant, systematic effect: reducing grid sizes directly reduces upward mass flux at the gust front, which causes weaker triggering probabilities. These findings are expected to be even more relevant for km-scale, numerical weather prediction models. We thus expect that a better representation of cold-pool-driven convective initiation will improve forecasts of convective precipitation.

Description: Reliable and accurate weather forecasts, particularly those of rainfall and its extremes, have the potential to improve living conditions in densely populated southern West Africa (SWA). The limited availability of observations has long impeded a rigorous evaluation of current state-of-the-art forecast models. The field campaign of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project in June–July 2016 has created an unprecedentedly dense set of measurements from surface stations and radiosondes. Here we present results from a comprehensive evaluation of both numerical model forecasts and satellite products using these data on a regional and local level. Results reveal a substantial observational uncertainty showing considerable underestimations in satellite estimates of rainfall and low-cloud cover with little correlation at the local scale. Models have a dry bias of 0.1–1.9 mm·day−1 in rainfall and too low column relative humidity. They tend to underestimate low clouds, leading to excess surface solar radiation of 43 W·m−2. Remarkably, most models show some skill in representing regional modulations of rainfall related to synoptic-scale disturbances, while local variations in rainfall and cloudiness are hardly captured. Slightly better results are found with respect to temperature and for the post-onset rather than for the pre-onset period. Delicate local features such as the Maritime Inflow phenomenon are also rather poorly represented, leading to too cool, dry and cloudy conditions at the coast. Differences between forecast days 1 and 2 are relatively small and hardly systematic, suggesting a relatively quick error saturation. Using explicit convection leads to more realistic spatial variability in rainfall, but otherwise no marked improvement. Future work should aim at improving the subtle balance between the diurnal cycles of low clouds, surface radiation, the boundary layer and convection. Further efforts are also needed to improve the observational system beyond field campaign periods.

Description: Quantifying the anthropogenic fluxes of CO2 is important to understand the evolution of carbon sink capacities, on which the required strength of our mitigation efforts directly depends. For the historical period, the global carbon budget (GCB) can be compiled from observations and model simulations as is done annually in the Global Carbon Project's (GCP) carbon budgets. However, the historical budget only considers a single realization of the Earth system and cannot account for internal climate variability. Understanding the distribution of internal climate variability is critical for predicting the future carbon budget terms and uncertainties. We present here a decomposition of the GCB for the historical period and the RCP4.5 scenario using single‐model large ensemble simulations from the Max Planck Institute Grand Ensemble (MPI‐GE) to capture internal variability. We calculate uncertainty ranges for the natural sinks and anthropogenic emissions that arise from internal climate variability, and by using this distribution, we investigate the likelihood of historical fluxes with respect to plausible climate states. Our results show these likelihoods have substantial fluctuations due to internal variability, which are partially related to El Niño‐Southern Oscillation (ENSO). We find that the largest internal variability in the MPI‐GE stems from the natural land sink and its increasing carbon stocks over time. The allowable fossil fuel emissions consistent with 3 C warming may be between 9 and 18 Pg C yr−1. The MPI‐GE is generally consistent with GCP's global budgets with the notable exception of land‐use change emissions in recent decades, highlighting that human action is inconsistent with climate mitigation goals.

Description: Key Points: We use a single‐model large ensemble to estimate uncertainties from internal climate variability in the global carbon budget. The land sink accounts for most internal climate uncertainty which may permit 9–18 Pg C yr−1 in allowable emissions by 2050 (for 3°C warming).

Description: European Union's Horizon 2020

Description: research

Description: Water isotopologues, as natural tracers of the hydrological cycle on Earth, provide a unique way to assess the skill of climate models in representing realistic atmospheric‐terrestrial water pathways. This study presents the newly developed WRF‐Hydro‐iso, which is a version of the coupled atmospheric‐hydrological WRF‐Hydro model enhanced with a joint soil‐vegetation‐atmospheric description of water isotopologue motions. It allows the consideration of isotopic fractionation processes during water phase changes in the atmosphere, the land surface, and the subsurface. For validation, WRF‐Hydro‐iso is applied to two different climate zones, namely Europe and Southern Africa under the present climate conditions. Each case is modeled with a domain employing a 5 km grid‐spacing coupled with a terrestrial subgrid employing a 500 m grid‐spacing in order to represent lateral terrestrial water flow. A 10‐year slice is simulated for 2003–2012, using ERA5 reanalyses as driving data. The boundary condition of isotopic variables is prescribed with mean values from a 10‐year simulation with the Community Earth System Model Version 1. WRF‐Hydro‐iso realistically reproduces the climatological variations of the isotopic concentrations δPO18 and δPH2 from the Global Network of Isotopes in Precipitation. In a sensitivity analysis, it is found that land surface evaporation fractionation increases the isotopic concentrations in the rootzone soil moisture and slightly decreases the isotopic concentrations in precipitation. Lateral terrestrial water flow minorly affects these isotopic concentrations through changes in evaporation‐transpiration partitioning.

Description: Plain Language Summary: Global climate models are limited by their coarse resolution, which may reduce their meaningfulness. This problem can be circumvented for a specific region with regional climate models, which provide, for example, a detailed description of clouds and land‐atmosphere interactions. But it remains a question: How realistic is the model representation of water transport through the different compartments of the hydrological cycle, the atmosphere, the land, and the sea? A unique way to assess modeled water transport is the comparison to natural tracers, such as water isotopologues, which requires to include the fate of these water isotopologues in the model. This is what we pursue here with the newly developed WRF‐Hydro‐iso model. A model description and a proof of concept are provided for two climate zones, using the Global Network of Isotopes in Precipitation data set as reference.

Description: Key Points: A new coupled atmospheric‐hydrological regional modeling system of water isotopologues is presented. Land surface evaporation fractionation increases the isotopic concentrations in the rootzone. Lateral terrestrial water flow has a minor effect on isotopic concentrations in the rootzone.

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: German Federal Ministry of Science and Education

Description: Bavarian State Ministry of Science and the Arts

Description: Weather regime forecasts are a prominent use case of sub‐seasonal prediction in the midlatitudes. A systematic evaluation and understanding of year‐round sub‐seasonal regime forecast performance is still missing, however. Here we evaluate the representation of and forecast skill for seven year‐round Atlantic–European weather regimes in sub‐seasonal reforecasts from the European Centre for Medium‐Range Weather Forecasts. Forecast calibration improves regime frequency biases and forecast skill most strongly in summer, but scarcely in winter, due to considerable large‐scale flow biases in summer. The average regime skill horizon in winter is about 5 days longer than in summer and spring, and 3 days longer than in autumn. The Zonal Regime and Greenland Blocking tend to have the longest year‐round skill horizon, which is driven by their high persistence in winter. The year‐round skill is lowest for the European Blocking, which is common for all seasons but most pronounced in winter and spring. For the related, more northern Scandinavian Blocking, the skill is similarly low in winter and spring but higher in summer and autumn. We further show that the winter average regime skill horizon tends to be enhanced following a strong stratospheric polar vortex (SPV), but reduced following a weak SPV. Likewise, the year‐round average regime skill horizon tends to be enhanced following phases 4 and 7 of the Madden–Julian Oscillation (MJO) but reduced following phase 2, driven by winter but also autumn and spring. Our study thus reveals promising potential for year‐round sub‐seasonal regime predictions. Further model improvements can be achieved by reduction of the considerable large‐scale flow biases in summer, better understanding and modeling of blocking in the European region, and better exploitation of the potential predictability provided by weak SPV states and specific MJO phases in winter and the transition seasons.

