15 research outputs found

    Validation and data characteristics of methane and nitrous oxide profiles observed by MIPAS and processed with Version 4.61 algorithm

    Get PDF
    The ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS is based on a number of balloon-borne, aircraft, satellite and ground-based correlative measurements. In particular the activities of validation scientists were coordinated by ESA within the ENVISAT Stratospheric Aircraft and Balloon Campaign or ESABC. As part of a series of similar papers on other species [this issue] and in parallel to the contribution of the individual validation teams, the present paper provides a synthesis of comparisons performed between MIPAS CH4 and N2O profiles produced by the current ESA operational software (Instrument Processing Facility version 4.61 or IPF v4.61, full resolution MIPAS data covering the period 9 July 2002 to 26 March 2004) and correlative measurements obtained from balloon and aircraft experiments as well as from satellite sensors or from ground-based instruments. In the middle stratosphere, no significant bias is observed between MIPAS and correlative measurements, and MIPAS is providing a very consistent and global picture of the distribution of CH4 and N2O in this region. In average, the MIPAS CH4 values show a small positive bias in the lower stratosphere of about 5%. A similar situation is observed for N2O with a positive bias of 4%. In the lower stratosphere/upper troposphere (UT/LS) the individual used MIPAS data version 4.61 still exhibits some unphysical oscillations in individual CH4 and N2O profiles caused by the processing algorithm (with almost no regularization). Taking these problems into account, the MIPAS CH4 and N2O profiles are behaving as expected from the internal error estimation of IPF v4.61 and the estimated errors of the correlative measurements

    Koordinierte Messkampagnen mit flugzeug-, ballon- und satellitengetragenen Mikrowellen-Sensoren zur Bestimmung der CIO-Verteilung in der arktischen Winter-Atmosphaere. T. 1 und 2 Uebersicht. Anhaenge: A, B und C. Abschlussbericht

    No full text
    The campaigns of measurement carried out in the winter months since 1991/92 with the sub-mm atmospheric sounder experiment in the Arctic have shown a 'disturbed chemistry' similar to the conditions in the Antarctic hole in the ozone layer. Due to the successful measurements and the still open questions of the destruction of the ozone, the present project is carried on as the extension of the project 'Coordinated measurement campaign with microwave sensors carried in aircraft and satellites in the Arctic winter atmosphere' of the winter of 1992/93. (orig./AKF)Die seit 1991/92 in den Wintermonaten durchgefuehrten Messkampagnen mit dem SUMAS-Experiment (sub-mm Atmospheric Sounder) in der Arktis haben eine 'gestoerte Chemie', aehnlich den Verhaeltnissen im antarktischen Ozonloch, aufgezeigt. Aufgrund der erfolgreichen Messungen und der noch offenstehenden Fragen zum Ozonabbau wurde das jetzige Projekt als Verlaengerung des im Winter 1992/93 durchgefuehrten Projekts 'Koordinierte Messkampagne mit flugzeug- und satellitengetragenen Mikrowellensensoren in der arktischen Winteratmosphaere' gefuehrt. (orig./AKF)Available from TIB Hannover: F96B69+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); Stichting Ruimteonderzoek Nederland (SRON), Groningen (Netherlands); European Space Research and Technology Centre, Noordwijk (Netherlands); Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Optoelektronik; Max-Planck-Institut fuer Aeronomie (MPAE), Katlenburg-Lindau (Germany)DEGerman

    Validation and data characteristics of methane and nitrous oxide profiles observed by MIPAS and processed with Version 4.61 algorithm.

