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: The variability of the Atlantic meridional overturning circulation (AMOC) and its governing processes during the Last Glacial Maximum (LGM) is investigated in the Kiel Climate Model. Under LGM conditions, multidecadal AMOC variability is mainly forced by the surface heat flux variability linked to the East Atlantic pattern (EAP). In contrast, the multidecadal AMOC variability under preindustrial conditions is mainly driven by the surface heat flux variability associated with the North Atlantic Oscillation. Stand-alone atmosphere model experiments show that relative to preindustrial conditions, the change in AMOC forcing under LGM conditions is tightly linked to the differences in topography.

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: At regional to local scales internal variability is expected to be a dominant source of uncertainty in analyzing precipitation extremes and mean precipitation even far into the 21st century. A debated topic is whether a faster increase in subdaily precipitation extremes can be expected. Here we analyzed seasonal maximum precipitation in various time steps (3 hr, days, and 5 days) from a high-resolution 50-member large-ensemble (CRCM5-LE) and compared them to changes in mean precipitation over Europe. Our results show that the magnitude of change in extreme precipitation varies for season and duration. Subdaily extremes increase at higher rates than daily extremes and show higher scaling with temperature. Northern Europe shows widespread scaling above Clausius-Clapeyron of subdaily extremes in all seasons and for daily extremes in winter/spring. Scaling above Clausius-Clapeyron is also visible over Eastern Europe in winter/spring. For most regions and seasons the forced response emerges from the internal variability by midcentury.

Description: An abundance of evidence indicates that the tropics are expanding. Despite many attempts to decipher the cause, the underlying dynamical mechanism driving tropical expansion is still not entirely clear. Here, based on observations, multimodel simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5) and purposefully designed numerical experiments, the variations and trends of the tropical width are explored from a regional perspective. We find that the width of the tropics closely follows the displacement of oceanic midlatitude meridional temperature gradients (MMTG). Under global warming, as a first-order response, the subtropical ocean experiences more surface warming because of the mean Ekman convergence of anomalously warm water. The enhanced subtropical warming, which is partially independent of natural climate oscillations, such as the Pacific Decadal Oscillation, leads to poleward advance of the MMTG and drives the tropical expansion. Our results, supported by both observations and model simulations, imply that global warming may have already significantly contributed to the ongoing tropical expansion, especially over the ocean-dominant Southern Hemisphere.

Description: Vb cyclones are major drivers of extreme precipitation and floods in the study area of hydrological Bavaria (Germany). When assessing climate change impacts on Vb cyclones, internal variability of the climate system is an important underlying uncertainty. Here, we employ a 50-member single-model initial-condition large ensemble of a regional climate model to study climate variability and forced change on Vb cyclones. An artificial neural network detects cutoff lows over central Europe, which are associated with extreme precipitation Vb cyclones. Thus, machine learning filters the large ensemble prior to cyclone tracking. Our results show a striking change in Vb seasonality with a strong decrease of Vb cyclones in summer (−52%) and a large increase in spring (+73%) under the Representative Concentration Pathway 8.5. This change exceeds the noise of internal variability and leads to a peak shift from summer to spring. Additionally, we show significant increases in the daily precipitation intensity during Vb cyclones in all seasons.

Description: A new global climate model setup using FESOM2.0 for the sea ice-ocean component and ECHAM6.3 for the atmosphere and land surface has been developed. Replacing FESOM1.4 by FESOM2.0 promises a higher efficiency of the new climate setup compared to its predecessor. The new setup allows for long-term climate integrations using a locally eddy-resolving ocean. Here it is evaluated in terms of (1) the mean state and long-term drift under preindustrial climate conditions, (2) the fidelity in simulating the historical warming, and (3) differences between coarse and eddy-resolving ocean configurations. The results show that the realism of the new climate setup is overall within the range of existing models. In terms of oceanic temperatures, the historical warming signal is of smaller amplitude than the model drift in case of a relatively short spin-up. However, it is argued that the strategy of “de-drifting” climate runs after the short spin-up, proposed by the HighResMIP protocol, allows one to isolate the warming signal. Moreover, the eddy-permitting/resolving ocean setup shows notable improvements regarding the simulation of oceanic surface temperatures, in particular in the Southern Ocean.

Description: Land use and climate changes both affect terrestrial ecosystems. Here, we used three combinations of Shared Socioeconomic Pathways and Representative Concentration Pathways (SSP1xRCP26, SSP3xRCP60, and SSP5xRCP85) as input to three dynamic global vegetation models to assess the impacts and associated uncertainty on several ecosystem functions: terrestrial carbon storage and fluxes, evapotranspiration, surface albedo, and runoff. We also performed sensitivity simulations in which we kept either land use or climate (including atmospheric CO2) constant from year 2015 on to calculate the isolated land use versus climate effects. By the 2080–2099 period, carbon storage increases by up to 87 ± 47 Gt (SSP1xRCP26) compared to present day, with large spatial variance across scenarios and models. Most of the carbon uptake is attributed to drivers beyond future land use and climate change, particularly the lagged effects of historic environmental changes. Future climate change typically increases carbon stocks in vegetation but not soils, while future land use change causes carbon losses, even for net agricultural abandonment (SSP1xRCP26). Evapotranspiration changes are highly variable across scenarios, and models do not agree on the magnitude or even sign of change of the individual effects. A calculated decrease in January and July surface albedo (up to −0.021 ± 0.007 and −0.004 ± 0.004 for SSP5xRCP85) and increase in runoff (+67 ± 6 mm/year) is largely driven by climate change. Overall, our results show that future land use and climate change will both have substantial impacts on ecosystem functioning. However, future changes can often not be fully explained by these two drivers and legacy effects have to be considered.