Description: The overall sub‐seasonal forecast performance (biases and skill) for predicting seven year‐round Atlantic–European weather regimes is highest in winter and lowest in summer. The year‐round skill horizon is shortest for the European Blocking and longest for the Zonal Regime and Greenland Blocking (see figure). Furthermore, the winter skill horizon tends to be enhanced following a strong stratospheric polar vortex but reduced following a weak one. Madden–Julian Oscillation phases 4 and 7 tend to increase and phase 2 to decrease the year‐round skill horizon.

Description: Helmholtz‐Gemeinschaft http://dx.doi.org/10.13039/501100001656

Description: We investigate the glacial climate conditions in the southeastern Carpathian Basin (Vojvodina, Serbia) based on the reconstruction of malacological palaeotemperatures and results from a high‐resolution regional climate simulation. Land snail assemblages from eight loess profiles are used to reconstruct July temperatures during the Last Glacial Maximum (LGM). The malacological reconstructed temperatures are in good agreement with the simulated LGM July temperatures by the Weather Research and Forecast model. Both methods indicate increasing temperatures from the northwestern towards the southeastern parts of the study area. LGM aridity indices calculated based on the regional climate model data suggest more arid conditions in the southeastern parts compared with more humid conditions in the northwestern parts. However, for present‐day conditions, the moisture gradient is reversed, exhibiting more humid (arid) conditions in the southeast (northwest). An explanation for the reversed LGM aridity pattern is provided by an analysis of the prevailing wind directions over the South Banat district (Serbia). The prevailing moist northwesterly winds during summer are not able to compensate for the annual lack of moisture induced by the dry winds from the southeast that are more frequent during the LGM for the other seasons.

Description: Helmholtz Association http://dx.doi.org/10.13039/501100009318

Description: Past Global Changes http://dx.doi.org/10.13039/100010439

Description: The Tianshan Mountains, with their status as ‘water tower’, receive quantities of precipitation that are among the highest in Central Asia. There are considerable knowledge gaps regarding the understanding of spatial and temporal patterns of precipitation over this water‐scarce region. Based on the Global Precipitation Climatology Centre (GPCC) data set, this study evaluated the precipitation variations over Tianshan Mountains on different time scales by using Mann‐Kendall (M‐K) test approaches and the ensemble empirical mode decomposition (EEMD) method. The results show that (a) most parts of Tianshan experienced increasing annual precipitation during 1950–2016 while Western Tianshan, which is the wettest region, faced a downtrend of precipitation during the same 67 years; (b) the annual precipitation in the Tianshan Mountains has exhibited high‐frequency variations with 3‐ and 6‐year quasi‐periods and low‐frequency variations with 12‐, 27‐year quasi‐periods. On the decadal scale, Tianshan had two dry periods (1950–1962 and 1973–1984) and two wet periods (1962–1972 and 1985–2016) and has experienced a tendency of continuous humidification since 2004; (c) the precipitation over the Tianshan Mountains shows a strong seasonality. In total, 63.6% of all precipitation falls in spring and summer. Distinctive differences are found in seasonal precipitation variations among the sub‐Tianshan regions. Obvious upward trends of precipitation over Eastern Tianshan were found in all seasons, with Eastern Tianshan entering a humid period as early as 1986. Northern and Central Tianshan experienced a decreasing trend in summer and spring. However, in the other seasons, those two sub‐Tianshan regions have been in humid periods since the 1990s. The precipitation over Western Tianshan showed an upward trend in summer and autumn. The obvious downward trends in spring and winter have led to dry periods in these two seasons from 1997–2014 to 2008–2016, respectively.

Description: Most parts of Tianshan experienced increasing annual precipitation during 1950–2016 while Western Tianshan, which is the wettest region, faced a downtrend of precipitation during the same 67 years. Distinctive differences are found in seasonal precipitation variations among the sub‐Tianshan regions.

Description: Humboldt‐Universität zu Berlin National Natural Science Foundation of China

Description: China Scholarship Council (CSC)

Description: The European Space Agency Earth Explorer mission Aeolus with the first spaceborne Doppler Wind Lidar onboard provides global coverage of wind profiles twice per day. This paper discusses the impact of assimilating Aeolus winds on the quality of tropical analyses and forecasts using the observing system experiments of the European Centre for Medium‐Range Weather (ECMWF). Presented examples show that Aeolus wind profiles bring changes to the Kelvin wave structure in the layers with a significant vertical shear during the easterly phase of the quasi‐biennial oscillation in the period May to September 2020. Comparing Kelvin waves in analyses and forecasts with and without Aeolus winds, it is argued that improved ECMWF forecasts in the tropical tropopause layer are due to vertically propagating Kelvin waves.

Description: Plain Language Summary: The tropics are the region with the largest uncertainties in the initial states for numerical weather prediction, called analyses. Analysis uncertainties are largest in the tropical upper troposphere and the lower stratosphere (UTLS). One of the reasons is a lack of wind profiles which are more useful than temperature profiles in the tropics. This classical effect was described by Smagorinsky as “Not all data are equal in their information‐yielding capacity. Some are more equal than others.” ESA's ongoing Aeolus mission provides the first global wind profile observations from space. Despite their small number and relatively large random error, Aeolus winds have a positive impact on the quality of global weather forecasts, especially in the UTLS. In this paper, we discuss the impact of the Aeolus winds in UTLS focusing on the vertically propagating Kelvin waves, which are a major contributor to tropical variability. Several case studies are presented using the ECMWF model and data assimilation with and without Aeolus winds. The studied period May to September 2020 was characterized by a weakening easterly phase of the quasi‐biennial oscillation (QBO). Results suggest that a stronger impact of Aeolus winds in May than later in summer was associated with the QBO and the background flow.

Description: Key Points: Impact of assimilating Aeolus winds in the ECMWF system from May to September 2020 is coupled to the easterly QBO phase. Aeolus assimilation modifies the representation of vertically propagating Kelvin waves in the tropical UTLS. Forecast improvements in May 2020 could be associated with the alteration in the upward‐propagating Kelvin waves.

