11 ms·

Rain falls at the summit of Greenland Ice Sheet for first time on record

150 points by yboris 5y ago

the-dude 5y ago
"On record" seems to be 32 years ( from TFA ). Then the article concludes : And now rainfall: in an area where rain never fell.
- SamBam 5y ago
  Huh? From TFA, I assume you're referring to > In fact, temperatures at the site only rose above freezing three times before this in the past 32 years, according to observations at Summit Station from 1989. These were the years of the most recent melts. It doesn't say there was rainfall.
h2odragon 5y ago
linked earlier: https://nsidc.org/greenland-today/2021/08/rain-at-the-summit-of-greenland/ https://nsidc.org/greenland-today/2021/08/rain-at-the-summit... > Earlier melt events in the instrumental record occurred in 1995, 2012, and 2019; prior to those events, melting is inferred from ice cores to have been absent since an event in the late 1800s. doesn't that make "first time on record" a stretch too far?
- ceejayoz 5y ago
  You’re mixing up rainfall and melt events. You can have a melting ice cap without it raining.
adrianN 5y ago
See also https://news.ycombinator.com/item?id=28240552 https://news.ycombinator.com/item?id=28240552
- teddyh 5y ago
  And https://news.ycombinator.com/item?id=28245506 https://news.ycombinator.com/item?id=28245506
the_third_wave 5y ago
This year has seen both a high melt [1] as well as a high accumulation [2] of snow, the balance of which currently lies clearly at the positive end - Greenland has far more accumulated snow than average. These images come from the Danish polar portal [3] which I assume to be a canonical source given that Greenland is a Danish province. The explanation with the images reads as follows: The map illustrates what the ice sheet’s total surface gains and losses have been over the year since 1 September compared to the period 1981-2010. It does not include the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater. The animation shows one frame every seven days going back to the previous 1 September. The blue curve shows the current season, whilst the red curve shows the corresponding development for the 2011-12 season, when the degree of melting was record high. The dark grey curve traces the mean value from the period 1981-2010. The light grey band shows differences from year to year. For any calendar day, the band shows the range over the 30 years (in the period 1981-2010), however with the lowest and highest values for each day omitted. [1] http://polarportal.dk/fileadmin/polarportal/meltarea/MELTA_combine_SM_EN_20210819.png http://polarportal.dk/fileadmin/polarportal/meltarea/MELTA_c... [2] http://polarportal.dk/fileadmin/polarportal/surface/SMB_combine_SM_acc_EN_20210819.png http://polarportal.dk/fileadmin/polarportal/surface/SMB_comb... [3] http://polarportal.dk/en/greenland/surface-conditions/ http://polarportal.dk/en/greenland/surface-conditions/
- cs702 5y ago
  FYI, there's a school of thought which has concluded that global warming will lead to another glacial period within the current ice age, because higher temperatures disrupt ocean currents -- particularly the Gulf Stream, which redistributes warm water from the Gulf of Mexico to northern Europe. As the Gulf Stream makes its deposits of warm water along the coasts of Great Britain and northwest Europe, it keeps the temperatures in northwest Europe warmer than in eastern Canada, even though they both are roughly the same distance from the equator. The hypothesis is that, if Arctic ice melts as a result of global warming, huge amounts of fresh water will pour into the North Atlantic and slow down the Gulf Stream, cooling Europe, and triggering a feedback loop with colder and longer European winters, and more and more ice building up on the planet's surface.[a][b] [a] The book "Ice Age" by Cambridge-trained astrophysicist John Gribbin and his wife Mary has a good high-level overview of this school of thought: https://reanimus.com/store/?item=1420 https://reanimus.com/store/?item=1420 [b] Recent studies of circulation in the North Atlantic already show a significant reduction in currents flowing north from the Gulf Stream: https://www.realclimate.org/index.php/archives/2020/09/new-studies-confirm-weakening-of-the-gulf-stream-circulation-amoc/ https://www.realclimate.org/index.php/archives/2020/09/new-s...
oenetan 5y ago
https://ghostarchive.org/archive/Z5ypj https://ghostarchive.org/archive/Z5ypj https://archive.is/nkILZ https://archive.is/nkILZ
- dredmorbius 5y ago
  #TIL GhostArchive. https://ghostarchive.org/index.html https://ghostarchive.org/index.html
dredmorbius 5y ago
It's worth noting that the record here extends back 32 years, to 1989. And that the weather station isn't equipped with rain guages, as those were seen as not useful. The story also mentions that the liquid precipitation should form a distinctive ice layer which will be preserved in the snowpack, and detecatable in future ice cores. For those curious about any previous liquid precipitation events, that ice record might give some indication of when those might have occurred. According to the article, "ice core data shows that the last time melting occurred at the ice cap top dates to the 1880s." Which suggests not within at least 130-ish years. This is a reminder that the duration of direct observations of meterological conditions is limited in both time and geography. Similarly for satellite observations: very comprehensive in territorial coverage, but beginning only in the 1960s and making great strides in each decade since. Paleometerological records are limited in location to places where weather events can be reliably recorded, and often it's only a specific set of characteristics which are (ice cores, pollen samples, isotopic characteristics, etc.). But they do provide a view across a broad span of time. Both temporal and spatial aspects have enormous significance.
