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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #500 on: August 16, 2019, 08:17:12 AM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 15 August 2019

On this day
... the end-of-season downward gentle slope continues to accelerate

Melt  below yesterday's. At below average..

Precipitation  not that low, and as a result ......

SMB (Surface Mass Balance) loss less than yesterday . Around 3GT mass loss on this day, but still about 1 gt more than average.
______________________________________________________
5 day outlook

Melt / Temperatures. Southern & Eastern Greenland cold. A part of the North & West still a bit above average.

Precipitation 5 day outlook.
Still looking lowish or very dry. But as the Greenland High shrinks and weakens signs of precipitation at both North and South fringes.

This should mean that though melt is reducing, SMB mass loss might still be above average for a few days more.

High pressure has been, is, and will be stuck over Greenland - but certainly looks like continuing to shrink.

The melting season now quickens its fade into history as the Greenland summer has ended, the oh so short Autumn has started and winter arrives with thump - very soon - unless something weird happens.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
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FrostKing70

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Re: Greenland 2019 Melt Season
« Reply #501 on: August 16, 2019, 08:29:07 PM »
I think 10 - 20 GT remaining seems about right.  The average is a bit less than that, but we are trending with greater loss, and the season might extend out a day or a few days.

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #502 on: August 17, 2019, 05:26:19 AM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 16 August 2019

On this day
... the end-of-season downward gentle slope continues to accelerate

Melt  Same as yesterday's, so returns to average for the day..

Precipitation  not that low, and as a result ......

SMB (Surface Mass Balance) loss less than yesterday . Less than 3GT mass loss on this day, less than 1 gt more than average.
______________________________________________________
5 day outlook

Melt / Temperatures. Southern & Eastern Greenland cold. A part of the North & West still a bit above average.

Precipitation 5 day outlook.
Still looking lowish or very dry. But as the Greenland High shrinks and weakens signs of precipitation at both North and South fringes.

This should mean that though melt is reducing, SMB mass loss might still be above average for a few days more.

High pressure has been, is, and will be stuck over Greenland - but certainly looks like continuing to shrink.

The melting season now quickens its fade into history as the Greenland summer has ended, the oh so short Autumn has started and winter arrives with thump - very soon - unless something weird happens.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
[/quote]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #503 on: August 18, 2019, 09:30:27 AM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 16 August 2019

On this day
... the end-of-season downward gentle slope continues to accelerate

Melt  Slightly lower, at average for the day..

Precipitation  not that low, and as a result ......

SMB (Surface Mass Balance) loss less than yesterday . Just over 2GT mass loss on this day, just less than average.
______________________________________________________
5 day outlook

Melt / Temperatures. Southern & Eastern Greenland cold. A part of the North & West still a bit above average.

Precipitation 5 day outlook.
Still looking lowish or very dry. But as the Greenland High shrinks and weakens signs of precipitation at both North and South fringes.

This should mean that though melt is reducing, SMB mass loss might still be above average for a few days more.

High pressure has been, is, and will be stuck over Greenland - but certainly looks like continuing to shrink.

The melting season now quickens its fade into history as the Greenland summer has ended, the oh so short Autumn has started and winter arrives with thump - very soon - unless something weird happens.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #504 on: August 19, 2019, 02:58:22 PM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 18 August 2019

On this day
... the end-of-season downward gentle slope continues to accelerate

Melt  Slightly lower, at average for the day..

Precipitation  precipitation in the far north and the far south, and as a result ......

SMB (Surface Mass Balance) loss less than yesterday . Just over 1GT mass loss on this day, at
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe with some warmth left.

Precipitation 5 day outlook.
Still looking lowish or very dry. But as the Greenland High shrinks and weakens signs of precipitation at both North and South fringes.

This should mean that though melt is reducing, SMB mass loss might still happen for a few days more.

High pressure has been, is, and will be stuck over Greenland - but certainly looks like continuing to shrink.

The melting season now quickens its fade into history as the Greenland summer has ended, the oh so short Autumn has started and winter arrives with thump - very soon - unless something weird happens.

Season over - but not quite dead?
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #505 on: August 20, 2019, 11:24:16 AM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 19 August 2019

On this day
... the end-of-season downward gentle slope continues

Melt  Slightly lower, at average for the day..

