Light Intensity, Nutrient, and pCO2 Controls on Boron Isotope Fractionation in Laboratory Cultured Corals

对碳酸盐系统敏感的硼同位素可能是了解珊瑚化学的重要工具，并且具有追踪pCO2变化的有趣可能性，无论是长时间尺度的全球变化还是珊瑚本身介导的内部“碳库”条件的记录。出于这个原因，PI将确定两组不同的人工珊瑚样本的硼同位素组成，以增加我们对硼同位素的吸收和分选的了解。一组在受控光强和营养条件下培养的珊瑚样本将解决对天然珊瑚中硼同位素组成的季节变化的观测解释是否正确。第二组在特定温度和二氧化碳分压水平下生长的珊瑚，将解决这两个参数对硼同位素组成的影响，并具体回答珊瑚中硼同位素是否可以用作古ph值代表的问题。硼同位素作为pH值替代物的潜在应用可能为我们了解冰期/间冰期时间尺度上二氧化碳分压的全球变化，以及海洋-大气相互作用和全球气候变化提供进一步的见解。

ABSTRACTOCE-0083061Boron isotopes, sensitive to the carbonate system, may be an important tool in understanding coral chemistry and has the intriguing possibility of tracking changes in pCO2, whether it be global changes over long time scales or a record of internal 'carbon pool' conditions mediated by the coral itself. For this reason, the PI will determine the boron isotopic composition for two separate sets of cultured coral samples to increase our knowledge on the uptake and fractionation of boron isotopes. One suite of coral samples cultured under controlled light intensity and nutrient conditions will address whether the interpretation of observed seasonal variation in the boron isotopic composition of a natural coral is correct. The second set of corals grown under specified temperature and pCO2 levels, will address the influence of these two parameters on the boron isotopic composition, as well as specifically answer the question as to whether boron isotopes in corals can be used as a paleo-pH proxy. The potential application of boron isotopes as a proxy for pH may provide further insights into our understanding of global changes in pCO2 over glacial/interglacial time scales, and thus ocean-atmosphere interactions and global climate change.