基于走航观测数据的ERA5南海北部夏季短波辐射收支评估  

Estimation of ERA5 shortwave radiation budget in the northern South China Sea in summer based on navigation observation data

作　　者：章振 张功 刘长炜 吴仁豪 齐木荣 邓汉虞 陈剑桥 韩博 Zhang Zhen;Zhang Gong;Liu Changwei;Wu Renhao;Qi Murong;Deng Hanyu;Chen Jianqiao;Han Bo(Key Laboratory of Tropical Atmospheric and Marine System Science,Ministry of Education,School of Atmospheric Sciences,Sun Yatsen University,Zhuhai 519082,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China)

机构地区：[1]中山大学大气科学学院热带大气海洋系统科学教育部重点实验室,广东珠海519082 [2]南方海洋科学与工程广东省实验室(珠海),广东珠海519082

出　　处：《海洋学报》2023年第2期51-61,共11页

基　　金：国家重点研发计划(2020YFA0608804);南方海洋科学与工程广东省实验室(珠海)自主立项项目(SML2020SP007,SML2021SP201);广东省基础与应用基础研究基金(2020A1515110675);广东省自然资源厅广东省海洋经济发展(海洋六大产业)专项资金(粤自然资合[2022]18号)。

摘　　要：海表短波辐射收支是海–气界面能量交换的重要物理过程。本研究利用2019年南海北部夏季科考航次的走航观测数据,评估了ERA5再分析数据的海表短波辐射通量收支。结果表明,ERA5的向下短波辐射相比观测偏小,11时和15时(北京时间)的偏差最大,可达-100 W/m^(2)。与此同时,ERA5的海表反照率整体偏低,其中高太阳高度角时段偏差较小,约为-0.03,低太阳高度角时段偏差较大,约为-0.15。向下短波辐射和反照率的偏差共同造成ERA5白天平均海表净短波辐射通量比观测偏小约25.4 W/m^(2);其中,反照率低估抵消了约50%向下短波辐射偏差的贡献。研究表明,在不同大气透射率情况下,ERA5的海表辐射收支偏差存在不同表现。ERA5海表反照率的低估可能与其采用的参数化方案在南海北部的适用性不足有关。基于观测本研究也给出了一个简单的参数优化方案。The short wave radiation budget on the sea surface is an important physical process of energy exchange at the sea-air interface.In this study,the sea surface short wave radiation flux budget of ERA5 reanalysis data is evaluated by using the observed data of summer scientific research voyages in the northern South China Sea in2019.The results show that the downward short wave radiation of ERA5 is smaller than the observed data,and the deviation is the largest at 11:00 and 15:00(Beijing time),up to-100 W/m~2.At the same time,the sea surface albedo of ERA5 is generally lower than observed.The bias in ERA5 is small under a high solar altitude angle,being about-0.03,but can reach-0.15 under a low solar altitude.The bias in the downward shortwave radiation and sea surface albedo jointly caused an underestimation of 25.4 W/m~2 in the daytime average sea surface net shortwave radiation flux in ERA5.In particular,the albedo underestimation offsets about 50% of the contribution of downward shortwave radiation bias.The results show that ERA5 has different manifestations of sea surface radiation budget deviation under different atmospheric transmittance conditions.We also found that the underestimation of sea surface albedo in ERA5 is caused by its parameterization schemes and put an optimization based on our observation.

关 键 词：海表反照率 向下短波辐射通量 大气透射率 太阳高度角 

分 类 号：P444[天文地球—大气科学及气象学]