 |
| Titel |
Aerosol seasonal variability over the Mediterranean region and relative impact of maritime, continental and Saharan dust particles over the basin from MODIS data in the year 2001 |
| VerfasserIn |
F. Barnaba, G. P. Gobbi |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 4, no. 9/10 ; Nr. 4, no. 9/10 (2004-11-30), S.2367-2391 |
| Datensatznummer |
250001418
|
| Publikation (Nr.) |
 copernicus.org/acp-4-2367-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| The one-year (2001) record of aerosol data from the space borne Moderate
Resolution Imaging Spectroradiometer (MODIS) is analyzed focusing on the
Mediterranean region. The MODIS aerosol optical thickness standard product
(AOT at 550nm) provided over both land and ocean is employed to evaluate
the seasonal and spatial variability of the atmospheric particulate over the
region. Expected accuracy of the MODIS AOT is (±0.05±0.2xAOT)
over land and (±0.03±0.05xAOT) over ocean. The
seasonal analysis reveals a significant AOT variability all over the region,
with minimum values in Winter (AOT<0.15) and maximum in Summer (AOT>0.2).
The spatial variability is also found to be considerable, particularly
over land. The impact of some major urban sites and industrialized areas is
detectable. For the sole Mediterranean basin, a method (aerosol mask) was
implemented to separate the contribution of maritime, continental and desert
dust aerosol to the total AOT. Input of both continental and desert dust
particles is well captured, showing North-to-South and South-to-North AOT
gradients, respectively. A quantitative summary of the AOT seasonal and
regional variability is given for different sectors of the Mediterranean
basin. Results of this summary were also used to test the aerosol mask
assumptions and indicate the method adopted to be suitable for the aerosol
type selection. Estimates of the atmospheric aerosol mass load were
performed employing specifically-derived mass-to-extinction efficiencies
(α). For each aerosol type, a reliable mean α value was
determined on the basis of both lidar measurements of extinction and aerosol
models. These estimates indicate a total of 43Mtons of desert dust
suspended over the basin during 2001. A comparable value is derived for
maritime aerosol. Opposite to the dust case, a minor seasonal variability
(within 15%) of maritime aerosol mass is found. This latter result is
considered a further check of the suitability of the methodology adopted to
separate, on the basis of MODIS data, the three aerosol types which dominate
the Mediterranean region. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|