Mineral Dust and its Microphysical Interactions with Clouds - Mineral Dust: A Key Player in the Earth System - page 297

Table 12.1 List of major field campaigns involving the study of dust and its hygroscopicity

Campaign Focus Major findings

AMMA, Matsuki et al.
( 2010 )

Characteristics of mineral
dust incorporated in
cloud droplets and related
cloud processing

Secondary sulfate, nitrate, and
chlorate found on many dust
particles; enhanced in clouds
Strong differences between
calcium-rich and silicate
particles; carbonates containing
secondary species in
significantly larger frequency
and amount

NASA portion of AMMA,
Twohy et al. ( 2009 )

Hygroscopicity of sampled
aerosol and effect of
Saharan dust on clouds in
the area

Saharan dust particles do
commonly act as CCN in the
eastern North Atlantic
Due to slightly hygroscopic nature,
even submicron dust can be
important as CCN
Due to its dual nature to act as both
CCN and IN, dust can impact
not only droplet size in small
clouds but ice formation in
deep convective clouds

MEIDEX, Levin et al.
( 2005 )

Size distribution and
chemical composition of
aerosol particles during a
dust storm

Approximately 35 % of the coarse
particles up to about 1 km in
height were internal mixtures
of dust and sea salt
Depending on whether dust
particles are active as GCCN
and/or effective IN, droplet
concentration, diameter,
lifetime, area cover, and
amount of rain may differ

Beijing, Li and Shao
( 2009b )

Study of the sizes,
morphologies, and
composition of samples
collected during brown
haze and dust episodes

In haze events, almost 90 % of the
mineral particles were covered
by visible coating, whereas
only 5 % in the dust events
were coated
The majority of coatings were Ca-,
Mg-, and Na-rich, containing
oxygen and nitrogen (possibly
nitrates) and minor amounts of
sulfur

SAMUM-2, Schladitz
et al. ( 2011 )

Particle number size
distributions, mixing
state, and hygroscopicity
of aerosol in Cape Verde

The sampled Saharan dust aerosol
was an external mixture of
nearly hygrophobic and
hygroscopic particles with
values ranging from 0.3 to 1
(continued)