PhillipS

Apologies if I'm splitting hairs, Bluewave, but August didn't see an increase in Arctic SIV, it saw a decrease in the anomaly. Arctic SIV continued to drop, albeit at a slower rate.

It's easy to just focus on the recent melt seasons but I got a jolt when I looked at the PIOMAS sea ice volume plot. The SIV is currently around 6.75K km3, just behind 2012 as ORH reported above, but the 1979-2001 average for this time of years is almost 17,000 km3, more 10,000 km3 greater than today - a loss I find sobering.

Dr Barry is welcome to come here to engage.

More open Arctic ocean -> increased evaporation -> increased water vapor -> increased precipitation. But GIS Surface Mass Balance is only half of the situation. It does not include dynamic GIS processes such as glacial calving, basal melting, or meltwater runoff. Look at the Total Mass Change data for the complete situation. As you can see, the GIS has lost around 3,600 km3 (3,600 Gtons) of ice since 2003.

Keeping in mind that SMB is only half of the mass balance equation, it looks like 2016 was the fifth worst melt season of the instrumental period, and the second greatest season for runoff. Just eyeballing the graph it looks like there is a long-term decline in snowfall but I don't know if that's due to less precipitation overall or more precip falling as rain. Here's the GRACE plot of total mass balance since 2003. I expect that 2016 will have a net mass loss of around 300 Gtons (300 km3).

Greenland saw a steep, but brief, resurgence of surface melting DMI shows the 2014 -2015 GIS melt season (which runs Sept through Aug) as being about 75 gigatons below the long term average, and about 250 gigatons above the record surface melt in 2011 - 2012. So it was a strong, but not exceptional GIS surface melt season. The overall net mass balance hasn't been announced yet - but with recent large calving events reported I would estimate a net mass loss for 2015 of between 300 and 400 gigatons.

Peter Sinclair has an interesting post up at ClimateCrocks on the effect of increased rainfall on the GIS. [link]

Thank you for the correction - the mistake in the estimated area was mine alone. I should of checked my numbers before I hit Post.

Here is a comment on the recent Jakobshavn glacier at Nevins. And a Washington Post article that includes quotes from Jason Box and Richard Alley And last, but certainly not least, is the NASA Earth Observatory post. There is a lot of uncertainty in the estimates of the size of the calving event, but this size of event will have a big impact on the net mass balance analysis for the 2015 melt season. Many estimates put it at around 125 12.5 km2 in area, so if the glacier is 1,000 meters thick at the calving site, that would mean a loss of roughly 125 12.5 Gtons of mass in four days. And the calving goes on all year, unlike the surface melt.

Since the SMB is only one component of the GIS net mass balance, and not even the biggest component, it's a bit early to declare it a bust. The DMI calculates the GIS melt season as Sept through August, and typically DMI posts a melt season summary late in the year that combines all factors. Here is the current accumulated SMB In my estimation, 2015 will be a net 275 - 325 km3 mass loss for the GIS, well below the record in 2012 of around 400 km3.

Don't attribute to boldness what can be better explained by confusion. I found the wording of the poll, particularly the second question, rather vague.

The GIS is also experiencing a large amount of mass loss through glacial calving. Here's a short video of one event in June where roughly 1 km3 (1 gigaton) calved off in a matter of minutes : http://climatecrocks.com/2015/07/02/watch-as-empire-state-size-chunk-breaks-off-greenland/

Latest from NSIDC on GIS surface melting: I believe it is safe to say that recent surface melting has made up for the slow start to the melt season. I wonder is some of the acceleration of the surface melting is due to the snow melting off and exposing the darker surface of the glacial ice. Here is the albedo change plot from DMI: The DarkSnow team, led by Dr Jason Box, is now in Greenland studying the processes that affect the albedo of glacial ice. If you haven't visited their website [link], it's worth a read

After a slow start the GIS surface melting is picking up its pace. From NSIDC: The melting is increased by the albedo change of the GIS surface. From the DMI:

DMI has begun updating their PolarPortal website to show 2015 surface conditions. Here is the daily and accumulated Surface Mass Balance (SMB) plots: I found it interesting that over the winter Greenland had a lot more surface accumulation than 2012 did, but currently 2015 is starting the melt season from about the same point as 2012. NSIDC is also showing the GIS as having a slow start to the melt season: