Water vapor plays an important role in many aspects of the climate system, by affecting radiation, cloud formation, atmospheric chemistry and dynamics. Even the low water vapor content of the stratosphere provides an important climate feedback, but current climate models have a substantial moist bias in the lowermost stratosphere. Here we present strong sensitivity of the atmospheric...
This presentation reviews the recent developments in the model system ICON-ART (ICOsahedral Nonhydrostatic model with Aerosols and Reactive Trace gases) with respect to the detailed treatment of emissions, chemistry, aerosol dynamics and aerosol-radiation-cloud interactions from large eddy to global scale. The results show that the ability of the model to precisely simulate cross-scale...
Climate services for adaptation heavily depend on regional to local information about future developments of the climate. One tool to translate results of coarse global climate models from CMIP into local information is dynamical downscaling with regional climate models. The Climate Service Center Germany (GERICS) has been developing its own regional climate model REMO for many years in order...
The influence of increased model resolution and tailored settings on the reproduction of heat waves is addressed. Therefore, different regional climate model outputs for Germany and the near surroundings between 1980–2009 were evaluated. This included outputs of a six-member EURO-CORDEX ensemble with 12.5 km resolution and outputs from a high resolution (5 km) WRF run, which was especially...
A hydraulic module is presented to simulate stomatal and non-stomatal impacts of drought stress in trees, including sapwood- and leaf senescence.
Atmospheric aerosols degrade air quality on regional and global scales and play a significant role in climate change. Depending on their composition, aerosols affect the energy budget of the Earth's atmosphere by scattering and absorbing solar radiation (direct effect) and by influencing the reflective properties of clouds, their lifetime, and precipitation formation (indirect effects)....
Atmospheric tides are thermally excited oscillations induced mainly by solar radiation absorption by ozone and water vapor, and latent heat release due to deep convection. We study atmospheric tides by their manifestations, which instigate high-frequency harmonics in atmospheric density and its spatial gradients. These mass variations excite variations in the gravity field which can be...
The ICOsahedral Non-hydrostatic (ICON) modelling system was developed by DWD and MPI-M to study various weather forecast and climate applications. The Aerosol and Reactive Trace Gases (ART) submodule, integrated within ICON, was contributed by KIT to analyze composition interactions in the atmosphere. ICON-ART model configurations employ flexible options for horizontal and vertical grids and...
Variations in the strength and speed of the solar wind related to solar coronal holes, coronal mass ejections, or corotating interaction regions, can initiate geomagnetic storms in the Earth’s magnetosphere. These enhance electron fluxes and energies in the radiation belts and ring currents, but also precipitation of electrons over a large energy range from keV to MeV into the high-latitude...
In order to investigate the driving of the QBO a high-resolution, convection-permitting run of the ICON model with 5km grid spacing was performed. We analyze the GWs in the model by applying a small-volume sinusoidal fit. By using a cascade of cube sizes, horizontal wavelengths of 150km - 2000km are addressed. This acts as a compromise between spectral resolution and spatial location. Phase...
Severe biomass burning events are predicted to become more frequent as well as intense in future due to the rapidly changing climate. These will affect also higher atmospheric layers from the upper troposphere to even the mid-stratosphere in extreme cases. In this important region for Earth’s radiative budget, aerosols as well as ozone are influenced by the mix of different trace-gases. Remote...
The European Research Infrastructure IAGOS utilizes state-of-the-art instruments onboard passenger aircraft to measure trace gases, aerosols, and cloud particles. The vertical profiles of climate- and air quality-relevant species (O3, CO, NO, NO2, NOX, CO2, CH4, and H2O/relative humidity) near airports in highly populated urban areas (e.g., Frankfurt (Main) and Paris) complement surface-based...
Vertical profiles of temperature and trace gase concentrations, including O3,H2O, CH4, N2O, CO, HNO3, NO2, NO, HNO4, BrONO2, N2O5,PAN, ClONO2, ClO, CH3Cl, COCl2, CFC-11, CFC-12, HCFC-22, CFC-113, C2H6, C2H2, HCN, OCS, SF6, and others, as well as several aerosol products, are based on improved level-1 calibration and level-2 processing of MIPAS measurements. This global data set provided by...