Description: Abstract One of the most intriguing facets of the climate system is that it exhibits variability across all temporal and spatial scales; pronounced examples are temperature and precipitation. The structure of this variability, however, is not arbitrary. Over certain spatial and temporal ranges, it can be described by scaling relationships in the form of power laws in probability density distributions and autocorrelation functions. These scaling relationships can be quantified by scaling exponents which measure how the variability changes across scales and how the intensity changes with frequency of occurrence. Scaling determines the relative magnitudes and persistence of natural climate fluctuations. Here, we review various scaling mechanisms and their relevance for the climate system. We show observational evidence of scaling and discuss the application of scaling properties and methods in trend detection, climate sensitivity analyses, and climate prediction.

Description: We reconstructed the variability of the Earth's strongest hydrological system, the Indian monsoon, over the interval 6.24 to 4.91 Ma at International Ocean Discovery Program (IODP) Expedition 353 Site U1448 in the Andaman Sea. We integrated high-resolution benthic and planktic foraminiferal carbon and oxygen isotopes with Mg/Ca measurements of the mixed layer foraminifer Trilobatus sacculifer to reconstruct the isotopic composition of seawater (δ18Osw) and the gradient between planktic and benthic foraminiferal δ13C. A prominent increase in mixed layer temperatures of ~4°C occurred between 5.55 and 5.28 Ma, accompanied by a change from precession- to obliquity-driven variability in planktic δ18O and δ18Osw. We suggest that an intensified cross-equatorial transport of heat and moisture, paced by obliquity, led to increased summer monsoon precipitation during warm stages after 5.55 Ma. Transient cold stages were characterized by reduced mixed layer temperatures and summer monsoon failure, thus resembling late Pleistocene stadials. In contrast, an overall cooler background climate state with a strengthened biological pump prevailed prior to 5.55 Ma. These findings highlight the importance of internal feedback processes for the long-term evolution of the Indian monsoon.

Description: Forest canopies present irregular surfaces that alter both the quantity and spatiotemporal variability of precipitation inputs. The drop size distribution (DSD) of rainfall varies with rainfall event characteristics and is altered substantially by the forest stand properties. Yet, the influence of two major European tree species, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. karst), on throughfall DSD is largely unknown. In order to assess the impact of these two species with differing canopy structures on throughfall DSD, two optical disdrometers, one above and one below the canopy of each European beech and Norway spruce, measured DSD of both incident rainfall and throughfall over 2 months at a 10-s resolution. Fractions of different throughfall categories were analysed for single-precipitation events of different intensities. While penetrating the canopies, clear shifts in drop size and temporal distributions of incoming rainfall were observed. Beech and spruce, however, had different DSD, behaved differently in their effect on diameter volume percentiles as well as width of drop spectrum. The maximum drop sizes under beech were higher than under spruce. The mean ± standard deviation of the median volume drops size (D50) over all rain events was 2.7 ± 0.28 mm for beech and 0.80 ± 0.04 mm for spruce, respectively. In general, there was a high-DSD variability within events indicating varying amounts of the different throughfall fractions. These findings help to better understand the effects of different tree species on rainfall partitioning processes and small-scale variations in subcanopy rainfall inputs, thereby demonstrating the need for further research in high-resolution spatial and temporal properties of rainfall and throughfall.

Description: Precipitation extremes with devastating socioeconomic consequences within the South American Monsoon System (SAMS) are expected to become more frequent in the near future. The complexity in SAMS behavior, however, poses severe challenges for reliable future projections. Thus, robust paleomonsoon records are needed to constrain the high spatiotemporal variability in the response of SAMS rainfall to different climatic drivers. This study uses Ti/Ca ratios from X-ray fluorescence scanning of a sediment core retrieved off eastern Brazilian to trace precipitation changes over the past 322 Kyr. The results indicate that despite the spatiotemporal complexity of the SAMS, insolation forcing is the primary pacemaker of variations in the monsoonal system. Additional modulation by atmospheric pCO2 suggests that SAMS intensity over eastern Brazil will be suppressed by rising CO2 emissions in the future. Lastly, our record reveals an unprecedented strong and persistent wet period during Marine Isotope Stage 6 driven by anomalously strong trade winds.

Description: Winter chill is expected to decrease in many of the suitable growing regions for deciduous trees. Argentinean North Patagonia hosts extensive fruit tree cultivation, which provides an important contribution to both local and global food security. Using historic records from 11 weather stations from North Patagonia, we evaluate the possible impacts of climate change on fruit tree cultivation. We assess winter chill and seasonal heat availability, and the risk of spring frost events based on outputs from 15 Global Climate Models (GCMs) for two Representative Concentration Pathway (RCP) scenarios and two future time periods (represented by central years 2050 and 2085). Metrics were estimated for 47 years of records from the weather stations, as well as typical conditions for 10 past scenarios and 60 future GCM and RCP projections. Scenarios consisted of 100 plausible annual temperature records produced by a weather generator. Results suggest that fruit tree dormancy in Argentinean North Patagonia will not be strongly affected by climate change. Compared to the past, winter chill may only decrease by 9% in the RCP4.5 scenario by 2050 in the northeastern and eastern subregion, while in the central-south and west the reduction seems unlikely to exceed 6% by the same RCP scenario and year. Our models project stable high growing season heat in the northeastern and eastern regions, and major increases in the south by 2085 in both RCP scenarios. Projections of spring frost events varied between 0 and about 25 hours below 0°C depending on the site. Increasing heat availability may create opportunities for fruit and nut growers to introduce new species and cultivars to the region. Our results provide a basis for planning such introductions and for enabling growers to exploit new opportunities for producing temperate orchard crops beyond their traditional ranges.

Description: Wheat production plays an important role in Morocco. Current wheat forecast systems use weather and vegetation data during the crop growing phase, thus limiting the earliest possible release date to early spring. However, Morocco's wheat production is mostly rainfed and thus strongly tied to fluctuations in rainfall, which in turn depend on slowly evolving climate dynamics. This offers a source of predictability at longer time scales. Using physically guided causal discovery algorithms, we extract climate precursors for wheat yield variability from gridded fields of geopotential height and sea surface temperatures which show potential for accurate yield forecasts already in December, with around 50% explained variance in an out-of-sample cross validation. The detected interactions are physically meaningful and consistent with documented ocean-atmosphere feedbacks. Reliable yield forecasts at such long lead times could provide farmers and policy makers with necessary information for early action and strategic adaptation measurements to support food security.

Description: Rising global temperatures over the last decades have increased heat exposure among populations worldwide. An accurate estimate of the resulting impacts on human health demands temporally explicit and spatially resolved monitoring of near-surface air temperature (Ta). Neither ground-based nor satellite-borne observations can achieve this individually, but the combination of the two provides synergistic opportunities. In this study, we propose a two-stage machine learning-based hybrid model to estimate 1 × 1 km2 gridded intra-daily Ta from surface skin temperature (Ts) across the complex terrain of Israel during 2004–2016. We first applied a random forest (RF) regression model to impute missing Ts from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua and Terra satellites, integrating Ts from the geostationary Spinning Enhanced Visible and InfraRed Imager (SEVIRI) satellite and synoptic variables from European Centre for Medium-Range Weather Forecasts' (ECMWF) ERA5 reanalysis data sets. The imputed Ts are in turn fed into the Stage 2 RF-based model to estimate Ta at the satellite overpass hours of each day. We evaluated the model's performance applying out-of-sample fivefold cross validation. Both stages of the hybrid model perform very well with out-of-sample fivefold cross validated R2 of 0.99 and 0.96, MAE of 0.42°C and 1.12°C, and RMSE of 0.65°C and 1.58°C (Stage 1: imputation of Ts, and Stage 2: estimation of Ta from Ts, respectively). The newly proposed model provides excellent computationally efficient estimation of near-surface air temperature at high resolution in both space and time, which helps further minimize exposure misclassification in epidemiological studies.

Description: Using seven single-model ensembles and the two multimodel ensembles CMIP5 and CMIP6, we show that observed and simulated trends in sea surface temperature (SST) patterns are globally consistent when accounting for internal variability. Some individual ensemble members simulate trends in large-scale SST patterns that closely resemble the observed ones. Observed regional trends that lie at the outer edge of the models' internal variability range allow two nonexclusive interpretations: (a) Observed trends are unusual realizations of the Earth's possible behavior and/or (b) the models are systematically biased but large internal variability leads to some good matches with the observations. The existing range of multidecadal SST trends is influenced more strongly by large internal variability than by differences in the model formulation or the observational data sets.

Description: Mapping spatial and temporal variability of urban microclimate is pivotal for an accurate estimation of the ever-increasing exposure of urbanized humanity to global warming. This particularly concerns cities in arid/semi-arid regions which cover two fifths of the global land area and are home to more than one third of the world's population. Focusing on the desert city of Be'er Sheva Israel, we investigate the spatial and temporal patterns of urban–rural and intra-urban temperature variability by means of satellite observation, vehicular traverse measurement, and computer simulation. Our study reveals a well-developed nocturnal canopy layer urban heat island in Be'er Sheva, particularly in the winter, but a weak diurnal cool island in the mid-morning. Near surface air temperature exhibits weak urban–rural and intra-urban differences during the daytime (〈1°C), despite pronounced urban surface cool islands observed in satellite images. This phenomenon, also recorded in some other desert cities, is explained by the rapid increase in surface skin temperature of exposed desert soils (in the absence of vegetation or moisture) after sunrise, while urban surfaces are heated more slowly. The study highlights differences among the three methods used for describing urban temperature variability, each of which may have different applications in fields such as urban planning, climate change mitigation, and epidemiological research.

Description: During the DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa) field campaign ∼900 radiosondes were launched from 12 stations in southern West Africa from 15 June to 31 July 2016. Subsequently, data-denial experiments were conducted using the Integrated Forecasting System of the European Centre for Medium-range Weather Forecasts (ECMWF) to assess the radiosondes' impact on the quality of analyses and forecasts. As observational reference, satellite-based estimates of rainfall and outgoing long-wave radiation (OLR) as well as the radiosonde measurements themselves are used. With regard to the analyses, the additional observations show positive impacts on winds throughout the troposphere and lower stratosphere, while large lower-tropospheric cold and dry biases are hardly reduced. Nonetheless, downstream, that is farther inland from the radiosonde stations, we find a significant increase (decrease) in low-level night-time temperatures (monsoon winds) when incorporating the DACCIWA observations, suggesting a possible linkage via weaker cold air advection from the Gulf of Guinea. The associated lower relative humidity leads to reduced cloud cover in the DACCIWA analysis. Closer to the coast and over Benin and Togo, DACCIWA observations increase low-level specific humidity and precipitable water, possibly due to changes in advection and vertical mixing. During daytime, differences between the two analyses are generally smaller at low levels. With regard to the forecasts, the impact of the additional observations is lost after a day or less. Moderate improvements occur in low-level wind and temperature but also in rainfall over the downstream Sahel, while impacts on OLR are ambiguous. The changes in precipitation appear to also affect high-level cloud cover and the tropical easterly jet. The overall rather small observation impact suggests that model and data assimilation deficits are the main limiting factors for better forecasts in West Africa. The new observations and physical understanding from DACCIWA can hopefully contribute to reducing these issues.