Precipitation  precipitation in the far north and the far south but a bit lower, and as a result ......

SMB (Surface Mass Balance) loss a bit more than yesterday . Nearly 2GT mass loss on this day, more than 1 G|T greater than average.
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe with some warmth left.

Precipitation 5 day outlook.
Still looking lowish or very dry for 3 days, then more precipitation in the SE. .

This should mean that though melt is reducing, SMB mass loss might still happen for a few days more.

High pressure has been, is, and will be stuck over Greenland - but certainly looks like continuing to shrink.

The melting season now quickens its fade into history as the Greenland summer has ended, the oh so short Autumn is well underway and winter arrives with thump - very soon - unless something weird happens.

Season over - but not quite dead?
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
[/quote]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Klondike Kat

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Re: Greenland 2019 Melt Season
« Reply #506 on: August 20, 2019, 02:00:44 PM »
Gerontocrat,
Wonderful, as usual.  As we approach the end of the season, do you have an idea as to where the 2019 melt falls in relation to recent years, not just the record low?  Thanks.

johnm33

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Re: Greenland 2019 Melt Season
« Reply #507 on: August 20, 2019, 02:55:23 PM »
Another look at the outflow from Zach/79N and Humbolt curious that despite clear evidence of flows from Jakobshvn no sign of freshwater. The second gif shows the uplift in temp around 5/6 Aug. 9c associated with the outflow at Zach/79N. 1, 30days from 27:07. 2, 10 days from 01:08


blumenkraft

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Re: Greenland 2019 Melt Season
« Reply #508 on: August 20, 2019, 05:14:36 PM »
Another look at the outflow from Zach/79N and Humbolt curious that despite clear evidence of flows from Jakobshvn no sign of freshwater. The second gif shows the uplift in temp around 5/6 Aug. 9c associated with the outflow at Zach/79N. 1, 30days from 27:07. 2, 10 days from 01:08



Well, warm Atlantic waters even made it up to Kane Basin. No wonder all this freshwater is getting salty...
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johnm33

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Re: Greenland 2019 Melt Season
« Reply #509 on: August 20, 2019, 07:30:45 PM »
"Well, warm Atlantic waters even made it up to Kane Basin" Or did it arrive from the north?

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Re: Greenland 2019 Melt Season
« Reply #510 on: August 20, 2019, 07:45:09 PM »
Possible, but how i see it coming from the south is more likely. There is no southward surface current in NS for weeks. Mercator model sees it coming from the south too ( http://bulletin.mercator-ocean.fr/en/PSY4/animation ).
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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #511 on: August 20, 2019, 10:03:30 PM »
Gerontocrat,
Wonderful, as usual.  As we approach the end of the season, do you have an idea as to where the 2019 melt falls in relation to recent years, not just the record low?  Thanks.
Still assembling data

Attached are graphs & Tables:-

Components of SMB 1960 to 2018 - but anomalies,
Components of SMB 1980 to 2014  - actual amounts

And from a recent paper https://www.pnas.org/content/116/19/9239
Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018, which has an Excel data file attached. From that I've bashed up a graph of SMB, discharge (i.e. calving and glacier melt by seawater), and net Mass Gain / Loss.

In this paper it looks like they've defined the year as July to June. DMI use Sept to August - which is more logical.

NSIDCs Greenland Today will produce a report later this year. But I would say SMB gain this year will likely be in the bottom 5.

Still hoping for GRACE-FO Greenland Ice Sheet overall mass loss data late this month or next month to get the complete picture.


« Last Edit: August 20, 2019, 10:09:43 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #512 on: August 21, 2019, 12:49:23 PM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 19 August 2019

On average, from this day average daily melt is reducing to the point that average daily precipitation exceeds melt. I.e. Surface Mass starts to increase

However, on this day[/b]...

Melt  was slightly lower, a little below average for the day..

Precipitation  precipitation in the far north and the far south but very low, and as a result..

SMB (Surface Mass Balance) loss the same as yesterday . Nearly 2GT mass loss on this day, while average loss for the day is down to zero.
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe with some warmth left, increasing a bit after 3 days.

Precipitation 5 day outlook.
Still looking lowish or very dry for 3 days, then more precipitation in the SE. .

