 |
| Titel |
HCOOH measurements from space: TES retrieval algorithm and observed global distribution |
| VerfasserIn |
K. E. Cady-Pereira, S. Chaliyakunnel, M. W. Shephard, D. B. Millet, M. Luo, K. C. Wells |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 7 ; Nr. 7, no. 7 (2014-07-30), S.2297-2311 |
| Datensatznummer |
250115859
|
| Publikation (Nr.) |
 copernicus.org/amt-7-2297-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Presented is a detailed description of the TES (Tropospheric Emission Spectrometer)-Aura satellite formic acid
(HCOOH) retrieval algorithm and initial results quantifying the global
distribution of tropospheric HCOOH. The retrieval strategy, including the
optimal estimation methodology, spectral microwindows, a priori constraints,
and initial guess information, are provided. A comprehensive error and
sensitivity analysis is performed in order to characterize the retrieval
performance, degrees of freedom for signal, vertical resolution, and limits
of detection. These results show that the TES HCOOH retrievals (i) typically
provide at best 1.0 pieces of information; (ii) have the most vertical
sensitivity in the range from 900 to 600 hPa with ~ 2 km vertical
resolution; (iii) require at least 0.5 ppbv (parts per billion by volume) of HCOOH for detection if
thermal contrast is greater than 5 K, and higher concentrations as thermal
contrast decreases; and (iv) based on an ensemble of simulated retrievals,
are unbiased with a standard deviation of ±0.4 ppbv. The relative
spatial distribution of tropospheric HCOOH derived from TES and its
associated seasonality are broadly correlated with predictions from a
state-of-the-science chemical transport model (GEOS-Chem CTM). However, TES
HCOOH is generally higher than is predicted by GEOS-Chem, and this is in
agreement with recent work pointing to a large missing source of atmospheric
HCOOH. The model bias is especially pronounced in summertime and over biomass
burning regions, implicating biogenic emissions and fires as key sources of
the missing atmospheric HCOOH in the model. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|