Description: European Space Agency (ESA) http://dx.doi.org/10.13039/501100000844

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: https://doi.org/10.5281/zenodo.5207392

Description: Molecular hydrogen (H2) released during serpentinization of mantle rocks is one of the main fuels for chemosynthetic life. Processes of H2 production at slow-spreading mid-ocean ridges (MORs) have received much attention in the past. Less well understood is serpentinization at passive continental margins where different rock types are involved (lherzolite instead of harzburgite/dunite at MORs) and the alteration temperatures tend to be lower (〈200°C vs. 〉200°C). To help closing this knowledge gap we investigated drill core samples from the West Iberia margin. Lherzolitic compositions and spinel geochemistry indicate that the exhumed peridotites resemble sub-continental lithospheric mantle. The rocks are strongly serpentinized, mainly consist of serpentine with little magnetite, and are generally brucite-free. Serpentine can be uncommonly Fe- rich, with XMg Mg/(Mg + Fe) 〈 0.8, and shows distinct compositional trends toward a cronstedtite endmember. Bulk rock and silicate fraction Fe(III)/ Fe ratios are 0.6–0.92 and 0.58–0.8, respectively; our data show that 2/3 of the ferric Fe is accounted for by Fe(III)- serpentine. Mass balance and thermodynamic calculations suggest that the sample’s initial serpentinization produced ∼120 to 〉300 mmol H2 per kg rock. The cold, late-stage weathering of the serpentinites at the seafloor caused additional H2 formation. These results suggest that the H2 generation potential evolves during the transition from continental break-up to ultraslow and, eventually, slow MOR spreading. Metamorphic phase assemblages systematically vary between these settings, which has consequences for H2 yields during serpentinization. At magma-poor rifted margins and ultraslow- spreading MORs, serpentine hosts most Fe(III). Hydrogen yields of 120 to 〉300 mmol and 50–150 mmol H2 per kg rock, respectively, may be expected at temperatures of 〈200°C. At slow-spreading MORs, in contrast, serpentinization may produce 200–350 mmol H2, most of which is related to magnetite formation at 〉200°C. Since, in comparison to slow-spreading MORs, geothermal gradients at magma-poor margins and ultraslow-spreading MORs are lower, larger volumes of low-temperature serpentinite should form in these settings. Serpentinization of lherzolitic rocks at magma-poor margins should produce particularly high amounts of H2 under conditions within the habitable zone. Magma-poor margins may hence be more relevant environments for hydrogenotrophic microbial life than previously thought.

Description: research

Description: https://doi.org/10 .1594/PANGAEA.920208

Description: research

Description: Few data exist that provide insight into pro- cesses affecting the long-term carbon cycle at shallow fore- arc depths. To better understand the mobilization of C in sediments and crust of the subducting slab, we investigated carbonate materials that originate from the subduction chan- nel at the Mariana forearc (〈 20 km) and were recovered during International Ocean Discovery Program Expedition 366. Calcium carbonates occur as vein precipitates within metavolcanic and metasedimentary clasts. The clasts repre- sent portions of the subducting lithosphere, including ocean island basalt, that were altered at lower blueschist facies conditions and were subsequently transported to the fore- arc seafloor by serpentinite mud volcanism. Euhedral arag- onite and calcite and the lack of deformation within the veins suggest carbonate formation in a stress-free environ- ment after peak metamorphism affected their hosts. Inter- growth with barite and marked negative Ce anomalies in car- bonate attest the precipitation within a generally oxic envi- ronment, that is an environment not controlled by serpen- tinization. Strontium and O isotopic compositions in car- bonate (87Sr/86Sr = 0.7052 to 0.7054, δ18OVSMOW = 20 to 24 ‰) imply precipitation from slab-derived fluids at tem- peratures between ∼ 130 and 300 ◦C. These temperature es- timates are consistent with the presence of blueschist facies phases such as lawsonite coexisting with the carbonates in some veins. Incorporated C is inorganic (δ13CVPDB = −1 ‰ to +4 ‰) and likely derived from the decarbonation of cal- careous sediment and/or oceanic crust. These findings pro- vide evidence for the mobilization of C in the downgoing slab at depths of 〈 20 km. Our study shows for the first time in detail that a portion of this C forms carbonate precipitates in the subduction channel of an active convergent margin. This process may be an important asset in understanding the deep carbon cycle since it highlights that some C is lost from the subducting lithosphere before reaching greater depths.

Description: research

Description: Changes in penguin populations on the Antarctic Peninsula have been linked to several environmental factors, but the potentially devastating impact of volcanic activity has not been considered. Here we use detailed biogeochemical analyses to track past penguin colony change over the last 8,500 years on Ardley Island, home to one of the Antarctic Peninsula’s largest breeding populations of gentoo penguins. The first sustained penguin colony was established on Ardley Island c. 6,700 years ago, pre-dating sub-fossil evidence of Peninsula- wide occupation by c. 1,000 years. The colony experienced five population maxima during the Holocene. Overall, we find no consistent relationships with local-regional atmospheric and ocean temperatures or sea-ice conditions, although the colony population maximum, c. 4,000–3,000 years ago, corresponds with regionally elevated temperatures. Instead, at least three of the five phases of penguin colony expansion were abruptly ended by large eruptions from the Deception Island volcano, resulting in near-complete local extinction of the colony, with, on average, 400–800 years required for sustainable recovery.

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3080_ESM.xlsx

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3081_ESM.xlsx

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3082_ESM.xlsx

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3083_ESM.xlsx

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3084_ESM.xlsx

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3085_ESM.xlsx

Description: https://static-content.springer.com/esm/art%3A10.1038%2Fncomms14914/MediaObjects/41467_2017_BFncomms14914_MOESM3086_ESM.xlsx

Description: research

Description: Warming of the North Atlantic region in climate history often was associated with massive melting of the Greenland Ice Sheet. To identify the meltwater's impacts and isolate these from internal variability and other global warming factors, we run single‐forcing simulations including small ensembles using three complex climate models differing only in their ocean components. In 200‐year‐long preindustrial climate simulations, we identify robust consequences of abruptly increasing Greenland runoff by 0.05 Sv: sea level rise of 44 ± 10 cm, subpolar North Atlantic surface cooling of 0.7°C, and a moderate AMOC decline of 1.1–2.0 Sv. The latter two emerge in under three decades—and reverse on the same timescale after the perturbation ends in year 100. The ocean translates the step‐change perturbation into a multidecadal‐to‐centennial signature in the deep overturning circulation. In all simulations, internal variability creates notable uncertainty in estimating trends, time of emergence, and duration of the response.

