东北半干旱地区夏季能量水分传输过程分析

利用2015年8月锦州气象站的观测资料和中国地面气候资料日值数据集(V3.0),分析东北半干旱地区夏季能量水分传输过程。结果表明:锦州地区8月两次降水过程对近地面气象要素造成的差异较为明显。锦州站2 m气温和比湿都具有明显的日变化特征,较深层土壤升温与浅层土壤升温相比存在滞后效应。8月锦州站的CO2通量平均值为-0.17 mg/(m2·s),表现为"碳汇"。陆—气之间的能量交换主要依赖于水汽相变所传输的能量。地表反照率的日变化趋势大致为"U"型。潜热通量和感热通量平均值分别为71.9、29.7 W/m2。强烈的向下短波辐射使土壤和地表增温,同期降水量也偏少,是2015年夏季该地区出现的干旱的主要原因。能量不平衡的现象普遍存在,在考虑能量平衡时,考虑土壤热储量情况下的能量闭合率比不考虑时高2%～3%,夜间数据可以忽略。云量的增多会降低能量闭合程度。

Analysis of energy and water transmission in semi-arid area of Northeast China in summer

Based on the observation data of Jinzhou station in August 2015 and China Surface Climate Daily Data Set (V3.0), it is analyzed that the energy and water transmission in the semi-arid area of Northeast China in summer. Results show that: The difference of ground meteorological elements caused by two precipitation processes in August in Jinzhou is obvious. 2-m temperature and specific humidity have significant diurnal variation in Jinzhou station, and the deeper soil heating lags behind the shallow soil heating. The average CO2 flux of the ecosystem in Jinzhou station was -0.17mg/(m2s), which indicates a "carbon sink" in August. The land-atmosphere energy exchange mainly depends on the energy transmitted by heterogeneous condensation in Jinzhou station. The diurnal variation of the surface albedo is roughly a "U" type. The intense downward shortwave radiation increased soil and surface temperature, and there is low precipitation during the same period, which is the main reason for the drought in the summer of 2015. The energy imbalance widespread exists. The soil heat reserve needs to be considered for energy balance, but night-time data can be ignored. The increase of cloud cover reduces the energy closure rate.