Description: The driving factors that influence the spatial and annual variability of thunderstorms across Europe are still poorly understood. Due to a lack of long-term, reliable and consistent information about the occurrence of convective storms, a weather type classification has been developed that estimates thunderstorm probability from a combination of appropriate meteorological quantities on the mesoscale. Based on this approach, the temporal and spatial variability of convection-favouring environments is investigated between 1958 and 2014 using a high-resolution reanalysis dataset. To identify potential drivers for convective days, typical upper-level flow patterns were deduced using a multivariate approach. Our results suggest a strong link between local-scale thunderstorm activity and large-scale flow and air mass properties, such as stability, moisture, or vertical lifting. For example, while all over central Europe the most prominent pattern is given by a southwesterly flow type over the respective area, distinct regional discrepancies regarding further favourable flow types are observed. The crucial role of large-scale flow is further studied by assessing the relation between Northern Hemisphere teleconnection patterns and widespread convective activity. It is found that positive phases of the East Atlantic or Scandinavian patterns go along with a significant enhancement of convection-favouring conditions in several European regions, which can be explained by anomalies in the large-scale temperature and flow fields. Sea-surface temperature over the Bay of Biscay likewise impacts the convective environment, with the largest positive effect over the western part of the study area.

Description: The methods to quantify equilibrium climate sensitivity are still debated. We collect millennial-length simulations of coupled climate models and show that the global mean equilibrium warming is higher than those obtained using extrapolation methods from shorter simulations. Specifically, 27 simulations with 15 climate models forced with a range of CO2 concentrations show a median 17% larger equilibrium warming than estimated from the first 150 years of the simulations. The spatial patterns of radiative feedbacks change continuously, in most regions reducing their tendency to stabilizing the climate. In the equatorial Pacific, however, feedbacks become more stabilizing with time. The global feedback evolution is initially dominated by the tropics, with eventual substantial contributions from the mid-latitudes. Time-dependent feedbacks underscore the need of a measure of climate sensitivity that accounts for the degree of equilibration, so that models, observations, and paleo proxies can be adequately compared and aggregated to estimate future warming.

Description: The Svalbard archipelago in the Arctic North Atlantic is experiencing rapid changes in the surface climate and sea ice distribution, with impacts for the coupled climate system and the local society. This study utilizes observational data of surface air temperature (SAT) from 1980–2016 across the whole Svalbard archipelago, and sea ice extent (SIE) from operational sea ice charts to conduct a systematic assessment of climatologies, long-term changes and regional differences. The proximity to the warm water mass of the West Spitsbergen Current drives a markedly warmer climate in the western coastal regions compared to northern and eastern Svalbard. This imprints on the SIE climatology in southern and western Svalbard, where the annual maxima of 50–60% area ice coverage are substantially less than 80–90% in the northern and eastern fjords. Owing to winter-amplified warming, the local climate is shifting towards more maritime conditions, and SIE reductions of between 5 and 20% per decade in particular regions are found, such that a number of fjords in the west have been virtually ice-free in recent winters. The strongest decline comes along with SAT forcing and occurs over the most recent 1–2 decades in all regions; while in the 1980s and 1990s, enhanced northerly winds and sea ice drift can explain 30–50% of SIE variability around northern Svalbard, where they had correspondingly lead to a SIE increase. With an ongoing warming it is suggested that both the meteorological and cryospheric conditions in eastern Svalbard will become increasingly similar to what is already observed in the western fjords, namely suppressed typical Arctic climate conditions.

Description: We present the new Atmospheric Raman Temperature and Humidity Sounder (ARTHUS). We demonstrate that ARTHUS measurements resolve (1) the strength of the inversion layer at the planetary boundary layer top, (2) elevated lids in the free troposphere during daytime and nighttime, and (3) turbulent fluctuations in water vapor and temperature, simultaneously, also during daytime. Very stable and reliable performance was demonstrably achieved during more than 2,500 hr of operations time experiencing a huge variety of weather conditions. ARTHUS provides temperature profiles with resolutions of 10–60 s and 7.5–100 m vertically in the lower free troposphere. During daytime, the statistical uncertainty of the water vapor mixing ratio is 〈2 % in the lower troposphere for resolutions of 5 min and 100 m. Temperature statistical uncertainty is 〈0.5 K even up to the middle troposphere. ARTHUS fulfills the stringent WMO breakthrough requirements on nowcasting and very short range forecasting.

