Ocean Acidification - Category 1: Climatological Mean Distribution of pH in Surface Waters in the Unified pH Scale and Mean Rate of changes in Selected Areas

在这个项目中，哥伦比亚大学拉蒙特-多尔蒂地球天文台的研究人员将根据对表层水中二氧化碳、总碱度和总二氧化碳离子浓度(DIC)的观测，在一个统一的尺度上获得全球表层海洋pH的分布。他们将利用他们自己三十年的二氧化碳分压和DIC数据，这些数据基于David Keeling(和ERL/NOAA的继任者Pieter Tans)WMO测压二氧化碳标准，以及来自WOCE计划(Dickson等人，2003年)和包括BATS、HOT和ESTOC在内的时间序列站的经过良好校准的碱度数据。这些数据将使全球海洋酸碱度和碳酸盐浓度基线的建立牢牢地固定在大气和海洋二氧化碳测量共同的国际二氧化碳标准之上。不同年份的PCO2和DIC数据将被修正为参考年份2000，并将使用Lueker等人的碳酸和硼酸的离解常数来计算总氢离子标度和碳酸盐离子浓度中月平均pH的气候分布。(2000)和Dickson(1990)。这将作为描述未来海洋酸化特征的世界海洋基线分布。在北大西洋、北太平洋和南大洋的一些数据丰富的地区，将展示变化的速度。由于与直接酸碱度测量相关的校准问题，基于观测的全球海洋酸碱度分布图是不可能的；目前的信息是基于没有陆地相互作用的海洋GCM研究。然而，研究小组S对碱度数据的持续分析表明，在孟加拉湾、阿拉伯海、阿拉斯加湾和白令海等陆地相互作用的广泛区域，碱度的分布与公海不同。这表明，由于忽略了河流和陆地的相互作用，模型结果是有偏差的。我们拟议的调查结果将用于验证全球生物地球化学海洋模型，并将有助于将全球海洋酸化研究建立在更坚实的基础上。更广泛的影响：需要基线信息来准确描述全球环境变化。这项研究的目的是利用过去几十年获得的广泛的二氧化碳、碱度和DIC数据库，为在统一的pH标度下计算的水域的pH和碳酸盐离子浓度提供全球表层海洋基线。这应该作为一个参考水平，可以参照未来和过去的变化。

In this project, researchers at the Lamont-Dougherty Earth Observatory of Columbia University will obtain the global distribution of surface ocean pH in a single unified scale based on the observations for pCO2, total alkalinity and total CO2 ion concentration (DIC) in surface waters. They will utilize three decades of their own pCO2 and DIC data, which are based on David Keeling's (and successor Pieter Tans at ERL/NOAA) WMO manometric CO2 standard, and the well-calibrated alkalinity data from the WOCE program (Dickson et al., 2003) and the time-series stations including BATS, HOT and ESTOC. These data will allow establishment of a global ocean pH and carbonate concentration baseline anchored firmly to the international CO2 standards common to the atmospheric and oceanic CO2 measurements. The pCO2 and DIC data obtained in different years will be corrected to a reference year 2000, and a climatological distribution of monthly mean pH in the total hydrogen ion scale and carbonate ion concentrations will be computed using the dissociation constants for carbonic and boric acids of Lueker et al. (2000) and Dickson (1990). This will serve as a world ocean baseline distribution for the characterization of future ocean acidification. In some data-rich areas of the North Atlantic, North Pacific and Southern Ocean, the rate of change will be demonstrated. Because of calibration problems associated with direct pH measurements, an observation-based global ocean pH distribution map is not possible; presently the information is based on ocean GCM studies without land interactions. The research team?s ongoing analysis of the alkalinity data shows, however, that its distribution differs from the open oceans in the broad regions of land interactions such as in the Bay of Bengal, Arabian Sea, Gulf of Alaska and Bering Sea. This suggests that the model results are biased by the omission of rivers and land interactions. The results of our proposed investigation will be used for the validation of global biogeochemical ocean models and will help to place the global ocean acidification study on a much firmer base. Broader Impacts: Baseline information is needed for accurate characterization of global environmental changes. The purpose of this study is to provide a global surface ocean baseline for pH and carbonate ion concentration in waters computed in a uniform pH scale using an extensive pCO2, alkalinity and DIC database obtained for past several decades. This should serve as a reference level, against which the future and past changes may be referenced.