Greenland 2019 Melt Season

[Tor Bejnar]

Sleepy posted a global daily 'normal' precipitation GIF.  I've extracted the approx. minimum and maximum images for Greenland.  It shows that the north or northwest is basically a desert and the southeast is 'wet'.  Also, the wet season for much of Greenland goes from (approximately) August through February while the dry season is only April and May.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 10 May 2019

Melt was lower, but precipitation was minimal so the 10th May was the fourth day of negative change (although very small) to overall SMB, most unusual  for the time of year.

This is becoming apparent on the accumulated SMB graph.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 11 May 2019

Melt was lower again, but precipitation was nearly zero so 11 May was the fifth day of negative change (although very small) to overall SMB, most unusual  for the time of year.

This is becoming apparent on the accumulated SMB graph.

From Tuesday onwards it looks like melt will tick up, while precipitation will remain low, so SMB change should be -ve or close to zero..
_____________________________________________________
ps: Note how that warmth is spread over most of Baffin Bay, Hudson Bay and much of the eastern CAA.

[Stephan]

Off-topic, but these temperatures also should affect Hudson Bay Sea ice seriously, at least in its southern tip...

[vox_mundi]

Airborne NASA Scientists Just Filmed Something Troubling In Greenland
https://mashable.com/article/greenland-melt-2019-climate-change/



Scientists aboard a NASA airplane swooped over some of Greenland's largest glaciers on Monday, spotting melted ice and raging rivers.

It's significant, because though it's not nearly summer, large blue ponds have already formed on the icy ground. NASA’s Operation IceBridge researchers observed this as part of their mission to watch for changes in Earth’s giant masses of polar ice. Greenland, in particular, has been melting at an accelerated rate for some two decades.

"Although the story of the summer of 2019 in Greenland hasn’t yet been written, it's starting on a worrying note," said Joe MacGregor, the project scientist for Operation IceBridge.

While such profound early season melting isn't unprecedented, typically these melt ponds form in late May to early June, explained MacGregor. This spring, there's one obvious culprit: really warm temperatures. Last week in Greenland — one of the coldest parts on Earth — temperatures measured in the upper 50s to low 60s Fahrenheit, he said.

MacGregor is on land in the U.S., but his IceBridge colleague, glaciologist Brooke Medley, captured footage of the early melt creating big pools of water, seen below.


https://twitter.com/DrBrookeMedley/status/1125873350448906240

https://twitter.com/i/videos/1125873350448906240

@NASA #IceBridge ✈ observed surface melt north of Jakobshavn ... While the blue water is breathtaking, the early onset of melt over Greenland is concerning for Earth ... "Concerning" - what a uselessly weak verb. Totally fails to convey the gravity of these images ... meltwater ponds also visible on Landsat/Sentinel/Modis pics...caused by record breaking warmth since end of April (Kangerlussuaq up to19deg C).


A mosaic from the CAMBOT instrument on #IceBridge shows a melt pond with surface rippling, as seen on Sunday's flight.



From Sunday's #IceBridge flight: Emerald green ponds weave around ice and debris near the terminus of Russell Glacier, which is showing signs of an early onset into the melt season

"The melt has the potential to accelerate," said MacGregor.

------------------------------------

Tsunami Signals to Measure Glacier Calving in Greenland
https://www.sciencedaily.com/releases/2019/05/190508093748.htm

Scientists have employed a new method utilizing tsunami signals to calculate the calving magnitude of an ocean-terminating glacier in northwestern Greenland, uncovering correlations between calving flux and environmental factors such as air temperature, ice speed, and ocean tides.

[vox_mundi]

https://mobile.twitter.com/ZLabe/status/1125073637797552129

Zack Labe: Well above average temperatures across all of #Greenland over the last week. Follow forecasts for Greenland (weather and surface mass balance) this summer using the MARv3.9 model (forced by GFS) at http://climato.be/cms/index.php?climato=the-2019-melt-season-over-greenland-as-simulated-by-marv3-9




See http://climato.be/cms/index.php?climato=the-2019-melt-season-over-greenland-as-simulated-by-marv3-9 for description.

NASA IceBridge: Scientists film twin troubles plaguing Greenland's melting glaciers   
https://www.google.com/amp/s/www.firstpost.com/tech/science/nasa-icebridge-scientists-film-twin-troubles-plaguing-greenlands-melting-glaciers-6599841.html/amp

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 12 May 2019

Melt was lower yet again, but precipitation was nearly zero so 12 May was the sixth day of negative change (although very small) to overall SMB, most unusual  for the time of year.

This is becoming even more apparent on the accumulated SMB graph.

From Tuesday onwards it looks like melt will tick up, while precipitation will remain low, so SMB change should be -ve or close to zero..
_____________________________________________________
ps: For newcomers. SMB = Surface Mass Balance, i.e. looks at precipitation and melting only. Mass loss from calving from glaciers and ice shelves is NOT included.

pps: The unusual happenings on Greenland are stirring interest in the scientific community. This thread might be getting quite lively.

pppps: NASA still promising mass change data from this summer - and it might go part of the way backwards to fill part of the missing data from early 2017.

[oren]

After an ominous SMB winter, April saw a large catch up, but the last week is giving me that nasty feeling again.
When will GRACE data finally be published??

[gerontocrat]

After an ominous SMB winter, April saw a large catch up, but the last week is giving me that nasty feeling again.
When will GRACE data finally be published??

From https://media.gfz-potsdam.de/gfz/sec12/pdf/GRACE_FO_SDS_newsletter_No2.pdf
@
https://www.gfz-potsdam.de/en/section/global-geomonitoring-and-gravity-field/projects/gravity-recovery-and-climate-experiment-follow-on-grace-fo-mission/

Since launch (May-22, 2018), GRACE-FO has collected approximately 7 months of the science
data which will be part of the first Level-1A/B data scheduled for release on or before May 28,
2019. The Level-2 gravity products and the observations from the LRI (Laser Ranging
Interferometer) technology demonstration will be released as planned on or before July-27,
2019. The Science Data System will release the data through the US PO.DAAC
(http://podaac.jpl.nasa.gov) and the German ISDC (https://isdc.gfz-potsdam.de/grace-fo-isdc)
data portals (see important updates for PO.DAAC data access below). Detailed documentation
of the Level-1 data processing and the adopted calibration strategies will be released
concurrently with the data.

[Alexander555]

The unusual happenings, that's the early melt/mass loss on Greenland ?

[gerontocrat]

The unusual happenings, that's the early melt/mass loss on Greenland ?

What is unusual is that Surface Mass should start to reduce this early. Normally the Surface Mass increases as snow continues to fall that outweighs surface melting for about another month. However, in a normal year total snowfall exceeds total surface melting, so Greenland accumulates additional surface mass of around 400gt.

Meanwhile glaciers calve and wend their way into the ocean at normally over 600 gt per annum. This normally exceeds gain in surface mass by at least 200 gt in each year. the GRACE project give us the accurate figure for this net mass loss.

 Read the blurb at http://polarportal.dk/en/greenland/surface-conditions/

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 13 May 2019

Melt
Melt was lower again, but looks like getting a bit more vigorous over the next week or so as pulses of warmth enter Baffin Bay and occasionally the East Coast up the Greenland sea.

Precipitation
Precipitation was nearly zero on 13 May. But although melt was quite low and confined to the fringe, there was considerable sublimation, extending further inland in the SW.

It looks like precipitation may return to something like normal, i.e. mostly falling in the SE, progressively drier North and West. The question is (to me) how much of that precipitation in the South East will fall as rain?

Overall SMB

the 13th May was the sixth day of negative change (although very small) to overall SMB, most unusual  for the time of year. This is becoming very apparent on the accumulated SMB graph.

The SMB -ve anomaly in the West contrasts ever more strongly with the +ve SMB anomaly in the SE.

My forecast (gulp) is for daily -ve SMB to continue and possibly increase.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 14 May 2019

Precipitation outweighs melt on this day.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 16 May 2019

16 May Precipitation outweighs melt on this day, but not by much.

Next 10 days Looks like melt to continue at around the same level, and precipitation to be fairly low. So perhaps overall SMB gain to be below average.

[Observer2019]

Question: How can there be melt in areas where the temps are showing under -10c ?

[b_lumenkraft]

Greenland Melt off to a Fast Start in 2019

[b_lumenkraft]

Question: How can there be melt in areas where the temps are showing under -10c ?

