ALBERT

Beschreibung: The microphysical processes inside convective clouds play an important role in climate. They directly control the amount of detrainment of cloud hydrometeor and water vapor from updrafts. The detrained water substance in turn affects the anvil cloud formation, upper-tropospheric water vapor distribution, and thus the atmospheric radiation budget. In global climate models, convective parameterization schemes have not explicitly represented microphysics processes in updrafts until recently. In this paper, the authors provide a review of existing schemes for convective microphysics parameterization. These schemes are broadly divided into three groups: tuning-parameter-based schemes (simplest), single-moment schemes, and two-moment schemes (most comprehensive). Common weaknesses of the tuning-parameter-based and single-moment schemes are outlined. Examples are presented from one of the two-moment schemes to demonstrate the performance of the scheme in simulating the hydrometeor distribution in convection and its representation of the effect of aerosols on convection.

Beschreibung: In situ observations of cloud properties made by airborne probes play a critical role in ice cloud research through their role in process studies, parameterization development, and evaluation of simulations and remote sensing retrievals. To determine how cloud properties vary with environmental conditions, in situ data collected during different field projects processed by different groups must be used. However, because of the diverse algorithms and codes that are used to process measurements, it can be challenging to compare the results. Therefore it is vital to understand both the limitations of specific probes and uncertainties introduced by processing algorithms. Since there is currently no universally accepted framework regarding how in situ measurements should be processed, there is a need for a general reference that describes the most commonly applied algorithms along with their strengths and weaknesses. Methods used to process data from bulk water probes, single-particle light-scattering spectrometers and cloud-imaging probes are reviewed herein, with emphasis on measurements of the ice phase. Particular attention is paid to how uncertainties, caveats, and assumptions in processing algorithms affect derived products since there is currently no consensus on the optimal way of analyzing data. Recommendations for improving the analysis and interpretation of in situ data include the following: establishment of a common reference library of individual processing algorithms, better documentation of assumptions used in these algorithms, development and maintenance of sustainable community software for processing in situ observations, and more studies that compare different algorithms with the same benchmark datasets.

Beschreibung: The authors present an observationally based evaluation of the vertically resolved cloud ice water content (CIWC) and vertically integrated cloud ice water path (CIWP) as well as radiative shortwave flux downward at the surface (RSDS), reflected shortwave (RSUT), and radiative longwave flux upward at top of atmosphere (RLUT) of present-day global climate models (GCMs), notably twentieth-century simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), and compare these results to those of the third phase of the Coupled Model Intercomparison Project (CMIP3) and two recent reanalyses. Three different CloudSat and/or Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) combined ice water products and two methods are used to remove the contribution from the convective core ice mass and/or precipitating cloud hydrometeors with variable sizes and falling speeds so that a robust observational estimate can be obtained for model evaluations. The results show that, for annual mean CIWC and CIWP, there are factors of 2–10 (either over- or underestimate) in the differences between observations and models for a majority of the GCMs and for a number of regions. Most of the GCMs in CMIP3 and CMIP5 significantly underestimate the total ice water mass because models only consider suspended cloud mass, ignoring falling and convective core cloud mass. For the annual means of RSDS, RLUT, and RSUT, a majority of the models have significant regional biases ranging from −30 to 30 W m−2. Based on these biases in the annual means, there is virtually no progress in the simulation fidelity of RSDS, RLUT, and RSUT fluxes from CMIP3 to CMIP5, even though there is about a 50% bias reduction improvement of global annual mean CIWP from CMIP3 to CMIP5. It is concluded that at least a part of these persistent biases stem from the common GCM practice of ignoring the effects of precipitating and/or convective core ice and liquid in their radiation calculations.

Beschreibung: Yanai and coauthors utilized the meteorological data collected from a sounding network to present a pioneering work in 1973 on thermodynamic budgets, which are referred to as the apparent heat source (Q1) and apparent moisture sink (Q2). Latent heating (LH) is one of the most dominant terms in Q1. Yanai’s paper motivated the development of satellite-based LH algorithms and provided a theoretical background for imposing large-scale advective forcing into cloud-resolving models (CRMs). These CRM-simulated LH and Q1 data have been used to generate the look-up tables in Tropical Rainfall Measuring Mission (TRMM) LH algorithms. A set of algorithms developed for retrieving LH profiles from TRMM-based rainfall profiles is described and evaluated, including details concerning their intrinsic space–time resolutions. Included in the paper are results from a variety of validation analyses that define the uncertainty of the LH profile estimates. Also, examples of how TRMM-retrieved LH profiles have been used to understand the life cycle of the MJO and improve the predictions of global weather and climate models as well as comparisons with large-scale analyses are provided. Areas for further improvement of the TRMM products are discussed.

Beschreibung: The authors survey a series of modeling studies that have examined the influences that cloud microphysical processes can have on tropical cyclone (TC) motion, the strength and breadth of the wind field, inner-core diabatic heating asymmetries, outer-core convective activity, and the characteristics of the TC anvil cloud. These characteristics are sensitive to the microphysical parameterization (MP) in large part owing to the cloud-radiative forcing (CRF), the interaction of hydrometeors with radiation. The most influential component of CRF is that due to absorption and emission of longwave radiation in the anvil, which via gentle lifting directly encourages the more extensive convective activity that then leads to a radial expansion of the TC wind field. On a curved Earth, the magnitude of the outer winds helps determine the speed and direction of TC motion via the beta drift. CRF also influences TC motion by determining how convective asymmetries develop in the TC inner core. Further improvements in TC forecasting may require improved understanding and representation of cloud-radiative processes in operational models, and more comprehensive comparisons with observations are clearly needed.

