Cryogenic stage for laser microscope

点击翻译按钮获取中文摘要

Arctic sea-ice is disappearing rapidly, this is going to have a profound impact on global climate, carbon cycling and sequestration calculations, and biological and human systems, particularly in the Arctic and on the continental shelf. The processes that dictate the atmosphere-ocean cycling of CO2 in sea-ice dominated environments are not well understood and constitute a critical gap in our understanding of the global carbon cycle. Uptake by polar seas is thought to be 2-3 times higher than the global ocean average where high rates of uptake are attributed to seasonal algal blooms in cold nutrient rich water and brine-driven convection associated with rapid ice formation. This process allows for carbon taken in at the surface to be transported to the deep ocean. "Frost flowers" growing on first year sea-ice are significantly mineralized; they contain CaCO3 (often as ikaite). Using laser ablation inductively coupled plasma mass spectrometry we will analyze the mineral content of the ice inclusions in situ and at different depths in ice cores. We expect to establish the 1) source of the major elements making up the mineral inclusions; 2) establish the sequence of mineral development and compositional evolution of the inclusion system at different depths in the ice; 3) relate composition and age to assess the effectiveness of the pumping model in different thicknesses of ice; and 3) test whether inclusion assemblages (including trace elements) trace elements can be used to source the sea-ice geographically. A parallel study will model elemental exchange in experimentally grown sea-ice and in Prairie saline lakes, which have remarkably similar ecology and mineralogy. It is crucial that we provide the best estimates we can for mass balance(s) involving carbon fluxes in the Arctic sea-ice system. The mineralogical content of sea ice has essentially gone unaccounted in this system. Without the mineralogical data our estimates of CO2 and Ca cycling will be wrong.