Hello and welcome to the forum.

There is a lot of sunlight in the Arctic these days. Even if the ice looks very white, the albedo is not 100%. If you have a dark underground, for example, energy will be absorbed. Or dark particles that sit on the ice are warming and with them the ice around.

Air pressure is a factor moving the melting point of water slightly.

[oren]

There's also sublimation - ice turning to water vapor under the effects of wind and sunlight.

[b_lumenkraft]

Ah, and there is also rain. If it rains below zero, snow and ice would melt.

[Tor Bejnar]

As the reported temperatures are based on models with few ground-truthing opportunities, some local temperatures (especially on a slope receiving more direct sunshine that hour) will be higher than 'reported' (Edit: although 10C may be a stretch - see below; proof I'm not an expert!).  Of course, lower 'actual' temperatures are equally possible (especially when a slope is in shade).  [note: I am not writing as an expert in such things.]

[vox_mundi]

Add foehn winds to the equation ...
https://en.m.wikipedia.org/wiki/Foehn_wind



Föhn winds can raise temperatures by as much as 14 °C (25 °F)[4] in just a matter of minutes.

Winds of this type are also called "snow-eaters" for their ability to make snow and ice melt or sublimate rapidly. This is a result not only of the warmth of foehn air, but also its low relative humidity.

[b_lumenkraft]

(although 10C may be a stretch)

Not necessarily. The Amery Ice Shelf region in Antarctica is melting in summer even with temperatures at -20˚C and below.

Like here in this last clear Sentinel shot from February >>https://apps.sentinel-hub.com/sentinel-playground/?source=S2&lat=-72.19325109680253&lng=68.45306396484375&zoom=11&preset=CUSTOM&layers=B01,B02,B03&maxcc=20&gain=1.0&gamma=1.0&time=2018-08-01%7C2019-02-21&atmFilter=&showDates=false&evalscript=cmV0dXJuIFtCOEEqMSxCMDMqMSxCMDIqMV0%3D

(not an expert either!)

[Carex]

Another little twist is that the air temp is measured and modeled at 1.5m or 2m above the surface.  Much of the energy from solar radiation will pass through the air but be absorbed by the surface, especially where dirt and soot are present.  Light isn't converted to heat until it is absorbed.  So the surface can warm and start to melt while the air 2m above it is still below freezing.  On slopes facing the sun the effect will be greater as the solar angle to the surface increases.  I'm sure this can be said much more scientifically. 

[magnamentis]

Another little twist is that the air temp is measured and modeled at 1.5m or 2m above the surface.  Much of the energy from solar radiation will pass through the air but be absorbed by the surface, especially where dirt and soot are present.  Light isn't converted to heat until it is absorbed.  So the surface can warm and start to melt while the air 2m above it is still below freezing.  On slopes facing the sun the effect will be greater as the solar angle to the surface increases.  I'm sure this can be said much more scientifically.

this is 100% correct and well explained which is all that's necessary. we don't all need doctorates to understand more than what's in hour palmares and/or diplomas

BTW even ice is melting under the sun at temps way below zero at this time of the year. a good source for those who don't live in typical ice and snow covered areas would be webcams like the one in barrows

[wdmn]

Yeah, the north side of a road, which is not shaded, melts much faster than the south side, which does not get any sun. Just as the areas without trees melt much more quickly than the forested areas.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 18 May 2019

16 to 18 May Precipitation outweighs melt on these days, but not by much.

Next 5 days Looks like melt to continue at around the same level, and precipitation to be fairly low. So perhaps overall SMB gain to be below average, maybe even -ve on one or two days.

______________________________________________
NOTES
- the DMI and NSIDC models both try to make allowances for melt / rain that refreezes / freezes where it happens, i.e. does not run-off the ice-sheet and reduce mass.
- they are models, but are tested against real observations from weather stations and other field data. Mind you, I believe the NSIDC and DMI models did end up with markedly different results about the amount of above average SMB  in the 2018-19 Greenland year.
- they are the best we have - and even if in error, are consistent over time which gives the direction of travel. Last 2 years - high above average SMB gain - this year, well below average so far.

