| 摘要: |
| 基于阿拉斯加湾（Gulf of Alaska， GOA）2002—2020年的Argo浮标数据，本研究分析了该海湾逆温现象的时空变化特征，并探讨其年际变化与水体垂向位温异常的联系。结果显示，阿拉斯加湾逆温现象存在明显的时空变化。空间上，逆温幅度（ΔT）在湾北部最大，湾东南部次之，湾西南部最弱。逆温厚度（ΔD）在湾西南部最厚，湾北部和东南部依次变薄。在季节尺度上，湾北部逆温现象的季节变化最明显，冬季ΔT最大和ΔD最厚，随季节性的加热和混合作用，ΔT持续减弱，ΔD不断变薄。在湾东南部，ΔT分别在3月和9月具有0.46、0.40 ℃的峰值；ΔD在整个海湾中最薄，冬季最大为44 m，而秋季最小仅为23 m。在湾西南部，ΔT介于0.24~0.33 ℃之间，分别于4月和10月具有0.31、0.33 ℃的峰值；ΔD冬季最大超过100 m，秋季最薄约为57 m。年际变化上，ΔT在2002、2007—2009、2012、2017年表现为正异常，但在2003—2005、2010、2013—2016、2018—2020年表现为负异常；ΔD在2002、2007—2008、2012、2017—2020年主要偏厚，在2003—2006、2015—2016年偏薄。湾北部和东南部ΔT和ΔD的年际变化较为一致，但两者在西南部并没有明显的联系。ΔT和ΔD年际变化与水体垂向位温异常有密切联系。当水体位温具有冷（暖）异常时，整个海湾ΔT往往具有正（负）异常，湾北部和东南部ΔD趋于偏厚（薄），但湾西南部ΔD趋于偏薄（厚）。 |
| 关键词: 海洋水文学 逆温 时空变化 位温异常 阿拉斯加湾 |
| DOI：10.3969/J.ISSN.2095-4972.2023.02.012 |
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| 基金项目:全球变化与海气相互作用（二期）专项(GASI-01-NPAC-STsum);国家自然科学基金（42130406） |
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| Spatiotemporal variations of temperature inversion in the Gulf of Alaska |
| GUO Shaojing,ZHENG Jianhua,JING Chunsheng,WANG Weibo,FENG Jianjie |
| (Third Institute of Oceanography, MNR, Xiamen 361005, China;Fujian Provincial Key Laboratory of Marine Physical and Geological Processes, Xiamen 361005, China;Xiamen Institute of Environmental Science, Xiamen 361024, China) |
| Abstract: |
| The spatiotemporal variations of temperature inversion in the Gulf of Alaska (GOA) are analyzed based on 2002-2020 Argo data and relationship between its interannual variations and vertical potential temperature anomaly also is investigated. The results show that there are considerable spatiotemporal variations of temperature inversion. Spatially, temperature difference (ΔT) is the largest, moderate and the weakest in the northern GOA (NGOA), southeastern GOA (SEGOA) and southwest (SWGOA), respectively. The inversion thickness (ΔD) is the thickest in the SWGOA, relatively thinner in the NGOA and thinnest in the SEGOA. As for seasonal change, ΔT and ΔD in the NGOA change apparently with the largest ΔT and ΔD in winter, then they decrease because of seasonal heating and vertical mixing. In the SEGOA, ΔT peaks in March (0.46 ℃) and September (0.40 ℃). There has a ΔD maximum (44 m) in winter and a ΔD minimum (only 23 m) in autumn. In the SWGOA, ΔT changes with seasonal alternations in 0.24-0.33 ℃ producing two peaks 0.31 and 0.33 ℃ in April and October, respectively. ΔD is larger than 100 m in winter and is the thinnest about 57 m in autumn. At interannual time scales, ΔT displayed positive anomalies in 2002, 2007-2009, 2012 and 2017, but negative anomalies in 2003-2005, 2010, 2013-2016 and 2018-2020. ΔD is mainly thicker than normal in 2002, 2007-2008, 2012 and 2017-2020, while thinner than normal in 2003-2006 and 2015-2016. The interannual variations of ΔT and ΔD in the NGOA and SEGOA are well consistent with each other, but there is no clear connection between them in the SWGOA. Moreover, ΔT and ΔDchanges are closely related to vertical potential temperature anomaly. When the vertical potential temperature of seawater was in cold (warm) anomaly, ΔT revealed a positive (negative) anomaly in the whole GOA, ΔD tended to be thicker (thinner) in the NGOA and SEGOA , but thinner (thicker) in the SWGOA. |
| Key words: marine hydrography temperature inversion spatiotemporal variation potential temperature anomaly Gulf of Alaska |