    Get PDF
    The ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS is based on a number of balloon-borne, aircraft, satellite and ground-based correlative measurements. In particular the activities of validation scientists were coordinated by ESA within the ENVISAT Stratospheric Aircraft and Balloon Campaign or ESABC. As part of a series of similar papers on other species [this issue] and in parallel to the contribution of the individual validation teams, the present paper provides a synthesis of comparisons performed between MIPAS CH4 and N2O profiles produced by the current ESA operational software (Instrument Processing Facility version 4.61 or IPF v4.61, full resolution MIPAS data covering the period 9 July 2002 to 26 March 2004) and correlative measurements obtained from balloon and aircraft experiments as well as from satellite sensors or from ground-based instruments. In the middle stratosphere, no significant bias is observed between MIPAS and correlative measurements, and MIPAS is providing a very consistent and global picture of the distribution of CH4 and N2O in this region. In average, the MIPAS CH4 values show a small positive bias in the lower stratosphere of about 5%. A similar situation is observed for N2O with a positive bias of 4%. In the lower stratosphere/upper troposphere (UT/LS) the individual used MIPAS data version 4.61 still exhibits some unphysical oscillations in individual CH4 and N2O profiles caused by the processing algorithm (with almost no regularization). Taking these problems into account, the MIPAS CH4 and N2O profiles are behaving as expected from the internal error estimation of IPF v4.61 and the estimated errors of the correlative measurements

    Validation of ACE-FTS N2O measurements

    Get PDF
    The Atmospheric Chemistry Experiment (ACE), also known as SCISAT, was launched on 12 August 2003,carrying two instruments that measure vertical profiles of atmospheric constituents using the solar occultation technique.One of these instruments, the ACE Fourier Transform Spectrometer (ACE-FTS), is measuring volume mixing ratio profiles of nitrous oxide (N2O) from the upper troposphere to the lower mesosphere. In this study, the quality of the ACE-FTS version 2.2 N2O data is assessed rough comparisons with coincident measurements made by other satellite, balloon-borne, aircraft, and ground-based instruments.These consist of vertical profile comparisons with the SMR, MLS, and MIPAS satellite instruments, multiple aircraft flights of ASUR, and single balloon flights of SPIRALE and FIRS-2, and artial column comparisons with a network of ground-based Fourier Transform InfraRed spectrometers(FTIRs). Overall, the quality of the ACE-FTS version 2.2 N2O VMR profiles appears to be good over the entire altitude range from 5 to 60 km. Between 6 and 30 km, the meanabsolute differences for the satellite comparisons lie between -42 ppbv and +17 ppbv, with most within 20 ppbv, correspondingto relative deviations from the mean that are mostly within 5%. Between 18 and 30 km, the mean absolute differences are generally within 10 ppbv, with relative deviations from the mean within 20%, except for the aircraft and balloon comparisons. From 30 to 60 km, the mean absolute differences are within 4 ppbv, and are mostly between -2 and +1 ppbv. Given the small N2O VMR in this region, therelative deviations from the mean are therefore large at these altitudes, with most suggesting a negative bias in the ACEFTS data between 30 and 50 km. In the comparisons with the FTIRs, the mean relative differences between the ACE-FTS and FTIR partial columns are within 6.6% for eleven of thetwelve contributing stations. This mean relative difference is negative at eight stations, suggesting a small negative bias in the ACE-FTS partial columns over the altitude regions compared.Excellent correlation (R=0.964) is observed between the ACE-FTS and FTIR partial columns, with a slope of 1.01and an intercept -0.20 on the line fitted to the data

    Trajectory Studies of Large HNO3-Containing PSC Particles in the Arctic: Evidence for the Role of NAT

    Get PDF
    Large (5 to >20 micron diameter) nitric-acid-containing polar stratospheric cloud (PSC) particles were observed in the Arctic stratosphere during the winter of 1999-2000. We use a particle growth and sedimentation model to investigate the environment in which these particles grew and the likely phase of the largest particles. Particle trajectory calculations show that, while simulated nitric acid dihydrate (NAD) particle sizes are significantly smaller than the observed maximum particle sizes, nitric acid trihydrate (NAT) particle trajectories are consistent with the largest observed particle sizes
    corecore