[Stephan]

Update of weather and forecast in Narssarsuaq, South Greenland. Melting all the time. Much sun and, possibly later next week, some rain. Not good for the ice in that area...

[Tor Bejnar]

Further north, not so warm, but expect some sunshine next week (and therefore some melt on sun-facing slopes).  Hans Island is in Nares Strait.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 19 May 2019

16 to 19 May Precipitation outweighs melt on these days, but not by much.

Next 5 days Looks like melt to continue at around the same level (warm afternoons, and precipitation to be fairly low and confined to the SE. So perhaps overall SMB gain to be below average, maybe even -ve on one or two days.

During / after next weekend looks like a weather change. Warmth, rain and snow from the south enters Baffin Bay and impacts the west coast of Greenland. It is that balance between rain and snow that will determine the change in SMB? (See also post by Sleepy above)
______________________________________________

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 19 May 2019

16 to 20 May Precipitation outweighs melt on these days, but not by much.
The weekly update of the accumulated SMB anomaly is also attached. +ve  noamlies are alsmost totally confined the the coastal fringe of the SE. The contrast between the dry NW and the wet SE is much higher than average.

Next 5 days Looks like melt to continue at around the same level (warm afternoons, and precipitation to be fairly low and confined to the SE. So perhaps overall SMB gain to be below average, maybe even -ve on one or two days.

During / after next weekend looks like a weather change. Warmth, rain and snow from the south enters Baffin Bay and impacts the west coast of Greenland. It is that balance between rain and snow that will determine the change in SMB? (See also post by Sleepy above)
______________________________________________

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 21 May 2019

16 to 21 May Precipitation outweighs melt on these days, but not by much.

Next 10 days The GFS forecast has changed a lot. It now looks as if Greenland will be very dry, with even the SE looking much dryer than average. With above zero temperatures on much of the East and West coastal fringes in the long afternoons, my prediction that belongs to me is that there will be an occasional day of SMB loss.

[Tealight]

Even if we have slightly more melt than precipitation right now. Most losses are happening in June and July. On the attached gif I compared the 10th July 2012 with today. It almost looks like we have no melt right now.

[gerontocrat]

Even if we have slightly more melt than precipitation right now. Most losses are happening in June and July. On the attached gif I compared the 10th July 2012 with today. It almost looks like we have no melt right now.

What we have at the moment is much lower SMB gain compared with both the average and 2012..In June and July 2012 SMB fell off a cliff. All one can say is that this year as at May 21 is perhaps ahead of the game compared with 2012 - darker surface at least on the fringes where melt has been quite strong and very persistent.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 22 May 2019

16 to 21 May Precipitation outweighs melt on these days, but not by much.
22 May Melt outweighs precipitation on this day, by a smidgeon.

Next 10 days The GFS forecast still saying Greenland will be very dry, with even the SE looking much dryer than average. With above zero temperatures on much of the East and West coastal fringes in the long afternoons, my prediction that belongs to me is that there will be more occasional days of SMB loss.

[Tor Bejnar]

Next 10 days The GFS forecast still saying Greenland will be very dry, with even the SE looking much dryer than average.

Per Reply #100, this "dryer than average" is quite expected, climatologically.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 23 May 2019

16 to 21 May Precipitation outweighs melt on these days, but not by much.
22 May Melt outweighs precipitation on this day, by a smidgeon .
23 May Melt outweighs precipitation on this day, by more than a smidgeon .

Next 10 days The GFS forecast still saying Greenland will be very dry, with even the SE looking dryer than average. With above zero temperatures on much of the East and West coastal fringes in the long afternoons, my prediction that belongs to me is that there will be more occasional days of SMB loss.

The persistence of melt, and the persistent low precipitation is unusual, hence the accumulated SMB gain in the 2018-19 year at circa 60 GT below average, in contrast to the above average gains in the previous 2 years.

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 23 May 2019

16 to 21 May Precipitation outweighs melt on these days, but not by much.
22 May Melt outweighs precipitation on this day, by a smidgeon .
23 May Melt outweighs precipitation on this day, by more than a smidgeon .
24 May Melt outweighs precipitation on this day, by even more than more than a smidgeon .

