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| Titel |
Intercomparison of stratospheric gravity wave observations with AIRS and IASI |
| VerfasserIn |
Lars Hoffmann, M. Joan Alexander, Cathy Clerbaux, Alison W. Grimsdell, Catrin I. Meyer, Thomas Rößler, Bernard Tournier |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101913
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| Publikation (Nr.) |
 EGU/EGU2015-1475.pdf |
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| Zusammenfassung |
| Gravity waves are an important driver for the atmospheric circulation and have
substantial impact on weather and climate. Satellite instruments offer excellent
opportunities to study gravity waves on a global scale. This study focuses on observations
from the Atmospheric Infrared Sounder (AIRS) onboard the National Aeronautics
and Space Administration’s Aqua satellite and the Infrared Atmospheric Sounding
Interferometer (IASI) onboard the European MetOp satellites. The main aim of
this study is an intercomparison of stratospheric gravity wave observations of both
instruments. In particular, we analyzed AIRS and IASI 4.3 μm brightness temperature
measurements, which directly relate to stratospheric temperature. Three case studies
showed that AIRS and IASI provide a clear and consistent picture of the temporal
development of individual gravity wave events. Statistical comparisons based on a
five-year period of measurements (2008 – 2012) showed similar spatial and temporal
patterns of gravity wave activity. However, the statistical comparisons also revealed
systematic differences of variances between AIRS and IASI that we attribute to the
different spatial measurement characteristics of both instruments. We also found
differences between day- and nighttime data that are partly due to the local time
variations of the gravity wave sources. While AIRS has been used successfully in many
previous gravity wave studies, IASI data are applied here for the first time for that
purpose. Our study shows that gravity wave observations from different hyperspectral
infrared sounders such as AIRS and IASI can be directly related to each other, if
instrument-specific characteristics such as different noise levels and spatial resolution
and sampling are carefully considered. The ability to combine observations from
different satellites provides an opportunity to create a long-term record, which is an
exciting prospect for future climatological studies of stratospheric gravity wave
activity.
Reference: Hoffmann, L., Alexander, M. J., Clerbaux, C., Grimsdell, A. W., Meyer, C. I.,
Rößler, T., and Tournier, B.: Intercomparison of stratospheric gravity wave observations with
AIRS and IASI, Atmos. Meas. Tech. Discuss., 7, 8415-8464, doi:10.5194/amtd-7-8415-2014,
2014. |
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