Stephanie Fiedler

Universität Heidelberg · Institute of Environmental Physics

We evaluate trends in terrestrial water storage over 1950–2100 in CMIP6 climate models against a new global reanalysis from assimilating GRACE and GRACE-FO satellite observations into a hydrological model. To account for different timescales in our analysis, we select regions in which the influence of interannual variability is relatively small and...

• Low renewable power production events occur more frequently in summer with future installed capacities. • Stationary weather patterns show a prevalent role in prolonged low production events. • Stationary cyclonic patterns are prevalent in summer events and anticyclonic patterns in winter events. • Relation between the direction of cross-border t...

The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) was endorsed by the Coupled-Model Intercomparison Project 6 (CMIP6) and was designed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. AerChemMIP provided the first consistent calculation of Effective Radiative Forcing (ERF) for a wide range of...

The Atacama Desert is amongst the driest places on Earth yet large dust outbreaks seem rare. We present the first quantitative assessment of dust events in the Atacama for 1950–2021 based on station observations. A total of 1920 dust days were recorded with less than 10% being classified as dust storms. We calculated the wind speeds at 5%, 25% and...

Plain Language Summary El Niño‐Southern Oscillation (ENSO) is the dominant mode of climate variability with far‐reaching impacts. El Niños, the warm events, occur in different flavors. In particular extreme Eastern Pacific (EP) El Niño events are associated with heavy precipitation events and extreme droughts, thus cause large socio‐economic impact...

Low‐level jets (LLJs), vertical profiles with a wind speed maxima in the lowest hundred meters of the troposphere, have multiple impacts in the Earth system, but a global present‐day climatology based on contemporary data does not exist. We use the spatially and temporally complete data set from ERA5 reanalysis to compile a global climatology of LL...

The climate science community aims to improve our understanding of climate change due to anthropogenic influences on atmospheric composition and the Earth's surface. Yet not all climate interactions are fully understood, and uncertainty in climate model results persists, as assessed in the latest Intergovernmental Panel on Climate Change (IPCC) ass...

Weather causes extremes in photovoltaic and wind power production. Here we present a comprehensive climatology of anomalies in photovoltaic and wind power production associated with weather patterns in Europe considering the 2019 and potential 2050 installations, and hourly to ten-day events. To that end, we performed kilometer-scale numerical simu...

Mineral dust is one of the most abundant atmospheric aerosol species and has various far‐reaching effects on the climate system and adverse impacts on air quality. Satellite observations can provide spatio‐temporal information on dust emission and transport pathways. However, satellite observations of dust plumes are frequently obscured by clouds....

We investigate the drivers of global and regional changes in the potential for photovoltaic (PV) power production from the pre-industrial (1850) to present-day (1985-2014) and until the end of the century (2071-2100), based on output from the Coupled Model Intercomparison Project phase six (CMIP6). Our assessment separates regional contributions fr...

Low-level jets (LLJs), wind speed maxima in the lower troposphere, impact several environmental and societal phenomena. In this study we take advantage of the spatially and temporally complete meteorological dataset from ERA5 to present a global climatology of LLJs taking into consideration their formation mechanisms, characteristics and trends dur...

Mineral dust is one of the most abundant atmospheric aerosol species and has various far-reaching effects on the climate system and adverse impacts on air quality. Satellite observations can provide spatio-temporal information on dust emission and transport pathways. However, satellite observations of dust plumes are frequently obscured by clouds....

Survival in hyperarid deserts is a major challenge for plant life, requiring the development of evolutionary strategies. The Atacama Desert presents harsh conditions such as limited rainfall, crusted soils, high soil salinity, high altitude, and intense solar radiation. These conditions, together with paleoclimatic variability since the past millio...

This planetary boundaries framework update finds that six of the nine boundaries are transgressed, suggesting that Earth is now well outside of the safe operating space for humanity. Ocean acidification is close to being breached, while aerosol loading regionally exceeds the boundary. Stratospheric ozone levels have slightly recovered. The transgre...

Numerical weather prediction models operate on grid spacings of a few kilometers, where deep convection begins to become resolvable. Around this scale, the emergence of coherent structures in the planetary boundary layer, often hypothesized to be caused by cold pools, forces the transition from shallow to deep convection. Yet, the kilometer-scale r...

