Using in situ airborne measurements to evaluate three cloud phase products derived from CALIPSO

Abstract : We compare the cloud detection and cloud phase determination of three independent climatologies based on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) to airborne in situ measurements. Our analysis of the cloud detection shows that the differences between the satellite and in situ measurements mainly arise from three factors. First, averaging CALIPSO Level l data along track before cloud detection increases the estimate of high-and low-level cloud fractions. Second, the vertical averaging of Level 1 data before cloud detection tends to artificially increase the cloud vertical extent. Third, the differences in classification of fully attenuated pixels among the CALIPSO climatologies lead to differences in the low-level Arctic cloud fractions. In another section, we compare the cloudy pixels detected by colocated in situ and satellite observations to study the cloud phase determination. At midlatitudes, retrievals of homogeneous high ice clouds by CALIPSO data sets are very robust (more than 94.6% of agreement with in situ). In the Arctic, where the cloud phase vertical variability is larger within a 480 m pixel, all climatologies show disagreements with the in situ measurements and CALIPSO-General Circulation Models-Oriented Cloud Product (GOCCP) report significant undefined-phase clouds, which likely correspond to mixed-phase clouds. In all CALIPSO products, the phase determination is dominated by the cloud top phase. Finally, we use global statistics to demonstrate that main differences between the CALIPSO cloud phase products stem from the cloud detection (horizontal averaging, fully attenuated pixels) rather than the cloud phase determination procedures.
Type de document :
Article dans une revue
Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2016, 121 (10), pp.5788-5808. 〈10.1002/2015jd024334〉
Liste complète des métadonnées

Littérature citée [35 références]  Voir  Masquer  Télécharger

https://hal-clermont-univ.archives-ouvertes.fr/hal-01891508
Contributeur : Catherine Moitrier <>
Soumis le : mardi 9 octobre 2018 - 16:27:33
Dernière modification le : jeudi 11 octobre 2018 - 14:26:02

Fichier

2015JD024334.pdf
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

Citation

G. Cesana, H. Chepfer, D. Winker, B. Getzewich, X. Cai, et al.. Using in situ airborne measurements to evaluate three cloud phase products derived from CALIPSO. Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2016, 121 (10), pp.5788-5808. 〈10.1002/2015jd024334〉. 〈hal-01891508〉

Partager

Métriques

Consultations de la notice

39

Téléchargements de fichiers

6