近百年中国总辐射场变化的基本特征

ESSENTIAL FEATURES OF SOLAR RADIATION FIELD VARIATION IN CHINA DURING THE RECENT HUNDRED YEARS

本文根据文献[1]重建的中国近百年(1881—1980年)总辐射月总量场资料序列,分析其多年变化特征。结果表明,中国近百年总辐射场主要变化趋势为东部广大地区自本世纪初至四十年代末全年各季均有明显上升趋势,其后至七十年代末期则呈下降趋势,但就整个时段来说,总辐射无明显增大或减少;其余地区(除东南沿海、青藏高原的个别季节与东部不一致外)基本变化趋势都与东部地区一致,但新疆北部和青藏高原夏季变化趋势不明显。在主趋势背景下,中国总辐射场百年序列中还具有明显的三种准周期振动,主要集中于周期为30～48年,10～15年和5～7年三个频段。对比近百年我国气温场变化趋势,从一个侧面佐证“温室效应”。

The essential features of monthly amount variation for solar radiation are analyzed using the reconstructed records of the solar radiation field during the period of 1881-1980 ys. It is shown by the first three principal components of solar radiation field series for each seasonal typical month (e. g. 1, 4, 7, 10 month) that the trend of interannual change of the solar radiation may be divided into three stages in the whole eastern region of China: the first stage is the descending trend before early the century, second stage is ascending trend from early the century until the middle 1950 s of the century, the following stage is also descending. It is very similar to above feature that the trend of the interannual change during the past 100 years for the solar radiation field in the other regions of China except the southern China coast (spring) and Qinghai-Xizang plateau (autumn). On the other hand* three frequency bounds of quasi-cyde fluctuation are revealed by mealed by means of the maximum entropy spectrum method. They are the periodic component of 30-48,10-15 and 5-7 years respectively.