In mid-March 2021, one of the strongest dust storms of the last decade hit East Asia with adverse impacts on socio-economic activities and loss of life. The aim of this study is to assess the atmospheric dynamics involved in the temporal evolution of the Mongolian extra-tropical cyclone driving the dust event in different dust source regions in Eas...

The Radiative Forcing Model Intercomparison Project (RFMIP) allows estimates of effective radiative forcing (ERF) in the Coupled Model Intercomparison Project phase six (CMIP6). We analyze the RFMIP output, including the new experiments from models that use the same parameterization for anthropogenic aerosols (RFMIP‐SpAer), to characterize and bett...

Land degradation is a cause of many social, economic, and environmental problems. Therefore identification and monitoring of high-risk areas for land degradation are necessary. Despite the importance of land degradation due to wind and water erosion in some areas of the world, the combined study of both types of erosion in the same area receives re...

Plain Language Summary Low‐level jets (LLJ) are strong winds that occur in the lowest few hundred meters of the atmosphere. Their influence ranges from transporting moisture and pollutants, to impacts on aviation safety and wind power production. LLJs typically occur at night, when the surface strongly cools, for example, during cloud‐free skies. N...

This study investigates the seasonal variability of the cloud radiative effects (CREs) over Congo Basin (CB) using 15-year observations from Clouds and the Earth’s Radiant Energy System (CERES) Energy Budget and Filled (EBAF) Ed4.1 level 3b dataset involving CERES and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board Terra...

The climate science community aims to improve our understanding of climate change due to anthropogenic influences on atmospheric composition and the Earth's surface. Yet not all climate interactions are fully understood and diversity in climate model experiments persists as assessed in the latest Intergovernmental Panel on Climate Change (IPCC) ass...

Geomorphic and sedimentologic data indicate that the climate of today's hyper-arid Atacama Desert (northern Chile) was more humid during the mid-Pliocene to Late Pliocene. The processes, however, leading to increased rainfall in this period are largely unknown. To uncover these processes we use both global and regional kilometre-scale model experim...

We present the first observational evidence for convectively generated cold pools (CP) as driving mechanism for low-level jets (LLJ). Our findings are based on a unique campaign dataset that allowed us to perform a systematic assessment of the process. During the three-month campaign in Germany, 4.7\% of all identified LLJ profiles were connected t...

Land degradation is a cause of many social, economic, and environmental problems. Therefore identification and monitoring of high-risk areas for land degradation are necessary. Despite the importance of land degradation, the topic receives often relatively little attention. The present study aims to create a land degradation map in terms of soil er...

This study investigates the mesoscale dynamics involved in the 8–11 October 2008 unseasonably strong African dust episode, during which dust was transported to the Iberian Peninsula (IP). We employ observational datasets and a high‐resolution Weather Research and Forecasting model coupled with Chemistry simulations. The analysis shows that during 0...

Geomorphic and sedimentologic data indicate that the climate of today’s hyper-arid Atacama Desert (Northern Chile) was more humid during the Mid-to Late Pliocene. The processes, however, leading to increased rainfall in this period are largely unknown. To uncover these processes we use both global and regional kilometre-scale model experiments for...

Solar radiation received at the Earth's surface (Rs) is comprised of two components, the direct radiation (Rd) and the diffuse radiation (Rf). Rd, the direct beam from the sun, is essential for concentrated solar power generation. Rf, scattered by atmospheric molecules, aerosols, or cloud droplets, has a fertilization effect on plant photosynthesis...

A challenge of an energy system that nowadays more strongly depends on wind power generation is the spatial and temporal variability in winds. Nocturnal low-level jets (NLLJs) are typical wind phenomena defined as a maximum in the vertical profile of the horizontal wind speed. A NLLJ has typical core heights of 50–500 m a.g.l. (above ground level),...

Doppler wind lidars (DWLs) have increasingly been used over the last decade to derive the mean wind in the atmospheric boundary layer. DWLs allow the determination of wind vector profiles with high vertical resolution and provide an alternative to classic meteorological tower observations. They also receive signals from altitudes higher than a towe...