Description: The seasonal cycle of rainfall over the Greater Horn of Africa (GHA) is dominated by the latitudinal migration and activity of the tropical rain belt (TRB). The TRB exhibits high interannual variability in the GHA and the reasons for the recent dry period in the Long Rains (March–May) are poorly understood. In addition, few studies have addressed the rainfall fluctuations during the Msimu Rains (Dec.–Mar.) in the southern GHA region. Interannual variations of the seasonal cycle of the TRB between 1981 and 2018 were analysed using two statistical indices. The Rainfall Cluster Index (RCI) describes the seasonal cycle as a succession of six characteristic rainfall patterns, while the Seasonal Location Index (SLI) captures the latitudinal location of the TRB. The SLI and RCI depict the full seasonal cycle of the TRB supporting interpretations of the interannual variations and trends. The Msimu Rains are dominated by two clusters with opposite rainfall characteristics between the Congo Basin and Tanzania. The associated anomalies in moisture flux and divergence indicate variations in the location of the TRB originating from an interplay between low-level air flows from the Atlantic and Indian Oceans and tropical and subtropical teleconnections. The peak period of the Long Rains shows a complex composition of five clusters, which is tightly connected to intraseasonal and interannual variability of latitudinal locations of the TRB. A persistent location of the TRB near the equator, evidenced in a frequent occurrence of a cluster related to an anomalously weak Walker circulation, is associated with wet conditions over East Africa. Dry Long Rains are associated with strong and frequent latitudinal variations of the TRB position with a late onset and intermittent rainfall. These results offer new opportunities to understand recent variability and trends in the GHA region.

Description: Earth's equilibrium climate sensitivity (ECS) is the long-term response to doubled atmospheric CO2 and likely between 1.5 and 4.5 K. Conventional general circulation models do not convincingly narrow down this range, and newly developed nonhydrostatic models with relatively fine horizontal resolutions of a few kilometers have thus far delivered diverse results. Here we use the nonhydrostatic ICON model with the physics package normally used for climate simulations at resolutions as fine as 5 km to study the response to a uniform surface warming in an aquaplanet configuration. We apply the model in two setups: one with convection parametrization employed and one with explicit convection. ICON exhibits a negative total feedback independent of convective representation, thus providing a stable climate with an ECS comparable to other general circulation models, though three interesting new results are found. First, ECS varies little across resolution for both setups but runs with explicit convection have systematically lower ECS than the parametrized case, mainly due to more negative tropical clear-sky longwave feedbacks. These are a consequence of a drier mean state of about 6% relative humidity for explicit convection and less midtropospheric moistening with global warming. Second, shortwave feedbacks switch from positive to negative with increasing resolution, originating foremost in the tropics and high latitudes. Third, the model shows no discernible high cloud area feedback (iris effect) in any configuration. It is possible that ICON's climate model parametrizations applied here are less appropriate for cloud resolving scales, and therefore, ongoing developments aim at implementing a more advanced prognostic cloud microphysics scheme.

Description: Climate models have substantial biases in the climatological latitude of the Southern Hemisphere eddy-driven jet and the time scale of annular mode variability and disagree on the jet response to climate change. Zonally symmetric dry dynamical cores are often used for idealized modeling of the jet response to forcing and its sensitivity to model setup changes. The limits to which these models represent the key mechanisms that control the jet in complex models or the real world have not been systematically investigated. Here we show that substantial intermodel differences in jet latitude and strength can arise from differences in dynamical cores and resolved topography. Including topography and a more realistic surface drag in a dry model substantially alters the jet response to changes in drag strength. Using real-world maps, enhanced drag over land shifts the jet poleward, whereas enhanced drag over the ocean leads to an equatorward shift. No universal relationship between annular mode time scale and forced response emerges in the dry model with topography. These results suggest that zonally symmetric models with Rayleigh drag lack important mechanisms that control the behavior of the midlatitude jet in coupled climate models. A dry model with topography and quadratic surface drag can fill this gap in the model hierarchy.

Description: This study provides a comprehensive evaluation of a great variety of state-of-the-art precipitation datasets against gauge observations over the Karun basin in southwestern Iran. In particular, we consider (a) gauge-interpolated datasets (GPCCv8, CRU TS4.01, PREC/L, and CPC-Unified), (b) multi-source products (PERSIANN-CDR, CHIRPS2.0, MSWEP V2, HydroGFD2.0, and SM2RAIN-CCI), and (c) reanalyses (ERA-Interim, ERA5, CFSR, and JRA-55). The spatiotemporal performance of each product is evaluated against monthly precipitation observations from 155 gauges distributed across the basin during the period 2000–2015. This way, we find that overall the GPCCv8 dataset agrees best with the measurements. Most datasets show significant underestimations, which are largest for the interpolated datasets. These underestimations are usually smallest at low altitudes and increase towards more mountainous areas, although there is large spread across the products. Interestingly, no overall performance difference can be found between precipitation datasets for which gauge observations from Karun basin were used, versus products that were derived without these measurements, except in the case of GPCCv8. In general, our findings highlight remarkable differences between state-of-the-art precipitation products over regions with comparatively sparse gauge density, such as Iran. Revealing the best-performing datasets and their remaining weaknesses, we provide guidance for monitoring and modelling applications which rely on high-quality precipitation input.

Description: research

Description: It is well established that Africa is particularly exposed to climate extremes including heat waves, droughts, and intense rainfall events. How exposed Africa is to the co-occurrence of these events is however virtually unknown. This study provides the first analysis of projected changes in the co-occurrence of five such compound climate extremes in Africa, under a low (RCP2.6) and high (RCP8.5) emissions scenario. These changes are combined with population projections for a low (SSP1) and high (SSP3) population growth scenario, in order to provide estimates of the number of people that may be exposed to such events at the end of the 21st century. We make use of an ensemble of regional climate projections from the Coordinated Output for Regional Evaluations (CORE) project embedded in the Coordinated Regional Climate Downscaling Experiment (CORDEX) framework. This ensemble comprises five different Earth System Model/Regional Climate Model (ESM/RCM) combinations with three different ESMs and two RCMs. We show that all five compound climate extremes will increase in frequency, with changes being greater under RCP8.5 than RCP2.6. Moreover, populations exposed to these changes are greater under RCP8.5/SSP3, than RCP2.6/SSP1, increasing by 47- and 12-fold, respectively, compared to the present-day. Regions of Africa that are particularly exposed are West Africa, Central-East Africa, and Northeast and Southeast Africa. Increased exposure is mainly driven by the interaction between climate and population growth, and the effect of population alone. This has important policy implications in relation to climate mitigation and adaptation.

Description: Data-driven approaches, most prominently deep learning, have become powerful tools for prediction in many domains. A natural question to ask is whether data-driven methods could also be used to predict global weather patterns days in advance. First studies show promise but the lack of a common data set and evaluation metrics make intercomparison between studies difficult. Here we present a benchmark data set for data-driven medium-range weather forecasting (specifically 3–5 days), a topic of high scientific interest for atmospheric and computer scientists alike. We provide data derived from the ERA5 archive that has been processed to facilitate the use in machine learning models. We propose simple and clear evaluation metrics which will enable a direct comparison between different methods. Further, we provide baseline scores from simple linear regression techniques, deep learning models, as well as purely physical forecasting models. The data set is publicly available at https://github.com/pangeo-data/WeatherBench and the companion code is reproducible with tutorials for getting started. We hope that this data set will accelerate research in data-driven weather forecasting.

Description: Meteorological droughts have large impacts on society and the environment. A better understanding and quantification of their occurrences can be highly relevant for the development of proper climate change mitigation, adaptation and resilience strategies. Here we examine meteorological droughts from observed data covering the 1971–2000 period for the Fulda catchment in Germany by means of the Standardized Precipitation Index. The joint dependency of drought duration and severity is modelled by a copula function, which relates their univariate distributions in a functional relationship. Recurrence intervals are further calculated as a function of the joint relationship and univariate marginals. Future projections are investigated in which downscaled EURO-CORDEX Regional Climate Model (RCM) projections for the period 2021–2050 are used together with the three Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5, in order to analyse and compare future joint patterns of duration and severity of events. We find that drought duration and severity present a clear interdependency supporting the choice of a bivariate model. Results suggest substantial differences in the future joint relationship duration–severity. Depending on the RCM and RCP, drought patterns show different magnitude of changes in the future. The projected changes are different for the different returns periods. RCP8.5 shows more severe events and longer drought durations than RCP2.6 and RCP4.5. The uncertainties of the projected patterns also depend on the RCP and RCM and are larger for higher return periods.

Description: Abstract Global climate models provide only partial information on local-scale phenomenon, such as precipitation, primarily due to their coarse resolution. In this study, statistical downscaling algorithms, based on both weather regimes and past analogues, are operated for 18 Israeli rain gauges with an altitude ranging between −200 and ~1,000 m above sea level (ASL). To project seasonal precipitation over Israel and its hydrologic basins, the algorithms are applied to six Coupled Model Inter-comparison Project Phase 5 (CMIP5) models for the end of the 21st century, according to the RCP4.5 and RCP8.5 scenarios. The downscaled models can capture quite well the seasonal precipitation distribution, though with underestimation in winter and overestimation in spring. All models display a significant reduction of seasonal precipitation for the 21st century according to both scenarios. The winter reductions for the end of the century and the RCP8.5 scenario are found to be ~22 and ~37% according to the weather regimes and the analogues downscaling methods, respectively. Spring reductions are found to be ~10–20% larger than winter reductions. It is shown that the projected reduction results from a decrease in the frequency of the rain-bearing systems, as well as a decrease in the average daily precipitation intensity. The areas with the largest reductions in seasonal precipitation are found over the central mountains, the Mediterranean coastal area, and the Sea of Galilee hydrologic basins, which are the main fresh-water aquifers and reservoirs of Israel. The statistical downscaling methods applied in this study can be easily transferred to other regions where long-term data sets of observed precipitation are available. This study and others may serve as a basis for priority and policy setting toward better climate adaptation with associated uncertainties related to the methods used and nonstationary of the climate system.

Description: Research on improving the prediction skill of climate models requires refining the quality of observational data used for initializing and tuning the models. This is especially true in the polar regions where uncertainties about the interactions between sea ice, ocean, and atmosphere are driving ongoing monitoring efforts. The Copernicus Imaging Microwave Radiometer (CIMR) is an European Space Agency (ESA) candidate mission which promises to offer high resolution, low uncertainty observation capabilities at the 1.4, 6.9, 10.65, 18.7, and 36.5 GHz frequencies. To assess the potential impact of CIMR for sea ice parameter retrieval, a comparison is made between retrievals based on present AMSR2 observations and a retrieval using future CIMR equivalent observations over a data set of validated sea ice concentration (SIC) values. An optimal estimation retrieval method (OEM) is used which can use input from different channel combinations to retrieve seven geophysical parameters (sea ice concentration, multi-year ice fraction, ice surface temperature, columnar water vapor, liquid water path, over ocean wind speed, and sea surface temperature). An advantage of CIMR over existing radiometers is that it would provide higher spatial resolution observations at the lower frequency channels (6.9, 10.65, and 18.7 GHz) which are less sensitive to atmospheric influence. This enables the passive microwave based retrieval of SIC and other surface parameters with higher resolution and lower uncertainty than is currently possible. An information content analysis expands the comparison between AMSR2 and CIMR to all retrievable surface and atmospheric parameters. This analysis quantifies the contributions to the observed signal and highlights the differences between different input channel combinations. The higher resolution of the low frequency CIMR channels allow for unprecedented detail to be achieved in Arctic passive microwave sea ice retrievals. The presence of 1.4 GHz channels on board CIMR opens up the possibility for thin sea ice thickness (SIT) retrieval. A combination of collocated AMSR2 and SMOS observations is used to simulate a full CIMR suite of measurements, and the OEM is modified to include SIT as a retrieval parameter. The output from different retrieval configurations is compared with an operational SIT product. The CIMR instrument can provide increased accuracy for SIC retrieval at very high resolutions with a combination of the 18.7 and 36.5 GHz channels while also maintaining sensitivity for atmospheric water vapor retrieval. In combination with the 1.4 GHz channels, SIT can be added as an eighth retrieval parameter with performance on par with existing operational products.

