524 
PACIFIC SCIENCE, Vol. VII, October, 1953 
2.4 5.1 1 1.0 23.7 61.1 
PARTICLE RADIUS AT 99 % RH ( W ) 
Fig. 2, Vertical distribution of sea-salt particles over 
the sea in Hawaii (21°30'N, 157°40'W), May 30, 1952, 
1300 local time. Surface wind 80°, force 4 to 5. Height 
of scattered cumulus cloud bases varied from 690 to 
820 meters. Temperature at 2,740 meters 12.8°C. The 
short transverse lines on the distribution curves mark 
the first quartile, median, and third quartile weight 
distribution points, reading left to right. The distribu- 
tion curves are read as follows: at a height of 518 
meters there are about 10,000 particles larger than 100 
/x/i grams. 
detailed physical changes in the air associated 
with these frequently recurring processes. 
The presence of the great mountain Mauna 
Kea (see Fig. 1), extending up to almost 
14,000 feet, makes it possible to obtain direct 
visual estimates of maximum cloud heights 
among the orographic clouds over the high- 
rainfall region during extended time periods 
which make air craft observation impractic- 
able. These estimates can be made at the same 
time that rain and cloud drops are being sam- 
pled within the cloud along the roadway be- 
low. One can drive a car up to a point at the 
9,500 foot level, which is near a site over- 
looking the high-rainfall region A. 
In this area of Hawaii, nature is producing 
rain very regularly and under simple condi- 
tions usually uncomplicated vertically by mul- 
tiple layering of air masses of different origin 
and physical history. Geophysical events of 
the past and present seem to have fortuitously 
conspired to produce a setting in which sim- 
ple natural experiments in rain-making are an 
almost daily occurrence. Through the use of 
local roadways and aircraft, the whole ex- 
perimental area is readily accessible for study, 
and the observations of one day can com- 
monly be tested or extended on the following 
day under the nearly constant natural condi- 
tions. The author knows of no other geo- 
graphical setting so uniquely advantageous 
for cloud physics studies. 
The importance of rainfall to the economy 
of the Hawaiian Islands has led to extensive 
activity by local organizations in the study of 
various weather factors and in the accumula- 
tion of data from numerous observing sta- 
tions. These organizations— the U. S. Weather 
Bureau, the Pineapple Research Institute, the 
Experiment Station of the Hawaiian Sugar 
Planters’ Association, and the Territorial Cat- 
tlemen’s Council— located at Honolulu, Ha- 
waii, are interested in fostering cloud physics 
research and are able to supply valuable 
climatological data from long-period records 
as well as current radiosonde and other data 
from numerous local stations. — A. H. 
Woodcock^ Woods Hole Oceanographic Institu- 
tion. (Contribution No. 660 of the Woods 
Hole Oceanographic Institution.) 
