Relevant Analysis of Grassland Temperature and Ground Net Radiation in Guilin

[Objective] The aim was to study the relevance of grassland temperature and ground net radiation in Guilin.[Method] By dint of ground observation data and net radiation of national benchmark climate station in Guilin from 2007 to 2009,the changes of grassland temperature and ground net radiation were expounded and their relations were pointed out.[Result] The annual changes trends of grassland temperature and ground net radiation in Guilin were basically the same.Monthly average maximum value all appeared in summer(July to August).Monthly average lowest value appeared in winter(December to next January);monthly average grassland temperature and monthly average ground net radiation had positive relation.Grassland temperature and ground net radiation had basically same distribution in four seasons.The average largest value of ground net radiation in summer was the largest and average smallest value was the smallest;the average largest value of ground net radiation in cloudy days was the smallest and average minimum value was the largest;the daily difference was the largest in sunny day and daily difference was the smallest in cloudy day.The daily changes trend of grassland temperature and ground net radiation in different weather state were basically the same;when it was sunny or cloudy,the daily largest value of grassland temperature and ground net radiation occurred between 15:00 and 19:00;when it was overcast,there was no distinct peak and daily changes.The largest value of the daily extreme value of grassland temperature and ground net radiation took place from 12:00 to 15:00.The daily lowest value took place from 20:00 to 07:00 on the next day.[Conclusion] The study provided reference for the analysis of temperature changes in Guilin.

SOLAR RADIATION AT GROUND IN EAST-ASIA FROM DATA OF THE GEOSTATIONARY SATELLITE GMS

A method(Rieland,1985)has been modified to determine the downward solar radiation at ground over East Asia,using GMS-3 data of the satellite with a spatial resolution of 10×10 krn^2 and a time interval of 3 hours.The distributions of the monthly mean global radiation are obtained for January,April,July and October of 1985.These results illustrate that the topography effect of the Tibetan Plateau is not negligible.The values of global radiation over the high Tibetan Plateau during all seasons are higher than those in the lower-level surroundings.By comparing model results with ground observed data, the relative errors in monthly averages of global radiation are 2.8％ for clear sky and 6.3％,5.3％,5.0％ and 4.5％ for cloudy sky in January,April, July and October,respectively.The relative error in daily global radiation during the snow-free season is less than 20％ and larger than 20％ in snow-covered winter.We,however,had no data for these comparisons which were measured directly at the Plateau during the year 1985.