Beschreibung: The Asian monsoon is a planetary-scale circulation system powered by the release of latent heat, but important features of deep convection and rainfall distribution cannot be adequately represented by the large-scale patterns. This is mainly due to the strong influences of terrain that are important across a wide range of horizontal scales, especially over the Maritime Continent where the complex terrain has a dominant effect on the behavior of convective rainfall during the boreal winter monsoon. This chapter is a review and summary of published results on the effects on monsoon convection due to interactions between the Maritime Continent terrain and large-scale transient systems. The Maritime Continent topographic features strongly affect both the demarcation of the boreal summer and winter monsoon regimes and the asymmetric seasonal marches during the transition seasons. In the western part of the region, the complex interactions that lead to variability in deep convection are primarily controlled by the cold surges and the synoptic-scale Borneo vortex. The Madden–Julian oscillation (MJO) reduces the frequency of weaker surges through an interference with their structure. It also influences convection, particularly on the diurnal cycle and when synoptic activities are weak. When both surges and the Borneo vortex are present, interactions between these circulations with the terrain can cause the strongest convection, which has included Typhoon Vamei (2001), which is the only observed tropical cyclone that developed within 1.5° of the equator. The cold surges are driven by midlatitude pressure rises associated with the movement of the Siberian high. Rapid strengthening of surge northeasterly winds can be explained as the tropical response via a geostrophic adjustment process to the pressure forcing in the form of an equatorial Rossby wave group. Dispersion of meridional modes leads to a northeast–southwest orientation that allows the surge to stream downstream through the similarly oriented South China Sea. This evolution leads to a cross-equatorial return flow and a cyclonic circulation at the equator, and thus a mechanism for equatorial cyclogenesis. Although the narrow width of the southern South China Sea facilitates strengthening of the cold surge, it also severely restricts the likelihood of cyclone development so that Vamei remains to be the only typhoon observed in the equatorial South China Sea. Climate variations from El Niño–Southern Oscillation to climate change may impact the interactions between the large-scale motion and Maritime Continent terrain because they lead to changes in the mean flow. The thermodynamic effects on the interaction between MJO and the monsoon surges and Borneo vortex over the complex terrain also need to be addressed. These and other questions such as any possible changes in the likelihood of equatorial tropical cyclogenesis as a result of climate change are all important areas for future research.

Beschreibung: It has been known that aerosol particles act as nuclei for ice formation for over a century and a half (see Dufour). Initial attempts to understand the nature of these ice nucleating particles were optical and electron microscope inspection of inclusions at the center of a crystal (see Isono; Kumai). Only within the last few decades has instrumentation to extract ice crystals from clouds and analyze the residual material after sublimation of condensed-phase water been available (see Cziczo and Froyd). Techniques to ascertain the ice nucleating potential of atmospheric aerosols have only been in place for a similar amount of time (see DeMott et al.). In this chapter the history of measurements of ice nucleating particles, both in the field and complementary studies in the laboratory, are reviewed. Remaining uncertainties and artifacts associated with measurements are described and suggestions for future areas of improvement are made.

Beschreibung: Insights by Professor Michio Yanai on tropical waves, which have been vital ingredients for progress in tropical meteorology over the last half-century, are recollected. This study revisits various aspects of research on tropical waves over the last five decades to examine, in Yanai’s words, “the nature of ‘A-scale’ tropical wave disturbances and the interaction of the waves and the ‘B-scale’ phenomena (cloud clusters),” the fundamental problem posed by Yanai at the design phase of the GARP Atlantic Tropical Experiment (GATE) in 1971. The various contributions of Michio Yanai to the current understanding of the dynamics of the tropical atmosphere are briefly reviewed to show how his work has led to several current theories in this field.

Beschreibung: It is well known that the envelope of the Madden–Julian oscillation (MJO) consists of smaller-scale convective systems, including mesoscale convective systems (MCS), tropical cyclones, and synoptic-scale waves called “convectively coupled equatorial waves” (CCW). In fact, recent results suggest that the fundamental mechanisms of the MJO involve interactions between the synoptic-scale CCW and their larger-scale environment (Majda and Stechmann). In light of this, this chapter reviews recent and past work on two-way interactions between convective systems—both MCSs and CCW—and their larger-scale environment, with a particular focus given to recent work on MJO–CCW interactions.

Beschreibung: This volume consists of some papers presented at the AMS Symposium held to honor the memory of the late Professor Michio Yanai as well as additional works inspired by his research. By the nature of this volume, many of the contributed papers describe the development of tropical meteorology over the past half-century or so in connection with Professor Yanai’s influence on it. While most of the chapters address specific areas and discuss timely issues, in this prologue I will describe some of Professor Yanai’s contributions during the early period of his career from my own point of view. As this is a personal reminiscence, I would like to emphasize how Professor Yanai influenced me. Both Professor Yanai and I became graduate students at the University of Tokyo to begin our career as meteorologists in 1956 and 1957, respectively. Since we studied and worked together so closely for a long time, in this article I will call him Yanai-san as I have done in our personal interactions.

Beschreibung: This chapter reviews Professor Michio Yanai’s contributions to the discovery and science of the Madden–Julian oscillation (MJO). Professor Yanai’s work on equatorial waves played an inspirational role in the MJO discovery by Roland Madden and Paul Julian. Professor Yanai also made direct and important contributions to MJO research. These research contributions include work on the vertically integrated moist static energy budget, cumulus momentum transport, eddy available potential energy and eddy kinetic energy budgets, and tropical–extratropical interactions. Finally, Professor Yanai left a legacy through his students, who continue to push the bounds of MJO research.

Beschreibung: The life cycle of individual (initially line shaped) contrails behind aircraft and of contrail cirrus (aged contrails mixed with other ice clouds) is described. The full contrail life cycle is covered, from ice formation for given water, heat, and particulate emissions; to changes in the jet, wake, and dispersion phases; through final sublimation or sedimentation. Contrail properties are deduced from various in situ, remote sensing, and model studies. Aerodynamically induced contrails and distrails are explained briefly. Contrails form both in clear air and inside cirrus. Young contrails consume most of the ambient ice supersaturation. Optical properties of contrails are age and humidity dependent. Contrail occurrence and radiative forcing depends on the ambient Earth–atmosphere conditions. Contrail cirrus seems to be optically thicker than assessed previously and may not only increase cirrus coverage but also thicken existing cirrus. Some observational constraints for contrail cirrus occurrence and radiative forcing are derived. Key parameters controlling contrail properties—besides aircraft and fuel properties, ambient pressure, temperature, and humidity—are the number of ice particles per flight distance surviving the wake vortex phase, the contrail depth, and particle sedimentation, wind shear, turbulence, and vertical motions controlling contrail dispersion. The climate impact of contrails depends among other things on the ratio of shortwave to longwave radiative forcing (RF) and on the efficacy with which contrail RF contributes to surface warming. Several open issues are identified, including renucleation from residuals of sublimated contrail ice particles.

Beschreibung: Two features of Yanai et al.’s profiles of Q1 and Q2—the commonly observed double-peak structure to Q2 and an inflection in the Q1 profile below the melting level—are explored using estimates of convective and stratiform rainfall partitioning based on Massachusetts Institute of Technology (MIT) radar reflectivity data collected during TOGA COARE. The MIT radar data allow the Q1 and Q2 profiles to be classified according to stratiform rain fraction within the radar domain and, within the limitations of the datasets, allow interpretations to be made about the relative contributions of convective and stratiform precipitation to the mean profiles. The sorting of Q2 by stratiform rain fraction leads to the confirmation of previous findings that the double-peak structure in the mean profile is a result of a combination of separate contributions of convective and stratiform precipitation. The convective contribution, which has a drying peak in the lower troposphere, combines with a stratiform drying peak aloft and low-level moistening peak to yield a double-peak structure. With respect to the inflection in the Q1 profile below the 0°C level, this feature appears to be a manifestation of melting. It is the significant horizontal dimension of the stratiform components of tropical convective systems that yields a small but measurable imprint on the large-scale temperature and moisture stratification upon which the computations of Q1 and Q2 are based. The authors conclude, then, that the rather subtle features in the Q1/Q2 profiles of Yanai et al. are directly linked to the prominence of stratiform precipitation within tropical precipitation systems.