The changing-atmosphere infra-Red Tomography (CAIRT) mission candidate for ESA's earth explorer 11 proposes a limb imager for a spatial sampling of 25 km across-track, 50 km along-track, and 1 km in the vertical. From this, we expect to infer directional GW momentum fluxes, as well as trace gases, from the tropopause to 70 km or higher. This will allow longstanding scientific questions to be...
GHG inventories are important for climate policy. For the agricultural sector, the IPCC defines a Tier system to be followed for UNFCCC reporting. The simplest and most commonly used Tier 1 approach is based on default emission factors, while the most complex and rarely used Tier 3 approach is based on the best available science using process models. Here we present ongoing work on using the...
In recent years our knowledge of the atmosphere and the underlying processes has grown a lot. However, there are still many open questions. One research field of high complexity is the atmospheric aerosol, and related to it, the topic of aerosol formation, processing, and aging.
In addition to natural sources of aerosol particles like secondary aerosol formation from biogenic precursors,...
The ICOsahedral Non-hydrostatic (ICON) modelling system was originally developed by DWD and MPI-M for a range of weather (forecast) and climate applications. An Aerosols and Reactive Tracers (ART) module was added by KIT to enable a comprehensive assessment of composition interactions within the atmospheric domain. Recognising that atmospheric processes happen on a multitude of temporal and...
Tropospheric ozone is harmful to human health and ecosystems. The mixing ratio of ground-level ozone at any given location is influenced by a wide array of factors including local chemical production and long-range transport over intercontinental distances. Here we present a system for the attribution of ground-level ozone to its emitted precursors and use it to show how ozone precursor...
In West Africa, the effects of climate change are already being felt, with increases in the intensity of extreme rainfall observed in rain gauge and satellite datasets over the last few decades. Given the region’s high vulnerability, an understanding of how extreme rainfall events may change further in the future climate is vital.
West Africa receives the majority of its rainfall via...
Severe thunderstorms over South America are among the most intense worldwide. However, due to low population density and limited research activities their distribution and characteristics are less understood than in other regions, although this information is crucial, for instance for insurance companies. We use a well-established hail hazard modeling approach, which has already been used over...
The Swabian MOSES field campaign investigated atmospheric drivers responsible for the frequently observed initiation of severe thunderstorms between the Black Forest and the Swabian Jura. A suspected triggering mechanism is lee-side flow convergence, but detailed observational evidence of this phenomena is largely missing. To gain insight into flow characteristics, first measurements with a...
Air pollution from South Asia, in particular heavily polluted Indo-Gangetic Plain (IGP) impact public health, ecosystems, and climate not only in the region but also the downwind regions like the Himalayan and Tibetan Plateau mountain regions. According to the latest IPCC report this region is still one of the least studied regions in the world in terms of atmospheric observations and many air...
The impact of the changing climate on cloud properties is still not fully understood. To improve our knowledge and thus the representation of clouds in models, the goal of ACTRIS (Aerosol, Clouds and Trace gases Research Infrastructure) Topical Center CIS (Cloud In Situ) is to establish a monitoring network for key cloud properties.
CIS consists of four units to measure (1) ice nucleating...
Emission data as the main input to air quality forecast models introduce large uncertainties. These data originate from emission inventories that provide estimates of spatially distributed emissions. The impact of fixed temporal distribution functions in contrast to variable societal behavior and meteorological implications are rarely considered. To evaluate the annual emission totals of...
Field, source and kinetic isotope analyzes are combined with a Lagrangian approach of receptor modeling to separate chemical degradation from changes related to source strength. Eventually, the local vs. long-range transport, as well as biogenic vs anthropogenic contribution of investigated pollutants can be differentiated.
We present a new empirical model of electron density in the ionosphere, which is a crucial parameter impacting radio signal propagation and GNSS systems. Our model utilizes radio occultation profiles obtained from CHAMP, GRACE, and COSMIC missions. We assume a linear decrease in scale height with altitude and consider four parameters: F2-peak density and height (NmF2 and hmF2), as well as the...
While clouds are a key component of the climate system, cloud processes and aerosol-cloud interactions are still poorly understood. This is also the case for fog and low stratus clouds, which are particularly affected by aerosol emissions at the surface and by land-atmosphere interactions.
In this study, Extreme gradient boosting (XGBoost) and xAI methods such as SHapley Additive...
Climate models are limited in their ability to accurately represent highly variable atmospheric phenomena on small scales. Downscaling techniques are employed to resolve fine-scale physical processes and reveal local impacts.