Description: Plain Language Summary: Enhanced melting of Greenland's glaciers is considered to be a major player in past rapid climate transitions and anticipated to soon impact ocean circulation under current global warming. Global warming triggers complex processes and feedbacks, of which greater amounts of meltwater slowing the large‐scale ocean circulation is only one. To better understand the sensitivity of the real but also the model ocean to just this meltwater, we run idealized experiments with up‐to‐date climate models, which use the same atmosphere and land but different ocean components. We find that sea level rise, cooling of the North Atlantic region, and slowing of the ocean circulation are responses common to all models while regional magnitudes of these responses differ considerably. Once we stop adding freshwater, all three models show that surface temperature and ocean circulation recover as quickly (or slowly) as they changed at the beginning of the experiment. Sea level rise is a lasting impact though.

Description: Key Points: Sudden increase in Greenland freshwater release is turned into century scale change by deep ocean dynamics. Upper ocean responses to moderately enhanced freshwater release from Greenland reverse on the same timescale once release ceases. Ocean model formulation affects regional expressions but basin‐scale responses are robust, so is the timing on decadal to centennial scales.

Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347

Description: Accurate and reliable precipitation data with high spatial and temporal resolution are essential in studying climate variability, water resources management, and hydrological forecasting. A range of global precipitation data are available to this end, but how well these capture actual precipitation remains unknown, particularly for mountain regions where ground stations are sparse. We examined the performance of three global high‐resolution precipitation products for capturing precipitation over Central Asia, a hotspot of climate change, where reliable precipitation data are particularly scarce. Specifically, we evaluated MSWEP, CHIRPS, and GSMAP against independent gauging stations for the period 1985–2015. Our results show that MSWEP and CHIRPS outperformed GSMAP for wetter periods (i.e., winter and spring) and wetter locations (150–600 mm·year−1), lowlands, and mid‐altitudes (0–3,000 m), and regions dominated by winter and spring precipitation. MSWEP performed best in representing temporal precipitation dynamics and CHIRPS excelled in capturing the volume and distribution of precipitation. All precipitation products poorly estimated precipitation at higher elevations (〉3,000 m), in drier areas (〈150 mm), and in regions characterized by summer precipitation. All products accurately detected dry spells, but their performance decreased for wet spells with increasing precipitation intensity. In sum, we find that CHIRPS and MSWEP provide the most reliable high‐resolution precipitation estimates for Central Asia. However, the high spatial and temporal heterogeneity of the performance call for a careful selection of a suitable product for local applications considering the prevailing precipitation dynamics, climatic, and topographic conditions.

Description: We present the first quantitative evaluation of global high‐resolution (below 12 km) precipitation products against independent ground observations over Central Asia. Our results show that MSWEP was best at representing temporal precipitation dynamics, and CHIRPS was most prominent in representing the volume and distribution of precipitation. This is especially the case of wet seasons, altitudes below 3,000 m, and regions dominated by spring and winter precipitation. Our analysis provides key insights on the precipitation products' suitability for local hydrological applications.

Description: Leibniz‐Institut für Agrarentwicklung in Transformationsökonomien

Description: Volkswagen Foundation http://dx.doi.org/10.13039/501100001663

Description: Observation‐based and modeling studies have identified the Eastern Mediterranean and Middle East (EMME) region as a prominent climate change hotspot. While several initiatives have addressed the impacts of climate change in parts of the EMME, here we present an updated assessment, covering a wide range of timescales, phenomena and future pathways. Our assessment is based on a revised analysis of recent observations and projections and an extensive overview of the recent scientific literature on the causes and effects of regional climate change. Greenhouse gas emissions in the EMME are growing rapidly, surpassing those of the European Union, hence contributing significantly to climate change. Over the past half‐century and especially during recent decades, the EMME has warmed significantly faster than other inhabited regions. At the same time, changes in the hydrological cycle have become evident. The observed recent temperature increase of about 0.45°C per decade is projected to continue, although strong global greenhouse gas emission reductions could moderate this trend. In addition to projected changes in mean climate conditions, we call attention to extreme weather events with potentially disruptive societal impacts. These include the strongly increasing severity and duration of heatwaves, droughts and dust storms, as well as torrential rain events that can trigger flash floods. Our review is complemented by a discussion of atmospheric pollution and land‐use change in the region, including urbanization, desertification and forest fires. Finally, we identify sectors that may be critically affected and formulate adaptation and research recommendations toward greater resilience of the EMME region to climate change.

Description: Key Points: The Eastern Mediterranean and Middle East is warming almost two times faster than the global average and other inhabited parts of the world. Climate projections indicate a future warming, strongest in summers. Precipitation will likely decrease, particularly in the Mediterranean. Virtually all socio‐economic sectors will be critically affected by the projected changes.

Description: European Union Horizon 2020

Description: https://esg-dn1.nsc.liu.se/search/esgf-liu/

Description: In this paper we coupled a crop growth model to the Weather Research and Forecasting model with its land surface model Noah‐MP and demonstrated the influence of the weather driven crop growth on land‐atmosphere (L‐A) feedback. An impact study was performed at the convection permitting scale of 3 km over Germany. While the leaf area index (LAI) in the control simulation was the same for all cropland grid cells, the inclusion of the crop growth model resulted in heterogeneous crop development with higher LAI and stronger seasonality. For the analyses of L‐A coupling, a two‐legged metric was applied based on soil moisture, latent heat flux and convective available potential energy. Weak atmospheric coupling is enhanced by the crop model, the terrestrial coupling determines the regions with the L‐A feedback. The inclusion of the crop model turns regions with no L‐A feedback on this path into regions with strong positive coupling. The number of non‐atmospherically controlled days between April and August is increased by 10–15 days in more than 50% of Germany. Our work shows that this impact results in a reduction of both cold bias and warm biases and thus improves the metrics of distributed added value of the monthly mean temperatures. The study confirms that the simulation of the weather driven annual phenological development of croplands for the regional climate simulations in mid‐latitudes is crucial due to the L‐A feedback processes and the currently observed and expected future change in phenological phases.

