About
139
Publications
34,560
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,895
Citations
Citations since 2017
Publications
Publications (139)
Background:
The prevalence of stunting in the Democratic Republic of the Congo (DRC) is one of the highest globally. However, only a few studies have attempted to measure the association between stunting and vegetation, which is an important food source. The leaf area index (LAI) is an excellent measure for the vegetation state.
Objective:
This...
Providing tailor-made climate information to end-users and developing appropriate tools to clearly communicate this information are challenging and require the involvement of end-users in the development process from the beginning. In the project called “Land surface processes as a determinant of climate change in Africa – scenarios, high-resolutio...
Providing tailor-made climate information to end-users and developing appropriate tools to clearly communicate this information are challenging and require the involvement of end-users in the development process from the beginning. In the project called “Land surface processes as a determinant of climate change in Africa – scenarios, high-resolutio...
Providing tailored climate information to end-users and developing appropriate tools to clearly communicate this information are challenging and require the involvement of end-users in the development process from the beginning. Only the joint development and design of climate service tools with end-users ensures that the tool firstly provides the...
The strongly rain-fed African agriculture is highly vulnerable to the changing precipitation amounts and patterns induced by climate change. One aim of the WASCAL WRAP2.0 LANDSURF-project is to make reasonable statements for future precipitation amounts and the evolution of crop-dependent agricultural indices. For this, a thorough analysis of the m...
Climate models are the tool of choice for scientists researching climate change. Like all models they suffer from errors, particularly systematic and location-specific representation errors. One way to reduce these errors is model output statistics (MOS) where the model output is fitted to observational data with machine learning. In this work, we...
The current study evaluates the regional climate model REMO (v2015) and its new version REMO-iMOVE, including interactive vegetation and plant functional types (PFTs), over two Central Asian domains for the period of 2000-2015 at two different horizontal resolutions (0.44° and 0.11°). Various statistical metrices along with mean bias patterns for p...
Session 'Technology adoption and dissemination II', September 14 - 16, 2022, poster presentation.
Session 'Crops and cropping sytems II', September 14 - 16, 2022, poster presentation.
First results of investigating the performance of the rainy season over West Africa in CORDEX-CORE simulations and selected validation data (CHIRPS, ERA5, GPCC, TAMSAT) regarding its onset, length, and cessation are presented.
The climate over Central Asia has been investigated using the REMO (v2015) and its recent vegetation coupled version, REMO-iMOVE for the period of 2000-2015 at horizontal resolutions of 0.44° and 0.11°. Model evaluation is performed using the mean monthly bias patterns for temperature, precipitation, and leaf area index along with different statist...
The climate over Central Asia has been investigated using the REMO (v2015) and its recent vegetation coupled version, REMO-iMOVE for the period of 2000-2015 at horizontal resolutions of 0.44° and 0.11°. Model evaluation is performed using the mean monthly bias patterns for temperature, precipitation, and leaf area index along with different statist...
A fuzzy classification scheme that results in physically interpretable meteorological patterns associated with rainfall generation is applied to classify homogeneous regions of boreal summer rainfall anomalies in Germany. Four leading homogeneous regions are classified, representing the western, southeastern, eastern, and northern/northwestern part...
Climate adaptation supports organizations in dealing with the current and projected effects of climate change by recognizing challenges as opportunities and increasing their economic efficiency. Based on the regional climate model REMO and 13 expert interviews with representatives from mainly manufacturing companies analyzed by the Grounded Theory...
Soil sealing affects local climate via changes in the energy and radiation budget and represents a major causation for urban-rural temperature differences. In the present study, we investigate to what extent and at what spatial scales soil sealing accounts for significant spatial differences in mean near-surface climate characteristics as given by...
High-resolution grain size distribution maps for geographical regions are used to model soil-hydrological processes that can be used in climate models. However, measurements are expensive or impossible, which is why interpolation methods are used to fill the gaps between known samples. Common interpolation methods can handle such tasks with few dat...
Tropical Africa has been experiencing a long term drying trend for the last two decades. Climate change and variability has an influence on rain-fed agriculture under the Tropics. Many studies have investigated on the role of climate change and variability on crop yields, but with a limited number of predictors. We use detailed gridded crop statist...
It is still an open question, which processes lead to the spatiotemporal specifications of observed near-surface temperature changes over recent decades. Here, we contribute to this debate by investigating a large number of theory-based atmospheric fields referring to the radiation and energy budget and to atmospheric dynamics that may serve as pre...
Climate models are an important tool for the assessment of prospective climate change effects but they suffer from systematic and representation errors, especially for precipitation. Model output statistics (MOS) reduce these errors by fitting the model output to observational data with machine learning. In this work, we explore the feasibility and...
In this study, we investigate the technical application of the regularized regression method Lasso for identifying systematic biases in decadal precipitation predictions from a high-resolution regional climate model (CCLM) for Europe. The Lasso approach is quite novel in climatological research. We apply Lasso to observed precipitation and a large...
In cooperation with the Climate Service Center Germany (GERICS) we want to improve the land surface module in the regional climate model REMO. High resolution
resolution climate models are essential to analyze the local impacts of the climate change. However, the surface boundary data in climate models are usually insufficient for
highest resolutio...
Plant phenology is well known to be affected by meteorology. Observed changes in the occurrence of phenological phases are commonly considered some of the most obvious effects of climate change. However, current climate models lack a representation of vegetation suitable for studying future changes in phenology itself. This study presents a statist...
A main task of climate research is to provide estimates about future climate change under global warming conditions. The main tools for this are dynamic climate models. However, different models vary quantitatively - and in some aspects even qualitatively - in the climate change signals they produce. In this study, this uncertainty about future cli...
Projections of seasonal extreme precipitation changes in eight Mediterranean subregions between the end of the twentieth and the end of the twenty-first century are analyzed using weighted multi-model ensembles. Weights are based on the performance of predictor variables in the scope of statistical downscaling. Two indices of precipitation scarcity...
In recent years, the mid‐latitudes are characterized by more intense heat waves in summer and sometimes severe cold spells in winter that might emanate from changes in atmospheric circulation, including synoptic‐scale and planetary wave activity in the mid‐latitudes. In this study, we investigate the heat and momentum exchange between the mean flow...
A cross-validated model output statistics (MOS) approach is applied to precipitation data from the high-resolution regional climate model CCLM for Europe. The aim is to remove systematic errors of simulated precipitation in decadal climate predictions. We developed a two-step bias-adjustment approach. In step one, we estimate model errors based on...
We investigate the projected precipitation changes of the 21st century in the Mediterranean area with a model ensemble of all available CMIP3 and CMIP5 data based on the four future scenarios A1B, A2, RCP4.5 and RCP8.5. The Mediterranean region represents a so-called hot spot of climate change. Season-based analyses are carried out for eight Medite...
Assessing paleo-climatic changes and the underlying driving mechanisms are an essential (and often poorly understood) first-step for understanding if natural variability in Earth's climate system from tectonic processes and orbital forcing could produce observed changes in surface processes. In this study, we take this first step of evaluating clim...
Initialized decadal climate predictions with coupled climate models are often marked by substantial climate drifts that emanate from a mismatch between the climatology of the coupled model system and the data set used for initialization. While such drifts may be easily removed from the prediction system when analyzing individual variables, a major...
This study investigates the projected precipitation changes of the 21st century in the Mediterranean area with a model ensemble of all available CMIP3 and CMIP5 data based on four different scenarios. The large spread of simulated precipitation change signals underlines the need of an evaluation of the individual general circulation models in order...
The heavily debris-covered Inylchek glaciers in the central Tian Shan are the largest glacier system in the Tarim catchment. It is assumed that almost 50% of the discharge of Tarim River are provided by glaciers. For this reason, climatic changes, and thus changes in glacier mass balance and glacier discharge are of high impact for the whole region...