- mzs 5y ago
  "ice core data shows that the last time melting occurred at the ice cap top dates to the 1880s." That could have been melting instead of rainfall though, right?
  - dredmorbius 5y ago
    Correct. It's the most recent possible occurence, or candidate occurrence. Not the most recent definite occurrence. We do know that it has not rained at that location for at least 130 years, at least sufficient to leave an ice-core trace. We do NOT know when it did rain most recently, previously, based on the information in the article.
- dalbasal 5y ago
  Any larger, perennial or otherwise noteworthy deeper in those ice cores?
cozzyd 5y ago
Hah I was up there up until about a month ago. We did not design our equipment to be resistant to rain. Oops, apparently.
- echelon 5y ago
  Totally unrelated question. Greenland has so few people, yet so much land. I get that this is on account of the temperatures, but would it be possible to build large cities there if there were demand? Or are the geography and natural resources insufficient to support cities of scale?
  - bpodgursky 5y ago
    I mean, it's 98% ice, miles of it. It's certainly possible for people to live on ice if there's demand and energy, but there are a lot of other open areas of the earth for people to build cities on.
  - cozzyd 5y ago
    If you're talking about building on the ice sheet, building on ice is very difficult, the snow is constantly drifting and requires a lot of maintenance (lifting or moving buildings every few years, etc.). And only the 109th national guard operates ski-equipped C-130's that can bring supplies. Smaller planes can come (Baslers or Twin Otters) but those can't carry nearly as much. They used to have a traverse from the air force base at Thule but they stopped due to difficulty getting on the ice sheet from there. On the coast it would be more reasonable to build a city, though the topography is rough and getting enough food would be expensive. The only place I've been on the coast is Kangerlussuaq (the main commercial airport for Greenland, and also a base for the 109th ANG which is how I got to Greenland and to Summit). You can explore on street view what it looks like: https://www.google.com/maps/@67.0035567,-50.6859212,3a,75y,316.76h,95.51t/data=!3m7!1e1!3m5!1sYEdICDsdM12SPe9kTsPHMg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DYEdICDsdM12SPe9kTsPHMg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D160%26pitch%3D-20%26thumbfov%3D100!7i13312!8i6656 https://www.google.com/maps/@67.0035567,-50.6859212,3a,75y,3... . It actually has the largest road network in Greenland and a seaport. But... there isn't that much room to build if you wanted to and I think that's more or less the story everywhere in Greenland. For example, ere is Nuuk, the capital and largest city: https://www.google.com/maps/@64.1770542,-51.7239805,3a,75y,42.76h,99.55t/data=!3m6!1e1!3m4!1sSHD_drWAczdQeYU1nFWVkA!2e0!7i13312!8i6656 https://www.google.com/maps/@64.1770542,-51.7239805,3a,75y,4... Not great terrain for city building...
irrational 5y ago
Yesterday I noticed that on July 2nd someone left a review for a movie that said in part "They did have to put in Climate change nonsense. Wonder if that is a requirement with funding so AL gore can get billions of more tax dollars. 1168 people found this helpful." It is incredible to me that climate change is still considered to be nonsense by so many people.
- SubiculumCode 5y ago
  I used to assume that people, on the whole, were rational and reasonable. I now understand that most people can maintain rationality only for the domains in which they have first-hand experience or education, and otherwise will resort to hearsay, fantastical speculations, conspiratorial thinking, and propaganda of all sorts. It is becoming ever more clear to me that the potential genius of a representative system of government is the chance for citizens to put their trust into informed and reasoned individuals to make decisions in their name. We should elect reasoned people, and review their record, not day to day, but bi-yearly, so that our ignorance does not impede their work. Of course, when the representative system has been distorted as it has, we do not trust or respect our representatives.
- anonymousiam 5y ago
  Yes, and many of those people are scientists. Skepticism is (or should be) a normal part of the scientific method. Controls and reproducible results need to happen before results can be considered conclusive. I understand that sometimes this is impossible in climate science. Climate change is a fact. Humans being responsible for increasing CO2 levels is a fact. Whether the consequences of raising CO2 levels will be more detrimental than beneficial is yet to be seen. There is little that the western world can do to slow CO2 emission growth. Raising taxes doesn't accomplish much. Also, accurate observations of Greenland (present day and historical) are available here: http://polarportal.dk/en/greenland/surface-conditions/ http://polarportal.dk/en/greenland/surface-conditions/
  - gamegoblin 5y ago
    Even setting aside warming affects of CO2, it’s well-understood that increasing atmospheric carbon leads to ocean acidification which is much more inarguably a massive net negative.
ChrisArchitect 5y ago
more discussion yesterday already: https://news.ycombinator.com/item?id=28240552 https://news.ycombinator.com/item?id=28240552

