{"title":"美国东海岸的 pH 值分布和确定过程","authors":"Xinyu Li, Yuan-Yuan Xu, Wei-Jun Cai","doi":"10.1029/2024JC020993","DOIUrl":null,"url":null,"abstract":"<p>pH is a key index in ocean biogeochemical and acidification research. However, there remains a limited understanding of the spatial patterns and drivers of pH across different coastal oceans. In this study, we present the distribution of spectrophotometric pH<sub>T</sub> (in total proton scale) from a synoptic summer cruise in 2018. We examine the processes controlling pH<sub>T</sub> along the U.S. East Coast, covering the South Atlantic Bight (SAB), Mid-Atlantic Bight (MAB), and Gulf of Maine (GoM). Our findings reveal a continuous low pH<sub>T</sub> band associated with the oxygen minimum and CO<sub>2</sub> maximum zone along the slope of the entire east coast, extending from the bottom layer (∼1,000 m) in the SAB to the middle layer (300–500 m) in the MAB and GoM. We also identified unique low pH<sub>T</sub> features in each subregion, including an onshore upwelling of the low pH<sub>T</sub> slope water in the SAB, a seasonal low pH<sub>T</sub> feature on the bottom of the MAB shelf associated with the Cold Pool water, and an inflow of low pH<sub>T</sub> slope water to the bottom of the GoM. Our findings suggest that net biological production plays a prominent role in regulating sea-surface pH<sub>T</sub>, driving it away from the air-sea equilibrated pH<sub>T</sub> and mitigating the pH<sub>T</sub> decrease caused by the anthropogenic carbon dioxide (CO<sub>2</sub>) uptake. Furthermore, net biological respiration dominates the interior pH<sub>T</sub> distributions. Our analysis provides new insights and establishes a foundation for interpreting future pH changes in response to processes such as water masses shifting, ocean warming, and anthropogenic carbon uptake in coastal oceans.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"pH Distributions and Determining Processes Along the U.S. East Coast\",\"authors\":\"Xinyu Li, Yuan-Yuan Xu, Wei-Jun Cai\",\"doi\":\"10.1029/2024JC020993\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>pH is a key index in ocean biogeochemical and acidification research. However, there remains a limited understanding of the spatial patterns and drivers of pH across different coastal oceans. In this study, we present the distribution of spectrophotometric pH<sub>T</sub> (in total proton scale) from a synoptic summer cruise in 2018. We examine the processes controlling pH<sub>T</sub> along the U.S. East Coast, covering the South Atlantic Bight (SAB), Mid-Atlantic Bight (MAB), and Gulf of Maine (GoM). Our findings reveal a continuous low pH<sub>T</sub> band associated with the oxygen minimum and CO<sub>2</sub> maximum zone along the slope of the entire east coast, extending from the bottom layer (∼1,000 m) in the SAB to the middle layer (300–500 m) in the MAB and GoM. We also identified unique low pH<sub>T</sub> features in each subregion, including an onshore upwelling of the low pH<sub>T</sub> slope water in the SAB, a seasonal low pH<sub>T</sub> feature on the bottom of the MAB shelf associated with the Cold Pool water, and an inflow of low pH<sub>T</sub> slope water to the bottom of the GoM. Our findings suggest that net biological production plays a prominent role in regulating sea-surface pH<sub>T</sub>, driving it away from the air-sea equilibrated pH<sub>T</sub> and mitigating the pH<sub>T</sub> decrease caused by the anthropogenic carbon dioxide (CO<sub>2</sub>) uptake. Furthermore, net biological respiration dominates the interior pH<sub>T</sub> distributions. Our analysis provides new insights and establishes a foundation for interpreting future pH changes in response to processes such as water masses shifting, ocean warming, and anthropogenic carbon uptake in coastal oceans.</p>\",\"PeriodicalId\":54340,\"journal\":{\"name\":\"Journal of Geophysical Research-Oceans\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2024-09-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geophysical Research-Oceans\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1029/2024JC020993\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"OCEANOGRAPHY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research-Oceans","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2024JC020993","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OCEANOGRAPHY","Score":null,"Total":0}
pH Distributions and Determining Processes Along the U.S. East Coast
pH is a key index in ocean biogeochemical and acidification research. However, there remains a limited understanding of the spatial patterns and drivers of pH across different coastal oceans. In this study, we present the distribution of spectrophotometric pHT (in total proton scale) from a synoptic summer cruise in 2018. We examine the processes controlling pHT along the U.S. East Coast, covering the South Atlantic Bight (SAB), Mid-Atlantic Bight (MAB), and Gulf of Maine (GoM). Our findings reveal a continuous low pHT band associated with the oxygen minimum and CO2 maximum zone along the slope of the entire east coast, extending from the bottom layer (∼1,000 m) in the SAB to the middle layer (300–500 m) in the MAB and GoM. We also identified unique low pHT features in each subregion, including an onshore upwelling of the low pHT slope water in the SAB, a seasonal low pHT feature on the bottom of the MAB shelf associated with the Cold Pool water, and an inflow of low pHT slope water to the bottom of the GoM. Our findings suggest that net biological production plays a prominent role in regulating sea-surface pHT, driving it away from the air-sea equilibrated pHT and mitigating the pHT decrease caused by the anthropogenic carbon dioxide (CO2) uptake. Furthermore, net biological respiration dominates the interior pHT distributions. Our analysis provides new insights and establishes a foundation for interpreting future pH changes in response to processes such as water masses shifting, ocean warming, and anthropogenic carbon uptake in coastal oceans.