Greenland 2013

[LithiaWx]

No matter which data set you look at melt season can pretty much be called over and has been for about a week now.

The GIS posted pretty much a zero sum for a couple of days now.

[LithiaWx]

The euro says bye bye to any chances of a late season melt and hello to possible snowstorms for an extended period.

[LithiaWx]

Euro 500mb

[Jonger]

Looks like iceland could be looking at snow.

[The_Global_Warmer]

On the flip side, with less diesel soot and more environmental controls, eventually that remaining soot will wash off and sink deep into the ice and thus absorb less solar energy.

 

 

 

boots on the ice offer a close look (and to sample) impurities concentrating at the surface. The fact is, much of this dark material is from cyanobacteria and blue-green algae. Photo J. Box.

 

[Jonger]

Probably depends on the source or region, I was just reading last week that a sample was taken and was found to be 75% diesel and coal soot.

[The_Global_Warmer]

Probably depends on the source or region, I was just reading last week that a sample was taken and was found to be 75% diesel and coal soot.

 

 

I am not surprised.  I am not sure if it will wash off.  We have to watch how much is from wildfires as well.

 

temps are expected to climb in the region the next century by a lot.  This melting is so albedo driven it was poorly predicted. 

[skierinvermont]

There's a lot of miscommunication going on in this thread between Marrietta, Friv, and Phillip. 

 

Here's how I see it. I believe Marrietta when he says he made his 275-375Gt prediction for the results of the DMI model. I don't know when that prediction was made, but it does appear to be correct. It does appear he was initially unaware of how significant calving and runoff are, or that they were not included in the DMI model. While the DMI model shows that the average annual gain is 400GT (what period is this for) and that 2012 had a slight annual gain, we know from GRACE that GIS has been losing about 300GT/yr the last decade, and 500GT last year. These peer-reviewed results have been posted on this forum on and off for 6+ years and most recently I think DonS (or maybe it was bluewave) started a thread showing the latest study. So let's not harp on Marrietta for not knowing this, as long as we all recognize the validity and significance of these results for Greenland, for SLR and also for closing the Sea level budget (OHC expansion + mass gain).

 

I feel pretty comfortable that the DMI model is at least a decent approximation. It shows 2012 to be a record setting year in terms of melt season loss, which makes sense.

 

The model Phillip has posted is not "cherry-picking" because it only starts in April.. it just doesn't work for the winter months although it does conveniently show GRACE data for those months which is helpful. 

 

And the DMI model is not "cherry-picking" because it starts on Sept 1 and ends August 31.

 

Also I am curious, Friv, was your 500GT loss for 2013 for the melt season or for the year as a whole? If it was for whole year, it will probably bust high. If it was for melt season alone, it will probably be pretty accurate.  

 

A lot of these accusations seem to be misunderstandings. 

[The_Global_Warmer]

500GT is for the melt season on Grace.

 

My beef with the model is that it shows essentially 500GT of ice mass gain each winter.

 

 

Grace doesn't show anything near that on any method of using the grace data I have ever seen.

 

 

Maybe winter calving takes place to off-set it?

 

 

We are over a decade into grace with multiple collaborating papers on how to derive its data into ice mass loss.  On top of that.  The sea level rise has been pretty strong over this period.  That models assumes GIS is only seeing a 200GT loss per year by calving.  maybe that doesn't include the post 2010 years.

 

[skierinvermont]

Yes that is what I believe is happening on GRACE, there is winter (and by winter I mean any month not June or July) calving to offset much (or ALL in May, September August) of the surface balance gain. On the peripheral months (August, September, May) this may keep the mass balance on GRACE negative, while the DMI model has a positive mass balance. So the season of balance gain on GRACE is shorter and weaker than on DMI, because DMI only looks at surface balance. The season of balance gain on GRACE is 8 months and averages 100-200GT, on DMI, it is 9-10 months averages 400GT.

 

Also remember the DMI base period may be longer comparing the mean to the short 10 year record of GRACE may be a bit of an apples to oranges comparison. DMI might show more moderate gains post-2000 than it does pre-2000. For example, in 2012 it shows near-zero mass balance. Which would imply there was about 500GT of calving and runoff.

 

What's the base period for the DmI model?

[The_Global_Warmer]

The Danish appointed Jason Box their Ice God.  He launched version 2.0 an has helped build the promice network.

 

http://www.meltfactor.org/blog/

 

 

take sometime to look at those stations the data they collect is amazing.  I won't be surprised if smaller glaciers get this technology too.  between argo, ITPS, this kind of stuff, remote sensing we are getting a very accurate network of energy balance.  I wonder if we will be able to take our tracking up a notch into a a truely accurate near real time tracking system of the energy balance that is accurate enough that we can use it for a predictor some day.

