A5017063726- Atmospheric Ozone and Climate
- Meteorological Phenomena and Simulations
- Atmospheric aerosols and clouds
- Ionosphere and magnetosphere dynamics
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Wind and Air Flow Studies
- Climate variability and models
- Geophysics and Gravity Measurements
- Fluid Dynamics and Turbulent Flows
- Seismic Waves and Analysis
- Wind Energy Research and Development
- Solar and Space Plasma Dynamics
- Advanced Aircraft Design and Technologies
- Tropical and Extratropical Cyclones Research
- Aeolian processes and effects
- Fluid Dynamics and Vibration Analysis
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Aerodynamics and Fluid Dynamics Research
- Vehicle emissions and performance
- Geophysics and Sensor Technology
- Planetary Science and Exploration
- Aerospace and Aviation Technology
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2015-2024
Ludwig-Maximilians-Universität München
2021
NSF National Center for Atmospheric Research
2016-2020
Dienstleistungszentrum Ländlicher Raum
2020
Northwest Research Associates
2020
United States Naval Research Laboratory
2016-2019
Czech Academy of Sciences, Institute of Atmospheric Physics
1994-2019
G & A Technical Software (United States)
2019
Yale University
2019
Colorado Sleep Institute
2018
Abstract The Midlatitude Cirrus experiment (ML-CIRRUS) deployed the High Altitude and Long Range Research Aircraft (HALO) to obtain new insights into nucleation, life cycle, climate impact of natural cirrus aircraft-induced contrail cirrus. Direct observations properties their variability are still incomplete, currently limiting our understanding clouds’ on climate. Also, dynamical effects clouds feedbacks not adequately represented in today’s weather prediction models. Here, we present...
Abstract The North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) explored the impact of diabatic processes on disturbances jet stream their influence downstream high-impact weather through deployment four research aircraft, each with a sophisticated set remote sensing in situ instruments, coordinated suite ground-based measurements. A total 49 flights were performed, including, for first time, aircraft: German High Altitude Long Range Research Aircraft (HALO), Deutsches...
Abstract The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic other sources regions of dissipation at high altitudes. core DEEPWAVE field phase took place May through July 2014 using a comprehensive suite airborne ground-based instruments providing measurements Earth’s surface ∼100 km. Austral winter chosen observe deep GW propagation based on South Island, New Zealand, provide access the Zealand Tasmanian...
Abstract During spring 2020, the COVID-19 pandemic caused massive reductions in emissions from industry and ground airborne transportation. To explore resulting atmospheric composition changes, we conducted BLUESKY campaign with two research aircraft measured trace gases, aerosols, cloud properties boundary layer to lower stratosphere. From 16 May 9 June performed 20 flights early lockdown phase over Europe Atlantic Ocean. We found up 50% nitrogen dioxide concentrations urban areas GOME-2B...
Abstract. Powering aircraft by sustainable aviation fuels (SAFs) is a pathway to reduce the climate impact of lowering lifecycle CO2 emissions and reducing ice crystal numbers radiative forcing from contrails. While effect SAF blends on contrails has been measured previously, here we present novel measurements particle emission 100 % combustion. During ECLIF3 (Emission CLimate Impact alternative Fuels) campaign, collaboration between Deutsches Zentrum für Luft- und Raumfahrt (DLR), Airbus,...
The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) instrument measured stratospheric temperatures trace species concentrations with high precision spatial resolution during two missions. measuring technique is infrared limb‐sounding of optically thin emissions. In a general approach, we investigate applicability to measure gravity waves (GWs) in retrieved temperature data. It shown that GWs wavelengths order 100–200 km horizontally can be detected. results are...
A comprehensive investigation of polar stratospheric clouds was performed on 25 January 2000 with instruments onboard a balloon gondola flown from Kiruna, Sweden. Cloud layers were repeatedly encountered at altitudes between 20 and 24 kilometers over wide range atmospheric temperatures (185 to 197 kelvin). Particle composition analysis showed that large fraction the cloud composed nitric acid trihydrate (NAT) particles, containing water molar ratio 3:1; this confirmed these long-sought solid...
Ten years of high‐resolution radiosonde data are contrasted with fifteen ECMWF reanalysis (ERA) to explore the tropopause region above two midlatitude stations (Munich and Stuttgart) in Southern Germany. We present time‐averaged vertical profiles several meteorological parameters relative tropopause. A strong mean inversion at is evident from a extension about 2 km temperature increase 4 K. The impact definition on strength this discussed as well relevance baroclinic eddies forming it....
Abstract. A PSC was detected on 6 February 2003 in the Arctic stratosphere by in-situ measurements onboard high-altitude research aircraft Geophysica. Low number densities (~10-4cm-3) of small nitric acid (HNO3) containing particles (d<6µm) were observed at altitudes between 18 and 20km. Provided temperatures remain below NAT equilibrium temperature TNAT, these have potential to grow further remove HNO3 from stratosphere, thereby enhancing polar ozone loss. Interestingly, formed less than...
Abstract On 4 July 2014, during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), strong low‐level horizontal winds of up to 35 m s −1 over Southern Alps, New Zealand, caused excitation gravity waves having largest vertical energy fluxes whole campaign (38 W −2 ). At same time, large‐amplitude mesospheric were detected by Temperature Lidar for Middle Atmospheric Research (TELMA) located at Lauder (45.0°S, 169.7°E), Zealand. The coincidence these two events leads question whether...
Abstract. Lineshaped contrails were detected with the research aircraft Falcon during CONCERT – CONtrail and Cirrus ExpeRimenT campaign in October/November 2008. The was equipped a set of instruments to measure particle size distribution, shape, extinction chemical composition as well trace gas mixing ratios sulfur dioxide (SO2), reactive nitrogen halogen species (NO, NOy, HNO3, HONO, HCl), ozone (O3) carbon monoxide (CO). During 12 mission flights over Europe, numerous contrails, cirrus...
