A hydraulic module is presented to simulate stomatal and non-stomatal impacts of drought stress in trees, including sapwood- and leaf senescence.
With an increasing probability of extreme events, their significance for agricultural production has also grown. Ecosystem models enable us to integrate current knowledge about plant-climate interactions with climate change scenarios. Since impacts of weather extremes differ depending on crop, intensity, length, and timing, a process-based approach is necessary to quantify to what extent...
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...
Aerosol closure studies shall compare aerosol microphysical and optical parameters derived simultaneously via in-situ and remote sensing instruments. Hence, a successful closure explains the radiative forcing of the aerosol, which is unfortunately still only roughly constrained in our climate system.
Due to our incomplete knowledge on the scattering of arbitrarily shaped particles, such a...
Atmospheric increases in CO2 and CH4 due to anthropogenic emissions are the dominant factor in global warming. Reliable ground-based measurements of these greenhouse gases (GHGs) are of utmost importance for the validation of space borne GHG observations. Therefore, the COllaborative Carbon Column Observing Network (COCCON) was initiated by KIT in cooperation with ESA. The instrumental...
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...
The Asian summer monsoon is an effective transport pathway for aerosols and gas phase species into the upper troposphere and lower stratosphere. Model simulations by CLaMS (Chemical Lagrangian Model of the Stratosphere) can show the transport and mixing of aerosol particles into the extratropical UTLS by making use of artificial tracers of air mass origin. Occasionally, CLaMS results show...
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...
The GNSS radio occultation (RO) technique has been established successfully during the previous two decades. It evolved into a valuable observation tool for precise atmospheric and ionospheric vertical profiling. Until today, there are about 18 million RO recordings available.
GNSS RO signals are very sensitive to vertical electron density gradients in the Earth’s ionosphere. They become...
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....
We introduce the Palau Atmospheric Observatory as an ideal site to detect changes in atmospheric composition and dynamics above the tropical West Pacific, the main global entry point for air masses into the stratosphere in boreal winter. The comprehensive set-up of the site consists of an aerosol and cloud lidar, a sun photometer, a Fourier Transform Infrared Spectrometer and a ground station...
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)...
