新旧气候态的差异及其对江西气候业务的影响

Difference Between New and Old Climatic States and Its Impact on the Climate Assessment in Jiangxi Province

利用1961—2022年江西74个气象站平均气温、最高气温、最低气温、降水量、相对湿度、平均风速和日照时数资料,对比分析了1991—2020年和1981—2010年新、旧气候态下气象要素差异,探讨气候平均值改变对气候影响评价和预测业务的影响。结果表明:新气候态下,江西省三类气温的年和季节平均值均上升,年降水量总体增加将弱化气温偏高、降水偏多的变化特征。年和季节平均风速距平山区减小而平原地区增大;年日照时数距平总体增加。极端高温年份减少,极端低温年份增多,其中平均气温和最低气温的极端高(低)温年发生概率的降幅(增幅)比最高气温更大。极端强降水年发生概率在赣西北、赣中大部、赣南西北部等地区夏季减少,赣南中南部地区冬季增大。全省历年极端日高温、低温和强降水事件发生站次总体减少。新、旧气候态的更替会对气候业务产生影响,如冬季气温偏冷的年份增加,偏暖的年份减少,需对冷、暖冬事件进行重新评估,夏季降水增多的变化特征减弱,将导致夏季降水预测量级和趋势发生改变。

Based on the data of average temperature,maximum temperature,minimum temperature,precipitation,relative humidity,average wind speed and sunshine duration from 74 meteorological stations in Jiangxi from 1961 to 2022,the difference between the new and old climatic states from 1991 to 2020 and from 1981 to 2010 was analyzed,and its impact on climate assessment and prediction was discussed.The results showed that under the new climatic state,the annual and seasonal values of the three types of temperature in Jiangxi increased congruously,as well as the annual precipitation,which weakened the characteristics of high temperature and excessive precipitation.The annual and seasonal average wind speed decreased in mountainous areas and increased in plain areas,and the annual sunshine duration anomaly generally increased.The number of extreme high temperature year decreased,while the number of extreme low temperature years increased.The occurrence probability decrease(increase)of extreme high(low)temperature year of the average and minimum temperature was more than that of the maximum temperature.The occurrence probability of extreme heavy rainfall annually decreased in summer over northwestern Jiangxi,most of central Jiangxi,and northwestern southern Jiangxi,while increased in winter over central southern Jiangxi.In general,the number of extreme daily high temperature,low temperature,and heavy precipitation events decreased over the years.The replacement of new and old climate states had an impact on climate service.For example,it was necessary to reassess the cold and warm winter events when the temperature in winter increased in years with lower temperatures or decreased in years with higher temperatures.The weakening of rainy summer precipitation would lead to changes in the magnitude and trend of summer precipitation predictions.