新、旧气候态的差异及对东北地区气候业务的影响

选取参与东北地区短期气候预测业务质量评估的53个气象站的月平均气温、降水资料，NCEP/NCAR再分析的月平均500 hPa位势高度场资料，以及由NOAA重构的海温场资料，对比了新、旧气候平均态下，冬、夏季东北地区气温、降水及全球500 hPa位势高度场及海温场差异, 并分析了气候平均值改变对气候变化、影响评价和预测业务的影响。结果表明：就东北大部分地区而言，新气候态（1981-2010年）表征的气候较旧气候态（1971-2000年）更暖湿；新气候态的全球500 hPa位势高度值和海温值较旧气候态均有所增大；新气候态下东亚大槽强度和西伯利亚高压强度变弱是造成东北冬季气温升高的主要原因；西太副高和鄂霍次克海阻塞高压强度增强，是造成东北地区大部分月份降水量增加的主要原因；而东北冷涡强度减弱是造成东北地区6月降水量减少的主要原因；9月和10月降水量减少可能与海温的变化有关。气候平均值的改变会对气候业务产生影响，如需对冷冬事件和ENSO事件重新评估，对极端事件重新分析，及对要素预报量级和趋势产生影响。

The Difference Between New and Old Climatic Stage and Its Influence on Climatic Operation in the Northeast China

Based on the monthly temperature and precipitation data of 53 observational stations in the Northeast China and NCEP/NCAR reanalysis data of monthly geopotential height data and monthly sea surface temperature data reconstructed by NOAA during 1961-2012, a comparison was made between the two 30-year climatic normal of meteorological elements as well as 500 hPa geopotential height and sea surface temperature field. The influence to climatic operation by the change of climatic normal condition was analyzed. The results suggest that for most part of the Northeast China, the climate in the new climatic normal condition is wetter and warmer than that in the old climatic normal condition; the global 500 hPa geopotential height and sea surface temperature values during the new climatic normal condition are all slightly higher than that in the old climatic normal condition; winter temperature rise in the Northeast China is largely caused by weakening intensity of East Asia trough and Siberian high; higher intensity of West Pacific subtropical high and Okhotsk blocking high, among others, is the major factor responsible for higher precipitation in most months in this region; reduced intensity of northeast cold vertex is the main reason that less precipitation occurs in June in this region; the reduction of precipitation in September and October may be associated with the change of sea surface temperature; variation in climatic normal condition produces effects on climatic operation such as climatic variation operation, climatic evaluation and climatic prediction, necessitating for example reevaluation of ENSO and warm winter event as well as reanalysis of extreme events, and may affect the trend and order of magnitude.