This should mean that though melt is reducing, SMB mass loss might still happen for a few days more.

High pressure has been, is, and will be stuck over Greenland - but stabilised on a smaller scale
______________________________________________________
Speculation: GFS 5-10 Day Outlook GFS suggests that both the East and West Coast could have some much warmer days. But on the other hand precipitation on the West Coast could also be much higher. The result on SMB is the question.
___________________________________________________________________

In theory, the melting season finishes as the so short Autumn is well underway and winter arrives with a thump. But maybe one more surprise in store.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

ArcticMelt2

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Re: Greenland 2019 Melt Season
« Reply #513 on: August 21, 2019, 02:19:51 PM »
The first data from new satellites

https://www.jpl.nasa.gov/news/news.php?feature=7481

Quote
The mission also measures mass changes in the thick ice sheets of Greenland and Antarctica. The May 2019 GRACE-FO map of Greenland shows that most of the island continued its long-term trend of ice mass loss. GRACE-FO data from June 2018 through early 2019 (see black-and-white graph) indicate a recent slowdown in Greenland ice loss that has also been observed in data from NASA's Oceans Melting Greenland airborne campaign. This slowdown has been attributed to cooler ocean waters around Greenland for the last few years.

The GRACE-FO science team is now looking at June 2019 data to assess how the unusually warm weather and rapid ice loss this summer will affect that trend. Greenland's significant ice melt in June and July this year was similar to the strong melting that occurred in the summer of 2012 and led to significant ice loss.


ArcticMelt2

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Re: Greenland 2019 Melt Season
« Reply #514 on: August 21, 2019, 02:24:26 PM »
The graph confirms the data that the last winter is not very snowy (record little snow over the entire observation period).

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #515 on: August 22, 2019, 04:05:30 PM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 21 August 2019

On average, from this day average daily melt is reducing to the point that average daily precipitation exceeds melt. I.e. Surface Mass starts to increase

However, on this day[/b]...

Melt was slightly lower, a little below average for the day..

Precipitation  precipitation was low, and as a result..

SMB (Surface Mass Balance) loss a bit lower yesterday . About 1.5GT mass loss on this day, while average loss for the day is down to zero.
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe, especially the North with some warmth left, increasing a bit after 3 days.

Precipitation 5 day outlook.
Still looking lowish;

This should mean that though melt is reducing, SMB mass loss might still happen for a few days more.

High pressure has been, is, and will be stuck over Greenland - but stabilised on a smaller scale
______________________________________________________
Speculation: GFS Aug 31 & Sep 1 GFS suggests that the West Coast could have a melt event. But on the other hand GFS predicts a significant storm roaring into and up Baffin Bay on the same 2 days - with high precipitation on the West Coast including rain penetrating well inland to higher altitudes.. The result on SMB is the question - if the event happens. (GFS has to be right sometimes, doesn't it?
___________________________________________________________________

In theory, the melting season finishes as the so short Autumn is well underway and winter arrives with a thump. But maybe one more surprise in store.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
[/quote]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #516 on: August 23, 2019, 08:29:10 AM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 22 August 2019

On average, from this day average daily melt is reducing to the point that average daily precipitation exceeds melt. I.e. Surface Mass starts to increase

However, on this day[/b]...

Melt was slightly lower, a little below average for the day..

Precipitation  precipitation was low, and as a result..

SMB (Surface Mass Balance) loss a bit lower than yesterday . About 1GT mass loss on this day, while average loss for the day is down to zero.
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe, especially the North with some warmth left.

Precipitation 5 day outlook.
Still looking lowish;

This should mean that though melt is reducing, SMB mass loss might still happen for a few days more.

High pressure has been, is, and will be stuck over Greenland - but stabilised on a smaller scale
______________________________________________________
Speculation: GFS Aug 31 & Sep 1 As usual, the GFS suggestion yesterday that the West Coast could have a melt event starting to look somewhat less impressive. And the GFS forecast of a significant storm roaring into and up Baffin Bay on the same 2 days  now becomes just an ordinary low clipping the every south of Greenland.  [iGFS has to be right sometimes, doesn't it? But not this time?[/i]
___________________________________________________________________

In theory, the melting season finishes as the so short Autumn is well underway and winter arrives with a thump.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
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FrostKing70

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Re: Greenland 2019 Melt Season
« Reply #517 on: August 23, 2019, 02:17:53 PM »
Thank you for putting all of the information here.  Is there a thread for GRACE and GRACE-FO?

