Spatial and Temporal Characteristics and Meteorological Factors of Frost Dates in Xianyang City
Based on daily ground observation data from 11 national meteorological stations in Xianyang City from 1971 to 2022,the distribution pattern and meteorological factors of frost were analyzed using methods such as linear tendency estimation,Mann-Kendall mutation test and rel-evant statistical analysis.The results showed that the first frost days in all counties(districts)of Xianyang were from mid-October to early No-vember,and the last frost days were from late March to late April,the frost-free period in the north was short and in the south was long,showing that the first frost day was delayed,the last frost day was advanced,and the frost-free period extended significantly.In 2004,2007 and 2005,the first frost date,the last frost date and the frost-free date were significantly delayed,advanced and prolonged respectively;the radiation frost was the most in the first frost period,the less cloud cover,the more frost days,the lower relative humidity and ground lowest temperature,the lower frost rate.The final frost period was mainly mixed frost,which had little relation with cloudiness.Compared with the first frost period,the hu-midity was lower,the temperature was higher and the wind speed was stronger.
Frost dateSpatial and temporal distributionMeteorological factorXianyang City
万方数据
维普