 

 

http://www.promice.org/home.html

[Jonger]

500GT is for the melt season on Grace.

 

My beef with the model is that it shows essentially 500GT of ice mass gain each winter.

 

 

Grace doesn't show anything near that on any method of using the grace data I have ever seen.

 

 

Maybe winter calving takes place to off-set it?

 

 

We are over a decade into grace with multiple collaborating papers on how to derive its data into ice mass loss.  On top of that.  The sea level rise has been pretty strong over this period.  That models assumes GIS is only seeing a 200GT loss per year by calving.  maybe that doesn't include the post 2010 years.

 

I'm trying to wrap my head around that chart. Is that figure supposed to directly correlate with melt off and not OHC expansion?

[The_Global_Warmer]

Yes that is what I believe is happening on GRACE, there is winter (and by winter I mean any month not June or July) calving to offset much (or ALL in May, September August) of the surface balance gain. On the peripheral months (August, September, May) this may keep the mass balance on GRACE negative, while the DMI model has a positive mass balance. So the season of balance gain on GRACE is shorter and weaker than on DMI, because DMI only looks at surface balance. The season of balance gain on GRACE is 8 months and averages 100-200GT, on DMI, it is 9-10 months averages 400GT.

 

Also remember the DMI base period may be longer comparing the mean to the short 10 year record of GRACE may be a bit of an apples to oranges comparison. DMI might show more moderate gains post-2000 than it does pre-2000.

 

What's the base period for the DmI model?

 

 

NCAR/NCEP charts confirm the near 500GT number in the precipitation charts.  They use the Euro and some specialized model for GIS based off the Euro.

 

 

 

This is the newest method of tracking with the Grace data via climo vs modis albedo extraction.

 

 

 

The model uses a longer climo period.

 

 

 

 

 

 

 

Left: Map of the surface mass balance today (in mm water equivalent per day). Right: The average surface mass balance for today’s calendar date over the period 1990-2011.

 

 

 

In-spite of the weather albedo was still pretty awful.  It's clear year to year damage has accumulated. 

 

 

[The_Global_Warmer]

I'm trying to wrap my head around that chart. Is that figure supposed to directly correlate with melt off and not OHC expansion?

 

 

Its just GT and the conversion to how many MM of SLR that would be

 

for every 360GT of land ice loss = 1MM of SLR.

 

While it may seem insignificant.  There has been a major acceleration of ice mass loss on GIS.  And almost every glacier on Earth since the late 1990s and it hasn't flatlined.  Most are at their worst and continuing to see larger losses.  The dark particle issue is nearly everywhere on Earth not just GIS.  Some places more or less.  But it seems we didn't account for it very well.  We put to much emphasis on temperature change and not enough on albedo change.

 

 

The natural fluctuations of ice albedo can not come anywhere near the enhanced lowering of albedo with dark particles.  we are talking a 100W/M2+ per day change just from the Earths surface on full albedo days during the high albedo months.  Ice albedo could get to the .55 range or so on GIS.  Maybe the .45 to .50 with melt ponds.  The dark particles take albedo down to .20 to .40 over  a large area that would be .55 to .70 without the dark particles.  They are rough estimates.

 

MId May to Mid June is huge.  If the weather is terrible the dark ice will be exposed before June 1st and that is how 2012 rolled.  So far we have seen the dark layer much worse post 2010, even 2013 is much worse than 2009 and before even though this years weather was very good. 

 

I think you understand that this could cause the bottom to drop out if it spreads.  It takes up like 5 percent of the ice sheet attm.  If that. 

 

This is the OHC chart for sea level rise.  That's like 4MM in 3 months.  Definitely helped the SLR rise. It's good that it wasn't ice but still a large jump.

 

 

 

 

[skierinvermont]

I'm trying to wrap my head around that chart. Is that figure supposed to directly correlate with melt off and not OHC expansion?

 

It is showing total ice loss from Greenland, as measured by gravity sensitive satellites. The ice loss can be measured in Gigatons (left scale) or in the amount it raises sea level (right scale). Both scales are measurements of ice loss, just in different units. Over the 11 years, Greenland has lost nearly 3,000 Gigatons of ice, which is equivalent to nearly 8mm of sea level rise, or a rate of .7mm/yr. Over the same period, total sea level rise has been at a rate of 3.2mm/yr. Breaking that down,.7mm/yr is coming from Greenland and 2.5mm/yr from other sources (primarily expansion due to OHC increase). 

[LithiaWx]

2GT gain yesterday on DMI

[TerryM]

I wonder if the rain in the north west is being counted as snow?

