A5070306176- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Ionosphere and magnetosphere dynamics
- Climate variability and models
- Atmospheric aerosols and clouds
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Meteorological Phenomena and Simulations
- Geophysics and Gravity Measurements
- Ocean Acidification Effects and Responses
- Climate change and permafrost
- Spacecraft and Cryogenic Technologies
- Spaceflight effects on biology
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Climate Change and Geoengineering
- Cryospheric studies and observations
- Tropical and Extratropical Cyclones Research
- Analytical Chemistry and Sensors
- Neutrino Physics Research
- Scientific Research and Discoveries
Forschungszentrum Jülich
2016-2025
Institute of Atmospheric Sciences and Climate
2020
Institut für Kälte-, Klima- und Energietechnik
2013-2014
Institute of Geosphere Dynamics
2009
Ernst Ruska Centre
2008
Bay Area Environmental Research Institute
2005
Technical University of Denmark
2005
Max Planck Society
1998
Langley Research Center
1997
Hampton University
1997
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 Polar stratospheric clouds (PSCs) play important roles in ozone depletion during winter and spring at high latitudes (e.g., the Antarctic hole). PSC particles provide sites for heterogeneous reactions that convert stable chlorine reservoir species to radicals destroy catalytically. PSCs also prolong by delaying deactivation through removal of gas‐phase HNO 3 H 2 O sedimentation large nitric acid trihydrate (NAT) ice particles. Contemporary observations spaceborne instruments...
Abstract The eruption of the submarine Hunga volcano in January 2022 was associated with a powerful blast that injected volcanic material to altitudes up 58 km. From combination various types satellite and ground-based observations supported by transport modeling, we show evidence for an unprecedented increase global stratospheric water mass 13% relative climatological levels, 5-fold aerosol load, highest last three decades. Owing extreme injection altitude, plume circumnavigated Earth only...
Recent satellite observations and dynamical studies have demonstrated the existence of filamentary structures in chemical tracer fields stratosphere. It is also evident that such features are often below spatial resolution highest‐resolution Eulerian models been used up to present time. These motivated development a novel Chemical Lagranigan Model Stratosphere (CLaMS) based on Lagrangian transport tracers. The description CLaMS divided into two parts: Part 1 (this paper) concentrates...
The first simulations of stratospheric chemistry using the Chemical Lagrangian Model Stratosphere (CLaMS) are reported. A comprehensive chemical assimulation procedure is described that combines satellite, airborne, and balloon‐borne tracer observations with results from a two‐dimensional photochemical model simulation. This uses tracer‐tracer tracer‐potential vorticity mapping techniques. It correctly reproduces all basic features observed distribution. methodology used to generate initial...
Abstract. Variations in the mixing ratio of trace gases tropospheric origin entering stratosphere tropics are interest for assessing both troposphere to transport fluxes and impact these on composition tropical lower stratosphere. Anomaly patterns carbon monoxide (CO) long-lived tracers allow conclusions about rate variability upwelling be drawn. Here, we present a simplified chemistry scheme Chemical Lagrangian Model Stratosphere (CLaMS) simulation, at comparatively low numerical cost, CO,...
To assess the impact of vertical velocity scheme on modeling transport in tropical tropopause layer (TTL), 3 month backward trajectories are initialized TTL for boreal winter and summer 2002. The calculations done either a kinematic scenario with pressure tendency as or diabatic cross‐isentropic deduced from various heating rates due to radiation (clear sky, all sky) latent, diffusive turbulent heating. This work provides guideline assessing sensitivity trajectory chemical model (CTM)...
Abstract. We present version 4.0 of the atmospheric chemistry box model CAABA/MECCA that now includes a number new features: (i) skeletal mechanism reduction, (ii) Mainz Organic Mechanism (MOM) chemical for volatile organic compounds, (iii) an option to include reactions from Master Chemical (MCM) and other mechanisms, (iv) updated isotope tagging, (v) improved photolysis modules (JVAL, RADJIMT, DISSOC). Further, when MECCA is connected global model, feature coexisting multiple mechanisms...
Abstract. Enhanced tropospheric trace gases such as CO, CH4 and H2O reduced stratospheric O3 were measured in situ the lowermost stratosphere over northern Europe on 26 September 2012 during TACTS aircraft campaign. The measurements indicate that these air masses clearly differ from background. calculation of 40-day backward trajectories with trajectory module CLaMS model shows are affected by Asian monsoon anticyclone. Some originate boundary layer Southeast Asia/West Pacific rapidly lifted...
We compare global water vapor observations from Microwave Limb Sounder (MLS) and simulations with the Lagrangian chemical transport model CLaMS (Chemical Model of Stratosphere) to investigate pathways into lower stratosphere during Northern Hemisphere (NH) summer. find good agreement between simulation observations, an effect satellite averaging kernel especially at high latitudes. The Asian American monsoons emerge as regions particularly mixing ratios in boreal In NH midlatitudes...
