{"id":1206,"date":"2020-04-08T10:51:44","date_gmt":"2020-04-08T14:51:44","guid":{"rendered":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/?page_id=1206"},"modified":"2020-04-30T13:01:56","modified_gmt":"2020-04-30T17:01:56","slug":"sea-surface-pco2-fluxes","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/results\/sea-surface-pco2-fluxes\/","title":{"rendered":"Sea surface pCO2 fluxes"},"content":{"rendered":"\n\t

Sea surface pCO2 fluxes<\/h1>\n\tSea surface\u00a0p<\/i>CO2<\/sub>\u00a0fluxes<\/b>\nMichael D.\u00a0 DeGradpre<\/b>\nDepartment of Chemistry, University of Montana, Missoula, Montana,USA\n\u00a0<\/b>\n

In 2012, sea ice extent dropped to 3.4 million km2<\/sup>, the lowest level since the satellite record began.\u00a0 Ice extent rebounded in 2013 to 5.1 million km2<\/sup>.\u00a0 The shipboard\u00a0p<\/i>CO2<\/sub>\u00a0measurements (Figure 1) show that offshore open water had\u00a0p<\/i>CO2<\/sub>\u00a0levels closer to atmospheric saturation whereas ice-covered areas were typically >100 \u00b5atm below saturation.\u00a0 The mechanisms for producing the higher open water\u00a0p<\/i>CO2\u00a0<\/sub>are not well understood but are possibly caused by the increase in atmospheric exchange, vertical mixing and heating that come with no ice coverage.\u00a0 We examined these mechanisms through correlations and modeling.<\/p>\n

The variability between the two years is compared by plotting the\u00a0p<\/i>CO2<\/sub>\u00a0versus temperature (Figure 2).\u00a0 In 2012, there was a much larger range of temperature and\u00a0p<\/i>CO2<\/sub>\u00a0even though the two data sets were obtained at the same time of the year and roughly over the same cruise track (Figure 1).\u00a0 The highest salinity water (26-28) typically had the lowest\u00a0p<\/i>CO2<\/sub>\u00a0levels (<350 \u00b5atm) and these levels correspond to highly ice-covered areas. Model calculations (not shown) suggest that much of the difference between 2012 and 2013 is from air-sea gas exchange and heating of the sea surface.\u00a0 It does not appear that biological production is a significant factor in offsetting the increase, a consequence of the lack of nutrients in the mixed-layer (i.e., increased light penetration does not increase production at the surface).\u00a0 These processes are likely to reduce the effectiveness of the Arctic Ocean as a CO2<\/sub>\u00a0sink as ice-cover continues to decline in the coming years. The expected rapid increase in CO2<\/sub>\u00a0levels will accelerate ocean acidification, with aragonite becoming undersaturated (~0.9,) when the sea surface reaches atmospheric CO2<\/sub>\u00a0saturation (data not shown).<\/p>\n

References<\/b><\/p>\n

Islam, F., DeGrandpre, M., Beatty, C., Krishfield, R., and J. Toole\u00a0(2016)<\/b>.\u00a0 Gas exchange of CO2<\/sub>\u00a0and O2<\/sub>\u00a0in partially ice-covered regions of the Arctic Ocean investigated using in situ sensors,\u00a0IOP Conf. Series: Earth and Environmental Science,\u00a0<\/i>35, doi:10.1088\/1755-1315\/35\/1\/012018.<\/p>\n

Evans, W., Mathis, J.T., Cross, J.N., Bates, N.R., Frey, K.E., Else, B.G.T., Papkyriakou, T.N., DeGrandpre, M.D., Islam, F., Cai, W.-J., Chen, B., Yamamoto-Kawai, M., Miller, L.A., Carmack, E., Williams, W.J. and T. Takahashi\u00a0(2015)<\/b>. Sea-air CO2<\/sub>\u00a0exchange in the western Arctic coastal ocean,\u00a0\u00a0Global Biogeochem. Cycles<\/i>, 10.1002\/2015GB005153.<\/p>\n\t\t\t\t\n\t\t\t\t\"Figure\n\t\t\t\t<\/a>\n\t\tFigure 1<\/strong>. The BGOS cruise track in 2012 (left) and 2013 (right) colored using the underway pCO2 measured by the University of Montana (DeGrandpre et al.). Data gaps in 2013 were caused by problems with the seawater line. Relative ice coverage is shown by gray to black shading.\n\t\t\t\t\n\t\t\t\t\"Figure\n\t\t\t\t<\/a>\n\t\tFigure 2<\/strong>. Underway pCO2 versus sea surface temperature for the 2012 (top) and 2013 (bottom) cruises. The color scale is based on the measured salinity.\n","protected":false},"excerpt":{"rendered":"

Sea surface pCO2 fluxes Sea surface\u00a0pCO2\u00a0fluxes Michael D.\u00a0 DeGradpre Department of Chemistry, University of Montana, Missoula, Montana,USA \u00a0 In 2012, sea ice extent dropped to 3.4 million km2, the lowest level since the satellite record began.\u00a0 Ice extent rebounded in 2013 to 5.1 million km2.\u00a0 The shipboard\u00a0pCO2\u00a0measurements (Figure 1) show that offshore open water had\u00a0pCO2\u00a0levels…<\/p>\n","protected":false},"author":83,"featured_media":0,"parent":1040,"menu_order":15,"comment_status":"closed","ping_status":"closed","template":"tpl-sidebar.php","meta":{"advanced-sidebar-menu\/link-title":"","advanced-sidebar-menu\/exclude-page":false},"_links":{"self":[{"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/pages\/1206"}],"collection":[{"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/users\/83"}],"replies":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/comments?post=1206"}],"version-history":[{"count":3,"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/pages\/1206\/revisions"}],"predecessor-version":[{"id":1527,"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/pages\/1206\/revisions\/1527"}],"up":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/pages\/1040"}],"wp:attachment":[{"href":"https:\/\/www2.whoi.edu\/site\/beaufortgyre\/wp-json\/wp\/v2\/media?parent=1206"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}