Terry

[The_Global_Warmer]

I wonder if the rain in the north west is being counted as snow?

Terry

 

It happens.  How far North the snowline is or in terms of elevation is up for debate without ground OBS.  But I have noticed the model be to cold from time to time.  I assume it plays into its large precip amounts but it matters if its frozen or not.

[TerryM]

Qaanaaq reported rain all day on the 26th and 27th. GRACE shouldn't be fooled, not so sure concerning the model.

Terry

[Jonger]

Qaanaaq reported rain all day on the 26th and 27th. GRACE shouldn't be fooled, not so sure concerning the model.

Terry

 

The average high there today is 43F, whats the issue?

[The_Global_Warmer]

The average high there today is 43F, whats the issue?

 

 

 

The model thinking snow reached down to that area.  Which means it assumes to much ice mass accumulates over GIS in Summer than really does.

[Bannor]

Scientists have discovered a huge canyon underneath the Greenland ice sheet.

 

 

This vast gorge might rival the Grand Canyon in splendor … if only it weren’t smothered by a couple of kilometers of ice. By stitching together data gathered by ice-penetrating radar equipment suspended from aircraft, researchers have discovered a massive canyon that has likely been hidden for millions of years This unexpected, yet-to-be-named feature stretches 750 kilometers—about twice the length the Grand Canyon—from central Greenland all the way to a fjord along the northwestern coast. It’s about as wide as the Grand Canyon (10 kilometers) and nearly half as deep at its deepest point (800 meters), the researchers report online today in Science.

 

 

Link: http://news.sciencemag.org/earth/2013/08/scienceshot-greenland%E2%80%99s-hidden-valley-revealed?rss=1

 

 

NASA video: https://www.youtube.com/watch?v=ENg9Hci9y3M

 

 

[The_Global_Warmer]

great post Bannor.

 

 

Wonder what kind of heat transfer is going on of significance if any.

[LithiaWx]

great post Bannor.

Wonder what kind of heat transfer is going on of significance if any.

The canyon is burried under 2 miles of ice, how would there be a heat transfer? It also runs from the northern tip to central Greenland. Straw grasping

[TerryM]

The canyon could be significant if the research indicates that there in no sill upstream in the Petermann Fjord. The sill near the entrance is >400M below sea level (quite low for a sill line), but the shoal waters in Nares Strait keep the deep warm Atlantic water from being much of a factor. The deep sill precludes Halo Syphoning from drawing deeper warmer waters in, but strong tidal action does force water over the sill.

The warm Baffin Bay waters come up the right hand side of Nares, enter by the south shore of Petermann then gnaw away at the glacier from underneath. When additional runoff occurs it speeds the current drawing more warm water against the ice. PII-2010 had a much larger surface area than PII-2012 but 2012 was/is much thicker & contains a much larger volume of ice.

Terry

[LithiaWx]

The euro says bye bye to any chances of a late season melt and hello to possible snowstorms for an extended period.

image.jpg

The euro delivered better than the mailman yesterday. An astonishing 6GT addition to the GIS on the 29th from a snowstorm.

[PhillipS]

The canyon is burried under 2 miles of ice, how would there be a heat transfer? It also runs from the northern tip to central Greenland. Straw grasping

 

Your comment is disingenuous for several reasons.  First, the GIS isn't 2 miles thick over the canyon as you claim - it's about 1.2 miles (2 km) over the head of the canyon in central Greenland and thins quite a bite towards the coast.  That sort of exaggeration just hurts your credibility.

 

Second, you are wrong to dismiss heat transfer from the bedrock beneath the GIS.  A cursory Google search turned up a bunch of relevant information.  Here are a few papers that caught my eye:

 

Fahnestock et al, 2001 [link]  

High Geothermal Heat Flow, Basal Melt, and the Origin of Rapid Ice Flow in Central Greenland

Age-depth relations from internal layering reveal a large region of rapid basal melting in Greenland. Melt is localized at the onset of rapid ice flow in the large ice stream that drains north off the summit dome and other areas in the northeast quadrant of the ice sheet. Locally, high melt rates indicate geothermal fluxes 15 to 30 times continental background. The southern limit of melt coincides with magnetic anomalies and topography that suggest a volcanic origin.

