Seasonal variability of heterogeneous ice formation in stratiform clouds over the Amazon Basin

Author(s)

Seifert, Patric ^[1] ; Kunz, Clara ^[1] ; Baars, Holger ^[1] ; Ansmann, Albert ^[1] ; Buehl, Johannes ^[1] ; Senf, Fabian ^[1] ; Engelmann, Ronny ^[1] ; Althausen, Dietrich ^[1] ; Artaxo, Paulo ^[2]

Affiliation

^[1] Leibniz Inst Tropospher Res, Leipzig - Germany

^[2] Univ Sao Paulo, Inst Phys, Sao Paulo - Brazil

• Document type: Journal article
• Source: Geophysical Research Letters; v. 42, n. 13, p. 5587-5593, JUL 16 2015.
• Web of Science Citations: 8

Abstract

Based on 11months of polarization lidar observations in the Amazon Basin near Manaus, Brazil (2.3 degrees S, 60 degrees W), the relationship between temperature and heterogeneous ice formation efficiency in stratiform clouds was evaluated in the cloud top temperature range between -40 and 0 degrees C. Between -30 and 0 degrees C, ice-containing clouds are a factor of 1.5 to 2 more frequent during the dry season. Free-tropospheric aerosol backscatter profiles revealed a twofold to tenfold increase in aerosol load during the dry season and a Monitoring Atmospheric Composition and ClimateInterim Implementation reanalysis data set implies that the aerosol composition during the dry season is strongly influenced by biomass burning aerosol, whereas other components such as mineral dust do not vary strongly between the seasons. The injection of smoke accompanied by the likely dispersion of biological material, soil dust, or ash particles was identified as a possible source for the increased ice formation efficiency during the dry season. (AU)

• FAPESP's process: 13/05014-0 - GoAmazon: interactions of the urban plume of Manaus with biogenic forest emissions in Amazonia
• Grantee: Paulo Eduardo Artaxo Netto
• Support type: Research Program on Global Climate Change - Thematic Grants