Cross-validation of MIPAS/ENVISAT and GPS-RO/CHAMP temperature profiles

Journal article

Authors/Editors

Tsidu, Gizaw

Research Areas

No matching items found.

Publication Details

Author list: Wang DY, Stiller GP, von Clarmann T, Fischer H, Lopez-Puertas M, Funke B, Glatthor N, Grabowski U, Hopfner M, Kellmann S, Kiefer M, Linden A, Tsidu GM, Milz M, Steck T, Jiang JH, Ao CO, Manney G, Hocke K, Wu DL, Romans LJ, Wickert J, Schmidt T

Publisher: American Geophysical Union

Place: WASHINGTON

Publication year: 2004

Journal: Journal of Geophysical Research: Atmospheres (2169-897X)

Journal acronym: J GEOPHYS RES-ATMOS

Volume number: 109

Issue number: D19

Number of pages: 15

ISSN: 2169-897X

eISSN: 2169-8996

Languages: English-Great Britain (EN-GB)

View in Web of Science | View on publisher site | View citing articles in Web of Science

Abstract

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board the ENVISAT and the Global Positioning System (GPS) receiver on the Challenging Mini-Satellite Payload (CHAMP) provide temperature profiles by limb-viewing midinfrared emission and radio occultation (RO) measurements, respectively. The MIPAS temperatures retrieved at the Institut fur Meteorologie und Klimaforschung (IMK) are compared with the GPS-RO/CHAMP observations derived at Jet Propulsion Laboratory (JPL) and GeoForschungsZentrum (GFZ) Potsdam. The three data sets show generally good agreement. The global mean differences averaged between 8 and 30 km in 14 days of September/October 2002 are -0.44 +/- 0.02 K and 0.07 +/- 0.02 K for MIPAS/GPS-RO JPL and GFZ comparisons, respectively. The MIPAS global mean temperatures below 25 km are slightly lower than those of GPS-RO JPL and GFZ by less than 1 K and 0.2 K, respectively. Above 25 km, the MIPAS temperatures are higher than the JPL and GFZ data, in particular near both poles and the equator, with maxima of 1 K for JPL and 1.5 K for GFZ at 30 km. The standard deviations are similar to2-4 K. Possible explanations for the observed differences include (1) effect of spatial and temporal mismatch between the correlative measurements on the observed standard deviations, in particular in regions and episodes of enhanced wave activity; (2) a negative bias in GPS-RO/CHAMP temperatures in regions of increased humidity; (3) a mapping of initialization temperature profiles on GPS-RO/CHAMP retrievals at altitudes where low refraction contains no information on air density; and (4) measurement errors of both instruments, particularly the errors due to insufficient knowledge of the instrument line shape and spectroscopy in current MIPAS retrievals.

Keywords

CHAMP, MIPAS, temperature

Documents