Abstract. Multi-annual simulations with the Chemical Lagrangian Model of Stratosphere (CLaMS) were conducted to study seasonality O3 within stratospheric part tropical tropopause layer (TTL), i.e. above θ=360 K potential temperature level. In agreement satellite (HALOE) and in-situ observations (SHADOZ), CLaMS show a pronounced annual cycle in O3, at θ=380 K, highest mixing ratios late boreal summer. Within model, this is driven by both upwelling in-mixing. The latter process occurs through...
Abstract. The Asian summer monsoon provides an important pathway of tropospheric source gases and pollution into the lower stratosphere. This transport is characterized by deep convection steady upwelling, combined with confinement inside a large-scale anticyclonic circulation in upper troposphere stratosphere (UTLS). In this paper, we show that barrier to horizontal along 380 K isentrope anticyclone can be determined from local maximum gradient potential vorticity (PV), following methods...
Abstract. The radiative role of ice clouds in the atmosphere is known to be important, but uncertainties remain concerning magnitude and net effects. However, through measurements microphysical properties cirrus clouds, we can better characterize them, which ultimately allow for their more accurately ascertained. Recently, two types differing by formation mechanism have been classified – situ liquid origin cirrus. In this study, present observational evidence show that distinct do exist....
Abstract. The impact of different boundary layer source regions in Asia on the chemical composition Asian monsoon anticyclone, considering its intraseasonal variability 2012, is analysed by simulations Chemical Lagrangian Model Stratosphere (CLaMS) using artificial emission tracers. horizontal distribution simulated CO, O3, and tracers for India/China are good agreement with patterns found satellite measurements O3 CO Aura Microwave Limb Sounder (MLS). Using addition, correlations potential...
Abstract. Global simulations with the Chemical Lagrangian Model of Stratosphere (CLaMS) using artificial tracers air mass origin are used to analyze transport mechanisms from Asian monsoon region into lower stratosphere. In a case study, masses anticyclone originating in India/China by an eastward-migrating which broke off main on 20 September 2012 and filaments separated at northeastern flank analyzed. Enhanced contributions young (younger than 5 months) found within confined top thermal...
Abstract The Polar Stratosphere in a Changing Climate (POLSTRACC) mission employed the German High Altitude and Long Range Research Aircraft (HALO). payload comprised an innovative combination of remote sensing situ instruments. instruments provided high-resolution observations cirrus polar stratospheric clouds (PSCs), large number reactive long-lived trace gases, temperature at aircraft level. Information above underneath level was achieved by as well dropsondes. took place from 8 December...
Abstract. We use a combination of spaceborne instruments to study the unprecedented stratospheric plume after Tonga eruption 15 January 2022. The aerosol was initially formed two clouds at 30 and 28 km, mostly composed submicron-sized sulfate particles, without ash, which is washed out within first day following eruption. large amount injected water vapour led fast conversion SO2 aerosols induced descent 24–26 km over 3 weeks by radiative cooling. Whereas returned background levels end...
The three‐dimensional (3‐D) formulation of the Chemical Lagrangian Model Stratosphere (CLaMS‐3d) is presented that extends isentropic version CLaMS to cross‐isentropic transport. velocities air parcels are calculated with a radiation module and by taking into account profiles ozone water vapor derived from HALOE climatology. 3‐D extension mixing maintains most important feature 2‐D as mainly controlled horizontal deformations wind fields. In version, additionally driven vertical shear in...
Abstract. The Halogen Occultation Experiment (HALOE) on board the Upper Atmosphere Research Satellite (UARS) has observed mixing ratios of important trace species in stratosphere for more than a decade since 1991. Here we present climatology compiled from HALOE O3, H2O, CH4, NOx, HCl, and HF data period 1991 to 2002. In this approach, are averaged over equivalent latitude instead order correctly reproduce gradients at transport barriers like polar vortex edge. is 5 degree bins. Seasonal...
Abstract. High-resolution water measurements from three tropical airborne missions in Northern Australia, Southern Brazil and West Africa different seasons are analysed to study the transport transformation of tropopause layer (TTL) its impact on stratosphere. The mean profiles quite according season location campaigns, with lowest mixing ratios below 2 ppmv at cold point during Australian mission November/December high TTL African August. We present backward trajectory calculations...
We analyze horizontal transport from midlatitudes into the tropics (in‐mixing) and its impact on seasonal variations of ozone, carbon monoxide water vapor in Tropical Tropopause Layer (TTL). For this purpose, we use three‐dimensional backward trajectories, driven by ECMWF ERA‐Interim winds, a conceptual one‐dimensional model chemical composition TTL. find that fraction in‐mixed midlatitude air shows an annual cycle with maximum during NH summer, resulting superposition two inversely phased...
Abstract. Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to current understanding, nucleation nitric acid trihydrate (NAT) polar stratosphere does not only occur on preexisting ice particles. In order explain NAT clouds observed over mid-December 2009, a heterogeneous mechanism is required, occurring via immersion freezing surface solid particles, likely meteoritic origin. For first time, detailed microphysical modelling this...
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...