Description: Key Points: Coupling a crop growth model with the Weather and Research Forecasting model significantly improves the simulation of the leaf area index. Land‐atmosphere coupling strength is enhanced by weather dependent crop growth simulation. The distributed added value metric shows a reduction in temperature biases of up to 80% in croplands throughout the season in Germany.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: https://opendata.dwd.de/climate_environment/CDC/grids_germany/daily/Project_TRY/air_temperature_mean/

Description: https://doi.org/10.5281/zenodo.6501984

Description: http://land.copernicus.eu/pan-european/corine-land-cover/clc-2006/view

Description: https://doi.org/10.1594/WDCC/WRF_NOAH_HWSD_world_TOP_SOILTYP

Description: Lake‐level reconstructions are a key tool in hydro‐climate reconstructions, based on the assumption that lake‐level changes primarily reflect climatic changes. Although it is known that land cover changes can affect evapotranspiration and groundwater formation, this factor commonly receives little attention in the interpretation of past lake‐level changes. To address this issue in more detail, we explore the effects of land cover change on Holocene lake‐level fluctuations in Lake Tiefer See in the lowlands of northeastern Germany. We reconstruct lake‐level changes based on the analysis of 28 sediment records from different water depths and from the shore. We compare the results with land cover changes inferred from pollen data. We also apply hydrological modelling to quantify effects of land cover change on evapotranspiration and the lake level. Our reconstruction shows an overall lake‐level amplitude of about 10 m during the Holocene, with the highest fluctuations during the Early and Late Holocene. Only smaller fluctuations during the Middle Holocene can unambiguously be attributed to climatic fluctuations because the land cover was stable during that period. Fluctuations during the Early and Late Holocene are at least partly related to changes in natural and anthropogenic land cover. For several intervals the reconstructed lake‐level changes agree well with variations in modelled groundwater recharge inferred from land cover changes. In general, the observed amplitudes of lake‐level fluctuations are larger than expected from climatic changes alone and thus underline that land cover changes in lake catchments must be considered in climatic interpretations of past lake‐level fluctuations.

Description: Helmholtz Association http://dx.doi.org/10.13039/501100001656

Description: Leibniz‐Gemeinschaft http://dx.doi.org/10.13039/501100001664

Description: In‐depth understanding of the potential implications of climate change is required to guide decision‐ and policy‐makers when developing adaptation strategies and designing infrastructure suitable for future conditions. Impact models that translate potential future climate conditions into variables of interest are needed to create the causal connection between a changing climate and its impact for different sectors. Recent surveys suggest that the primary strategy for validating such models (and hence for justifying their use) heavily relies on assessing the accuracy of model simulations by comparing them against historical observations. We argue that such a comparison is necessary and valuable, but not sufficient to achieve a comprehensive evaluation of climate change impact models. We believe that a complementary, largely observation‐independent, step of model evaluation is needed to ensure more transparency of model behavior and greater robustness of scenario‐based analyses. This step should address the following four questions: (1) Do modeled dominant process controls match our system perception? (2) Is my model's sensitivity to changing forcing as expected? (3) Do modeled decision levers show adequate influence? (4) Can we attribute uncertainty sources throughout the projection horizon? We believe that global sensitivity analysis, with its ability to investigate a model's response to joint variations of multiple inputs in a structured way, offers a coherent approach to address all four questions comprehensively. Such additional model evaluation would strengthen stakeholder confidence in model projections and, therefore, into the adaptation strategies derived with the help of impact models.

Description: A comprehensive evaluation of climate change impact models combining both observation‐based and response‐based strategies.

Description: This article is categorized under: Climate Models and Modeling 〉 Knowledge Generation with Models Assessing Impacts of Climate Change 〉 Evaluating Future Impacts of Climate Change

Description: Alexander von Humboldt‐Stiftung http://dx.doi.org/10.13039/100005156

Description: Engineering and Physical Sciences Research Council http://dx.doi.org/10.13039/501100000266

Description: While the evidence for anthropogenic climate change continues to strengthen, and concerns about severe weather events are increasing, global projections of regional climate change are still uncertain due to model‐dependent changes in large‐scale atmospheric circulation, including over North Atlantic and Europe. Here, the Jenkinson–Collison classification of daily circulation patterns is used to evaluate past and future changes in their seasonal frequencies over Central Europe for the 1900–2100 period. Three reanalyses and eight global climate models from the Coupled Model Intercomparison Project phase 6, were used based on daily mean sea‐level pressure data. Best agreement in deriving relative frequencies of the synoptic types was found between the reanalyses. Global models can generally capture the interannual variability of circulation patterns and their climatological state, especially for the less frequent synoptic types. Based on historical data and the shared socioeconomic pathway 5 scenario, the evaluated trends show more robust signals during summer, given their lesser internal variability. Increasing frequencies were found for circulation types characterized by weak pressure gradients, mainly at the expense of decreasing frequencies of westerlies. Our findings indicate that given a high‐emission scenario, these signals will likely emerge from past climate variability towards the mid‐21st century for most altered circulation patterns.

Description: Daily synoptic circulation patterns are derived using the Jenkinson–Collinson automated classification over Central Europe to evaluate past and future changes in their temporal frequencies. Reanalyses and eight global climate models from the CMIP6 were used based on the historical experiment and a high‐emission scenario. More robust signals were found during the summer season leading to emerging changes towards the mid‐21st century.

Description: H2020 Marie Skłodowska‐Curie Actions http://dx.doi.org/10.13039/100010665

Description: EU International Training Network (ITN) Climate Advanced Forecasting of sub‐seasonal Extremes (CAFE)

Description: The moisture sources of precipitation in the Tianshan Mountains, one of the regions with the highest precipitation in Central Asia during 1979–2017 are comprehensively and quantitatively summarized by using a Lagrangian moisture source detection technique. Continental sources provide about 93.2% of the moisture for precipitation in the Tianshan Mountain, while moisture directly from the ocean is very limited, averaging only 6.8%. Central Asia plays a dominant role in providing moisture for all sub‐regions of the Tianshan Mountains. For the Western Tianshan, moisture from April to October comes mainly from Central Asia (41.4%), while moisture from November to March is derived primarily from Western Asia (45.7%). Nearly 13.0% of moisture to precipitation for Eastern Tianshan in summer originates from East and South Asia, and the Siberia region. There is a significant decreasing trend in the moisture contribution of local evaporation and Central Asia in the Eastern Tianshan during winter. The contribution of moisture from Europe to summer precipitation in the Central and Eastern Tianshan and the contribution of the North Atlantic Ocean to summer precipitation in the Northern, Central, and Eastern Tianshan also exhibit a decreasing trend. The largest increase in moisture in Western Tianshan stems from West Asia during extreme winter precipitation months. Europe is also an important contributor to extreme precipitation in the Northern Tianshan. The moisture from East and South Asia and Siberia during extreme precipitation months in both winter and summer is significantly enhanced in the Eastern Tianshan.

Description: Key Points: Local evaporation and Central Asia play a leading role in providing moisture for all sub‐regions of the Tianshan Mountains. The largest moisture component during the months of extreme winter precipitation for Western Tianshan derives from western Asia. Moisture from East and South Asia and Siberia during extreme precipitation months is significantly enhanced in the Eastern Tianshan.

