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Seasonal variability of heterogeneous ice formation in stratiform clouds over the Amazon Basin
Author(s) -
Seifert Patric,
Kunz Clara,
Baars Holger,
Ansmann Albert,
Bühl Johannes,
Senf Fabian,
Engelmann Ronny,
Althausen Dietrich,
Artaxo Paulo
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl064068
Subject(s) - aerosol , environmental science , atmospheric sciences , dry season , amazon rainforest , lidar , mineral dust , climatology , geology , meteorology , geography , remote sensing , ecology , cartography , biology
Based on 11 months of polarization lidar observations in the Amazon Basin near Manaus, Brazil (2.3 ∘ S, 60 ∘ 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 ∘ C. Between −30 and 0 ∘ 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 Climate—Interim 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.