Column aerosol characterization in a semi‐arid region around Marrakech during the WATERMED 2003 campaign

Abstract

In the framework of the WATERMED (WATer use efficiency in natural vegetation and agricultural areas by Remote sensing in the MEDiterranean basin) project, an experimental field campaign was carried out in a semi-arid region near Marrakech, Morocco, during March 2003. This work focused on the columnar aerosol characterization from spectroradiometric and photometric measurements of direct solar irradiance and sky radiance at ground level. The results show a high dependence of the aerosol optical properties on the air masses present in the area. Two periods with different aerosol loads were observed in the campaign. In the first, Atlantic-origin aerosols showed a marine particle accumulation mode combined with a dominant mode corresponding to coarse particles of local origin. In the second period the synoptic situation changed towards a Saharan + Atlantic origin, the Atlantic influence persisting at altitude while at lower levels the presence of air masses proceeding from the Saharan desert was observed. This dry air carried a large quantity of mineral particles that increased the area's turbidity, leading to a substantial increase in the volume of the whole distribution, a displacement of the accumulation mode radius towards higher values and an increasingly evident spread of the coarse particle mode, although the radius remained the same as that in the first period of the campaign.

Operational considerations to improve total ozone measurements with a Microtops II ozone monitor

“…Thanks to its portability and easy operation, it can be considered as a cheaper alternative to measure column ozone in intensive field campaigns (e.g. Gómez-Amo et al, 2006 and2008) or in remote locations where Brewer and Dobson measurements are not available. The short time needed to take a Microtops measurement allows total ozone measurements even in days with broken clouds (Köhler, 1999).…”

Operational considerations to improve total ozone measurements with a Microtops II ozone monitor

“…ozone in intensive field campaigns (e.g. Gómez-Amo et al, 2006, 2008 or in remote locations where Brewer and Dobson measurements are not available. The short time needed to take a Microtops measurement allow for total ozone measurement even in days with broken clouds (Köhler, 1999).…”