Beschreibung: Ice-phase precipitation occurs at Earth’s surface and may include various types of pristine crystals, rimed crystals, freezing droplets, secondary crystals, aggregates, graupel, hail, or combinations of any of these. Formation of ice-phase precipitation is directly related to environmental and cloud meteorological parameters that include available moisture, temperature, and three-dimensional wind speed and turbulence, as well as processes related to nucleation, cooling rate, and microphysics. Cloud microphysical parameters in the numerical models are resolved based on various processes such as nucleation, mixing, collision and coalescence, accretion, riming, secondary ice particle generation, turbulence, and cooling processes. These processes are usually parameterized based on assumed particle size distributions and ice crystal microphysical parameters such as mass, size, and number and mass density. Microphysical algorithms in the numerical models are developed based on their need for applications. Observations of ice-phase precipitation are performed using in situ and remote sensing platforms, including radars and satellite-based systems. Because of the low density of snow particles with small ice water content, their measurements and predictions at the surface can include large uncertainties. Wind and turbulence affecting collection efficiency of the sensors, calibration issues, and sensitivity of ground-based in situ observations of snow are important challenges to assessing the snow precipitation. This chapter’s goals are to provide an overview for accurately measuring and predicting ice-phase precipitation. The processes within and below cloud that affect falling snow, as well as the known sources of error that affect understanding and prediction of these processes, are discussed.

Beschreibung: Ice fog is a natural, outdoor cloud laboratory that provides an excellent opportunity to study ice microphysical processes. Ice crystals in fog are formed through similar pathways as those in elevated clouds; that is, cloud condensation or ice nuclei are activated in an atmosphere supersaturated with respect to liquid water or ice. The primary differences between surface and elevated ice clouds are related to the sources of water vapor, the cooling mechanisms and dynamical processes leading to supersaturation, and the microphysical characteristics of the nuclei that affect ice fog crystal physical properties. As with any fog, its presence can be a hazard for ground or airborne traffic because of poor visibility and icing. In addition, ice fog plays a role in climate change by modulating the heat and moisture budgets. Ice fog wintertime occurrence in many parts of the world can have a significant impact on the environment. Global climate models need to accurately account for the temporal and spatial microphysical and optical properties of ice fog, as do weather forecast models. The primary handicap is the lack of adequate information on nucleation processes and microphysical algorithms that accurately represent glaciation of supercooled water fog. This chapter summarizes the current understanding of ice fog formation and evolution; discusses operating principles, limitations, and uncertainties associated with the instruments used to measure ice fog microphysical properties; describes the prediction of ice fog by the numerical forecast models and physical parameterizations used in climate models; identifies the outstanding questions to be resolved; and lists recommended actions to address and solve these questions.

Beschreibung: This monograph on convection-coupled systems in the tropics was inspired by the life and career of Professor Michio Yanai, whose major contributions to the subject spanned more than five decades. From a distant perspective, Professor Yanai’s career can be understood in the context of Japanese scientists who immigrated to the United States in the decades of the 1950s and 1960s, enriching the meteorological research community in the United States as well as abroad (Lewis 1993). A closer look reminds us that the tapestry of scientific progress is created by the contributions of individual scientists with their unique backgrounds, motivations, and talents, and the serendipity of events that shape their lives.

Beschreibung: Professor Yanai is remembered in our hearts as an esteemed friend. Based on his accomplishments in tropical meteorology and with his flashes of insight he led his group at the University of California, Los Angeles, in the 1980s and 1990s to explore the thermal features of the Tibetan Plateau (TP) and its relation to the Asian monsoon, and he brought forward the TP meteorology established by Ye Duzheng et al. in 1957 to a new stage. In cherishing the memory of Professor Yanai and his great contribution to the TP meteorology, the authors review their recent study on the impacts of the TP and contribute this chapter as an extension of their chapter titled “Effects of the Tibetan Plateau” published by Yanai and Wu in 2006 in the book The Asian Monsoon. The influence of a large-scale orography on climate depends not only on the mechanical and thermal forcing it exerts on the atmosphere, but also on the background atmospheric circulation. In winter the TP possesses two leading heating modes resulting from the relevant dominant atmospheric circulations, in particular the North Atlantic Oscillation and the North Pacific Oscillation. The prevailing effect of the mechanical forcing of the TP in wintertime generates a dipole type of circulation, in which the anticyclonic gyre in the middle and high latitudes contributes to the warm inland area to the west, and the cold seashore area to the east, of northeast Asia, whereas the cyclonic gyre in low latitudes contributes to the formation of a prolonged dry season over central and southern Asia and moist climate over southeastern Asia. Such a dipole circulation also generates a unique persistent rainfall in early spring (PRES) over southern China. In 1980s, Yanai and his colleagues analyzed the in situ observation and found that the constant potential temperature boundary layer over the TP can reach about 300 hPa before the summer monsoon onset. This study supports these findings, and demonstrates that such a boundary layer structure is a consequence of the atmospheric thermal adaptation to the surface sensible heating, which vanishes quickly with increasing height. The overshooting of rising air, which is induced by surface sensible heating, then can form a layer of constant potential temperature with a thickness of several kilometers. The thermal forcing of the TP on the lower tropospheric circulation looks like a sensible heat–driven air pump (SHAP). It is the surface sensible heating on the sloping sides of the plateau that the SHAP can effectively influence the Asian monsoon circulation. In spring the SHAP contributes to the seasonal abrupt change of the Asian circulation and anchors the earliest Asian summer monsoon onset over the eastern Bay of Bengal. In summer, this pumping, together with the thermal forcing over the Iranian Plateau, produces bimodality in the South Asian high activity in the upper troposphere, which is closely related to the climate anomaly patterns over South and East Asia. Because the isentropic surfaces in the middle and lower troposphere intersect with the TP, in summertime the plateau becomes a strong negative vorticity source of the atmosphere and affects the surrounding climate and even the Northern Hemispheric circulation via Rossby wave energy dispersion. Future prospects in related TP studies are also addressed.

Beschreibung: In this chapter, a model parameterization for organized tropical convection and convectively coupled tropical waves is presented. The model is based on the main three cloud types, congestus, deep, and stratiform, that are observed to play an important role in the dynamics and morphology of tropical convective systems. The model is based on the self-similarity across scales of tropical convective systems and uses physically sound theory about the mutual interactions between the three cloud types and the environment. Both linear analysis and numerical simulations of convectively coupled waves and the Madden–Julian oscillation are discussed.