Description: China Scholarship Council

Description: Humboldt‐Universität zu Berlin

Description: https://zenodo.org/record/6451656#.YrrfbqhBwuU

Description: The significant climate feedback of stratospheric water vapor (SWV) necessitates quantitative estimates of SWV budget changes. Model simulations driven by the newest European Centre for Medium‐Range Weather Forecast reanalysis ERA5, satellite observations from the Stratospheric Water and OzOne Satellite Homogenized data set, Microwave Limb Sounder, and in situ frost point hygrometer observations from Boulder all show substantial and persistent stratospheric moistening after a sharp drop in water vapor at the turn of the millennium. This moistening occurred mainly during 2000–2006 and SWV abundances then remained high over the last decade. We find strong positive trends in the Northern Hemisphere and weak negative trends over the South Pole, mainly during austral winter. Moistening of the tropical stratosphere after 2000 occurred during late boreal winter/spring, reached values of ∼0.2 ppm/decade, was well correlated with a warming of the cold point tropopause by ∼0.4 K/decade and can only be partially attributed to El Nino‐Southern Oscillation and volcanic eruptions.

Description: Plain Language Summary: Water vapor is an effective greenhouse gas. Human‐induced climate change has led to warmer air in the troposphere, which consequently can hold more moisture, thus enhancing the greenhouse effect. The long‐term change in stratospheric water vapor (SWV) is less clear and currently under debate. Using satellite observations, balloon soundings and model simulations, we find an increase of SWV after 2000. This moistening occurred mainly during 2000–2006 and the stratospheric moisture content then remained high over the last decade. The increase of SWV is stronger in the Northern than in the Southern Hemisphere. Over the South Pole, a weak decrease was found. Moistening of the tropical stratosphere occurred mainly during late winter and spring, and was in line with warming of the tropical tropopause, the coldest region that separates the troposphere and stratosphere. Natural causes such as volcanic eruptions cannot completely explain this stratospheric moistening.

Description: Key Points: Stratospheric moistening after 2000 is clearly detectable in ERA5‐driven simulations, satellite and in situ observations. Hemispheric asymmetry is found with strong positive trends in the Northern Hemisphere and weak negative trends over the South Pole. Moistening of the lower tropical stratosphere is only partially caused by El Nino‐Southern Oscillation and volcanic eruptions.

Description: https://doi.org/10.5067/Aura/MLS/DATA2508

Description: https://doi.org/10.5067/GLOSSAC-L3-V2.0

Description: https://doi.org/10.5067/GLOSSAC-L3-V2.0

Description: Worldwide, rice production contributes about 10% of total greenhouse gas (GHG) emissions from the agricultural sector, mainly due to CH4 emissions from continuously flooded fields. Alternate Wetting and Drying (AWD) is a promising crop technology for mitigating CH4 emissions and reducing the irrigation water currently being applied in many of the world's top rice‐producing countries. However, decreased emissions of CH4 may be partially counterbalanced by increased N2O emissions. In this case study for the Philippines, the national mitigation potential of AWD is explored using the process‐based biogeochemical model LandscapeDNDC. Simulated mean annual CH4 emissions under conventional rice production for the time period 2000–2011 are estimated as 1,180 ± 163 Gg CH4 yr−1. During the cropping season, this is about +16% higher than a former estimate using emission factors. Scenario simulations of nationwide introduction of AWD in irrigated landscapes suggest a considerable decrease in CH4 emissions by −23%, while N2O emissions are only increased by +8%. Irrespective of field management, at national scale, the radiative forcing of irrigated rice production is always dominated by CH4 (〉95%). The reduction potential of GHG emissions depends on, for example, number of crops per year, residue management, amount of applied irrigation water, and sand content. Seasonal weather conditions also play an important role since the mitigation potential of AWD is almost double as high in dry as compared to wet seasons. Furthermore, this study demonstrates the importance of temporal continuity, considering off‐season emissions and the long‐term development of GHG emissions across multiple years.

Description: Plain Language Summary: Worldwide, rice production contributes to about 10% of total greenhouse gas emissions of the agricultural sector mainly due to CH4 emissions from fields that are continuously flooded. Alternate Wetting and Drying (AWD) is an alternative cropping practice where fields are irrigated a few days after the disappearance of the ponded water. This study explores the mitigation potential of nationwide introduction of AWD in the Philippines. Results from the application of a process‐based model suggest a considerable decrease in CH4 emissions by −23%. Compared to N2O, CH4 is responsible for more than 95% of the total radiative forcing under conventional or AWD field management.

Description: Key Points: Nationwide, Alternate Wetting and Drying (AWD) reduces CH4 emissions by −23%. N2O emissions contribute to less than 5% to the total radiative forcing under conventional or AWD field management. Mitigation of AWD depends on, for example, seasonal weather conditions, cropping intensity, irrigation, residue management, and soil texture.

Description: DFG

Description: https://doi.org/10.35097/588

Description: Natural forcing from solar and volcanic activity contributes significantly to climate variability. The post‐eruption cooling of strong volcanic eruptions was hypothesized to have led to millennial‐scale variability during Glacials. Cooling induced by volcanic eruption is potentially weaker in the warmer climate. The underlying question is whether the climatic response to natural forcing is state‐dependent. Here, we quantify the response to natural forcing under Last Glacial and Pre‐Industrial conditions in an ensemble of climate model simulations. We evaluate internal and forced variability on annual to multicentennial scales. The global temperature response reveals no state dependency. Small local differences result mainly from state‐dependent sea ice changes. Variability in forced simulations matches paleoclimate reconstructions significantly better than in unforced scenarios. Considering natural forcing is therefore important for model‐data comparison and future projections.

Description: Plain Language Summary: Climate variability describes the spatial and temporal variations of Earth's climate. Understanding these variations is important for estimating the occurrence of extreme climate events such as droughts. Yet, it is unclear whether climate variability depends on the mean surface temperature of the Earth or not. Here, we investigate the effects of natural forcing from volcanic eruptions and solar activity changes on climate variability. We compare simulations of a past (cold) and present (warm) climate with and without volcanism and solar changes. We find that overall, the climate system responds similarly to natural forcing in the cold and warm state. Small local differences mainly occur where ice can form. To evaluate the simulated variability, we use data from paleoclimate archives, including trees, ice‐cores, and marine sediments. Climate variability from forced simulations agrees better with the temperature variability obtained from data. Natural forcing is therefore critical for reliable simulation of variability in past and future climates.