Abstract. Spaceborne lidar measurements from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) are used to provide a vortex-wide perspective of the 2009–2010 Arctic PSC (polar stratospheric cloud) season complement more focused European Union RECONCILE (reconciliation essential process parameters for an enhanced predictability ozone loss its climate interactions) field campaign. The winter was unusually cold at levels mid-December 2009 until end January 2010, one...
Abstract The southern part of South America and the Antarctic peninsula are known as world’s strongest hotspot region stratospheric gravity wave (GW) activity. Large tropospheric winds deflected by Andes Peninsula excite GWs that might propagate into upper mesosphere. Satellite observations show large GW activity above mountains, Drake Passage, in a belt centered along 60°S. This scientifically highly interesting for studying dynamics was focus Southern Hemisphere Transport, Dynamics,...
Abstract A strong mountain wave, observed over Central Europe on 12 January 2016, is simulated in 2D under two fixed background wind conditions representing opposite tidal phases. The aim of the simulation to investigate breaking wave and subsequent generation nonprimary waves upper atmosphere. model results show that first breaks as it approaches a mesospheric critical level creating turbulence horizontal scales 8–30 km. These couple directly secondary scales, but those are prevented from...
Abstract. Atmospheric gravity waves are a major cause of uncertainty in atmosphere general circulation models. This affects regional climate projections and seasonal weather predictions. Improving the representation models is therefore primary interest. In this regard, measurements providing an accurate 3-D characterization needed. Using Gimballed Limb Observer for Radiance Imaging Atmosphere (GLORIA), first airborne implementation novel infrared limb imaging technique, wave event over...
Abstract Airborne coherent Doppler wind lidar measurements, acquired during the Gravity Wave Life-Cycle (GW-LCYCLE) I field campaign performed from 2 to 14 December 2013 in Kiruna, Sweden, are used investigate internal gravity waves (GWs) induced by flow across Scandinavian Mountains. Vertical speed is derived measurements with a mean bias of less than 0.05 m s −1 and standard deviation 0.2 correcting horizontal projections onto line-of-sight direction means ECMWF data. The retrieved...
The COVID-19 pandemic led to a 72% reduction of air traffic over Europe in March-August 2020 compared 2019. Modeled contrail cover declined similarly, and computed mean instantaneous radiative forcing dropped regionally by up 0.7 W m-2. Here, model predictions cirrus optical thickness the top-of-atmosphere outgoing longwave reflected shortwave irradiances are tested comparison Meteosat-SEVIRI-derived data. agreement between observations modeled data is slightly better when contributions...
Abstract Some of the largest and most persistent circulation errors in global numerical weather prediction climate models are attributable to inadequate representation impacts orography on atmospheric flow. Existing parametrization approaches attempting account for unresolved orographic processes, such as turbulent form drag, low-level flow blocking or mountain waves, have been successful some extent. They capture basic a qualitatively correct way led significant progress both modelling....
Polar stratospheric clouds (PSCs) at 22–26 km were observed over the Norwegian mountains by airborne lidar on January 15, 1995. Simulations using a mesoscale model reveal that they caused mountain‐induced gravity waves. The had highly detailed filamentary structure with bands as thin 100 m in vertical, and moved insignificantly 4 hours, suggesting them to be quasi‐stationary. aircraft flight path was parallel or close wind cloud level. Such quasi‐Lagrangian observation, together presence of...
At three successive days at the end of January 2000 Deutsches Zentrum für Luft‐ und Raumfahrt (DLR) airborne lidar Ozone Lidar Experiment explored mountain‐wave‐induced polar stratospheric clouds above Scandinavian mountain ridge. Global analyses and mesoscale modeling are applied to explain their complex internal structure day‐to‐day variability. Depending on synoptical‐scale meteorological conditions, temperature anomalies different amplitude horizontal extent generated by upward...
Abstract. The international research project RECONCILE has addressed central questions regarding polar ozone depletion, with the objective to quantify some of most relevant yet still uncertain physical and chemical processes thereby improve prognostic modelling capabilities realistically predict response layer climate change. This overview paper outlines scope general approach RECONCILE, it provides a summary observations in 2010 2011 that have generated an many respects unprecedented...
Abstract. The relatively warm 2009–2010 Arctic winter was an exceptional one as the North Atlantic Oscillation index attained persistent extreme negative values. Here, selected aspects of stratosphere during this inspired by analysis international field experiment RECONCILE are presented. First all, and a kind reference, evolution polar vortex in its different phases is documented. Special emphasis put on explaining formation exceptionally cold mid after sequence stratospheric disturbances...
Abstract. In January 2010 and December 2011, synoptic-scale polar stratospheric cloud (PSC) fields were probed during seven flights of the high-altitude research aircraft M-55 Geophysica within RECONCILE (Reconciliation essential process parameters for an enhanced predictability Arctic ozone loss its climate interaction) ESSenCe (ESSenCe: ESA Sounder Campaign) projects. Particle size distributions in a diameter range between 0.46 40μm recorded by four different optical situ instruments....
Abstract. This paper provides compelling evidence for the importance of heterogeneous nucleation, likely on solid particles meteoritic origin, and small-scale temperature fluctuations, formation ice in Arctic stratosphere. During January 2010, PSCs (polar stratospheric clouds) were shown by CALIPSO (Cloud-Aerosol Lidar Infrared Pathfinder Satellite Observations) to have occurred a synoptic scale (~1000 km dimension). observations also showed widespread containing NAT (nitric acid trihydrate)...