Beschreibung: The authors examined the maintenance mechanisms of perturbation kinetic energy (PKE) in the tropical regions for multiple time scales by computing and analyzing its budget equation. The emphasis has been placed on the mean features of synoptic and subseasonal variabilities using a 33-yr dataset. From analysis of the contributions from u-wind and υ-wind components, the PKE maximum in the Indian Ocean is attributed less to synoptic variability and more to intraseasonal variability in which the Madden–Julian oscillation (MJO) dominates; however, there is strong evidence of seasonal variability affiliated with the Asian monsoon systems. The ones in the eastern Pacific and Atlantic Oceans are closely related to both intraseasonal and synoptic variability that result from the strong MJO and the relatively large amplitude of equatorial waves. The maintenance of the PKE budget mainly depends on the structure of time mean horizontal flows, the location of convection, and the transport of PKE from the extratropics. In the regions with strong convective activities, such as the eastern Indian Ocean to the western Pacific, the production of PKE occurs between 700 and 200 hPa at the expense of perturbation available potential energy (PAPE), which is generated by convective heating. This gain in PKE is largely offset by divergence of the geopotential component of vertical energy flux; that is, it is redistributed to the upper- and lower-atmospheric layers by the pressure field. Strong PKE generation through the horizontal convergence of the extratropical energy flux takes place in the upper troposphere over the eastern Pacific and Atlantic Ocean, and is largely balanced by a PKE loss due to barotropic conversion, which is determined solely by the sign of longitudinal stretching deformation. However, over the Indian Ocean, there is a net PKE loss due to divergence of energy flux, which is compensated by PKE gain through the shear generation.

Beschreibung: State-of-the-art remote sensing techniques applicable to the investigation of ice formation and evolution are described. Ground-based and spaceborne measurements with lidar, radar, and radiometric techniques are discussed together with a global view on past and ongoing remote sensing measurement campaigns concerned with the study of ice formation and evolution. This chapter has the intention of a literature study and should illustrate the major efforts that are currently taken in the field of remote sensing of atmospheric ice. Since other chapters of this monograph mainly focus on aircraft in situ measurements, special emphasis is put on active remote sensing instruments and synergies between aircraft in situ measurements and passive remote sensing methods. The chapter concentrates on homogeneous and heterogeneous ice formation in the troposphere because this is a major topic of this monograph. Furthermore, methods that deliver direct, process-level information about ice formation are elaborated with a special emphasis on active remote sensing methods. Passive remote sensing methods are also dealt with but only in the context of synergy with aircraft in situ measurements.

Beschreibung: One of the most important contributions of Michio Yanai to tropical meteorology is the introduction of the concepts of apparent heat source Q1 and apparent moisture sink Q2 in the large-scale heat and moisture budgets of the atmosphere. Through the inclusion of unresolved eddy effects, the vertical profiles of apparent sources (and sinks) are generally quite different from those of true sources taking place locally. In low-resolution models, such as the conventional general circulation models (GCMs), cumulus parameterization is supposed to determine the apparent sources for each grid cell from the explicitly predicted grid-scale processes. Because of the recent advancement of computer technology, however, increasingly higher horizontal resolutions are being used even for studying the global climate, and, therefore, the concept of apparent sources must be expanded rather drastically. Specifically, the simulated apparent sources should approach and eventually converge to the true sources as the horizontal resolution is refined. For this transition to take place, the conventional cumulus parameterization must be either generalized so that it is applicable to any horizontal resolutions or replaced with the mean effects of cloud-scale processes explicitly simulated by a cloud-resolving model (CRM). These two approaches are called ROUTE I and ROUTE II for unifying low- and high-resolution models, respectively. This chapter discusses the conceptual and technical problems in exploring these routes and reviews the authors’ recent work on these subjects.

Beschreibung: This chapter proposes a working assumption as a way of conceptual simplification of the origin of Madden–Julian oscillation (MJO)-associated convection, or super cloud cluster (SCC). To develop the simplification, the importance of the synoptic-scale cold reservoir underlying the convection and its interaction with the accompanying zonal–vertical circulation is highlighted. The position of the convection with respect to that of climatological warm pool is postulated to determine the effectiveness of this framework. The authors introduce a prototype hypothesis to illustrate the usefulness of the above assumption based on a numerical simulation experiment with a global nonhydrostatic model for the boreal summer season. Premises for the hypothesis include 1) that the cloud cluster (CC) is a basic building block of tropical convection accompanying the precipitation-generated cold reservoir in its subcloud layer and 2) that a warm-pool-induced quasi-persistent zonal circulation is key for the upscale organization of CCs. The theory of squall-line structure by Rotunno, Klemp, and Weisman (hereafter RKW) is employed for the interpretation. No account is taken regarding the influences of equatorial waves as a first-order approximation. Given the premises, an SCC of O(1000) km scale is interpretable as a gigantic analog of a multicellular squall line embedded in the quasi-stationary westerly shear branch of the zonal circulation east of the warm water pool. A CC corresponds to the “cell,” and its successive formation to the east and westward movement represents an upshear-tilting core of intense updraft. The upshear-tilted SCC is favorably maintained with the precipitating area being separated from the gust front boundary between the cold reservoir and a low-level easterly, which is supported in the realm of the RKW theory where two horizontal vortices associated with the cold reservoir and vertical shear are opposite in sign but cold reservoir’s vorticity can be inferred to be larger, leading to upshear-tilted and multicellular behavior. As a counterexample, CCs to the west of the warm pool (Indian Ocean and Arabian Sea) are embedded in the easterly shear and organized into a less coherent cloud cluster complex (CCC) given the situation of RKW where two horizontal vortices associated with the cold reservoir and vertical shear are still opposite in sign, but the smaller vertical shear west of the warm pool causes even more suboptimal vorticity imbalance in the western flank of cold reservoir, leading to larger tilt with height and intermittent, less viable storm situations. A cold pool or cold reservoir, having been prevalent in mesoscale convection research, is argued to be important for the MJO as pointed out by the emerging evidence in the international field campaign for the MJO called Cooperative Indian Ocean Experiment on Intraseasonal Variability (CINDY)/DYNAMO. The simplified and idealistic hypothesis proposed here does not cover all aspects of MJO and its validation awaits further modeling and observational studies, but it can offer a framework for characterizing a fundamental aspect of the origin of MJO-associated convection.