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #518 on: August 24, 2019, 02:00:05 PM »
Thank you for putting all of the information here.  Is there a thread for GRACE and GRACE-FO?
I put some stuff on "satellite news" in "science". The GRACE-FO Level-3 product of ASCII files of Ice-Sheet Mass Changes are not yet there. I was promised something this month but.....

I was thinking of opening a thread for  next year, maybe  "2019-20 Snowfall & Melt (SMB) & Overall Mass Loss" (mainly but not only using GRACE-FO Data) as that is the complete picture - snow, melt, calving/melt from sea-water.
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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #519 on: August 24, 2019, 02:07:07 PM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 23 August 2019

On average, from this day average daily melt is reducing to the point that average daily precipitation exceeds melt. I.e. Surface Mass starts to increase

And, on this day[/b]...

Melt was  lower, a below average for the day..

Precipitation  precipitation was up, and as a result..

SMB (Surface Mass Balance) loss was zero, while average loss for the day is down to zero.
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe, especially the North with some warmth left.

Precipitation 5 day outlook.
Still looking lowish, but with low melt probably enough to prevent any further mass loss.

This may mean the end of SMB reductions.

High pressure has been, is, and will be stuck over Greenland - but stabilised on a smaller scale
______________________________________________________
Speculation: GFS Aug 31 & Sep 1 As usual, the GFS suggestion yesterday that the West Coast could have a melt event starting looks much less impressive. But the GFS forecast of a significant storm roaring into and up Baffin Bay on the same 2 days has returned, including significant rainfall on low altitudes..  [iGFS has to be right about something sometime , doesn't it? But not this time?[/i]
___________________________________________________________________

It may well be that the melting season is over as the so short Autumn is well underway and winter will arrive with a thump fairly soon.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
[/quote]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Tom_Mazanec

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Re: Greenland 2019 Melt Season
« Reply #520 on: August 25, 2019, 11:32:16 AM »
How do you "do" it on these kind of threads? Does the threadstarter, or Neven, just lock it it a few days?
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oren

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Re: Greenland 2019 Melt Season
« Reply #521 on: August 25, 2019, 12:53:28 PM »
The date-specific threads remain open for posterity, in case someone wants to add something later. For example if an article is published discussing the thread's subject and timeframe, or someone makes some relevant homemade charts and statistics.

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Re: Greenland 2019 Melt Season
« Reply #522 on: August 25, 2019, 01:40:30 PM »
I tried posting something on a 2017 Hurricane and the thread was locked? So I posted on some other peripherally related thread.
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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #523 on: August 25, 2019, 05:38:50 PM »
http://polarportal.dk/en/greenland/surface-conditions/ as at 24 August 2019

Last standard daily posting - unless there is a event.
After Aug 31 time to have a closer look at the overall year 2018-2019,
with another look when / if we get GRACE-FO ASCII data to end August.

____________________________________________________________-
On average, from this day average daily melt is reducing to the point that average daily precipitation exceeds melt. I.e. Surface Mass starts to increase

And, on this day[/b]...

Melt was  lower, below average for the day..

Precipitation  precipitation was moderate, and as a result..

SMB (Surface Mass Balance) loss was zero or even a small SMB gain, while average loss for the day is also above zero.
______________________________________________________
5 day outlook

Melt / Temperatures. Almost all Greenland cold - below zero. Some small parts of the fringe, especially the North with some warmth left.

Precipitation 5 day outlook.
Still looking lowish, but with low melt probably enough to prevent any further mass loss.

This may mean the end of SMB reductions.

