 |
| Titel |
The radiative impact of desert dust on orographic rain in the Cévennes–Vivarais area: a case study from HyMeX |
| VerfasserIn |
C. Flamant, J.-P. Chaboureau, P. Chazette, P. Di Girolamo, T. Bourrianne, J. Totems, M. Cacciani |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 21 ; Nr. 15, no. 21 (2015-11-04), S.12231-12249 |
| Datensatznummer |
250120140
|
| Publikation (Nr.) |
 copernicus.org/acp-15-12231-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The
study is focused on Intensive Observation Period (IOP) 14 of the
Hydrological Cycle in the Mediterranean Experiment first Special
Observing Period (HyMeX SOP 1) that took place from 17 to 19 October
2012
and was dedicated to the study of orographic rain in the Cévennes–Vivarais (CV) target area. During this IOP a dense dust plume
originating from northern Africa (the Maghreb and Sahara) was observed to
be transported over the Balearic Islands towards the south of
France. The plume was characterized by an aerosol optical depth
between 0.2 and 0.8 at 550 nm, highly variable in time and
space over the western Mediterranean Basin. The impact of this dust
plume, the biggest event observed during the 2-month-long HyMeX SOP 1,
on the precipitation over the CV area has been analyzed using high-resolution
simulations from the convection permitting mesoscale
model Meso-NH (mesoscale non-hydrostatic model) validated against measurements obtained from numerous
instruments deployed specifically during SOP 1 (ground-based/airborne
water vapor and aerosol lidars, airborne microphysics probes) as
well as space-borne aerosol products. The 4-day simulation
reproduced realistically the temporal and spatial variability
(including the vertical distribution) of the dust. The dust radiative impact
led to an average 0.6 K heating at the altitude of the dust
layer in the CV area (and up to +3 K locally) and an
average 100 J kg−1 increase of most unstable convective
available potential energy (and up to +900 J kg−1
locally) with respect to a simulation without prescribed dust
aerosols. The rainfall amounts and location were only marginally
affected by the dust radiative effect, even after 4 days of
simulation. The transient nature of this radiative effect in
dynamical environments such as those found in the vicinity of heavy
precipitation events in the Mediterranean is not sufficient to
impact 24 h of accumulated rainfall in the dust simulation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|