Project

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WADI: Atmospheric Water vapour from the ground to the mesopause: Detection and Interpretation

Applicant Kämpfer Niklaus
Number 124387
Funding scheme Project funding (Div. I-III)
Research institution Institut für angewandte Physik Universität Bern
Institution of higher education University of Berne - BE
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.04.2009 - 31.03.2011
Approved amount 521'435.00
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Keywords (8)

water vapor; ozone; climate; microwave radiometry; remote sensing; atmosphere; stratosphere; mesosphere

Lay Summary (English)

Lead
Lay summary
Water vapour is an important climate variable and it plays a key role in several issues of atmospheric processes. It is the most important natural greenhouse gas and it provides the largest positive feedback in model projections of climate change. Increasing concentrations of water vapour in the upper troposphere and lower stratosphere are of growing concern because of its influence on the radiation balance and the potential changes in the homogeneous and heterogeneous chemistry affecting ozone. Studying the distribution of water vapour and ozone thus gives insight in two of the prominent aspects of climate change: greenhouse warming and ozone depletion.The scientific objectives of this research project are aimed at understanding the significance of the variability in atmospheric H2O at mid-latitudes over different time scales and to investigate the links between ozone and water vapour. A special aspect will be devoted to sudden stratospheric warmings and their effect on ozone and water vapour and relation to dynamical phenomena in the middle atmosphere. A further topic is to compare data from our ground based instruments with satellite data and to participate in campaigns and validation experiments. Further insight into the atmospheric processes shall be obtained by combining our data with atmospheric models in cooperation with other research teams.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Collaboration

Group / person Country
Types of collaboration
Astronomical Institute University of Bern Switzerland (Europe)
- Research Infrastructure
EC project GEOMON Belgium (Europe)
- in-depth/constructive exchanges on approaches, methods or results
COST project WAVACS Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
PMOD/WRC Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
MeteoSchweiz Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Oeschger Centre for Climate Change Research Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
NDACC United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Sookmyung women's University, Seoul Korean Republic (South Korea) (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Associated projects

Number Title Start Funding scheme
115882 Water and its role in atmospheric processes 01.04.2007 Project funding (Div. I-III)
119908 Beam Shaping and Feed Optimization for Terahertz Waves 01.04.2008 Project funding (Div. I-III)
134684 WADI+: Atmospheric Water vapour from the ground to the mesopause: Detection and Interpretation 01.04.2011 Project funding (Div. I-III)
134613 Detection and Interpretation of Atmospheric Motions (DIAMO) 01.08.2011 Project funding (Div. I-III)
133791 R'EQUIP Microwave Vector Network Analyzer 01.02.2011 R'EQUIP

Abstract

Water vapour is an important climate variable and it plays a key role in several issues of atmospheric processes. It is the most important natural greenhouse gas and it provides the largest positive feedback in model projections of climate change (IPCC, 2007). Increasing concentrations of water vapour in the upper troposphere and lower stratosphere are of growing concern because of its influence on the radiation balance and the potential changes in the homogeneous and heterogeneous chemistry affecting ozone. Studying the distribution of water vapour and ozone thus gives insight in two of the prominent aspects of climate change: greenhouse warming and ozone depletion.To obtain a reliable global picture of the changing atmosphere, a coupled observational / modeling system is required. Such a system must include a network of ground-based instrumentation of different techniques including balloon sondes, millimeter wave radiometers, lidar etc. to measure relevant parameters such as stratospheric water vapour and ozone.Remote sensing of atmospheric constituents has been a main topic of research of the department of microwave physics at the IAP, University of Bern, since many years. Radiometers at microwave frequencies were developed and operated from the surface, from aircraft and space in order to determine the altitude distribution of constituents like H2O, O3, ClO and others. The scientific objectives of this research project are aimed at understanding the significance of the variability in atmospheric H2O at mid-latitudes over different time scales and to investigate the links between ozone and water vapour. A special aspect will be devoted to sudden stratospheric warmings and their effect on ozone and water vapour and relation to dynamical phenomena in the middle atmosphere. A further topic is to compare data from our ground based instruments with satellite data and to participate in campaigns and validation experiments. Further insight into the atmospheric processes shall be obtained by combining our data with atmospheric models in cooperation with other research teams.The proposed work can be split into two main units: one is devoted to instrumental aspects and the other one to the analysis of data in combination with models. Key instruments that are operated in the frame of the Network for Atmospheric Composition Change, NDACC, shall be equipped with new digital FFT spectrometers. This technique has been used successfully in other radiometers and our expertise in this field is mature. New spectrometers will allow widening the altitude range over which profiles of water vapour and ozone can be retrieved. In addition operation of the instruments will become even more reliable. In addition to this upgrade of the network-instruments we plan to build a new radiometer, using available parts, for the detection of lower mesospheric wind speed by using the classical Doppler shift of spectral lines, a concept that has not been realized so far but the concept was tested successfully in one of our aircraft campaigns.The atmospheric investigations will mainly be devoted to the analysis of the temporal variability of ozone and water vapour over different time scales from annual, seasonal, diurnal down to short time fluctuations based on our unique dataset in combination with models. A particular weight will be placed on the investigation of sudden stratospheric warmings and their effect on ozone and water vapour as well as the investigation of potential precursors of such events in the mesosphere.Participation in MOHAVE, the Measurements Of Humidity in the Atmosphere and Validation Experiments campaign at Table Mountain facility of NASA/JPL in 2009 will be an important element of this research proposal. This campaign will allow us to qualify a completely new microwave radiometer concept for middle atmospheric water vapour. Further it will allow to compare and to complement data from world top class instruments with different methodologies at one place. Concept studies for the retrieval of the tropospheric humidity profile shall be performed and we plan to continue the very fruitful observations of the integrated amount of water vapour and to foster our research devoted to climatological studies of the relation between humidity and changes in temperature and radiation. Trend analysis of the integrated water vapour amount (IWV) that has been successfully performed shall be continued and investigated in a broader sense. Not only humidity information from Bern but also other data available shall be used for assessment of regional and global trends
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