Climatology and Sugar Cane- -CHANG 
395 
TABLE 2 
Effective Rainfall as a Function of Annual Rainfall at Kohala 
(Assuming varying soil moisture storage capacities of 2, 3, and 4 inches) 
Annual rainfall (inches) 
Effective rainfall for: 
40 
50 
60 
70 
80 
90 
100 
2 -inch storage 
34 - 
40 
46 
52 
56 
60 
61 
3 -inch storage 
37 
43 
49 
55 
58 
62 
65 
4~inch storage 
37 
44 
50 
56 
60 
65 
69 
the climatic effect on juice quality has at least 
two practical applications. First, we can schedule 
planting and harvest dates accordingly, in order 
to best fit the seasonality of a climate; in this 
connection a study of climatic singularity would 
be valuable. Second, an understanding of the 
role played by climate could help us to interpret 
the results from many agronomic experiments. 
CONCLUDING REMARKS ON CLIMATOLOGICAL 
RESEARCH 
This review has demonstrated the broad scope 
of climatological research in the Hawaiian sugar 
industry. The application of this research, as 
Curry (1952) pointed out 10 years ago, could 
ultimately give new life to many an economic 
activity. Toward that end we have made only a 
beginning. Much work remains to be done. 
Future research should be planned in three 
general areas: 
L GENETIC CLIMATOLOGY: Only 20 years 
ago climatology was treated primarily as a study 
of statistical meteorology, replete with records 
but almost devoid of explanations. The post-war 
studies of the climate of Hawaii are among the 
pioneers in the field of genetic climatology. 
These studies bring a fair measure of systematic 
order into the otherwise incoherent climatic 
facts and explain many seemingly local phenom- 
ena in the light of general circulation. A better 
understanding of the dynamism and genesis of 
climate could conceivably lessen or avert agri- 
cultural hazards in many other parts of the 
world. It is hoped that Trewartha’s new book 
(1961) will stimulate interest and hasten de- 
velopment in this field. 
2. ENERGY BUDGET AND WATER BALANCE: 
Genetic climatology focuses its attention on the 
free atmosphere. Local variations, caused by 
the interaction of the atmosphere and the ter- 
rain, can best be understood by a study of the 
energy budget and water balance. Conven- 
tional observations, tied to the needs of synoptic 
forecasting, are often inadequate for the study 
of topoclimate. Urgently needed is an inter - 
nationally-standard field instrument for the 
measurement of solar radiation. The recent de- 
velopment of an instrument which measures 
net radiation (Soumi et al, 1954; Fritschen, 
1960£), or even net radiation minus soil heat 
flow (Portman, 1954), is most encouraging. 
Measurements of evapotranspiration by in- 
expensive field instruments are also needed on 
a wider scale. In humid climates evaporimeters, 
such as evaporation pans or atmometers (Halkais 
et al, 1955), have been of value. In arid climates, 
however, the problem is vexing. There the very 
concept of potential evapotranspiration is elu- 
sive and unrealistic. For potential evapotranspi- 
ration requires, by definition, a homogeneous soil 
moisture regime infinite in horizontal extent, 
and once the area upwind is adequately watered 
the climate is no longer arid. In actuality the 
effect of advective heat exists even in a very 
large irrigated area. Gal’tsov (1953), for in- 
stance, has observed decreasing water require- 
ments from the border towards the center of an 
irrigated region in Kazakhstan. It is difficult to 
evaluate the effect of advective heat. Perhaps an 
approach similar to but more refined than Be- 
lasco’s study ( 1952 ) on the modification of air 
mass is in order. 
To solve the water-balance equation the soil 
moisture storage capacity needs to be known. 
This requires the cooperation of soil scientists. 
On a global scale, representative figures of 
moisture storage capacity of the major geo- 
graphical regions are useful for many purposes. 
