Environmental Engineering Reference
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measurements at the following three Mediterranean sites: Barce-lona, Spain; Tel-
Aviv Israel; and Finokalia, Crete, Greece. It is known from previous studies that
there are some discrepancies between model data and SSA-measurements. We
found that specific features of the monitoring sites, located over the land, could
contribute to the discrepancies between model data and measurements. The full
description of this study has been previously submitted for publication to the
Journal of Geophysical Research (Kishcha et al., 2009).
2. Methodology
Numerical simulations of the sea-salt aerosols were conducted using the first version
of the DREAM-Salt prediction model. This model is based on the DREAM dust
aerosol model (Nickovic et al., 2001), which was adapted to function not only for
mineral dust but also for sea salt aerosols (Nickovic et al., 2007). In operational
use in Tel-Aviv University, DREAM-Salt produces daily forecasts of 3-D distri-
bution of sea-salt aerosol concentration over the Mediterranean model domain
20W-45E, 15N-50N (http://wind.tau.ac.il/salt-ina/salt.html). The model has 0.3°
horizontal resolution, and 24 vertical levels. Forecasts are made once every day,
starting from the 12:00 UTC objective analyses and providing forecasts up to 72 h
ahead. The NCEP/Eta regional atmospheric model (Janjic, 1994) drives the aerosol.
The aerosol emission scheme is based on the viscous sub-layer model (Janjic, 1994),
in which energy and mass transfers above the air-sea interface critically depend on
turbulent conditions. The aerosol concentration at the top of the viscous sub-layer
is used as the lower boundary condition. The sea-salt emission scheme defines the
lower boundary condition using the source function of Erickson et al. (1986).
Eight particle categories with sizes ranging from 1 to 8 μm are used in the model.
DREAM-Salt incorporates parameterizations of all other major phases of atmo-
spheric sea-salt aerosol life such as: diffusion, advection, gravitational settling, and
wet removal of sea-salt aerosols (Nickovic et al., 2001).
In Barcelona, the sea-salt measurements were taken 2 days/week during the 2-
year period, 2006-2007. In Tel-Aviv, a special sampling campaign was arranged,
which resulted in the collection of sea salt measurements from March 12 to April
9, 2006. Both in Barcelona and in Tel-Aviv, samples were collected over 24 h with
the usual start time of 0900 LT. In Finokalia, Crete, 6-h-averaged measurements
were taken from May 2-30, 2008.
3. Results and Discussion
Shown in
Fig. 1a,
a model-vs.-measurements comparison in Finokalia shows
similarities between model data and 6-h measurements. Some overestimation can
be partly explained by the fact that, in the sea, sea-salt aerosols are produced under