Beschreibung: This chapter distinguishes the mechanism of tropical convective disturbances, such as a hurricane, from that of the Madden–Julian oscillation (MJO). The hurricane is maintained by organized convection around the azimuth. In a hurricane the organization of convection, the generation of eddy available potential energy, and the transformation of eddy available potential energy into eddy kinetic energy all occur on the scale of the hurricane and these are called “in-scale processes,” which invoke quadratic nonlinearity. The MJO is not a hurricane type of disturbance; organized convection simply does not drive an MJO in the same manner. The maintenance of the MJO is more akin to a multibody problem where the convection is indeed organized on scales of tropical synoptic disturbances that carry a similar organization of convection and carry similar roles for the generation of eddy available potential energy and its conversion to the eddy kinetic energy for their maintenance. The maintenance of the MJO is a scale interaction problem that comes next, where pairs of synoptic-scale disturbances are shown to interact with a member of the MJO time scale, thus contributing to its maintenance. This chapter illustrates the organization of convection, synoptic-scale energetics, and nonlinear scale interactions to show the above aspects for the mechanism of the MJO.

Beschreibung: Cloud processes play a central role in the dynamics of the tropical atmosphere, but for many years the shortcomings of cloud parameterizations have limited our ability to simulate and understand important tropical weather systems such as the Madden–Julian oscillation. Since about 2001, “superparameterization” has emerged as a new path forward, complementing but not replacing studies based on conventional parameterizations. This chapter provides an overview of work with superparameterization, including a discussion of the method itself and a summary of key results.

Beschreibung: Ice particle formation in tropospheric clouds significantly changes cloud radiative and microphysical properties. Ice nucleation in the troposphere via homogeneous freezing occurs at temperatures lower than −38°C and relative humidity with respect to ice above 140%. In the absence of these conditions, ice formation can proceed via heterogeneous nucleation aided by aerosol particles known as ice nucleating particles (INPs). In this chapter, new developments in identifying the heterogeneous freezing mechanisms, atmospheric relevance, uncertainties, and unknowns about INPs are described. The change in conventional wisdom regarding the requirements of INPs as new studies discover physical and chemical properties of these particles is explained. INP sources and known reasons for their ice nucleating properties are presented. The need for more studies to systematically identify particle properties that facilitate ice nucleation is highlighted. The atmospheric relevance of long-range transport, aerosol aging, and coating studies (in the laboratory) of INPs are also presented. Possible mechanisms for processes that change the ice nucleating potential of INPs and the corresponding challenges in understanding and applying these in models are discussed. How primary ice nucleation affects total ice crystal number concentrations in clouds and the discrepancy between INP concentrations and ice crystal number concentrations are presented. Finally, limitations of parameterizing INPs and of models in representing known and unknown processes related to heterogeneous ice nucleation processes are discussed.

Beschreibung: The goal of this chapter is to synthesize information about what is now known about one of the three main types of clouds, cirrus, and to identify areas where more knowledge is needed. Cirrus clouds, composed of ice particles, form in the upper troposphere, where temperatures are generally below −30°C. Satellite observations show that the maximum-occurrence frequency of cirrus is near the tropics, with a large latitudinal movement seasonally. In situ measurements obtained over a wide range of cirrus types, formation mechanisms, temperatures, and geographical locations indicate that the ice water content and particle size generally decrease with decreasing temperature, whereas the ice particle concentration is nearly constant or increases slightly with decreasing temperature. High ice concentrations, sometimes observed in strong updrafts, result from homogeneous nucleation. The satellite-based and in situ measurements indicate that cirrus ice crystals typically differ from the simple, idealized geometry for smooth hexagonal shapes, indicating complexity and/or surface roughness. Their shapes significantly impact cirrus radiative properties and feedbacks to climate. Cirrus clouds, one of the most uncertain components of general circulation models (GCM), pose one of the greatest challenges in predicting the rate and geographical pattern of climate change. Improved measurements of the properties and size distributions and surface structure of small ice crystals (about 20 μm) and identifying the dominant ice nucleation process (heterogeneous versus homogeneous ice nucleation) under different cloud dynamical forcings will lead to a better representation of their properties in GCM and in modeling their current and future effects on climate.

Beschreibung: Germany lacks a systematic nation-wide approach for the governance of metropolitan regions. We observe a considerable variety of institutional solutions for the governance of metropolitan affairs. In particular since the 1990s many initiatives have blossomed at different scales giving different weight to economic development, infrastructure planning, spatial planning or waste management. Therefore, the German federal state can be seen as a laboratory for metropolitan governance with a few outstanding cases and some less successful ones. However, the current situation calls for more effective metropolitan governance in most of the German metropolitan regions. The article gives an historical overview, describes recent trends and illustrates four cases in more detail. The emergence of multi-scaled arrangements where different forms of governance function on different spatial scales seems to be the most recent pattern in Germany. The outlook remains unclear.

Beschreibung: Zusammenfassung Ein Schlagwort der Energiewende ist „Dezentralisierung“, schon allein weil die zugrunde liegenden Primärenergiequellen (z. B. Solarstrahlung und Wind) – bei räumlich differenzierten Nutzungspotenzialen – prinzipiell ubiquitär sind. Dadurch haben sich insbesondere im ländlichen Raum neuartige Infrastrukturen entwickelt. Ziel des Beitrags ist es, diese mit dem institutionellen und strukturellen Wandel des Large Technical Systems der Energieversorgung verbundenen dezentralen Wirkungen der Energiewende im ländlichen Raum darzustellen und die dortigen skalaren Handlungsmöglichkeiten im Umgang mit den Herausforderungen und Chancen der Energiewende aufzuzeigen. Dazu werden in einem ersten Schritt die neuen Energieinfrastrukturen im ländlichen Raum im Spannungsfeld zwischen Zentralität und Dezentralität sowie die dezentralen Wirkungen des Ausbaus erneuerbarer Energien erörtert. Weil die Funktionen erneuerbarer Energien sich nicht nur auf eine regionale Daseinsvorsorge erstrecken, ist mit der Dezentralität der Anlagen nicht per se die Dezentralität des daraus erwachsenden Nutzens verbunden. Die Bereitstellung von Flächen für Windkraft-, Photovoltaik- und Biogasanlagen wird in einem Landschaftswandel sichtbar, der mit Konflikten verbunden ist. Der ländliche Raum ist oftmals lediglich ein ,Installationsraum', der sich auf der Basis von außerhalb des jeweiligen räumlichen Kontextes getroffenen Investitionsentscheidungen entwickelt. Auf dieser analytischen Grundlage werden in einem zweiten Schritt die dezentralen Handlungsmöglichkeiten und die von den Akteuren verfolgten Gemeinwohlziele untersucht sowie Kriterien für kollektives Handeln abgeleitet. Demnach erscheint ein Engagement von Akteuren kommunaler und regionaler Handlungsräume erforderlich, um mit erneuerbaren Energien Gemeinwohlziele ökonomischer und sozialer Teilhabe zu erschließen. Indem kollektive Akteure Handlungsräume konstituieren, kann sich eine neue skalare Ebene der Erzeugung erneuerbarer Energien in regionalen ,Gestaltungsräumen' herausbilden.