Next 10 days The GFS forecast still saying Greenland will be very dry, with even the SE looking dryer than average. With above zero temperatures on much of the East and West coastal fringes in the long afternoons, my prediction that belongs to me is that there will be yet more occasional days of SMB loss.

The persistence of melt, and the persistent low precipitation is unusual, hence the accumulated SMB gain in the 2018-19 year at circa 60 GT below average, in contrast to the above average gains in the previous 2 years.

[Sailaway]

Just for clarification are we talking about Metric or Imperial Smidgeon

Thanks

[gerontocrat]

Just for clarification are we talking about Metric or Imperial Smidgeon

Thanks

There are 2,204.62 pounds in a Metric ton.
There are 2,240 pounds in an Imperial tonne.
There are 2,000 pounds in a US ton (lightweights!).

So difference not relevant when considering smidgeons, as in the US of A there are no smidgeons, only smidgens.. The 24th May SMB loss was just over 1 thousand million  (1,000,000,000 ) tonnes of smidgeons (1 GT or 1 KM³ of water).
______________________________________________

ps: The dictionary used by the ASIF is American - huh.

[Tor Bejnar]

If you thought you were mixing metaphors, you're right.  Those pounds in a metric ton are at sea level.  If the smidgeons are in Greenland, shouldn't they be called lille beløb [if Google is any help] and as many of them are atop the icecap, then your decimal places are wrong (even the 4 should be a 3!). 'Cause water boils at ~90C at 10,000 feet, but the factor is different.  So just get your units lined up and straights!   Edit: and nearly everybody has 'feet' and only engineers and the like have 'meters'.  so there!

But I do like the sound (in my imagination, as I know no Danish) of lille beløb!

[Shared Humanity]

 

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 25 May 2019

16 to 21 May Precipitation outweighs melt on these days, but not by much.
22 May Melt outweighs precipitation on this day, by a smidgeon .
23 May Melt outweighs precipitation on this day, by more than a smidgeon .
24-25 May Melt outweighs precipitation on this day, by even more than more than a smidgeon. SMB daily mass loss of 1 GT instead of mass gain of 2GT.

Next 10 days The GFS forecast still saying Greenland will be very dry, with even the SE looking extremely dry. Some, but not much precipitation drifting into the North East.  Very good conditions for insolation (that's sunshine all day and night 24/7). With above zero temperatures on much of the East and West coastal fringes in the long afternoons, my prediction that belongs to me is that there will be yet more days of SMB loss.

The persistence of melt, and the persistent low precipitation is unusual, hence the accumulated SMB gain in the 2018-19 year at circa 60 GT below average, in contrast to the above average mass gains in the previous 2 years.

[silkman]

Even if we have slightly more melt than precipitation right now. Most losses are happening in June and July. On the attached gif I compared the 10th July 2012 with today. It almost looks like we have no melt right now.

Here's a May 25th Worldview image of the area just to the South of Disko Bay showing a substantial number of melt ponds and an indication of decreasing albedo. It seems that the melt season is now well under way.

https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2019-05-25-T00%3A00%3A00Z&z=3&v=-261605.09040728386,-2356810.180814568,-130533.09040728386,-2270794.180814568

[gerontocrat]

And 2 images 4 days apart from Sisimiut area showing bare ground appearing where once was snow.

courtesy of DMI @ http://ocean.dmi.dk/arctic/sisimiut.uk.php (Hours of playtime here)

[gerontocrat]

http://polarportal.dk/en/greenland/surface-conditions/ as at 26 May 2019

Greenland is melting - early

[oren]

Damn. It almost feels as if SMB for the season has peaked. It's not really the melt which isn't extraordinary, just normal, so it must be the lack of sufficient precipitation that's taking it so low.

[Shared Humanity]

Earlier onset of melt and lower ending SMB than 2012. Wasn't 2012 a dreadful year for Greenland melt?

[gerontocrat]

Earlier onset of melt and lower ending SMB than 2012. Wasn't 2012 a dreadful year for Greenland melt?

Look at the graph in the post above. Yes, 2012 was extraordinary - and just as for sea ice, 2012 melt started late.

in 2019, melt is starting early after somewhat less than average snowfall mass gain.

[gerontocrat]

Images from Sisimiut on the West Coast

[b_lumenkraft]

One month of Sisimiut via Worldview: