全球海洋混合层深度和障碍层厚度计算及其时空变化特征分析-海洋预报

全球海洋混合层深度和障碍层厚度计算及其时空变化特征分析

作者：邢霄波¹ 2 贾永君³ 王斌¹ 2 李亚文¹ 2 党超群¹ 2 胡锦国¹ 2 吴宝勤⁴ 朱先德⁴

单位：1. 国家海洋技术中心, 天津 300112;
2. 自然资源部海洋观测技术重点实验室, 天津 300112;
3. 国家卫星海洋应用中心, 北京 100081;
4. 中国人民解放军 92859部队, 天津 300061

分类号：P731.2

出版年·卷·期（页码）：2024·41·第五期（62-76）

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ΔT₁＝0.2℃和ΔT₂＝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ΔT₁还是ΔT₂，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ΔT₂＝0.5℃的结果比基于阈值ΔT₁＝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 of ΔT₁=0.2 ℃ and ΔT₂=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 using ΔT₁ or ΔT₂. 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 of ΔT₂=0.5 ℃ is higher than that using the threshold of ΔT₁=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.

参考文献：

[1] 刘颖, 严幼芳, 凌征. 北印度洋障碍层厚度气候态和季节变化特征及其成因初步分析[J]. 热带海洋学报, 2020, 39(5):98-108. LIU Y, YAN Y F, LING Z. Preliminary analysis on climatological and seasonal variation of barrier layer thickness in the northern Indian Ocean and it's mechanism[J]. Journal of Tropical Oceanography, 2020, 39(5):98-108.
[2] 于瑶, 吴松华. 基于2007-2018年Argo数据分析全球混合层和障碍层时空特征[J]. 中国海洋大学学报, 2021, 51(12):123-132. YU Y, WU S H. Temporal and spatial characteristics of global mixed layer depth and barrier layer thickness based on Argo data from 2007 to 2018[J]. Journal of Ocean University of China, 2021, 51(12):123-132.
[3] 应美佳, 刘海龙, 王夫常, 等. 南大洋混合层的时空变化特征[J]. 海洋与湖沼, 2019, 50(6):1223-1232. YING M J, LIU H L, WANG F C, et al. Spatio-temporal variations of mixed layer depth in Southern Ocean[J]. Oceanologia et Limnologia Sinica, 2019, 50(6):1223-1232.
[4] GODFREY J S, LINDSTROM E J. The heat budget of the equatorial western Pacific surface mixed layer[J]. Journal of Geophysical Research:Oceans, 1989, 94(C6):8007-8017.
[5] 安玉柱, 张韧, 王辉赞, 等. 全球大洋混合层深度的计算及其时空变化特征分析[J]. 地球物理学报, 2012, 55(7):2249-2258. AN Y Z, ZHANG R, WANG H Z, et al. Study on calculation and spatio-temporal variations of global ocean mixed layer depth[J]. Chinese Journal of Geophysics, 2012, 55(7):2249-2258.
[6] 郭文仪, 邱云, 林新宇. 孟加拉湾障碍层年际变化及其与印度洋偶极子事件的联系[J]. 海洋学报, 2020, 42(9):38-49. GUO W Y, QIU Y, LIN X Y. The interannual variability of barrier layer in the Bay of Bengal and its relationship with IOD events[J]. Haiyang Xuebao, 2020, 42(9):38-49.
[7] LEVITUS S. Climatological atlas of the world ocean[J]. Eos, Transactions American Geophysical Union, 1983, 64(49):962-963.
[8] DE BOYER MONTÉGUT C, MADEC G, FISCHER A S, et al. Mixed layer depth over the global ocean:an examination of profile data and a profile-based climatology[J]. Journal of Geophysical Research:Oceans, 2004, 109(C12):C12003.
[9] KARA A B, ROCHFORD P A, HURLBURT H E. Mixed layer depth variability and barrier layer formation over the North Pacific Ocean[J]. Journal of Geophysical Research:Oceans, 2000, 105(C7):16783-16801.
[10] ALRADDADI T M, ALSAAFANI M A, ALBARAKATI A M, et al. Seasonal variability of mixed layer depth from Argo floats in the central Red Sea[J]. Arabian Journal of Geosciences, 2021, 14(6):496.
[11] HOSODA S, OHIRA T, SATO K, et al. Improved description of global mixed-layer depth using Argo profiling floats[J]. Journal of Oceanography, 2010, 66(6):773-787.
[12] TOYODA T, FUJII Y, KURAGANO T, et al. Interannual-decadal variability of wintertime mixed layer depths in the North Pacific detected by an ensemble of ocean syntheses[J]. Climate Dynamics, 2017, 49(3):891-907.
[13] LIU Q Y, LU Y Q. Role of horizontal density advection in seasonal deepening of the mixed layer in the subtropical Southeast Pacific[J]. Advances in Atmospheric Sciences, 2016, 33(4):442-451.
[14] GAUBE P, MCGILLICUDDY D J JR, MOULIN A J. Mesoscale eddies modulate mixed layer depth globally[J]. Geophysical Research Letters, 2019, 46(3):1505-1512.
[15] XIA R B, LIU Q Y, XU L X, et al. North Pacific eastern subtropical mode water simulation and future projection[J]. Acta Oceanologica Sinica, 2015, 34(3):25-30.
[16] 吴森森, 曹敏杰, 杜震洪, 等. 全球Argo资料共享与服务平台设计与实现[J]. 海洋通报, 2018, 37(3):287-295. WU S S, CAO M J, DU Z H, et al. Design and implementation of the global Argo data sharing and service platform[J]. Marine Science Bulletin, 2018, 37(3):287-295.
[17] HOLTE J, TALLEY L D, GILSON J, et al. An Argo mixed layer climatology and database[J]. Geophysical Research Letters, 2017, 44(11):5618-5626.
[18] HOLTE J, TALLEY L. A new algorithm for finding mixed layer depths with applications to Argo data and subantarctic mode water formation[J]. Journal of Atmospheric and Oceanic Technology, 2009, 26(9):1920-1939.
[19] MIGNOT J, DE BOYER MONTÉGUT C, LAZAR A, et al. Control of salinity on the mixed layer depth in the world ocean:2. Tropical areas[J]. Journal of Geophysical Research:Oceans, 2007, 112(C10):C10010.
[20] ZULBERTI A P, JONES N L, RAYSON M D, et al. Mean and turbulent characteristics of a bottom mixing-layer forced by a strong surface tide and large amplitude internal waves[J]. Journal of Geophysical Research:Oceans, 2022, 127(1):e2020JC017055.
[21] 邢小罡, 邱国强, 王海黎. Bio-Argo浮标观测北大西洋色素与颗粒物的季节分布[J]. 高技术通讯, 2014, 24(1):55-64. XING X G, QIU G Q, WANG H L. Seasonal distributions of pigment and particle in the North Atlantic observed by a BioArgo float[J]. Chinese High Technology Letters, 2014, 24(1):55-64.

服务与反馈：

【文章下载】【发表评论】【查看评论】【加入收藏】