New data for 2014 concerning the retreat of the calving front of the Jakobshavn glacier, Greenland, on the NASA Earth Observatory site. Add Comment Here's an article appearing on Bloomberg Magazine on April 2014 discussing the implications of melting for oil and mining in Greenland. Study points out to the link between iron from melting ice sheets and phytoplankton Growth05/25/2014 A study published on Nature Communications points out to the potential impact of melting over Greenland and phytoplankton growth in the surrounding sea. This might have potential implications for CO2 capture. The article is freely available here. The title, authors and abstract are here following: Ice sheets as a significant source of highly reactive nanoparticulate iron to the oceans Jon R. Hawkings, Jemma L. Wadham, Martyn Tranter, Rob Raiswell, Liane G. Benning, Peter J. Statham, Andrew Tedstone, Peter Nienow, Katherine Lee & Jon Telling The Greenland and Antarctic Ice Sheets cover ~10% of global land surface, but are rarely considered as active components of the global iron cycle. The ocean waters around both ice sheets harbour highly productive coastal ecosystems, many of which are iron limited. Measurements of iron concentrations in subglacial runoff from a large Greenland Ice Sheet catchment reveal the potential for globally significant export of labile iron fractions to the near-coastal euphotic zone. We estimate that the flux of bioavailable iron associated with glacial runoff is 0.40–2.54 Tg per year in Greenland and 0.06–0.17 Tg per year in Antarctica. Iron fluxes are dominated by a highly reactive and potentially bioavailable nanoparticulate suspended sediment fraction, similar to that identified in Antarctic icebergs. Estimates of labile iron fluxes in meltwater are comparable with aeolian dust fluxes to the oceans surrounding Greenland and Antarctica, and are similarly expected to increase in a warming climate with enhanced melting. The paper presents results concerning the detection of widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. This has potential implications for ice dynamics and how Greenland might contribute to sea level rise in the future, through the ocean thermal forcing. The paper can be found here. Here's the title, authors and abstract: Deeply incised submarine glacial valleys beneath the Greenland ice sheet M. Morlighem, E. Rignot, J. Mouginot, H. Seroussi and E. Larour Abstract. The bed topography beneath the Greenland ice sheet controls the flow of ice and its discharge into the ocean. Outlet glaciers move through a set of narrow valleys whose detailed geometry is poorly known, especially along the southern coasts1–3. As a result, the contribution of the Greenland ice sheet and its glaciers to sea-level change in the coming century is uncertain4. Here, we combine sparse ice-thickness data derived from airborne radar soundings with satellite derived high-resolution ice motion data through a mass conservation optimization scheme5.We infer ice thickness and bed topography along the entire periphery of the Greenland ice sheet at an unprecedented level of spatial detail and precision. We detect widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. Our findings imply that the outlet glaciers of Greenland, and the ice sheet as a whole, are probably more vulnerable to ocean thermal forcing and peripheral thinning than inferred previously from existing numerical ice-sheet models. A new study points published on PNAS highlights the synergy between the 2012 widespread melt event and forest fires. Here's the link and the significance of the study from the PNAS site:Through an examination of shallow ice cores covering a wide area of the Greenland Ice Sheet (GIS), we show that the same mechanism drove two widespread melt events that occurred over 100 years apart, in 1889 and 2012. We found that black carbon from forest fires and rising temperatures combined to cause both of these events, and that continued climate change may result in nearly annual melting of the surface of the GIS by the year 2100. In addition, a positive feedback mechanism may be set in motion whereby melt water is retained as refrozen ice layers within the snow pack, causing lower albedo and leaving the ice sheet surface even more susceptible to future melting. Here's a link to a documentary on Greenland featuring myself, Asa Rennermalm and Scott Luthcke (on the science side). The documentary was aired on the Special Edition of Christmas Eve on CCTV - America's Now show (here's the link to the original CCTV site http://cctv.cntv.cn/lm/americasnow/01/index.shtml). Most of the scenes of water rushing into the ice and other similar footage were collected by our team in the field in 2011. Enjoy ! Here's a movie showing the melt extent over Greenland for 2012, 2010 (the previous record) and the 1981 - 2010 mean that Mauri Pelto put together using data provided by me.You can find the same figure on our most recent paper on the records in 2012 (see post below). Thanks to Mauri and enjoy ! Here's the link to the updated results for the whole 2012 melting season in Greenland, including total mass loss from GRACE. Overall, in 2012 ALL of the considered parameters (albedo, bare ice, surface mass balance, melting, total mass change, etc.) set a new record ! The paper has been published on The Cryosphere Discussion. Here's the abstract of the paper, together with the title and the co-authors. The Surface mass balance form the model and the total mass change from GRACE Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis data M. Tedesco, X. Fettweis, T. Mote, J. Wahr, P. Alexander, J. Box, and B. Wouters I am re-posting an interesting message from Mauri Pelto on the Zachariae Isstrom ice loss. The original message is below .... ORIGINAL MESSAGE Dear Glacier Colleagues: Petermann has got lots of attention this summer but the losses in area of Zachariae Isstrom and the open water currently at its front are worth noting. Below is a link to a post on the glacier with numerous Landsat images, this is meant only as a visual update not a substitute for the detailed research that has been conducted and will continue on this important outlet glacier. http://glacierchange.wordpress.com/2012/08/27/zachariae-isstrom-further-retreat-ne-greenland/ Mauri Pelto |