 |
| Titel |
The structure of the haze plume over the Indian Ocean during INDOEX: tracer simulations and LIDAR observations |
| VerfasserIn |
G. Foret, C. Flamant, S. Cautenet, J. Pelon, F. Minvielle, M. Taghavi, P. Chazette |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 4 ; Nr. 6, no. 4 (2006-03-22), S.907-923 |
| Datensatznummer |
250003621
|
| Publikation (Nr.) |
 copernicus.org/acp-6-907-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| Three-dimensional, nested tracer simulations of a pollution plume originating
from the Indian sub-continent over the Indian Ocean, in the framework of the
Indian Ocean Experiment (INDOEX), between 5 and 9 March 1999, were performed
with the Regional Atmospheric Modeling System (RAMS), to provide insight into
the transport patterns of the pollutants, as well as to investigate the
dynamical mechanisms controlling the vertical structure of the plume and its
evolution in the vicinity of the Maldives Islands. Airborne and ground-based
LIDAR observations of the structure of the haze plume made on 7 March 1999
were used to assess the quality of the simulations, as well as the impact of
grid resolution on the vertical structure of the simulated plume. It is
shown that, over the Arabian Sea, in the vicinity of the Maldives Islands,
the pollutants composing the plume observed by the airborne LIDAR
essentially originated from the city of Madras and that the vertical
structure of the plume was controlled by the diurnal cycle of the
continental boundary layer depth. A combination of tracer simulations and
remote sensing observations (airborne LIDAR, ship-borne photometer,
ground-based LIDAR in Goa) was used to analyse the diurnal evolution of the
haze plume over the sea. We find evidence that the sea breeze circulation
and orographic lifting taking place in the southern part of the Indian
sub-continent during the daytime play a crucial role in the modulation of
the continental boundary layer depth, and in turn, the haze plume depth. The
eastward shift of the subtropical high from central India to the Bay of
Bengal after 6 March lead to an increase in the tracer concentrations
simulated over the Arabian Sea, in the region of intensive observations
north of the Maldives, as transport pathways form Hyderabad and Madras were
modified significantly. The nesting of a high horizontal resolution domain
(5 km, with 39 vertical levels below 4000 m above mean seal level) allows for a
better representation of local dynamics, the circulation of sea and mountains
breezes, and therefore a noticeable improvement in the representation
of the pollutants' plume in the simulation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|