High pressure has been, is, and will be stuck over Greenland - but stabilised on a smaller scale
______________________________________________________
Speculation: GFS Aug 31 & Sep 1 Melt Event ? - forget it.
___________________________________________________________________

It may well be that the melting season is over as the so short Autumn is well underway and winter will arrive with a thump fairly soon.
_______________________________________________
Quote from DMI (because every so often people get confused...
Quote
The term surface mass balance (SMB) is used to describe the isolated gain and loss of mass of the surface of the ice sheet – excluding the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater.
__________________________________________________________________
Quote
ps from me: Calving and melt from by relatively warm sea water on marine-terminating glaciers exceeds the annual overall SMB gain. It is the GRACE-FO satellite that is giving the data to give the overall net Greenland mass loss. The data up to the end of August 2019 might be produced sometime in late September. (Fingers crossed)
___________________________________________________________
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Tom_Mazanec

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Re: Greenland 2019 Melt Season
« Reply #524 on: August 25, 2019, 07:21:11 PM »
Just seems kinda weird the last bit of warm weather in Greenland is in the North.
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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #525 on: August 25, 2019, 08:31:00 PM »
I tried posting something on a 2017 Hurricane and the thread was locked? So I posted on some other peripherally related thread.
Neven can lock any thread at any time.
You can lock any thread you have created.

So either Neven locked it or the person who created it locked it.

These things happen from time to time.

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Klondike Kat

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Re: Greenland 2019 Melt Season
« Reply #526 on: August 26, 2019, 03:24:17 PM »
Gerontocrat,
Excellent posts, as usual.  As this season draws to a close, I look forward to your next thread.

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #527 on: August 27, 2019, 01:56:29 PM »
http://polarportal.dk/en/greenland/surface-conditions/ 25 & 26 Aug 2019

No significant event, but average melt and lowish precipitation means a small SMB loss instead of a small gain

The season is dying but not quite dead.
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Re: Greenland 2019 Melt Season
« Reply #528 on: August 27, 2019, 05:17:06 PM »
Gerontocrat,
Excellent posts, as usual.  As this season draws to a close, I look forward to your next thread.
What KKat said.

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Re: Greenland 2019 Melt Season
« Reply #529 on: August 27, 2019, 09:51:20 PM »
Gerontocrat
May I also offer a hat-tip for another season of consistent data posting on ASIF. Many thanks.
RC
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Re: Greenland 2019 Melt Season
« Reply #530 on: August 29, 2019, 10:23:44 PM »
Climate change melts 12.5bn tons of ice in Greenland 50 years earlier than predicted
https://www.telegraph.co.uk/news/2019/08/28/climate-change-melts-billions-tons-ice-greenland-fifty-years/
Quote
Billions of tonnes of ice in Greenland is melting 50 years ahead of climate change schedules, preventing inhabitants from moving around the country by sledge and leading to the surreal spectacle of children playing in the Arctic sea due to rising temperatures.

A heatwave gripping the Arctic region is causing unprecedented levels of melting ice, and has also seen global sea levels rise, in a clear sign that climate change is taking its severe toll much more quickly than predicted.
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Re: Greenland 2019 Melt Season
« Reply #531 on: August 30, 2019, 12:49:12 PM »
Season is not over yet. Currently and over the next few days, the western and northern coast is getting roasted. Temperature anomalies +10C in some places.

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Re: Greenland 2019 Melt Season
« Reply #532 on: August 30, 2019, 02:23:29 PM »
Season is not over yet. Currently and over the next few days, the western and northern coast is getting roasted. Temperature anomalies +10C in some places.
Very true - melt on average continues, gradually reducing, until the end of September, and there will be warm days (& cold days).

However, on the other hand precipitation increases - as Autumn / Winter storms increase (as was supposed to happen in the Arctic Ocean - prolonging extent and area loss).

So although there is melt, the SMB - Surface Mass Balance increases. And this is the key reason that DMI chose September to August as the Greenland year for analysing the data.

Mind you, as the years go by the models suggest that precipitation will increase, and so will rainfall instead of snowfall especially at lower latitudes. And when there are SMB losses after August 31 it will be a real event. That's AGW - messing up the scientists' nice neat definitions of the seasons.

So I have no intention of closing this thread, but I am going to open a Greenland 2019-20 SMB (Snowfall and Melt)  thread to initially occasionally post DMI's data on progress of the snowfall and remaining melt.