Description: Key Points: We present Glacial/Interglacial climate simulations and quantify effects of time‐varying volcanic and solar forcing on climate variability. The mean global and local response to these forcings is similar in Glacial and Interglacial climate, suggesting low state dependency. In both climate states, modeled temperature variance agrees better with palaeoclimate data when volcanic and solar forcing is included.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Heinrich Böll Stiftung (Heinrich Böll Foundation) http://dx.doi.org/10.13039/100009379

Description: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347

Description: https://doi.org/10.5281/zenodo.6074747

Description: https://github.com/paleovar/StateDependency

Description: https://doi.org/10.5281/zenodo.6474769

Description: The Madden–Julian oscillation (MJO) is the dominant component of tropical intraseasonal variability, with wide‐reaching impacts even on extratropical weather and climate patterns. However, predicting the MJO is challenging. One reason is the suboptimal state estimates obtained with standard data assimilation (DA) approaches. These are typically based on filtering methods with Gaussian approximations and do not take into account physical properties that are important specifically for the MJO. In this article, a constrained ensemble DA method is applied to study the impact of different physical constraints on the state estimation and prediction of the MJO. The quadratic programming ensemble (QPEns) algorithm utilized extends the standard stochastic ensemble Kalman filter (EnKF) with specifiable constraints on the updates of all ensemble members. This allows us to recover physically more consistent states and to respect possible associated non‐Gaussian statistics. The study is based on identical twin experiments with an adopted nonlinear model for tropical intraseasonal variability. This so‐called skeleton model succeeds in reproducing the main large‐scale features of the MJO and closely related tropical waves, while keeping adequate simplicity for fast experiments on intraseasonal time‐scales. Conservation laws and other crucial physical properties from the model are examined as constraints in the QPEns. Our results demonstrate an overall improvement in the filtering and forecast skill when the model's total energy is conserved in the initial conditions. The degree of benefit is found to be dependent on the observational setup and the strength of the model's nonlinear dynamics. It is also shown that, even in cases where the statistical error in some waves remains comparable with the stochastic EnKF during the DA stage, their prediction is improved remarkably when using the initial state resulting from the QPEns.

Description: Unsatisfactory predictions of the MJO are partly due to DA methods that do not respect non‐Gaussian PDFs and the physical properties of the tropical atmosphere. Therefore the QPEns, an algorithm extending a stochastic EnKF with state constraints, is tested here on a simplified model for the MJO and associated tropical waves. Our series of identical twin experiments shows, in particular, that a constraint on the truth's nonlinear total energy improves forecasts statistically and can, in certain situations, even prevent filter divergence. image

Description: Deutsche Forschungsgemeinschaft : Heisenberg Award (DFG JA1077/4‐1); Transregional Collaborative Research Center SFB / TRR 165 “Waves to Weather” http://dx.doi.org/10.13039/501100001659

Description: Office of Naval Research (ONR) http://dx.doi.org/10.13039/100000006

Description: Abundant rainfall over tropical land masses sustains rich ecosystems, a crucial source of biodiversity and sink of carbon. Here, we use two characteristics of the observed tropical precipitation distribution, its distinctive zonal arrangement and its partitioning between land and ocean, to understand whether land conditions the climate to receive more than its fair share of precipitation as set by the land‐sea distribution. Our analysis demonstrates that it is not possible to explain the tropics‐wide partitioning of precipitation unless one assumes that rain is favored over land. Land receives more than its fair share of precipitation by broadening and letting the tropical rainbelts move more, effectively underpinning a negative feedback between surface water storage and precipitation. In contrast, rain is disfavored over land in climate models. Our findings suggest that the abundance of rainfall that shapes the terrestrial tropical biosphere is more robust to perturbations than models have suggested.

Description: Plain Language Summary: Many ecosystems depend on the presence of a land surface exposed to precipitation to exist and prosper. In contrast to the marine biota, though, the terrestrial biosphere cannot directly tap into an unlimited reservoir of water molecules that can be recycled to support life. Yet, observations indicate that it rains in mean 3 mm day−1 over tropical land and 3 mm day−1 over tropical ocean, giving the surprising impression that precipitation amounts are not altered by the presence of land. Investigating the factors controlling this tropics‐wide partitioning of precipitation, we show that geometrical constraints actually would lead to a precipitation ratio of 0.86, not 1.0, if the presence of land would not matter. Comparing this theoretical value to observations, we find that the land receives more than its fair share of precipitation. This happens by broadening and letting the tropical rainbelt moves more over land. By quantifying the strength of the land control on the tropics‐wide partitioning of precipitation, we can also deduce that a negative feedback exists between evapotranspiration and precipitation. In contrast, repeating the same analysis with climate models reveals a positive feedback, questioning the ability of climate models to simulate regional tropical precipitation changes.

Description: Key Points: A conceptual model of tropical precipitation is derived to understand the tropics‐wide partitioning of precipitation between land and ocean. The size and location of continent constrain the tropical land‐to‐ocean precipitation ratio to lie between 0.74 and 0.95 with a mean of 0.86. Observed ratios from six data sets are larger than these values, indicating that land receives more than its fair share of precipitation.

Description: http://hdl.handle.net/21.11116/0000-000A-1DEC-D

Description: High ground‐level ozone concentrations and high air temperatures present two health‐relevant natural hazards. The most severe health outcomes are generally associated with concurrent elevated levels of both variables, representing so‐called compound ozone and temperature (o‐t‐) events. These o‐t‐events, their relationship with identified main meteorological and synoptic drivers, as well as ozone and temperature levels themselves and the linkage between both variables, vary temporally and with the location of sites. Due to the serious health burden and its spatiotemporal variations, the analysis of o‐t‐events across the European domain represents the focus of the current work. The main objective is to model and project present and future o‐t‐events, taking region‐specific differences into account. Thus, a division of the European domain into six o‐t‐regions with homogeneous, similar ground‐level ozone and temperature characteristics and patterns built the basis of the study. In order to assess region‐specific main meteorological and synoptic drivers of o‐t‐events, statistical downscaling models were developed for selected representative stations per o‐t‐region. Statistical climate change projections for all central European o‐t‐regions were generated to assess potential frequency shifts of o‐t‐events until the end of the 21st century. The output of eight Earth System Models from the sixth phase of the Coupled Model Intercomparison Project considering SSP245 and SSP370 scenario assumptions was applied. By comparing midcentury (2041–2060) and late century (2081–2100) time slice differences with respect to a historical base period (1995–2014), substantial increases of the health‐relevant compound o‐t‐events were projected across all central European regions.

Description: Plain Language Summary: Compound events with concurrent high levels of ozone, being a major pollutant present in the air near Earth's surface, and of air temperature, have strong negative impacts on the health of humans. In this study, these compound events were investigated under present and future European climate. Six regions of similar ozone and temperature characteristics and patterns were defined. For each region, representative stations being typical examples for the overall region were extracted. Models for these stations were developed and their results analyzed to define factors that highly influence the occurrence of compound ozone and temperature events in each region, for example, mean air temperature or humidity levels. The generated models were later applied to project future frequency shifts of these compound events under climate change in central Europe. As a major result of the study, the future health‐relevant compound ozone and temperature events were projected to occur more frequently in the middle as well as at the end of the 21st century across all central European regions.

Description: Key Points: A clustering approach based on ground‐level ozone and air temperature leads to a division of Europe into six ozone and temperature regions. Statistical downscaling models identify region‐specific main meteorological and synoptic drivers of compound ozone and temperature events. Climate change projections point to an increase in these compound events until the end of the 21st century in central Europe.

