陕北、渭北冬季负积温变化特征及趋势预测

利用陕北、渭北各气象站1960-1990年日平均气温资料统计各站的负积温，用小网格分析法分析其空间变化规律；选择榆林、绥德、延安、洛川和铜川等5个代表站，对40年负积温进行3年滑动平均模拟，分析时间变化特点和变化趋势，发现它们都有4年和9年的基本周期；分析确定了冬季冷暖评判指标；根据负积温变化趋势和变化规律，选择直线回归和方差分析叠加，对未来几年冬季冷暖状况进行预测。

Variation and Trend Prediction of Winter Negative Accumulated Temperature in Shaanbei and Weibei regions

Based on average daily air temperature of meteorological observation stations in Shaanbei and Weibei regions from 1960 to 1990, the negative accumulated temperatures for all stations were statistically calculated, and their spatial variations were analyzed with small grid method. The five stations in Yulin, Suide, Yan'an, Luochuan and Tongchuan respectively were selected as representatives for this region. The temporal variation and trend of negative accumulated temperature were analyzed by using three years moving average for 40 years. A 4-year and a 9-year variation period of the negative accumulated temperature were found. The cooling and warming index in winter was determined. The situations of cooling and warming in winter were predicted with linear repression and super posing variance analysis according to variation and trend of negative accumulated temperature.