Meanwhile.... http://polarportal.dk/en/greenland/surface-conditions/ 27-29 Aug 2019

Average melt but increasing precipitation has led to SMB gains to above 1 GT.
« Last Edit: August 30, 2019, 02:35:22 PM by gerontocrat »
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Re: Greenland 2019 Melt Season
« Reply #533 on: August 31, 2019, 01:58:47 PM »
http://polarportal.dk/en/greenland/surface-conditions/ 30 Aug 2019

Average melt up a little bit to just above average, and slightly lower precipitation has led to an SMB loss of 1 GT compared to an average gain of 1 GT on this day.
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Re: Greenland 2019 Melt Season
« Reply #534 on: September 01, 2019, 02:15:34 PM »
http://polarportal.dk/en/greenland/surface-conditions/ 31 Aug 2019

Average melt up a little bit to just above average, and but higher precipitation has led to an SMB gain at around average for the day..
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Re: Greenland 2019 Melt Season
« Reply #535 on: September 01, 2019, 03:02:14 PM »
The DMI Surface Mass Balance (SMB) year is over, but the melting season is not.

Nevertheless, here is a gif of the melting season to date since late June. Sorry, no images from May when it started. (next year?)

Click to start - should slow down a bit at the peak melting.
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Re: Greenland 2019 Melt Season
« Reply #536 on: September 01, 2019, 03:38:31 PM »
The DMI Surface Mass Balance (SMB) year is over, but the melting season is not.

Nevertheless, here is a gif of the melting season to date since late June. Sorry, no images from May when it started. (next year?)

Click to start - should slow down a bit at the peak melting.

Love the gif. I was thinking an animation would be useful back in july, but didn’t want to bug you and you already do too much.

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Re: Greenland 2019 Melt Season
« Reply #537 on: September 03, 2019, 05:18:56 PM »
First look at the DMI Greenland Year Sept 2018 to Aug 2019

Precipitation (Snowfall).
On average before melting starts in earnest, SMB increases by an average of around 580 GT from August to early June, i.e. dominated by snowfall.

The 2018-19 snowfall was at or below average for most of the time, with SMB increase about 60 GT lower than average, giving an SMB gain during this snowfall dominated part of the year of about 520 GT

(In contrast, 2012 saw an average SMB gain in this period)

Melt  started early, with a brief spike in April and then persistent melt above precipitation by the 3rd week in May.

As a result Surface Mass Balance (SMB) started consistent daily losses by the third week in May, about 2 weeks earlier than average, effectively extending the season for SMB losses by about 15%.

(In 2012, SMB loss commenced only a very few days earlier than average)

SMB losses during the melting period in 2018-19 were around 350GT,  about 130 GT more than the average of 220GT.

(In 2012, SMB losses during the melting period were a massive 540 GT)

So net SMB gain for the 2018-19 year was around 170 GT, about 300 GT less than the average yearly gain of 360 GT.

(In 2012, the net SMB gain was about 40 GT)

SUMMARY 2019 vs 2012
In 2012, because snowfall was average, the record low net gain was caused entirely by melt.
In 2019, the low net gain in SMB was mostly from melting, but partly from low snowfall.

2019 melt of 350 GT,
2012 Melt of 540 GT.

In other words, 2019 was an above average melt year, and an early melt year.
But NOT in the same league for melting as 2012.
« Last Edit: September 03, 2019, 05:46:07 PM by gerontocrat »
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Re: Greenland 2019 Melt Season
« Reply #538 on: September 03, 2019, 10:44:56 PM »
Gerontocrat - thank you for this analysis.
I have picked up from somewhere that 360 Gt ice melt results in 1 mm sea level rise [if this isn't correct, please tell me, in this case I will revise my notes]. So Greenland has almost made this millimeter in the 2019 melting season.

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Re: Greenland 2019 Melt Season
« Reply #539 on: September 04, 2019, 02:32:21 PM »
From a BBC article on Greenland melt:

Recent years have seen hundreds of billions of tonnes of ice lost - and a rough guide to the effect on sea level is that 362 billion tonnes of melt raises the average ocean level by a millimetre.

https://www.bbc.com/news/science-environment-49483580

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Re: Greenland 2019 Melt Season
« Reply #540 on: September 04, 2019, 06:01:37 PM »
Gerontocrat - thank you for this analysis.
I have picked up from somewhere that 360 Gt ice melt results in 1 mm sea level rise [if this isn't correct, please tell me, in this case I will revise my notes]. So Greenland has almost made this millimeter in the 2019 melting season.

