Apparent pressure derived from ADEOS-POLDER observations in the oxygen A-band over ocean

Claudine Vanbauce (1) , Jean-Claude Buriez (2) , Frédéric Parol (2) , Bernard Bonnel (2) , G. Sèze (3, 4) , P. Couvert (5, 6)

1 IRN - Interactions Rayonnement Nuages
2 LOA - Laboratoire d’Optique Atmosphérique - UMR 8518
3 IPSL - Institut Pierre-Simon-Laplace
4 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
5 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
6 CAE - Chimie Atmosphérique Expérimentale

The POLDER radiometer was on board the ADEOS satellite from August 1996 to June 1997. This instrument measures radiances in eight narrow spectral bands of the visible and near infrared spectrum. Two of them are centered on the O2 A-band in order to infer cloud pressure. By assuming the atmosphere behaves as a pure absorbing medium overlying a perfect reflector, an "apparent" pressure Papp is derived from POLDER data. For validation purposes, Papp is first compared to the sea-surface pressure Ps for clear-sky conditions; Papp is found to be close to Ps (within ∼30 hPa) for measurements in the sunglint region. For overcast conditions, Papp differs from the cloud-top pressure mainly because of multiple scattering inside the cloud. When Papp is compared to the cloud pressure determined from brightness temperature measurements, large differences are observed (typically 180 hPa).

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]

Claudine Vanbauce, Jean-Claude Buriez, Frédéric Parol, Bernard Bonnel, G. Sèze, et al.. Apparent pressure derived from ADEOS-POLDER observations in the oxygen A-band over ocean. Geophysical Research Letters, 1998, pp.3159-3162. ⟨10.1029/98GL02324⟩. ⟨hal-00809107⟩