Beschreibung: The paper focuses on the gap between the expectations and the effects of the recent rescaling of planning powers in France. Through a series of legislative reforms in 2010, 2014 and 2015, France has introduced “metropolises”. Designed for large cities of more than 500,000 inhabitants, metropolises are a new way of grouping municipalities (Etablissement Public de Coopération Intercommunale), more integrated than the previous bodies which they replace (communauté urbaine, communauté d’agglomération). With enlarged territories and increased decisional power, they were expected to become strong collective actors, providing better services for their inhabitants and making better use of their resources. However, the first outcomes of the reform do not meet these expectations. Metropolises are often smaller than expected. Their perimeters result more from political bargains than from geographical considerations. The emergence of a collective metropolitan power is slowed down by the mayors, who stick to localist approaches, as well as by the national government. Planning objectives have shifted from a redistributive approach (ensuring balanced territorial development) to a growth-oriented policy (enhancing metropolitan potentials). As a result, central areas are gaining economic weight and autonomy while peripheral areas keep declining: there are winners and losers.

Beschreibung: Which regions contribute most to national growth? Do large cities ‘need’ more expenditure per capita? The relation between these two questions is the subject of a current German discussion, but it is of importance for other countries as well. What precisely is the issue? The substantial German fiscal equalization systems between states (Länder) and between communities assign estimates of higher expenditure need per capita to larger cities. This paper argues that this is justified, because, following the arguments of new regional economics, the modern agglomerations are of crucial importance for national growth. To maintain this role they have to be able to keep or receive enough public finance. To assess this, total public flows out of and into regions have to be taken into account. The relevant analysis shows that their contribution to upperlevel (federal and Länder) finances is far above average, but that they receive relatively little from federal and Länder spending; consequently they experience large net fiscal outflows. The use of the abovementioned progressive scale of expenditure need in the equalization systems reduces this fiscal siphoning-off, at least to some extent.

Beschreibung: Zusammenfassung Die Bewertung der wirtschaftlichen Bedeutung von Universitäten steht zunehmend im politischen Interesse, wenn es um die Rechtfertigung des öffentlichen Mitteleinsatzes für Forschung und Bildung geht. Während regionale Wirkungsanalysen bisher meist auf der lokalen Ebene und für einzelne Einrichtungen durchgeführt wurden, bewertet dieser Beitrag erstmalig den monetären Effekt einer ganzen Hochschullandschaft auf die Wertschöpfung und den Arbeitsmarkt eines großen Flächenlandes in Deutschland. Einige der methodischen Schwächen der Wirkungsanalyse werden hierbei verbessert. Aufgrund einer erweiterten Multiplikatoranalyse, die sowohl produktions- als auch einkommensseitige Effekte integriert, einer differenziellen Analyse der Überschusswirkung von Universitäten gegenüber alternativen Verwendungen der staatlichen Grundmittel sowie der Modellerweiterung um Ausgabenströme im System der Sozialversicherungen trägt diese Untersuchung zu einer Weiterentwicklung der ökonomischen Wirkungsanalyse von Bildungseinrichtungen auf Länderebene bei. Mithilfe einer präzise regionalisierten Primärerhebung der Ausgaben aller neun Landesuniversitäten in Baden-Württemberg zeigt die Analyse, dass die Universitäten in ihrer Gesamtwirkung einen Beitrag zu Wertschöpfung und Beschäftigung leisten, der die eingesetzten Mittel der Grundfinanzierung des Landes nahezu verdoppelt. Die differenzielle Analyse ergibt ferner, dass alternative Verwendungen der Grundmittel kaum vergleichbare Wirkungen erzielen. Schließlich diskutiert der Beitrag wesentliche Faktoren, die die Hebelwirkung universitärer Ausgaben bestimmen.

Beschreibung: Zusammenfassung Der Wohnungsmarkt in Deutschland ist derzeit von gegensätzlichen Tendenzen geprägt: Angespannten Märkten mit zum Teil ausgeprägter Wohnungsknappheit stehen entspannte Märkte mit hohen, zum Teil sogar sehr hohen Wohnungsleerständen gegenüber. Für beide Situationen ist die Leerstandsquote eine maßgebliche Bezugs- und Messgröße, sie fungiert als Indikator für die Bewertung. Jedoch ist die Leerstandsquote bislang kein systematisch untersuchter bzw. elaborierter Indikator, sie wird in den unterschiedlichen wissenschaftlichen und politischen Diskursen unterschiedlich quantifiziert und qualifiziert. Hier setzt der Artikel an, indem er auf der Basis einschlägiger Literatur eine systematische Kategorisierung von Leerständen vorschlägt und eine Heuristik für die differenzierte Bewertung von Wohnungsleerständen aus verschiedenen Perspektiven entwickelt. Diese Heuristik wird anschließend mit den Daten der Gebäude- und Wohnungszählung (GWZ) 2011 empirisch veranschaulicht. Anhand dessen kann gezeigt werden, dass zwar der Großteil deutscher Kommunen eine angemessene Leerstandsquote zwischen 3 und 5 % aufweist, jedoch erhebliche regionale und raumstrukturelle Unterschiede auftreten. Aus der Analyse der Leerstandsquoten können insofern keine flächenhaften Generalisierungen bzw. vereinfachende Aussagen für dieWohnungs- bzw. Stadterneuerungspolitik abgeleitet werden. Dies macht deutlich, dass die Leerstandsquote der Qualifizierung bedarf, wenn sie für planerische und politische Entscheidungen genutzt werden soll.

Beschreibung: ZusammenfassungInnerhalb der kürzlich belebten Peripherisierungsdebatte und basierend auf qualitativen Forschungen zu Lebenswirklichkeiten in peripheren Räumen entstanden Forderungen, nicht nur sozialstrukturelle Aspekte zur Analyse des Zustandekommens räumlicher Ungleichheiten heranzuziehen, sondern auch die Wirkungen von Prozessen diskursiver Zuschreibungen in Betracht zu ziehen. Anhand erster empirischer Forschungsergebnisse des Projekts „Diskurs und Praktiken in schrumpfenden Regionen – Eine Untersuchung zur subjektiven Relevanz von Schrumpfungsdiskursen am Beispiel des Landkreises Altenburger Land" aus einer Auswahl von Interviews im Altenburger Land (Thüringen) verdeutlichen wir, inwieweit Konzepten wie „Kulturförderung" und „Infrastrukturförderung" von Akteuren der Politik, Verwaltung und des sozialen Bereiches hinsichtlich der Wanderungsentscheidungen von Bürgern kausale Wirkungen zugeschrieben werden. Darüber hinaus beleuchten wir deren Rationalisierungen, aber auch die explizit subjektiven Aspekte von Wanderungen, die diesen Rationalisierungen empirisch widersprechen. Wir schließen mit einer Zusammenfassung von Unsicherheiten, die in der Beforschung von Migration ebenso auftreten wie im politisch-praktischen Umgang mit Migrationsentscheidungen.

