Distribution and seasonal variation in the partial pressure of CO_2 during autumn and winter in Jiaozhou Bay, a region of high urbanization

摘要

We investigated the partial pressure of carbon dioxide (pCO_2) in Jiaozhou Bay (JZB), which is surrounded by the economically developed city of Qingdao, during two cruises undertaken in November, 2007 (autumn) and February, 2008 (winter). Results indicated that sea surface pCO_2 in autumn varied between 315 and 720 μatm, with an average level of 418 uatm. In winter the sea surface pCO_2 ranged from 145 to 315 μatm with an average of 249 uatm, which is below atmospheric pCO_2. Despite seasonal temperature variation between autumn and winter, it was noted that biological process (production and respiration) were responsible for both spatial and seasonal variation during these seasons. We found that Jiaozhou Bay served as a net atmospheric CO_2 source in autumn (November) (2.87 mmol m~(-2) d~(-1)), while in winter (February) it served as a net sink (-16.22 mmol m~(-2) d~(-1)).