Extreme Low Temperature Events in Northwest China and Their Response to Regional Warming in the Recent 45 Years
Using the daily minimum temperature data of 100 stations in Northwest China in 1960-2004, the thresholds of daily extreme low temperature are determined for different stations, diagnosis of the frequencies of temporal and spatial distributions of annual extreme low temperature events is made for the recent 45 a, and their response to regional warming in Northwest China is analyzed. The result shows that consistent anomaly distribution is the principal spatial mode of the frequencies of annual extreme low temperature events in Northwest Chinat it is found that the spatial mode can be divided into five key areas: north of Xinjiang Region, north of Qinghai Province, east of Northwest China, south of Xinjiang Region, and the plateau in south of Qinghai Province; It is proved that the frequencies of extreme low temperature events show a remarkable decreasing tendency in the north of Xinjiang Region, north of Qinghai Province, east of Northwest China and south of Xinjiang Region, with some abrupt changes. However, there is a wreak decreasing tendency in the plateau in south of Qinghai Province. It is also found that the vibration periods of 13 -15 a and 7 - 8 a are displayed very clear in all the five key areas. It is also proved that the frequencies of extreme low temperature events in Northwest China show a remarkable negative response to regional warming.
Northwest Chinaextreme low temperaturetemporal and spatial evolutionresponse to warming