Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
58
result(s) for
"Chang, Jen-hu"
Sort by:
GLOBAL DISTRIBUTION OF NET RADIATION ACCORDING TO A NEW FORMULA
A new formula for estimating net radiation has been derived from records of solar radiation, humidity, and air temperature. The formula is believed to be an improvement over the previous ones which used cloudiness instead of solar radiation. The correlation coefficient between the computed and actual values is 0.97 and the standard error of estimate is 2.57 langleys/day. The limitations of the formula, such as the use of standard values of reflection coefficients, the use of surface humidity instead of total precipitable water, and the exclusion of carbon dioxide, are discussed. The formula has been applied to 386 stations for the construction of world maps for four mid-season months as well as for the year. The distributional pattern differs somewhat from the world maps prepared by Budyko. Solar radiation retained as net radiation decreases from sixty percent in the tropics to less than twenty percent in high latitudes.
Journal Article
POTENTIAL PHOTOSYNTHESIS AND CROP PRODUCTIVITY
A model for estimating net photosynthesis is presented, based on the relationship between gross photosynthesis and solar radiation and daylength derived by Monteith, and the relationship between respiration and temperature derived by Thomas and Hill. The model has been applied to 386 stations, and world maps of potential photosynthesis for three different periods have been constructed. For the four-month summer period the highest potential photosynthesis is found along west coasts in high latitudes near sixty degrees latitude. For both the eight-month period and the annual mean, the Mediterranean type of climate has the highest growth potential. Potential photosynthetic rates for various climatic types and for latitudinal zones have been summarized. Actual crop yields of rice, cotton, and sugar cane of leading producing countries have been correlated with the computed potential photosynthesis. The correlations are highly significant. The implications of the study of potential photosynthesis in the strategy of land-use planning, particularly in the so-called underdeveloped countries, are discussed.
Journal Article
Some Aspects of Agroclimatology in Southeast Asia and New Guinea
Several aspects of energy budget and water balance problems in SE Asia and New Guinea are discussed and a new map showing the distribution of global radiation in SE Asia and New Guinea is presented. Potential evapotranspiration rates are calculated by the Penman equation and are compared with monthly rainfall to determine the length of the hydrological growing season. Potential rice yields are estimated based on a formula developed by the International Rice Research Institute. The extremely low maize yields of Asian humid tropics are explained by unfavorable climatic conditions, particularly high night temperature.
Journal Article