摘要
基于2002—2019年的Argo温盐数据计算得到海洋混合层深度(MLD)和障碍层厚度(BLT),利用阈值法在计算过程中设置不同的温度阈值ΔT_(1)=0.2℃和ΔT_(2)=0.5℃,并分别利用温度、密度以及由温度和密度计算得到全球海洋的MLD和BLT值,基于此描述不同温度阈值下得到的全球海洋混合层和障碍层分布特征。结果表明:不论阈值是ΔT_(1)还是ΔT_(2),基于温度和密度的计算结果较基于温度参数或密度参数的结果更为可靠。利用温度参数或密度参数计算得到的MLD值,不论是MLDT还是MLDD都能够在一定程度上体现全球海洋MLD的分布特征,两者在赤道附近和低纬度海域结果的一致性较好,在高纬度海域差异较大。基于阈值ΔT_(2)=0.5℃的结果比基于阈值ΔT_(1)=0.2℃的结果与现有MLD数据的相关性更高,但是均方根误差也更大,可能是由于不同海域适合的阈值选择不同,需进一步计算分析。全球海洋BLT较南北半球高纬度海域BLT值更大,BLT值随着纬度的降低而减小,空间分布特征在不同海域均存在明显差异,总体来说BLT随着纬度的降低而减小。
In this paper,the mixed layer depth(MLD)and barrier layer thickness(BLT)are calculated using the threshold method,based on in-situ ocean temperature and salinity measurements of the Argo profiles during 2002—2019.Different thresholds ofΔT_(1)=0.2℃andΔT_(2)=0.5℃,as well as different judgement rules,i.e.ocean temperature alone,ocean density alone,ocean temperature and density together,are involved in the calculation,and the differences in the MLD and BLT characteristics arose from different thresholds are described.The results show that the MLD judged by temperature and density together are more reliable than those judged by temperature alone or density alone,regardless of the threshold usingΔT_(1)orΔT_(2).Both the MLD judged by temperature alone(MLDT)and density alone(MLDD)can reflect the spatial characteristics of the MLD in the global ocean to a certain extent.The MLDT and MLDD are in good agreement with each other in the equatorial and low-latitude oceans,while divergent largely in the high-latitude oceans.The correlation of the derived MLD using the threshold ofΔT_(2)=0.5℃is higher than that using the threshold ofΔT_(1)=0.2℃with respect to other existing MLD data,but the former has a larger root-mean-square error than the latter,probably due to regional suitability of the selected threshold.The spatial characteristics of the BLT are significantly different in different ocean areas.In general,the BLT has a relative large value in the high-latitude oceans,and decreases equatorward.
作者
邢霄波
贾永君
王斌
李亚文
党超群
胡锦国
吴宝勤
朱先德
XING Xiaobo;JIA Yongjun;WANG Bin;LI Yawen;DANG Chaoqun;HU Jinguo;WU Baoqin;ZHU Xiande(National Marine Technology Center,Tianjin 300112,China;Key Laboratory of Marine Observation Technology,Ministry of Natural Resources,Tianjin 300112,China;National Satellite Ocean Application Service,Beijing 100081,China;PLA 92859,Tianjin 300061,China)
出处
《海洋预报》
CSCD
北大核心
2024年第5期62-76,共15页
Marine Forecasts
基金
自然资源部海洋环境信息保障技术重点实验室开放基金课题
自然资源部海洋观测技术重点实验室定向基金(2022klootB01)。
关键词
全球海洋
混合层深度
障碍层厚度
时空特征
global ocean
mixing layer depth
barrier layer thickness
temporal and spatial characteristics