 

Greve, 2005 [link]

 

Relation of measured basal temperatures and the spatial distribution of the geothermal heat flux for the Greenland ice sheet                    

 

 

The thermomechanical, three-dimensional ice-sheet model SICOPOLIS is applied to the Greenland ice sheet. Simulations over two glacial-interglacial cycles are carried out, driven by a climatic forcing interpolated between present conditions and Last Glacial Maximum anomalies. Based on the global heat-flow representation by Pollack and others (1993), we attempt to constrain the spatial pattern of the geothermal heat flux by comparing simulation results to direct measurements of basal temperatures at the GRIP, NorthGRIP, Camp Century and Dye 3 ice-core locations. The obtained heat-flux map shows an increasing trend from west to east, a high-heat-flux anomaly around NorthGRIP with values up to 135 mW m⁻² and a low-heat-flux anomaly around Dye 3 with values down to 20 mW m⁻². Validation is provided by the generally good fit between observed and measured ice thicknesses. Residual discrepancies are most likely due to deficiencies of the input precipitation rate and further variability of the geothermal heat flux not captured here.          

 

Buchardt et al, 2007 [link]

 

Estimating the basal melt rate at NorthGRIP using a Monte Carlo technique                    

 

From radio-echo sounding (RES) surveys and ice core data it can be seen that the ice sheet is melting at the base in a large area in Northern Greenland. The RES images reveal internal layers in the ice. The layers are former deposition surfaces and are thus isochrones. Undulations of the isochrones in regions where the base is smooth suggest that the basal melt rate changes over short distances. This indicates that the geothermal heat flux is very high and has large spatial variability in Northern Greenland. In this study, the basal melt rate at the NorthGRIP drill site in North-Central Greenland is calculated by inverse modelling. We use simple one- and two-dimensional flow models to simulate the ice flow along the NNW-trending ice ridge leading to NorthGRIP. The accumulation is calculated from a dynamical model. Several ice flow parameters are unknown and must be estimated along with the basal melt rate using a Monte Carlo method. The Monte Carlo inversion is constrained by the observed isochrones, dated from the timescale established for the NorthGRIP ice core. The estimates of the basal melt rates around NorthGRIP are obtained from both the one- and two-dimensional models. Combining the estimated basal melt rates with the observed borehole temperatures allows us to convert the basal melt rates to geothermal heat flow values. From the two-dimensional model we find the basal melt rate and geothermal heat flux at NorthGRIP to be 6.1 mm a⁻¹ and 129 mW m⁻², respectively.          

 

And your charge that TGW is grasping at straws is simply comical.  Your post clearly illustrates the difference between an honest skeptic, and a pseudo-skeptic.

[nzucker]

Philip,

I think his point is not that heat transfer from the canyon doesn't exist at all in any way, but that it's a very minor factor when compared to other factors. Ice loss is much more closely linked to summertime ridging due to a -NAO as well as warm SSTs surrounding Greenland in a +AMO regime. Ice gain is more closely linked to colder summertime temperatures in a +NAO pattern which extends the snow season, as well as the potential for increased amounts of precipitation falling in the higher elevations of the GIS as the world warms.

Overall, I think the canyon is a minor factor in both natural ice gain/loss as well as changes in Greemland due to anthropogenic warming. It's an interesting geographical feature which merits further study, but it has little implication for sea level rise or ice accumulation high on the ice sheet.

[PhillipS]

Philip,

I think his point is not that heat transfer from the canyon doesn't exist at all in any way, but that it's a very minor factor when compared to other factors. Ice loss is much more closely linked to summertime ridging due to a -NAO as well as warm SSTs surrounding Greenland in a +AMO regime. Ice gain is more closely linked to colder summertime temperatures in a +NAO pattern which extends the snow season, as well as the potential for increased amounts of precipitation falling in the higher elevations of the GIS as the world warms.

Overall, I think the canyon is a minor factor in both natural ice gain/loss as well as changes in Greemland due to anthropogenic warming. It's an interesting geographical feature which merits further study, but it has little implication for sea level rise or ice accumulation high on the ice sheet.

 

NZucker - you may well be right about the minor role that the newly described canyon plays - but I was just responding to MW's habit of lashing out any anyone he disagrees without providing information and links to support his position.  I feel that MW's approach lowers the quality of the forum and impedes open discussion.  If he or anyone else wants to engage in flames wars there are plenty of blogs to play on.

[The_Global_Warmer]

NZucker - you may well be right about the minor role that the newly described canyon plays - but I was just responding to MW's habit of lashing out any anyone he disagrees without providing information and links to support his position.  I feel that MW's approach lowers the quality of the forum and impedes open discussion.  If he or anyone else wants to engage in flames wars there are plenty of blogs to play on.

All I do is compliment the poster who brought it up.  Then ask about heat transfer. 

 

 

Seems like one of the most logical things to question.  I thought questioning things we do not know well would be considered skeptical.  What would you call the denying of asking those questions?

 

 

 

 

 

great post Bannor.

 

 

Wonder what kind of heat transfer is going on of significance if any.

 

I don't insinuate or imply there is some heat transfer.  I question if it exists and how strong it is if it exists.