Droughts can result in enormous impacts for environment, societies, and economy. In arid or semiarid regions with bordering high mountains, snow is the major source of water supply due to its role as natural water storage. The goal of this study is to examine the influence of snow water equivalent (SWE) on droughts in the United States and find lar...
A major task of climate science are reliable projections of climate change for the future. To enable more solid statements and to decrease the range of uncertainty, global general circulation models and regional climate models are evaluated based on a 2 × 2 contingency table approach to generate model weights. These weights are compared among diffe...
Some of the most obvious consequences of anthropogenic climate change are observed changes in the dates of the occurrence of phenological events. Most prominently, observations from the Northern Hemisphere’s extratropics indicate an earlier occurrence of spring events. Recent climate models include land surface schemes that provide representation o...
Assessing paleo-climatic changes across the Tibetan Plateau and the underlying driving mechanisms provides insights for the natural variability in the Earth's climate system in response to tectonic processes and global climate change. In this study, we use a high-resolution regional climate model to investigate various episodes of distinct climate...
Detection and attribution methods in climatological research aim at assessing whether observed climate anomalies and trends are still consistent with the range of natural climate variations or rather an indication of anthropogenic climate change. In this study, the authors pursue a novel approach by using discriminant analysis to enhance the distin...
One major challenge in climate-related issues is the lack of accurate high-resolution precipitation data on the part of observations and climate model simulations, imposing profound constraints on various impact studies, for instance in the fields of hydrology, glaciology, agronomy and hazard assessment. Here, we present a physical model approach f...
West African summer monsoon precipitation is characterized by distinct decadal variability. Due to its well-documented link to oceanic boundary conditions in various ocean basins it represents a paradigm for decadal predictability. In this study, we reappraise this hypothesis for several sub-regions of sub-Saharan West Africa using the new German c...
As main mode of interannual climate variability with worldwide teleconnections, El Niño-Southern Oscillation (ENSO) holds high ecological, economical and social relevance. So far, studies on future ENSO changes draw a rather incoherent picture across climate models and ENSO indices. Here, we assess climate change signals and respective uncertaintie...
This study is aimed at a better understanding of how upstream runoff formation affected the cropping intensity (CI: number of harvests) in the Aral Sea Basin (ASB) between 2000 and 2012. MODIS 250 m NDVI time series and knowledge-based pixel masking that included settlement layers and topography features enabled to map the irrigated cropland extent...
Climate protection and adaptive measures require reliable estimates of future climate change. Coupled global circulation models are still the most appropriate tool. However, the climate projections of individual models differ considerably, particularly at the regional scale and with respect to certain climate variables such as precipitation. Signif...
Climate change projections are subject to uncertainty arising from climate model deficiencies, unknown initial conditions and scenario assumptions. In the IPCC reports and many other publications climate changes and uncertainty ranges are usually displayed in terms of multi-model ensemble means and confidence intervals, respectively. In this study,...
The West African monsoon rainfall is essential for regional food production, and decadal predictions are necessary for policy-makers and farmers. However, predictions with global climate models reveal precipitation biases. This study addresses the hypotheses that global prediction biases can be reduced by dynamical downscaling with a multi-model en...
West African summer monsoon precipitation (WAM) is a promising candidate in the context of decadal predictability. WAM characteristics are closely connected to oceanic circulation patterns and specifically to long-term oscillations in Northern Hemisphere oceans. Besides ocean temperatures, West African climate is controlled by land-cover characteri...
The Mediterranean area is strongly vulnerable to future changes in temperature and precipitation, particularly concerning extreme events, and has been identified as a climate change hot spot. This study performs a comprehensive investigation of present-day and future Mediterranean precipitation extremes based on station data, gridded observations a...
Regional climate change arises from two processes which, in the real climate system, cannot be separated from each other: local radiative forcing and advection of air masses from regions which themselves have been subject to climate change. In this study, we present an experimental design based on a regional climate model allowing for the assessmen...