Beschreibung: ZusammenfassungDie im Zuge der Modernisierung („Urbanisierung") ländlicher Räume seit Mitte des 20. Jahrhunderts erfolgten staatlichen Interventionen und Investitionen sind wesentlich mitverantwortlich dafür, dass Daseinsvorsorge heute in hohem Maße mit der Vorstellung eines ,von oben', also vor allem durch die öffentliche Hand, bereitgestellten Gutes verbunden wird. Doch zum einen stimmte diese Wahrnehmung nie für alle Bereiche (denkt man etwa an die Freiwilligen Feuerwehren), zum anderen verwischt sich unter den Bedingungen kommunaler Haushaltsnot und des soziodemographischen Wandels die Arbeitsteilung zwischen anbietenden, nutzenden und moderierenden Akteuren. Zugleich befinden sich die Aufgabenbereiche und die Qualität dessen, was unter Daseinsvorsorge verstanden wird, in beständigem Wandel. In diesem Beitrag wird erstens argumentiert, dass es in der Bereitstellung von Daseinsvorsorge eine Verantwortungsverlagerung an ganz unterschiedliche Akteure gibt, woraus eine neue Unübersichtlichkeit und in der Bevölkerung ein Nichtwissen über die genauen Verantwortlichkeiten entstehen. In diesem neuen Akteursgeflecht werden zweitens die Bürger in einer neuen Rolle gesehen. Diese lässt sich als Responsibilisierung bezeichnen. Bezogen auf ländliche Räume knüpfen solche Zuschreibungen zwar an vorhandene Akteursrollen an und treffen auf eine gewisse Akzeptanz, doch resultieren aus der neuen Unübersichtlichkeit steigende Anforderungen an die Steuerungs- und Moderationsrolle staatlicher Verwaltungen. Empirisch wird dies an drei Bereichen der Daseinsvorsorge dargestellt: allgemeinbildende Schulen, Breitbandinternet und Freiwillige Feuerwehren. Die Analyse zeigt, dass in diesen Bereichen vor allem Prozesse der Selbstresponsibilisierung von Bedeutung sind – nicht aber, um den Staat als Akteur zu ersetzen, sondern um Daseinsvorsorge an neue Standards anzupassen oder weitere Verschlechterungen zu verhindern.

Beschreibung: Zusammenfassung Vor allem bezugnehmend auf die Beiträge von Zimmermann (2012) sowie Balke und Reimer (2016) in der Zeitschrift „Raumforschung und Raumordnung“ setzt sich der Zwischenruf mit den wissenschaftlichen Arbeiten auseinander, die unter den Stichworten Konstruktivismus, Diskursanalyse und Gouvernementalitätsforschung immer größere Verbreitung finden. Der Autor schildert am Beispiel der beiden genannten Beiträge seine Gedanken zum Verhältnis des aufstrebenden sozialkonstruktivistischen Paradigmas zum (bisherigen) Mainstream. Er plädiert dafür, in einer offenen Diskussion das Verständnis für die Gemeinsamkeiten und Unterschiede der Ansätze zu verbessern.

Beschreibung: ZusammenfassungDurch die Förderung ehrenamtlichen Engagements in der Bereitstellung von Daseinsvorsorgeinfrastruktur zeigt sich ein Raumdilemma: Die Mehrzahl der Engagierten findet sich in eher gut situierten Regionen, die von einer staatlichen Förderung des Ehrenamts im Gegensatz zu strukturschwachen Regionen profitieren. Im Beitrag wird dieses Raumdilemma empirisch bestätigt. Dazu wurden Initiativen bürgerschaftlichen Engagements, die sich an der Koproduktion von Daseinsvorsorgeinfrastruktur beteiligen, nach ihrer Lage im Raum ausgewertet. Dieser Zusammenhang kann negative Auswirkungen auf das Ziel gleichwertiger regionaler Lebensbedingungen haben. Das bedeutet jedoch keineswegs, dass Engagement und Koproduktion nicht auch in strukturschwächeren Regionen begünstigt werden kann. Dies zeigen in Fallstudien ermittelte Erfolgs- und Aktivierungsfaktoren, die im Beitrag diskutiert werden. Daher sollte nicht auf die Inwertsetzung des zivilgesellschaftlichen Engagements in der Regionalentwicklung verzichtet werden, weil alle Regionen – sowohl die schwachen als auch die starken Regionen – davon profitieren. Der Beitrag kommt vielmehr zu dem Schluss, dass das zivilgesellschaftliche Engagement in strukturschwachen Regionen in besonderer Weise gefördert werden sollte.

Beschreibung: Zusammenfassung Der Beitrag untersucht die Pendeldistanzen und die Dauer der Pendelwege im Kontext von Randwanderung und Geschlechterverhältnissen im Umland der Stadt Hagen (Westfalen). Die Ergebnisse zeigen, dass auch innerregionale Wanderungen häufig mit beruflichen Motiven verbunden sind. Die geschlechtsspezifischen Veränderungen im Pendeln nach dem Umzug sprechen für die Orientierung des Wohnstandorts am Arbeitsplatz des Mannes, wobei Frauen tendenziell die „Trailing-wife“-Position einnehmen. Darüber hinaus gehen die Wanderungen mit dem Versuch einer Begrenzung oder Verkürzung der Pendelwege auf der Haushaltsebene einher. Dies drückt sich nicht nur in der Pendeldauer aus, sondern auch in der räumlichen Konfiguration von Wohnen und Arbeiten bei erwerbstätigen Paaren, die hier über die relative Lage von Wohn- und Arbeitsorten zueinander abgebildet wurde. In einem Ring von 20–30 km um Hagen sind die Wohnstandortentscheidungen allerdings im Vergleich zum näheren Umland (〈 20 km von Hagen) mit deutlich längeren Pendeldistanzen nach dem Umzug verbunden, was den klassischen Befunden der Suburbanisierungsforschung entspricht. Insgesamt sprechen die Ergebnisse für sehr komplexe Beziehungen zwischen Geschlecht, sozialem Status, Wohnstandortwahl und Pendelverhalten. Dies wird auch vor dem Hintergrund der polyzentrischen Struktur der Region interpretiert. Schlussfolgerungen für die weitere Forschung ergeben sich aus einigen innovativen methodischen Ansätzen der Studie. Die planerische Bedeutung der Ergebnisse wird ebenfalls kurz diskutiert.