The SMB of Greenland (snow vs melt ratio) is never negative including the low of 2012 (+50GT). Any mass loss is due to calving only (which is mostly due to pressure of falling snow). Is there any data on mass of calving?

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Re: Greenland 2019 Melt Season
« Reply #541 on: September 05, 2019, 07:38:12 PM »
It looks like Dorian will pass just south of Greenland as a Tropical Storm.  Any thoughts / predictions on impact to the SMB?

I am not sure how much will fall as rain versus snow at higher elevations...

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Re: Greenland 2019 Melt Season
« Reply #542 on: September 05, 2019, 08:23:07 PM »
Gerontocrat - thank you for this analysis.
I have picked up from somewhere that 360 Gt ice melt results in 1 mm sea level rise [if this isn't correct, please tell me, in this case I will revise my notes]. So Greenland has almost made this millimeter in the 2019 melting season.

The SMB of Greenland (snow vs melt ratio) is never negative including the low of 2012 (+50GT). Any mass loss is due to calving only (which is mostly due to pressure of falling snow). Is there any data on mass of calving?
Mass loss is caused by calving and contact of marine-terminating glaciers with relatively warm ocean water. This latter melt is, apparently, much more significant than previously thought.

Calving is due to flow of the glaciers to the ocean edge, and is from gravity. Obviously snowfall is increasing downward weight, but the annual increase from a few metres of snow is far less important than the 1 to 3 kms thickness of the ice sheet. It seems that the average rate of  flow of glaciers to the ocean is double in summer, due to meltwater seeping through the glaciers (moulins etc) to the ice rock boundary - reducing friction.

We have data from 2 main sources on calving/melt by the ocean and overall mass change (SMB minus calving).

1- studies and field measurements. The latest one I've read (and copied their speadsheet) is
https://www.pnas.org/content/116/19/9239 Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018 - It is damn good

See attached graphs from the paper and one I made from their spreadsheet.

2- GRACE and GRACE-FO Mass Change data. I attach the latest graph I made from their data. I am still waiting for GRACE-FO to produce the data on a regular basis.

Net mass loss of the Greenland Ice Sheet is in excess of 200 GT per annum.
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Re: Greenland 2019 Melt Season
« Reply #543 on: September 05, 2019, 09:59:29 PM »
A long BBC article about Greenland's ice sheet.

https://www.bbc.co.uk/news/science-environment-49483580

Not hard science but a good intro.
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gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #544 on: September 06, 2019, 09:15:17 PM »
Germany is back from holiday and it looks like they are getting their GRACE-FO act together.

Corrected GRACE Ice Mass Data (still only to May 219) was posted, and I was able to add the map. Hopefully we will see later data apearing more regularly from now.

More details tomorrow on Greenland and about Antarctica (with links).

It is why have changed the name for the 2019-20 year as we will have much more complete data.

EDIT - Another Graph before bedtime
« Last Edit: September 06, 2019, 10:06:36 PM by gerontocrat »
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Re: Greenland 2019 Melt Season
« Reply #545 on: September 06, 2019, 09:43:15 PM »
Fascinating stuff, as usual!

Does anyone know if there is a similar graph for the basins, but done in percentage terms instead of GT?   

I stared at the graph for a while trying to understand why the orange (302) and red (305) lines were nearly flat.   Basin 302 feels correct, as the color coding is a mix of small gains and losses.   It took longer for it to sink in on basin 305, as most of the area shows significant loss.   

gerontocrat

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Re: Greenland 2019 Melt Season
« Reply #546 on: September 06, 2019, 10:10:36 PM »
Fascinating stuff, as usual!

Does anyone know if there is a similar graph for the basins, but done in percentage terms instead of GT?   

I stared at the graph for a while trying to understand why the orange (302) and red (305) lines were nearly flat.   Basin 302 feels correct, as the color coding is a mix of small gains and losses.   It took longer for it to sink in on basin 305, as most of the area shows significant loss.

Does anyone know if there is a similar graph for the basins, but done in percentage terms instead of GT?   

I know, because it is I who have made these graph from the raw data that only appeared on the website today.

And there isn't because I have not made it yet.

HINT:- That is why they say - prepared by GERONTOCRAT
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