Quantifying Rates of Biological Production to Better Understand the Carbon Cycle in the Canada Basin

为了预测快速变化的北冰洋未来的碳循环，需要更好地了解当今的碳循环，本研究将使用一些相对新颖的方法对此进行研究。气体示踪剂氧、氩和三氧同位素可分别用于量化群落净生产率和初级生产总值。净群落生产力被定义为光合作用减去群落呼吸，从而反映了二氧化碳的净吸收量？生物泵？总初级生产力被定义为总光合通量。净群落与初级生产总值的比率可以提供有关生态系统碳回收程度的信息。通过同时测量净群落和总初级生产率，这项工作将研究环境对光合作用和呼吸作用的影响，这项研究将使用O2与氩的比率和三重氧同位素来量化夏季巡航三年来在博福特环流区的生物生产率。加拿大盆地。这项工作的主要目标是更好地了解生物生产，海冰和温度之间的相互作用在加拿大盆地。该小组将使用2011年和2012年收集的数据，在2013年收集样本，并解释所有数据，以解决两个假设。第一，当夏季海冰范围较小时，总初级生产力增加，但净群落生产力不变。在这种情况下，碳循环将没有净变化，尽管如果使用叶绿素或生物量的传统指标，产量似乎会增加。第二个假设是，总初级生产率和碳循环率在活跃融冰的地区更高，也就是在？冰缘开花。这些冰缘水华应具有与开放水域相似的净群落生产率，并且不产生额外的净碳吸收。更广泛的影响-专业媒体设计师将制作一个关于北冰洋生物生产力变化的短片。这将在伍兹霍尔海洋展览中心和当地渡轮玛莎？葡萄园。此外，该项目将通过为研究生提供机会来促进教育。

In order to predict the future carbon cycle in a rapidly changing Arctic Ocean, a better understanding of the present-day carbon cycle is needed, and this research will study this with some relatively novel methods. The gas tracers oxygen, argon and triple oxygen isotopes can be used to quantify rates of net community production and gross primary production, respectively. Net community production is defined as photosynthesis minus community respiration and thus reflects the net amount of CO2 taken up by the ?biological pump.? Gross primary production is defined as the total photosynthetic flux. The ratio of net community to gross primary production yields information on how tightly an ecosystem is recycling its carbon. By concurrently measuring rates of net community and gross primary production, this work will study the environmental effects on photosynthesis and respiration, and this should allow a better mechanistic understanding of the processes controlling biological production.This research will use the ratio of O2 to Argon and triple oxygen isotopes to quantify rates of biological production on summertime cruises for three years in the Beaufort Gyre section of the Canada Basin. The main objective of this work is to gain a better understanding of the interplay among biological production, sea ice, and temperature in the Canada Basin. The team will use data collected in 2011 and 2012, collect samples in 2013 and interpret all the data in order to address two hypotheses. The first is that gross primary production increases when summer sea ice extent is smaller but that net community production does not change. In this case there will be no net change in the carbon cycle although production will seem elevated if one uses traditional metrics of chlorophyll or biomass. The second hypothesis is that rates of gross primary production and carbon recycling are higher in regions of actively melting ice, that is in ?ice edge blooms.? These ice edge blooms should have similar rates of net community production to the open water and be responsible for no additional net carbon uptake.Broader Impacts - Professional media designers will produce a short video about changing biological productivity in the Arctic Ocean. This will be shown at the Woods Hole Oceanographic Exhibit Center and on local ferries to Martha?s Vineyard. Additionally, this project will promote education by including opportunities for a graduate student.