Open AccessImpacts of aerosols produced by biomass burning on the s tratocumulus‐to‐cumulus transition in the equatorial Atlantic
Author(s) -
Ajoku Osinachi F.,
Miller Arthur J.,
Norris Joel R.
Publication year - 2021
Publication title -
atmospheric science letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.951
H-Index - 45
ISSN - 1530-261X
DOI - 10.1002/asl.1025
Subject(s) - atmospheric sciences , environmental science , troposphere , aerosol , climatology , monsoon , boundary layer , altitude (triangle) , planetary boundary layer , satellite , cloud cover , geology , meteorology , geography , cloud computing , physics , geometry , mathematics , aerospace engineering , computer science , engineering , thermodynamics , operating system
The impact of aerosols produced by biomass burning on the stratocumulus‐to‐cumulus transition (SCT) in the equatorial Atlantic is studied using satellite‐based and reanalysis data for the month of June. The month of June is highlighted because it represents monsoon onset as well as the largest sea surface temperature gradient in the summer, which is the peak season of tropical African biomass burning. Boundary layer deepening and increasing temperatures put the location of the SCT within the Gulf of Guinea. Satellite retrievals indicate that the bulk of aerosols occur near 1,500 m in altitude, either above or below the boundary layer depending on latitudinal position. Changes in smoke loading over the Gulf of Guinea due to greater transport from southern Africa leads to increases in low‐level cloud cover above cloud decks and decreases when mixed within the boundary layer. Further south, we find significant changes to temperature, cloud top height, tropospheric stability and moisture availability near maximum aerosol loading. In addition, changes in vertical velocity during dirty conditions further reinforce changes in tropospheric stability. These effects combine to shorten the SCT in space during increased aerosol loading episodes.