 |
| Titel |
Enviro-HIRLAM aerosol feedback modeling for the Northern Hemisphere |
| VerfasserIn |
Alexander Kurganskiy, Eigil Kaas, Alexander Baklanov, Roman Nuterman, Alexander Mahura, Kristian Pagh Nielsen, Bent Hansen Saas |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144627
|
| Publikation (Nr.) |
 EGU/EGU2017-8477.pdf |
|
|
|
|
|
| Zusammenfassung |
| Aerosol feedbacks have been considered in Coupled Chemistry-Meteorology Modeling
(CCMM) during the recent decades. Commonly, the feedbacks comprise direct and indirect
aerosol effects on meteorology. Direct aerosol effects (DAE) imply influence of atmospheric
aerosols on the short- and long-wave radiation and, as a consequence, air temperature.
Indirect aerosol effects (IDAE) denote impact of aerosols on cloud properties and
precipitation efficiency.
The online-coupled meteorology chemistry model Enviro-HIRLAM (Environment - High
Resolution Limited Area Model) was used to study the aerosol feedbacks for a modeling
domain covering the Northern Hemisphere regions with 0.72∘ horizontal resolution. The
model has been run for two case studies: 8th of August, 2010 (DAE run) and July, 2010
(IDAE run). Results of the model simulations were compared with those ones obtained from
a reference run (REF., i.e., without any feedbacks) to estimate the aerosol feedbacks on
meteorology.
The DAE study showed a reduction of the net downward short-wave surface
radiative fluxes due to aerosols with local maximum differences reaching up to
and above -100 W/m2. The net downward surface long-wave radiative fluxes are
mostly increased due to DAE in the modeling domain. A cooling effect was found at
the lowest vertical model level (∼32 m above ground level) in large parts of the
domain. The maximum regional air temperature difference was found to be around
2-3∘C.
The IDAE study indicated that cloud-aerosol interactions led to an increase of both total
cloud cover and cloud water content. Taking into account the IDAE significantly
reduced the total accumulated precipitation in the modeling domain in July, 2010. The
precipitation efficiency was also studied by analysis of the modeled (REF and IDAE) and
observed time series of the 12-hour accumulated precipitation on example of Arctic
meteorological sites: Alert and Ny-Alesund. The analysis showed that inclusion of
aerosol-cloud interactions (IDAE run) improved the model score by decreasing the mean
precipitation bias from 0.34 to 0.23 mm/12 hours at both measurement stations. |
|
|
|
|
|
|