A challenge of an energy system, that nowadays more strongly depends on wind power generation, is the spatial and temporal variability of winds. Nocturnal low-level jets (NLLJ) are typical wind phenomena defined as a maximum in the vertical profile of the horizontal wind speed. A NLLJ has typical core heights of 50–500 m above ground level (a.g.l.)...

Doppler wind lidars (DWLs) have increasingly been used over the last decade to derive the mean wind in the atmospheric boundary layer. DWLs allow the determination of wind vector profiles with high vertical resolution and provide an alternative to classic meteorological tower observations. They also receive signals from higher altitudes than a towe...

The Atacama Desert is one of the driest and oldest deserts on Earth. The extreme scarcity of rainfall and hence very limited runoff, paired with endorheism, allow sediments and deposited materials to largely remain in the pedosphere and for long periods of time, thereby leading to the generation of thick sediment, salt, and soil deposits. Aerosols...

Despite the implication of aerosols for the radiation budget, there are persistent differences in data for the aerosol optical depth (τ) for 1998–2019. This study presents a comprehensive evaluation of the large‐scale spatio‐temporal patterns of mid‐visible τ from modern data sets. In total, we assessed 94 different global data sets from eight sate...

Model estimates of expected photovoltaic (PV) power production rely on accurate irradiance data. Reanalysis and satellite products freely provide irradiance data with a high temporal and spatial resolution including locations for which no ground-based measurements are available. We assess differences in such gridded irradiance data and quantify the...

Knowledge of the spatial distribution of dust aerosols and their effects on crops is important for policy formulation and food security. This study aims to investigate the impact of dust source susceptibility areas (DSSA) on the loss of agricultural crop and corresponding water consumption in terms of Water Footprint in the Great Salt Desert, Iran....

The pandemic in 2020 caused an abrupt change in the emission of anthropogenic aerosols and their precursors. We estimate the associated change in the aerosol radiative forcing at the top of the atmosphere and the surface. To that end, we perform new simulations with the CMIP6 global climate model EC-Earth3. The simulations use the here newly create...

Lockdowns to avoid the spread of COVID-19 have created an unprecedented reduction in human emissions. While the country-level scale of emissions changes can be estimated in near real time, the more detailed, gridded emissions estimates that are required to run general circulation models (GCMs) of the climate will take longer to collect. In this pap...

Most air quality stations in Spain exceeded the European Union’s daily PM10 limit due to the February 2016 Saharan dust outbreak, which resulted from two successive dust storms in Northwest Africa. This study identifies the meso-β/meso-γ-scale dynamical processes responsible for developing these dust storms using observations and high-resolution We...

Many nations responded to the corona virus disease-2019 (COVID-19) pandemic by restricting travel and other activities during 2020, resulting in temporarily reduced emissions of CO2, other greenhouse gases and ozone and aerosol precursors. We present the initial results from a coordinated Intercomparison, CovidMIP, of Earth system model simulations...

We show how changes in the global distribution of anthropogenic aerosols favor different spatial patterns in the North Atlantic sea-surface temperature (NASST). The NASSTs largely show the expected decrease associated with the anthropogenic aerosols in the 1970s, but also an unusual warming response in the eastern sub-polar gyre, the region of the...

Spring 2020 broke sunshine duration records across Western Europe. The Netherlands recorded the highest surface irradiance since 1928, exceeding the previous extreme of 2011 by 13%, and the diffuse fraction of the irradiance measured a record low percentage (38%). The coinciding irradiance extreme and a reduction in anthropogenic pollution due to C...

Feedbacks play a fundamental role in determining the magnitude of the response of the climate system to external forcing, such as from anthropogenic emissions. The latest generation of Earth system models includes aerosol and chemistry components that interact with each other and with the biosphere. These interactions introduce a complex web of fee...

Lockdowns to avoid the spread of COVID-19 have created an unprecedented reduction in human emissions. While the country-level scale of emissions changes can be estimated in near-real-time, the more detailed, gridded emissions estimates that are required to run General Circulation Models (GCM) of the climate will take longer to collect. In this pape...

This study presents the meso-β/γ scale dynamical features involved in an extreme African dust outbreak, which occurred during 20-21 February 2016 over the Iberian Peninsula (IP), the southwest corner of Europe. During this episode, nearly 90% of the air quality stations in Spain exceeded the European Union's PM10 daily limit. We used observations a...