We present spateGAN, a conditional generative adversarial network for spatio-temporal precipitation downscaling in Germany. As a so-called video-superresolution...
As a novel remote sensing approach, GNSS Reflectometry (GNSS-R) offers unique potential for characterizing the complex Earth system with its different spheres on various spatiotemporal scales with numerous geoscientific applications. With the continuous increase of space-borne GNSS-R observation data volume, Artificial Intelligence (AI) offers an alternative data-driven direction of achieving...
Aerosol-cloud interaction remains the biggest source of uncertainty in radiative forcing estimations. The radiative properties of clouds are dependent on its phase, i.e. whether clouds consist of ice crystals, liquid droplets or a mixture of both. Ice-nucleating particles (INPs) faciliate the nucleation of supercooled cloud droplets at temperatures above -35 °C, thus promoting the transition...
Computational efforts for the calculation of chemical reactions are about 30% of the total resource requested to run simulations involving climate models. Finding alternatives to speed up the calculation of the chemistry module is then a crucial task.
Recent studies show that the calculation of the Jacobian matrix is the most computationally demanding part of the related ODEs and then...
In order to estimate the frequency of the precipitation event responsible for the devastating flood that struck western Germany and surrounding areas in mid-July 2021. The extremeness of the various precipitation events occurred in the last 71 years (1951-2021) was estimated utilizing the recently developed cross space-time scale weather extremity index xWEI. The probability analysis based on...
Clouds play a major role in the global radiative budget. Microphysical properties, such as the shape (or habit), of individual ice crystals define their optical properties and consequently affect the cloud radiative effect. Therefore, a better understanding of ice crystal morphology is crucial in improving climate modelling.
With the Particle Habit Imaging and Polar Scattering (PHIPS)...
Water fluxes between the land surface and the atmosphere are intricately linked. Understanding, measuring and modelling the underlying processes requires crossing spatiotemporal scales and relies on the availability, findability, accessibility, interoperability and reusability (FAIRness) of relevant Earth System Science data.
We actively support data management through different initiatives....
Regional air quality has been historically documented by ground-level monitoring networks around the world. However, such monitoring infrastructures come with high costs and very localized measurements that are limited to ground observations. Higher altitude measurements (up to 1 km) are of great interest for understanding the mixing and transport of pollutants. Unmanned aerial vehicles (UAVs)...
In the light of lacking progress in reaching the climate protection goals, plans for actively cooling Earth`s climate gain increasing public attention. The contribution is intended to foster internal discussions by introducing the scientific concepts of some of these approaches and highlighting open issues and side effects of climate interventions with a focus on Cirrus Cloud Thinning (CCT) in...
Humans have altered not only the Earth's atmosphere, but also changed the face of our planet - its surface. About three quarters of the Earth's surface has been altered by humans during the last millennium. This has significantly altered biogeochemical cycles and exchange processes between the 'critical zone' and the atmosphere.
Here I will show examples how those processes can be quantified...
The past decade has seen growing interest in climate engineering as less of a dubious last resort than a reasonable supplement to emissions reduction. This interest finds wide expression—in high-level reports, massive capital investments, best-selling novels, and scholarship that urges context upon engineering promises (cf. “transboundary effects,” “moral hazard). It seems the question is no...
The occurrence of heterogeneous chlorine activation through the presence of aerosol particles could cause stratospheric ozone destruction in summer. This chemical process requires low temperatures and is accelerated by an enhancement of the stratospheric water vapour and sulphate amount. We report on these processes based on the results of the Geoengineering Large Ensemble Simulations (GLENS)...
Process-based hydrological and dynamical meteorologic models are highly developed tools that describe meticulously the physical properties and dependencies of their respective realms. However, meso-scale meteorological models often overlook lateral water transport at the land surface and below, while hydrological models typically lack representations of atmospheric dynamics. Fully coupled...
Large and surprising extremes emerge more often from heavy-tailed distributions compared to the light-tailed distributions. Heavy-tailed distributions are characterized by a right tail which decays slower than the exponential one. Distributions of flood and precipitation records in Germany often show heavy-tail behavior. For sound flood risk management, controls of heavy-tail behavior need to...
This study presents the development of a non-stationary gridded weather generator for Central Europe region conditioned on large-scale weather circulation patterns and the regional average temperature. The generator is then employed to downscale the future meteorological fields such as precipitation and temperature for the region accounting their variability. An ensemble of the nine most...