Beschreibung: Zusammenfassung Vor dem Hintergrund des demographischen Wandels wird aktuell intensiv darüber diskutiert, wie die Lebensqualität in schrumpfenden Dörfern erhalten werden kann. In diesem Beitrag wird eine raumwissenschaftliche Perspektive eingenommen und mit dem psychologischen Konzept der Lebensqualität verknüpft. Die Ergebnisse einer qualitativen empirischen Untersuchung, in der 43 Dorfbewohner in vier niedersächsischen Dörfern danach gefragt wurden, wie sie selbst ihre Lebensqualität im Dorf bewerten und wo sie Handlungsbedarf, eigene Gestaltungsmöglichkeiten und Unterstützungsbedarf sehen, werden in Bezug gesetzt zu bestehenden und neuen Ansätzen der Dorfentwicklung. Im Ergebnis wird deutlich, dass die Dorfbewohner den sozialen Kontakten im Dorf eine hohe Bedeutung beimessen und dass diese einerseits direkt zur eigenen Lebenszufriedenheit beitragen, andererseits aber auch eine Basis für die gemeinschaftliche Gestaltung und Schaffung einer guten Lebensqualität im Dorf darstellen. Ausgehend von diesen Ergebnissen wird empfohlen, soziale Fragen der Dorfentwicklung in der Dorferneuerungsplanung stärker zu verankern sowie neue unterstützende Angebote weiter zu entwickeln. Insgesamt unterstreichen die Ergebnisse der Forschung die Bedeutung der zivilgesellschaftlichen Kraft der Dorfgemeinschaft, die als ein bedeutendes endogenes Potenzial eine stärkere Beachtung in der Dorfentwicklung verdient.

Beschreibung: Zusammenfassung In diesem Beitrag wird ein großer Teil der publizierten deutschsprachigen, raumwissenschaftlichen Forschungsergebnisse von 2003 bis 2014 auf eine vermutete Lücke zwischen theoriebasierter Forschung und der Planungspraxis hin betrachtet. Dazu werden insgesamt 1929 Beiträge aus Schriftenreihen der Akademie für Raumforschung und Landesplanung (ARL) und drei Fachzeitschriften in unterschiedlichem Detaillierungsgrad analysiert. Im ersten Schritt findet eine Typisierung statt, im zweiten Schritt folgen detailliertere Analysen. Die Vermutung der Diskrepanz wird insgesamt bestätigt. Nur ein Teil der untersuchten Artikel argumentiert erkennbar theoriebasiert. In diesen gelingt die empirische Überprüfung von Theorien meist nur ansatzweise und der praktische Nutzen der Forschungsergebnisse ist nur selten erkennbar. Positionierungen aus der Praxis argumentieren umgekehrt kaum forschungsbasiert. Dieser Befund zeigt auch, dass dem Anspruch der Planungswissenschaften auf Transdisziplinarität nur zum Teil Genüge getan werden kann. Das könnte zum einen auf Gründe im Forschungssystem zurückzuführen sein, ist aber auch forschungskonzeptionellen Defiziten der Raumplanungsforschung geschuldet.

Beschreibung: Zusammenfassung Der Umgang mit den Folgen des Klimawandels stellt Biosphärenreservate als Modellregionen für nachhaltige Entwicklung vor neue Herausforderungen. Obwohl Einflüsse auf Ökosysteme oder Landschaften nur begrenzt steuerbar und schwer absehbar sind, besteht der Auftrag, Klimawandelfolgen strategisch aufzugreifen. Zudem sind zahlreiche Akteure mit unterschiedlichen Perspektiven in Entscheidungen einzubeziehen, die vor dem Hintergrund unsicherer Zukunftsprognosen getroffen werden müssen. Der Beitrag zeigt am Beispiel des UNESCO-Biosphärenreservates Flusslandschaft Elbe-Brandenburg, welche konkreten Handlungsfelder sich abzeichnen und welche Arbeitsphasen ein planvoller Umgang mit dem Klimawandel haben kann. Es werden mögliche Maßnahmen für die Themen Landschaftswasserhaushalt, Vegetation, Fauna und Landnutzung aufgezeigt. An der Elbe kommt dem Flussgebietsmanagement eine besondere Bedeutung zu. Die Diskussion möglicher strategischer Handlungsfelder erläutert, welche Rollen die Verwaltung von Biosphärenreservaten in einem Prozess der Anpassung an den Klimawandel einnehmen kann. Die Möglichkeiten und der Umfang, in dem sich Biosphärenreservate zu Modellregionen für die Anpassung an den Klimawandel entwickeln, werden sich in der Praxis nach den vorhandenen Kapazitäten und der Expertise richten.

Beschreibung: Decentralized energy systems are increasingly seen as a key factor for a transition towards a low-carbon, renewable energy based society. Within the transition process, regional demand and supply of renewable energy carriers have to be aligned, while considering the environmental conditions of the region. This paper focuses on the energy demand from buildings, which makes up 35% of the total energy demand. It presents an approach for aligning the regional supply potential of renewable energy carriers with the dynamics of regional energy demand from buildings. The approach consists of two components. First, a dynamic model simulates regional energy demand from buildings taking into consideration envelope renovation, legislative standards, and adoption of heating technologies. Second, the regional supply is estimated based on the technical maximum possible, taking into consideration competing uses and spatial limitations. We show a first application in the case of the energy region Weiz-Gleisdorf, Austria, which aims to achieve CO2 neutrality and energy self-sufficiency by the year 2050. Our results show that in the year 2050 (i) energy demand from buildings will decrease by 40–55%, depending on envelope renovation rates and legislative standards; (ii) demand for the different renewable energy carriers will be determined by the choice of heating technology; (iii) the demand for wood could be met from regional forest resources, as long as there are no additional demands for other purposes; (iv) the demand for biomass for district heating would require 5–10% of the agricultural area to be used for the production of energy plants rather than food; and (v) in contrast to other forms of energy, the demand for electricity will remain constant or increase slightly over time. This demand could only be regionally met if significant areas of façades or gardens are used for photovoltaic electricity production in addition to roofs. Overall we identified several issues related to spatial planning and a need for further research regarding the transition towards decentralized energy systems. First, if biomass for central district heating systems is to come from regional production, areas should be allocated for cultivating energy crops used specifically to produce fuel. Second, if wood is used for district heating purposes, the extent to which the import of wood from neighboring regions would be a useful ecological solution must be evaluated; this would involve extending regional energy planning beyond the typical jurisdictional boundaries while considering ecological issues.