This study investigates whether a regional climate model (RCM) driven by a global general circulation model (GCM) in a nesting approach with observed atmospheric CO2 concentrations shows predictability for temperature and precipitation trends during 1961–1990 in the Mediterranean area, a region strongly influenced by large-scale circulation. Result...
[1] In this study, components of the Max Planck Institute Earth System Model (MPI-ESM) were used to explore how changes in lightning induced by climate change alter wildfire activity. To investigate how climate change alters global flash frequency simulations with the atmospheric general circulation model ECHAM6 were performed for the time periods...
Projected changes of extreme precipitation in the Mediterranean area up until the end of the 21st century are analysed by means of statistical downscaling. Generalized linear models are used as downscaling technique to assess different percentile-based indices of extreme precipitation on a fine-scale spatial resolution. In the region under consider...
This study focuses on the generation of reliable data for improving land and water use in Central Asia. An object-based remote sensing classification is applied and combined with the CropWat model developed by the Food and Agriculture Organization (FAO) to determine crop distribution and water requirements for irrigation of cotton and winter-wheat...
Climatic conditions such as relatively cold temperatures and dryness are able to limit malaria transmission. Climate change is therefore expected to alter malaria spread. A previous assessment of the potential impacts of climate change on the seasonality of malaria in Africa is revisited. Bias-corrected regional climate projections with a horizonta...
Western Africa has been discussed as a hot spot of environmental change. In the 1970ies and 80ies a drastic decrease in precipitation and severe droughts occurred in the Sahel. The degradation of the vegetation led to the desertification paradigm. But also in wetter regions south of the Sahel vegetation changes, mainly forest losses nhave happened....
Western Africa has been discussed as a hot spot of environmental change. In the 1970ies and 80ies a drastic decrease in precipitation and severe droughts occurred in the Sahel. The degradation of the vegetation led to the desertification paradigm. But also in wetter regions south of the Sahel vegetation changes, mainly forest losses have happened....
A statistical–dynamical downscaling (SDD) approach is applied to determine present day and future high-resolution rainfall distributions in the catchment of the river Aksu at the southern slopes of the Tienshan Mountains, Central Asia. First, a circulation weather type (CWT) classification is employed to define typical lower atmospheric flow regime...
The behaviour of precipitation and maximum temperature extremes in the Mediterranean area under climate change conditions is analysed in the present study. In this context, the ability of synoptic downscaling techniques in combination with extreme value statistics for dealing with extremes is investigated. Analyses are based upon a set of long-term...
The assessment of present-day and future climate change is of crucial socio-economic and ecological importance but, at the same time, subject to a variety of uncertainty factors that are partly inherent to the climate system. This implies that a statement about the Earth's future climate is definitely a probabilistic one. From a scientific point of...
Vegetation cover is a crucial component of the Earth’s climate system but, still, our understanding of the mechanisms governing the reciprocal influence between atmosphere and vegetation is limited. In this study, we investigate the unilateral atmospheric impact on vegetation cover in tropical and northern Africa, differentiated into regions with d...
Background Weather and climate play an important role in the spread of malaria. Suitable weather conditions for malaria are found in sub-Saharan Africa, where most of the worldwide malaria cases and deaths are found. For this reason, integrated weather-disease malaria models are useful tools to project the malaria future and to provide monthly-tose...
Regional climate models represent a promising tool to assess the regional dimension of future climate change and are widely used in climate impact research. While the added value of regional climate models has been highlighted with respect to a better representation of land-surface interactions and atmospheric processes, it is still unclear whether...
This study elucidates the effects of the projected climate variables and CO2 on yam yield in relation to three major soils in the Upper Ouémé basin (Benin Republic) on yam (Dioscorea alata) yield. The impact of the SRES climate scenarios A1B and B1 based on the output of the GCM ECHAM5 downscaled with the REMO model and the A1B scenario output of t...
The projected climate change will probably alter the range and
transmission potential of malaria in Africa. The potential impacts of
climate change on the malaria distribution is assessed for tropical
Africa. Bias-corrected regional climate projections with a horizontal
resolution of 0.5° are used from the Regional Model (REMO),