Aerosol impacts on subtropical low-level clouds: a satellite and modelling perspective

↓ Direkt till sidans innehåll
↓ Direkt till sidans sekundära innehåll (sidomenyn)

Search: WFRF:(Baró Pérez Alejandro 1991) > Aerosol impacts on ...

1 of 2
Previous record
Next record
To hitlist

Aerosol impacts on subtropical low-level clouds: a satellite and modelling perspective

Baró Pérez, Alejandro, 1991- (author): Stockholms universitet,Meteorologiska institutionen (MISU)

Ekman, Annica M.L. Professor (thesis advisor): Stockholms universitet,Meteorologiska institutionen (MISU)

Bender, Frida A.-M. Associate professor (thesis advisor): Stockholms universitet,Meteorologiska institutionen (MISU)

Devasthale, Abhay, Associate professor (thesis advisor): Meteorological Research Unit, Research and development, Swedish Meteorological and Hydrological Institute

Redemann, Jens, Professor (opponent): University of Oklahoma School of Meteorology

show less...

(creator_code:org_t)

ISBN 9789180142885
Stockholm : Department of Meteorology, Stockholm University, 2023
English 48 s.

Related links:: https://su.diva-port... (primary) (Raw object); show more...; https://su.diva-port... (Preview); https://urn.kb.se/re...; show less...

Doctoral thesis (other academic/artistic)

Abstract Subject headings

Complex interactions between aerosols, clouds, and radiation impact Earth's climate. However, several aspects of these interactions remain uncertain, which has led to extensive research over the last decades. This thesis explores some unresolved aspects by focusing on subtropical low-level stratocumulus (Sc) clouds, which have a significant cooling effect on climate. The clouds are also sensitive to varying aerosol conditions, which can influence their formation, properties, and lifetime. Clouds over the South East Atlantic have been studied in detail, using both numerical modeling and satellite observations, to shed light on the interactions between aerosols, clouds, and radiation. This geographical region displays a large and semi-permanent Sc cloud deck and is also subjected to meteorological conditions that bring large amounts of light-absorbing aerosols from biomass fires over the African continent. The biomass-burning plumes also bring enhanced levels of moisture, and the individual influence of the aerosols and the moisture on the low-level cloud properties have been investigated.The analysis of satellite retrievals showed a radiative impact (sensitive to aerosol composition and aerosol optical depth) of moist aerosol layers in the free troposphere over the South East Atlantic; however, it was not possible to observe a clear influence of these humid aerosol layers on the underlying low-level clouds. Aerosol-radiation interactions were implemented in a large eddy simulation (LES) code that was used to model stratocumulus to cumulus transitions (SCT) in weather situations where moist absorbing aerosol layers were in contact with low-level clouds and mixed into the marine boundary layer (MBL). In these simulations, the heating by the absorbing aerosol within the MBL affected the persistence of the Sc clouds by accelerating the SCT, especially during daylight and broken cloud conditions. However, the humidity accompanying the absorbing aerosol was also found to be important -- it reduced the deepening of the MBL when located above the Sc deck and delayed the SCT when in contact with clouds. Furthermore, the additional moisture resulted in a radiative cooling effect that was comparable to the radiative cooling effect caused by the aerosol itself. The simulated SCTs were found to be mostly driven by increased sea surface temperatures, regardless of aerosol conditions. This result was different compared to two other LES models where the SCT was driven by drizzle under the same low aerosol conditions. On a larger scale, it was found that an explicit description of aerosol-cloud interactions in a climate model led to smaller differences between the simulated and mean observed values of the shortwave cloud radiative effect compared to when a non-interactive parameterization was used.

Find in a library

Aerosol impacts on subtropical low-level clouds a satellite and modelling perspe... (Search the publication in LIBRIS)

To the university's database

1 of 2
Previous record
Next record
To hitlist

Find more in SwePub

By the author/editor: Baró Pérez, Alej ...; Ekman, Annica M. ...; Bender, Frida A. ...; Devasthale, Abha ...; Redemann, Jens, ...

About the subject

NATURAL SCIENCES: NATURAL SCIENCES; and Earth and Relate ...; and Meteorology and ...

By the university: Stockholm University

Search outside SwePub

Extend your search to:: Google; Google Book Search; Google Scholar

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

LIBRIS.kb.se

Aerosol impacts on subtropical low-level clouds: a satellite and modelling perspective

Subject headings

Keyword

Publication and Content Type

Find in a library

To the university's database

Find more in SwePub

Search outside SwePub