Link to an article on the growing interest for the 2014 melting season.
Article on Bloomberg Magazine highlights the oil exploration in greenland (using our data to discuss melting !)
Here's an article appearing on Bloomberg Magazine on April 2014 discussing the implications of melting for oil and mining in Greenland.
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.
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.
Melting in Greenland set a new record before the end of the melting season. Over the past days, the cumulative melting index over the entire Greenland ice sheet (defined as the number of days when melting occurs times the area subject to melting) on August 8th exceeded the record value recently set in 2010 for the whole melting season (which usually ends around the beginning or mid September).
Standardized melting index (SMI) for the period 1979 - 2012. the years between 1979 and 2011 use the full length season (May through September) where 2012 uses only the available period May through August 8th. Note that 2012 value is much higher than any of the previous years, despite the shorter period.
Here's a link to Jason Box 2012 analysis of albedo over the Greenland ice sheet. The reduction of the albedo is a critical factor for enhancing melting over the Greenland ice sheet. The image on the left shows the ice sheet albedo time series updated through July 2012 by Jason Box.
To better understand the importance of this mechanism you can check a recently published paper on the Cryosphere Discussion by Box et al. (2012) in which we focus on this problem or another paper (Tedesco et al., 2011) that we published on Environmental Research Letters focusing on the role of albedo and accumulation on the 2010 melting recording in Greenland. Both papers are also available in the Scientific Literature section of this site.
NOAA today posted the following focusing on melting at Summit during the month of July 2012.
Here's the full link:
The plot below shows the passive microwave brightness temperature time series over Summit recorded between 1979 and 2011 (the ensemble of gray lines) and the time series recorded during 2012 (black thick line). The ensemble clearly shows that things are relatively stable at Summit, with relatively small interannual variability.
Here's a message that Chris Shuman from UMBC/NASA Goddard posted on cryolist concerning the Summit Greenland temperatures. I am also attaching an updated figure from Chris showing that temperatures at Summit reached high values again over the past few days. I quickly looked at satellite data and though I could not see any melting for those days, the area undergoing melting was going up again. I will post an update later.
The recently observed melt extent record over Greenland has shown the capabilities of remote sensing data to monitor large areas on a daily basis. The melting observed at high elevations over Greenland did not generate meltwater that contributed (or could have contributed) directly to sea level rise, mainly because liquid water refroze after the event, creating the ice layer that has been used to confirm the event. The same remote sensing tools are used to observe melting at lower elevations, where it happens every summer. Here, meltwater can either directly contribute to SLR or it can impact ice sheet dynamics, modulating the ice velocity and shaping the evolution of the englacial summer system of channels through which meltwater flows (see this video, for example). Over the past years, surface melting over Greenland has been increasing, setting new a new record in 2010 and a close-to-record melting season in 2011.
So, what happened in 2012 over the rest of Greenland while the warm air was climbing up Summit ?
The graph below shows the Standardized Melting Index (SMI, obtained from the melting index by subtracting the mean for the period 1979 - 2012 and dividing by the standard deviation for the same period) for the period June 1st - July 20th. Values above 0 indicate those cases when melting was above the 1979 - 2012 mean. For the period when data is available, therefore, the SMI set a new record for the satellite era.