Description: Meteorologists in the energy industry increasingly draw upon the potential for enhanced sub-seasonal predictability of European surface weather following anomalous states of the winter stratospheric polar vortex (SPV). How the link between the SPV and the large-scale tropospheric flow translates into forecast skill for surface weather in individual countries – a spatial scale that is particularly relevant for the energy industry – remains an open question. Here we quantify the effect of anomalously strong and weak SPV states at forecast initial time on the probabilistic extended-range reforecast skill of the European Centre for Medium-Range Weather Forecasts (ECMWF) in predicting country- and month-ahead-averaged anomalies of 2 m temperature, 10 m wind speed, and precipitation. After anomalous SPV states, specific surface weather anomalies emerge, which resemble the opposing phases of the North Atlantic Oscillation. We find that forecast skill is, to first order, only enhanced for countries that are entirely affected by these anomalies. However, the model has a flow-dependent bias for 2 m temperature (T2M): it predicts the warm conditions in Western, Central and Southern Europe following strong SPV states well, but is overconfident with respect to the warm anomaly in Scandinavia. Vice versa, it predicts the cold anomaly in Scandinavia following weak SPV states well, but struggles to capture the strongly varying extent of the cold air masses into Central and Southern Europe. This tends to reduce skill (in some cases significantly) for Scandinavian countries following strong SPV states, and most pronounced, for many Central, Southern European, and Balkan countries following weak SPV states. As most of the weak SPV states are associated with sudden stratospheric warmings (SSWs), our study thus advices particular caution when interpreting sub-seasonal regional T2M forecasts following SSWs. In contrast, it suggests that the model benefits from enhanced predictability for a considerable part of Europe following strong SPV states.

Description: High-quality time series of meteorological observations are required for reliable assessments of climate trends. To analyze inhomogeneities in time series, parallel measurements can be used. Germany's national meteorological service DWD (Deutscher Wetterdienst) operates a network of climate reference stations. At these stations, manual and automatic observations have been taken in parallel. These parallel measurements therefore allow analyzing the impact of the transition on the homogeneity of time series of several meteorological parameters. Here, we present results for temperature. The differences between automatic and manual measurements are tested on breakpoints caused by instrumental defects or changes in the measurement conditions. The time series are highly correlated such that small breaks can be identified. The detected breakpoints are verified against metadata if available. In the case of no available metadata information, a procedure is suggested to identify the inhomogeneous time series (manual or automatic time series). Afterwards, the time series are homogenized. The homogenized time series are used to analyze the impact of changing the observing system from manual to automatic measurements on daily mean temperature.

Description: The paper describes an update of the GECCO (German contribution to the Estimating the Circulation and Climate of the Ocean project) ocean synthesis, now in its version 3, and provides an evaluation of the results with assimilated and independent data. GECCO3 covers the 71-year period 1948–2018 and differs from its predecessor by returning to a single assimilation window instead of partitioning the period in 5-year-long overlapping windows which was previously necessary to yield convergence. A solution to the convergence problem is presented. GECCO3 is intended to be used for the initialization of coupled climate models and is configured for the higher-resolution version of the earth system model (MPI-ESM) developed at the Max Planck Institute for Meteorology. It uses the bathymetry and grid of the MPI-ESM with quasi-uniform resolution of 0.4°, thereby providing the first global eddy-permitting synthesis based on the adjoint method. The synthesis additionally features the estimation of various mixing parameters and can regionally choose between explicit or parametrized eddy fluxes. Except for the altimeter data in tropical regions, GECCO3 is in better agreement with the assimilated data than GECCO2. The improvements relative to the in situ data partly result from the much larger amount of Argo data, which show lower model–data differences. Global heat content changes are in good agreement with recent estimates, but show uptake almost exclusively in the top 700 m. An alternative version of GECCO3, created by starting from different first-guess control parameters, was used to evaluate the uncertainty of the estimated parameters and state due to lack of convergence. This estimate suggests a large uncertainty related to the uptake of heat into the lower layers, while estimates of mean meridional transport of heat and freshwater are not affected.

Description: China is the world's second-largest economy, and its capital Beijing has been suffering from severe haze pollution in recent years. However, how the winter haze events in Beijing vary under different global warming scenarios is still open for debate. In order to analyse long-term winter haze characteristics in Beijing in the future, we have simulated haze events using the haze weather index (HWI) for the warming periods of 1.5 and 2.0°C, based on 20 Coupled Model Intercomparison Project Phase 5 (CMIP5) models under two representative concentration pathways (RCP4.5 and RCP8.5). Our results indicate that 16 CMIP5 models have preferable performance in simulating the spatial pattern and occurrence frequency of winter haze events in Beijing. We highlight that in the 1.5 and 2.0°C global warming period (2020s–2050s), Beijing will face a significant increasing trend (6–9% growth rate) in the occurrence of winter haze events compared with the reference period (1986–2005). The frequency of winter haze events under the RCP4.5 increases less than under the RCP8.5 in the 1.5°C warming period but is closer to RCP8.5 in the 2.0°C warming period. The increase of winter haze events with respect to natural factors in Beijing could be attributed to stronger atmospheric inversions, weaker East Asian winter monsoons, and a shallowing East Asian trough induced by global warming. Our results will provide scientific instructions for environmental departments to better face meteorological hazards, such as air pollution episodes, thereby improving the early warning mechanism system for global warming.

