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Climatology is reviewed and redefined in terms of relevance to geography, and a programmatic statement for future research is presented. Instead of enumerating substantive areas, physical geography is defined and ranked according to five levels of methodology and attendant philosophy. The essence of geographical climatology is the analysis and description of process-response systems of importance to mankind occurring within the planetary boundary layer, interface, and substrates. The future of a climatology useful to geographers appears to lie in the numerical modeling of such systems.

YIELD, a water-balance and crop-yield model that calculates production and water consumption variables for a variety of major crops, was applied specifically for wetland rice to China and Korea in order to estimate the region's potential and actual yields for irrigated and rainfed rice production. A network of 241 stations provided the climatic data averaged over approximately a 25-year period. Highest potential yields under full irrigation for a single rice crop occurred in Kansu-Niangsia, the Yangtze River plain, Yunnan-Szechwan-Kweichow, coastal China and Korea, and the islands of Hainan and Taiwan. The yields ranged from 6,000 to 10,000 kg/ha. Smallest yields were found for the western interior and the northeast. In areas where multiple cropping was possible, total yields exceeded 16,000 kg/ha in the south. Under rainfed conditions, only the central and southern China region retained a viable production. In order to achieve optimum crop yields, about 1.000 mm of irrigation water was needed in...

The urban energy balance climatology of the city and man in the Los Angeles basin was examined during a cloudy day (“Catalina eddy”) in September, 1968, from about sunrise to sunset, by measuring or estimating solar radiation, net radiation, ground heat flux, actual surface temperature, terrain radiant temperature, radiant sky temperature, and dry and wet-bulb temperature for the physical urban interface. An analogous theoretical model attempted to define the input of energy to the human interface via the solar heat load, and the disposal of human net radiation was shown via the channels of latent, sensible, and body heat flux. In spite of an apparent uniform cloud cover, the energy parameters had considerable areal variation in intensity and trend. During the daylight hours seventy percent of the solar radiation was absorbed. An additional thirty-two percent was removed by longwave radiation. Of the net radiation received on the dry surface (forty-seven percent of solar radiation), about eighty percent was disposed via sensible heat flux, and the remainder entered the pavement as storage. Air temperatures taken at shelter height were out of phase with the ongoing energy regime and were deemed of dubious value in urban climatic studies. Urban man received only thirty-seven percent and seventy percent of the values available at the horizontal pavement for solar radiation and net radiation, respectively. A series of empirical and theoretical models show high correlations with the observations. It appeared that solar radiation and net radiation (physical and human) could have been estimated via the solar constant and appropriate transmissivities.

A model which attempts to simulate urban absorption of solar radiation is concerned with direct solar radiation, diffuse sky radiation, diffuse radiation reflected by buildings and streets, and the shortwave energy absorbed by typical urban structures. The ratio between solar radiation absorbed by three-dimensional building-street systems and two-dimensional horizontal surfaces under cloudless conditions indicates that cities undergo great variations with latitude and season. High structure systems absorb more than six times the radiation of nonurban plains. Shading effects can create absorptance less than that of a level surface. Observations at street level may lead to erroneous conclusions concerning the energy input for the total urban interface. The examination of a circular synthetic city with varying latitudinal radiation responses indicates that daytime urban heat islands are migratory phenomena and probably influence convective air circulation in the city, that downtown areas often absor...

This study deals with human comfort expressed in a physio-climatic classification. Four physiological and psychological reactions of man to temperature, relative humidity, wind chill, and solar radiation are combined into two nomograms from which average human reactions can be deduced. Comfort and Wind Effect Indices are applied to meteorological data of the conterminous United States for July and January, daytime and nighttime, respectively. Maps combining both indices for July apply the classification on a larger scale (Southern California), and on a smaller scale (U.S.). A map of annual physio-climatic extremes synthesizes in generalized form how man tends to feel in various areas on a yearly basis. Thus, a three-step system results which attempts to revise certain conventional notions about comfort regions. No paradoxical distributions are apparent and the classification seems limited only by the availablity and reliability of data. The scheme is applicable to any dimension: time or region, a...

The relation between leaves (broad and needle leaves) in a canopy and parts of the soil-atmosphere environment is modeled and analyzed. The parameters examined are concerned with short and longwave radiation, reradiation, and latent and convectional heat fluxes at the leaf level. The resulting leaf energy budget is empirically linked to a generalized model of potential photosynthesis whose major inputs are solar radiation and leaf temperature. The predictions of the combined process-response system do not attempt to portray existing plants, but are used to infer the trend of the major forcing and response functions of leaves in general when exposed to a great variety of environmental conditions. Leaves in the topmost canopy exhibit the highest Bowen ratios and highest potential photosynthesis, whereas the opposite is the rule among interior leaves. During the growing season many middle latitude climates show higher potential productivity than moist, tropical climates.

A deterministic system of models relates man and other vertical objects to horizontal shortwave radiation under cloudless conditions, and permits comparison of actual conditions with an ideal standard. This is the first in a system of increasingly more complex models which will eventually solve the entire energy balance equation in bioclimatology. The parameters examined are concerned with direct solar radiation, diffuse sky radiation, diffuse radiation reflected from the ground, and the total solar heat load on man. Each latitude and each season has its own characteristic pattern of these components, which often differ drastically from data applicable to horizontal surfaces. Depending on the season, direct solar radiation on vertical objects poleward of latitude 30/sup 0/ can exceed several times the amounts incident on an equivalent horizontal surface. Direct solar radiation on vertical objects equatorward of latitude 30/sup 0/ is less than that incident on the horizontal interface.