The research project of this Program was the
Randomized Convective Cold Cloud Seeding
Experiment in Extended Areas (EXPerimento
aleatorizado de siembra de nubes en AReas
EXtensas, EXPAREX), based in silver iodide seeding
from the tops of growing convective clouds, which
design, general description and physical foundations
were presented in Martínez et al. (2007) and Pérez et
al., (2008). This experiment is being implemented in
Camagüey and the adjacent provinces of Ciego de
Ávila and Las Tunas from August 2005 as the
continuation and complementation of the previous
results of PCMAT (Koloskov et al., 1996).
The experimental units were defined as the
group of clouds located within a circle having a radius
of 25 km and centered at the location of the initial
treatment. The target clouds within the experimental
unit were growing convective clouds having, at least
0.5 g/m3 of supercooled cloud water (SCW), updraft
velocity greater than 5 m/s and top temperature of -7
to -20oC, as described in detail in Martínez et al.
(2007). The clouds were seeded from an
instrumented An-26 aircraft, under the dynamic
seeding hypothesis. The glaciogenic reagent applied
in the experiment is the pyrotechnic mixture of the
Russian flares PV-26. This mixture has an output of
1.7x1014 glaciogenic nuclei per gram at -10 oC and
7.0x1013 at -6 oC. The flares burn during 40s