Description: Ocean heat transport is often thought to play a secondary role for Arctic surface warming in part because warm water which flows northward is prevented from reaching the surface by a cold and stable halocline layer. However, recent observations in various regions indicate that occasionally, warm water is found directly below the surface mixed layer. Here we investigate Arctic Ocean surface energy fluxes and the cold halocline layer in climate model simulations from the Coupled Model Intercomparison Project Phase 5. An ensemble of 15 models shows decreased sea ice formation and increased ocean energy release during fall, winter, and spring for a high-emission future scenario. Along the main pathways for warm water advection, this increased energy release is not locally balanced by increased Arctic Ocean energy uptake in summer. Because during Arctic winter, the ocean mixed layer is mainly heated from below, we analyze changes of the cold halocline layer in the monthly mean Coupled Model Intercomparison Project Phase 5 data. Fresh water acts to stabilize the upper ocean as expected based on previous studies. We find that in spite of this stabilizing effect, periods in which warm water is found directly or almost directly below the mixed layer and which occur mainly in winter and spring become more frequent in high-emission future scenario simulations, especially along the main pathways for warm water advection. This could reduce sea ice formation and surface albedo.

Description: The Northern Hemisphere mid-latitudes will be exposed to hydroclimatic risk in next coming decades because the subtropical expansion. However, it is not clear when the anthropogenic signal will emerge from the internal climate variability. For this purpose, we investigate the time of emergence (ToE) of the hemispheric and regional shift of northern subtropical margins in the Max Planck Institute Grand Ensemble. For several indicators, the ToE of the poleward shift of Northern subtropical margin will not occur by the end of the 21st century, neither at regional nor at hemispheric scale. The exceptions are the Mediterranean/Middle East and, to a lesser degree, Western Pacific, where the ToE would occur earlier. According to our results, given the fundamental role played by internal variability, trends of Northern Hemisphere subtropical poleward shift that have been identified over last decades in reanalyses cannot be considered as robust signals of anthropogenic climate change.

Description: Nonrainy days have rather different hydrologic and radiative conditions than rainy days, but few investigations considered how these different conditions contribute to the observed global warming. Here, we show that global warming is considerably stronger on nonrainy days using observations from China. We find that trends in mean temperature on nonrainy days are about 0.1 ° C/10 yr higher than on rainy days, and that about 80% of the total temperature increase is contributed by nonrainy days. The main reason is likely to be a stronger sensitivity of downwelling longwave radiation to greenhouse forcing on nonrainy days due to fewer clouds and water vapor compared with rainy days, which is not a hydrological effect but mainly a radiative effect. Our findings are consistent with the stronger mean temperature trends in drier regions and imply that the different temperature sensitivities on nonrainy and rainy days may have profound effects on natural and social systems.

Description: The relationship between River Ammer flood frequency variability, extreme summer climate over Europe, and solar forcing is investigated. First, we used observational data to evaluate extreme weather and climate anomaly patterns associated with flood and solar forcing as well as the possible dynamical mechanisms behind them. Then, the annual resolution flood layer record from the Lake Ammer sediments is analysed to evaluate millennial-scale variability of floods and possible related extreme climate patterns back to 5,500 years BP. A composite analysis reveals that observed River Ammer flood frequency variability at interannual to multidecadal time scales is connected to large-scale extreme precipitation and temperature patterns. From a synoptic-scale perspective, the extreme precipitation pattern associated with floods is related to an increase in the frequency of high upper-level potential vorticity (PV) events over western Europe and a decrease over eastern Europe and western Russia. Increased (decreased) frequency of upper-level high PV events is related to more (less) surface extreme precipitation occurrence. Furthermore, we show that increased frequency of upper-level high PV events over western Europe is associated with enhanced blocking activity over eastern Europe. Therefore, the out of phase interannual to millennial-scale variations of River Ammer flood frequency and solar irradiance, as presented in previous studies, can be explained by a solar modulation of eastern European-western Russia summer blocking and associated upstream upper-level wave breaking activity. In addition, we identify two distinct quasi-periodic signals in both frequency of Lake Ammer flood layer and solar irradiance records with periods of ~900 years and ~2,300 years. We argue that similar cycles should dominate millennial-scale variations of blocking activity in eastern Europe-western Russia as well as extreme precipitation and flood frequency variability over central and western Europe during the last ~5,500 years.

Description: Opportunistic constant target matching is a new method for satellite intercalibration. It solves a long-standing issue with the traditional simultaneous nadir overpass (SNO) method, namely, that it typically provides only data points with cold brightness temperatures for humidity sounding instruments on sun-synchronous satellites. In the new method, a geostationary infrared sensor (SEVIRI) is used to select constant target matches for two different microwave sensors (MHS on NOAA 18 and Metop A). We discuss the main assumptions and limitations of the method and explore its statistical properties with a simple Monte Carlo simulation. The method was tested in a simple case study with real observations for this combination of satellites for MHS Channel 3 at 183 ± 1 GHz, the upper tropospheric humidity channel. For the studied 3-month test period, real observations are found to behave consistently with the simulations, increasing our confidence that the method can be a valuable tool for intercalibration efforts. For the selected case study, the new method confirms that the bias between NOAA 18 and Metop A MHS Channel 3 is very small, with absolute value below 0.05 K.