In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 23, No. 11 ( 2023-06-12), p. 6409-6430
Abstract:
Abstract. Dusty cirrus clouds are extended optically thick cirrocumulus decks that occur during strong mineral dust events. So far they have mostly been
documented over Europe associated with dust-infused baroclinic storms. Since today's global numerical weather prediction models neither predict
mineral dust distributions nor consider the interaction of dust with cloud microphysics, they cannot simulate this phenomenon. We postulate that
the dusty cirrus forms through a mixing instability of moist clean air with drier dusty air. A corresponding sub-grid parameterization is suggested
and tested in the ICOsahedral Nonhydrostatic model with Aerosol and Reactive Trace
gases (ICON-ART). Only with the help of this parameterization is ICON-ART able to simulate the formation of the dusty cirrus, which
leads to substantial improvements in cloud cover and radiative fluxes compared to simulations without this parameterization. A statistical
evaluation over six Saharan dust events with and without observed dusty cirrus shows robust improvements in cloud and radiation scores. The ability
to simulate dusty cirrus formation removes the linear dependency on mineral dust aerosol optical depth from the bias of the radiative fluxes. For
the six Saharan dust episodes investigated in this study, the formation of dusty cirrus clouds is the dominant aerosol–cloud–radiation effect of
mineral dust over Europe.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-23-6409-2023
DOI:
10.5194/acp-23-6409-2023-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2023
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
Bookmarklink