 |
| Titel |
Cloud type comparisons of AIRS, CloudSat, and CALIPSO cloud height and amount |
| VerfasserIn |
B. H. Kahn, M. T. Chahine, G. L. Stephens, G. G. Mace, R. T. Marchand, Z. Wang, C. D. Barnet, A. Eldering, R. E. Holz, R. E. Kuehn, D. G. Vane |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 8, no. 5 ; Nr. 8, no. 5 (2008-03-04), S.1231-1248 |
| Datensatznummer |
250005790
|
| Publikation (Nr.) |
 copernicus.org/acp-8-1231-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| The precision of the two-layer cloud height fields derived from the
Atmospheric Infrared Sounder (AIRS) is explored and quantified for a
five-day set of observations. Coincident profiles of vertical cloud
structure by CloudSat, a 94 GHz profiling radar, and the Cloud-Aerosol Lidar
and Infrared Pathfinder Satellite Observation (CALIPSO), are compared to
AIRS for a wide range of cloud types. Bias and variability in cloud height
differences are shown to have dependence on cloud type, height, and amount,
as well as whether CloudSat or CALIPSO is used as the comparison standard.
The CloudSat-AIRS biases and variability range from −4.3 to 0.5±1.2–3.6 km
for all cloud types. Likewise, the CALIPSO-AIRS biases range
from 0.6–3.0±1.2–3.6 km (−5.8 to −0.2±0.5–2.7 km) for
clouds ≥7 km (<7 km). The upper layer of AIRS has the greatest
sensitivity to Altocumulus, Altostratus, Cirrus, Cumulonimbus, and
Nimbostratus, whereas the lower layer has the greatest sensitivity to
Cumulus and Stratocumulus. Although the bias and variability generally
decrease with increasing cloud amount, the ability of AIRS to constrain
cloud occurrence, height, and amount is demonstrated across all cloud types
for many geophysical conditions. In particular, skill is demonstrated for
thin Cirrus, as well as some Cumulus and Stratocumulus, cloud types infrared
sounders typically struggle to quantify. Furthermore, some improvements in
the AIRS Version 5 operational retrieval algorithm are demonstrated.
However, limitations in AIRS cloud retrievals are also revealed, including
the existence of spurious Cirrus near the tropopause and low cloud layers
within Cumulonimbus and Nimbostratus clouds. Likely causes of spurious
clouds are identified and the potential for further improvement is
discussed. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|