Description: Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)

Description: During the period 2018–2020, Europe experienced a series of hot and dry weather conditions with significant socioeconomic and environmental consequences. Yet, the extremity of these multi‐year dry conditions is not recognized. Here, we provide a comprehensive spatio‐temporal assessment of the drought hazard over Europe by benchmarking past exceptional events during the period from 1766 to 2020. We identified the 2018–2020 drought event as a new benchmark having an unprecedented intensity that persisted for more than 2 years, exhibiting a mean areal coverage of 35.6% and an average duration of 12.2 months. What makes this event truly exceptional compared with past events is its near‐surface air temperature anomaly reaching +2.8 K, which constitutes a further evidence that the ongoing global warming is exacerbating present drought events. Furthermore, future events based on climate model simulations Coupled Model Intercomparison Project v5 suggest that Europe should be prepared for events of comparable intensity as the 2018–2020 event but with durations longer than any of those experienced in the last 250 years. Our study thus emphasizes the urgent need for adaption and mitigation strategies to cope with such multi‐year drought events across Europe.

Description: Plain Language Summary: This manuscript demonstrates that the 2018–2020 multi‐year drought event constitutes a new benchmark in Europe, with an unprecedented level of intensity over the past 250 years. What makes this event truly exceptional compared with past events is its temperature anomaly reaching +2.8 K. This finding provides new evidence that the ongoing global warming exacerbates current drought events. The key message of this study is that the projected future events across the European continent will have a comparable intensity as the 2018–2020 drought but exhibit considerably longer durations than any of those observed during the last 250 years. Our analysis also shows that these exceptional temperature‐enhanced droughts significantly negatively impact commodity crops across Europe.

Description: Key Points: The 2018–2020 multi‐year drought shows unprecedented level of intensity during the past 250 years. The 2018–2020 event reached record‐breaking +2.8 K temperature anomaly and negatively impacted major crops. Future drought events reach comparable intensity of 2018–2020 but with considerably longer durations.

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: Grantová Agentura České Republiky (GAČR) http://dx.doi.org/10.13039/501100001824

Description: Helmholtz‐Fonds (Helmholtz‐Fonds e.V.) http://dx.doi.org/10.13039/501100013655

Description: Smallholder livelihoods throughout Central America are built on rain‐fed agriculture and depend on seasonal variations in temperature and precipitation. Recent climatic shifts in this highly diverse region are not well understood due to sparse observations, and as the skill of global climate products have not been thoroughly evaluated. We examine the performance for several reanalysis and satellite‐based global climate data products (CHIRPS/CHIRTS, ERA5, MERRA‐2, PERSIANN‐CDR) as compared to the observation‐based GPCC precipitation dataset. These datasets are then used to evaluate the magnitude and spatial extent of hydroclimatic shifts and changes in aridity and drought over the last four decades. We focus on water‐limited regions that are important for rain‐fed agriculture and particularly vulnerable to further drying, and newly delineate those regions for Central America and Mexico by adapting prior definitions of the Central American Dry Corridor. Our results indicate that the CHIRPS dataset exhibits the greatest skill for the study area. A general warming of 0.2–0.8°C·decade−1 was found across the region, particularly for spring and winter, while widespread drying was indicated by several measures for the summer growing season. Changes in annual precipitation have been inconsistent, but show declines of 20–25% in eastern Honduras/Nicaragua and in several parts of Mexico. Some regions most vulnerable to drying have been subject to statistically significant trends towards summer drying, increases in drought and aridity driven by precipitation declines, and/or a lengthening of the winter dry season, highlighting areas where climate adaptation measures may be most urgent.

Description: Over the past four decades, precipitation trends are the main driver of drought trends, with temperature trends playing a small role. The most widespread drying and increases in aridity have occurred during the summer growing season. Based on delimitations of water‐limited and climate‐sensitive regions (brown shading) that are important for rain‐fed agriculture, some of these highly vulnerable regions overlap with areas of significant drying (red), highlighting potential prioritization areas for climate adaptation measures. image

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Frias Institute of Advanced Studies (FRIAS) http://dx.doi.org/10.13039/501100003190

Description: National Science Foundation http://dx.doi.org/10.13039/100000001

Description: Variability of the North Atlantic Oscillation (NAO) drives wintertime temperature anomalies in the Northern Hemisphere. Dynamical seasonal prediction systems can skilfully predict the winter NAO. However, prediction of the NAO‐dependent air temperature anomalies remains elusive, partially due to the low variability of predicted NAO. Here, we demonstrate a hidden potential of a multi‐model ensemble of operational seasonal prediction systems for predicting wintertime temperature by increasing the variability of predicted NAO. We identify and subsample those ensemble members which are close to NAO index statistically estimated from initial autumn conditions. In our novel multi‐model approach, the correlation prediction skill for wintertime Central Europe temperature is improved from 0.25 to 0.66, accompanied by an increased winter NAO prediction skill of 0.9. Thereby, temperature anomalies can be skilfully predicted for the upcoming winter over a large part of the Northern Hemisphere through increased variability and skill of predicted NAO.

Description: Plain Language Summary: Wintertime temperature in the Northern Hemisphere is regulated by the variations of atmospheric pressure, represented by the so‐called North Atlantic Oscillation (NAO). The NAO's phase—negative or positive—is associated with the pathways of cold and warm air masses leading to cold or warm winters in Europe. While the NAO phase can be predicted well, predictions of the NAO‐dependent air temperature remain elusive. Specifically, it is challenging to predict the strength of the NAO, the most important requirement for the accurate prediction of wintertime temperature. Here, we improve wintertime temperature prediction by increasing the strength of the predicted NAO. We use observation based autumn Northern Hemisphere ocean and air temperature, as well as ice and snow cover for statistical estimation of the first guess NAO for the upcoming winter. Then, we sub‐select only those simulations from the multi‐model ensemble, which are consistent with our first guess NAO. As a result, based on these selected members, the wintertime temperature prediction is substantially improved over a large part of the Northern Hemisphere.

Description: Key Points: Amplitude and skill of predicted North Atlantic Oscillation (NAO) improve significantly by subsampling of ensemble of existing seasonal prediction systems. Amplified NAO variability leads to significant improvement in predicting the upcoming winter temperature anomalies in the Northern Hemisphere.

Description: Deutsche Forschungsgemeinschaft

Description: Climate, Climatic Change, and Society

Description: Marine Institute grant

Description: European Union's Horizon 2020 research and innovation programme

Description: https://cds.climate.copernicus.eu/cdsapp#!/dataset/seasonal-original-single-levels?tab=overview

Description: http://www.ecmwf.int/en/forecasts/datasets