APPLIED CLIMATOLOGY 
By HELMUT E. LANDSBERG 
Research and Development Board, Washington, D. C. 
and WOODROW C. JACOBS 
Headquarters, Air Weather Service, Washington, D. C. 
Introduction 
Definition. If we consider climate as the statistical 
collective of individual conditions of weather, we can 
define applied climatology as the scientific analysis of 
this collective in the light of a useful application for an 
operational purpose. The term weather includes all at- 
mospheric events and the observation of individual 
weather elements as single series synoptically or other- 
wise combined. The term operational is also broadly 
interpreted as any useful endeavor, such as industrial, 
manufacturing, agricultural, or technological pursuits. 
Historical Note. This type of climatological work 
reflects an old and historical approach to the subject. 
The earliest scientific climatic observations, such as the 
ones sponsored by the Societas Meteorologica Palatina, 
,were made for the sake of knowledge. However, the 
networks of climatological stations inaugurated upon 
the urging of Thomas Jefferson, Surgeon General Joseph 
Lovell, Alexander von Humboldt, and others were di- 
rected toward the practical ends of land utilization, 
agriculture, and health. This pioneermg work took 
place considerably before meteorological networks were 
established to provide data for weather forecasting. 
Meteorological observations later became subservient 
to the aims of synoptic meteorology and remained so 
for many decades. Climatology became an adjunct 
devoted to a mere statistical summarization of the data. 
Only lately has there been a resurgence of the idea that 
the accumulated climatic data have a high practical 
value, far beyond their use for the descriptive average 
picture of the atmosphere used in comparative geog- 
raphy, a use which has dominated the field of clima- 
tology. 
Prefatory Note. The followimg discussion does not 
attempt to treat the subject of applied climatology 
exhaustively. Within the allotted space the current 
state of the art can, in many instances, be given only 
by references to pertinent papers. Most stress will be 
laid on the inadequacies and on the lines that might be 
explored profitably by future research work. 
Analysis of Requirements for Climatic Data in Various 
Activities 
The objective is to make climatic information useful 
for other pursuits. Therefore, the particular climatic 
data desired in each instance must be established. It 
is a fallacy to assume that the usual climatological 
observations, summarized in the classical format now 
standard at most weather offices, can immediately be 
applied to the practical problems at hand. Misuse of the 
readily available climatic data has led to many mis- 
conceptions and faulty interpretations, and in some 
cases has even discredited the science of climatology. 
First of all, climatic data should be interpreted by 
the expert climatologist. His position in relation to the 
user of this material is analogous to that of a physician 
or a lawyer or an architect in relation to his client. 
This makes it imperative that the climatologist should 
not only know the weather data but should also diagnose 
the case to which the data are to be applied. Usually, a ~ 
thorough analysis of the operations for which the cli- 
matic data are needed has to be made. Two questions 
have to be answered: 
1. Which climatic elements affect the operation? 
2. How can the available climatic material be inter- 
preted for the particular purpose at hand? 
In practice it is essential to go through a thought 
process which is roughly ‘sketched in the two ques- 
tionnaires given below. These lists of questions are not 
prepared for any specific case and must be altered to 
fit each individual problem. 
QUESTIONNAIRE I: ANALYSIS OF OPERATION 
(Climatic Anamnesis) 
1. Class of enterprise (business, industry, agriculture, 
etc.)? 
2. What operational subdivisions exist? 
3. Class of problem? 
a. To lead to a design. 
b. To affect a procedure. 
c. To make an operational decision as to ‘‘where”’ 
or ‘‘when.”’ 
4. How does the prospective user of the weather in- 
formation define his weather problem? 
5. How does he define his operational problem? 
6. Will the climatic or weather information the user 
believes he needs furnish a solution to the opera- 
tional problem? 
7. Have solutions previously been obtained for analo- 
gous operational problems? 
8. Can the operational problem be redefined in more 
realistic climatological terms? 
a. What periodic fluctuations (diurnal, seasonal, 
etc.) exist? 
b. What are the critical climatic and weather limi- 
tations on the operation? 
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