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.atmosenv.2020.117932. The duplicate article has therefore been withdrawn.. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdra...

We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multiscale observations and the Weather Research and Forecasting model Coupled with Chemistry simulations. The analyses indicate that the dust storm was initiated...

Spring 2020 broke sun duration records across western Europe. The Netherlands recorded the highest surface irradiance since 1928, exceeding the previous extreme by 13 %, and the diffuse fraction of the total irradiance measured a record low percentage (38 %). The coinciding irradiance extreme and a reduction in anthropogenic pollution due to the CO...

The effective radiative forcing, which includes the instantaneous forcing plus adjustments from the atmosphere and surface, has emerged as the key metric of evaluating human and natural influence on the climate. We evaluate effective radiative forcing and adjustments in 17 contemporary climate models that are participating in the Coupled Model Inte...

The increasing use of wind and solar power requires interventions to balance the associated variability in energy production. One option to reduce the costly interventions is to exploit the natural de-correlation of wind and irradiance. This study characterises the balancing potential of the natual variability in wind and photovoltaic energy produc...

We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multi-scale observations including ship data and Weather Research and Forecasting model Coupled with Chemistry simulations. The analyses indicate that the dust st...

Based on the numerical weather prediction model COSMO of Germany's national meteorological service (Deutscher Wetterdienst, DWD), regional reanalysis datasets have been developed with grid spacing of up to 2 km. This development started as a fundamental research activity within the Hans-Ertel-Centre for Weather Research (HErZ) at the University of...

The representation of tropical precipitation is evaluated across three generations of models participating in the Coupled Model Intercomparison Project (CMIP), phases 3, 5 and 6. Compared to state-of-the-art observations, improvements in tropical precipitation in the CMIP6 models are identified for some metrics, but we find no general improvement i...

The analysis of three extreme African dust outbreaks over the Iberian Peninsula (IP) shows that a double Rossby wave breaking (RWB) process in the polar jet (PJ) creates the conditions for dust storm formation over subtropical deserts in North Africa and the restructuring of upper-level air flows critical for the dust transport poleward after ablat...

We Simulated dust AOD using the WRF-CHEM model over the Sahara Desert. The emitted dust was not visible clearly in MSG-SEVIRI dust RGB during this episode to follow the evolution and long-range transport. This simulation has shown that the WRF-CHEM model can serve as an essential tool in operational dust forecasting.

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of...

Abstract. Feedbacks play a fundamental role in determining the magnitude of the response of the climate system to external forcing, such as from anthropogenic emissions. The latest generation of Earth system models include aerosol and chemistry components that interact with each other and with the biosphere. These interactions introduce a complex w...

Abstract. The effective radiative forcing, which includes the instantaneous forcing plus adjustments from the atmosphere and surface, has emerged as the key metric of evaluating human and natural influence on the climate. We evaluate effective radiative forcing and adjustments in 13 contemporary climate models that are participating in CMIP6 and ha...

a strong continental-scale Saharan dust outbreak was observed in satellite imagery over Mindelo, Cape Verde, located about 650 km off the coast of Senegal in West Africa. Horizontal visibility was reduced to 1100 m leading to major disruptions of the local air traffic. Dust mobilization was already observed over the foothills of the Saharan Atlas M...

a strong continental-scale Saharan dust outbreak was observed in satellite imagery over Mindelo, Cape Verde, located about 650 km off the coast of Senegal in West Africa. Horizontal visibility was reduced to 1100 m leading to major disruptions of the local air traffic. Dust mobilization was already observed over the foothills of the Saharan Atlas M...

A multi-scale atmospheric dynamics of a Saharan dust outbreak over Mindelo, Cape Verde Islands: A case study of early November 2017

This study assesses the change in anthropogenic aerosol forcing from the mid-1970s to the mid-2000s. Both decades had similar global-mean anthropogenic aerosol optical depths but substantially different global distributions. For both years, we quantify (i) the forcing spread due to model-internal variability and (ii) the forcing spread among models...

A new release of the Max Planck Institute for Meteorology Earth System Model version 1.2 (MPI-ESM1.2) is presented. The development focused on correcting errors in and improving the physical processes representation, as well as improving the computational performance, versatility, and overall user friendliness. In addition to new radiation and aero...