150 points by yboris 5y ago

"On record" seems to be 32 years ( from TFA ). Then the article concludes : And now rainfall: in an area where rain never fell.

SamBam 5y ago
Huh? From TFA, I assume you're referring to > In fact, temperatures at the site only rose above freezing three times before this in the past 32 years, according to observations at Summit Station from 1989. These were the years of the most recent melts. It doesn't say there was rainfall.

h2odragon 5y ago

linked earlier: https://nsidc.org/greenland-today/2021/08/rain-at-the-summit-of-greenland/ https://nsidc.org/greenland-today/2021/08/rain-at-the-summit... > Earlier melt events in the instrumental record occurred in 1995, 2012, and 2019; prior to those events, melting is inferred from ice cores to have been absent since an event in the late 1800s. doesn't that make "first time on record" a stretch too far?

ceejayoz 5y ago
You’re mixing up rainfall and melt events. You can have a melting ice cap without it raining.

adrianN 5y ago

See also https://news.ycombinator.com/item?id=28240552 https://news.ycombinator.com/item?id=28240552

teddyh 5y ago
And https://news.ycombinator.com/item?id=28245506 https://news.ycombinator.com/item?id=28245506

the_third_wave 5y ago

This year has seen both a high melt [1] as well as a high accumulation [2] of snow, the balance of which currently lies clearly at the positive end - Greenland has far more accumulated snow than average. These images come from the Danish polar portal [3] which I assume to be a canonical source given that Greenland is a Danish province. The explanation with the images reads as follows: The map illustrates what the ice sheet’s total surface gains and losses have been over the year since 1 September compared to the period 1981-2010. It does not include the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater. The animation shows one frame every seven days going back to the previous 1 September. The blue curve shows the current season, whilst the red curve shows the corresponding development for the 2011-12 season, when the degree of melting was record high. The dark grey curve traces the mean value from the period 1981-2010. The light grey band shows differences from year to year. For any calendar day, the band shows the range over the 30 years (in the period 1981-2010), however with the lowest and highest values for each day omitted. [1] http://polarportal.dk/fileadmin/polarportal/meltarea/MELTA_combine_SM_EN_20210819.png http://polarportal.dk/fileadmin/polarportal/meltarea/MELTA_c... [2] http://polarportal.dk/fileadmin/polarportal/surface/SMB_combine_SM_acc_EN_20210819.png http://polarportal.dk/fileadmin/polarportal/surface/SMB_comb... [3] http://polarportal.dk/en/greenland/surface-conditions/ http://polarportal.dk/en/greenland/surface-conditions/

cs702 5y ago
FYI, there's a school of thought which has concluded that global warming will lead to another glacial period within the current ice age, because higher temperatures disrupt ocean currents -- particularly the Gulf Stream, which redistributes warm water from the Gulf of Mexico to northern Europe. As the Gulf Stream makes its deposits of warm water along the coasts of Great Britain and northwest Europe, it keeps the temperatures in northwest Europe warmer than in eastern Canada, even though they both are roughly the same distance from the equator. The hypothesis is that, if Arctic ice melts as a result of global warming, huge amounts of fresh water will pour into the North Atlantic and slow down the Gulf Stream, cooling Europe, and triggering a feedback loop with colder and longer European winters, and more and more ice building up on the planet's surface.[a][b] [a] The book "Ice Age" by Cambridge-trained astrophysicist John Gribbin and his wife Mary has a good high-level overview of this school of thought: https://reanimus.com/store/?item=1420 https://reanimus.com/store/?item=1420 [b] Recent studies of circulation in the North Atlantic already show a significant reduction in currents flowing north from the Gulf Stream: https://www.realclimate.org/index.php/archives/2020/09/new-studies-confirm-weakening-of-the-gulf-stream-circulation-amoc/ https://www.realclimate.org/index.php/archives/2020/09/new-s...

oenetan 5y ago

https://ghostarchive.org/archive/Z5ypj https://ghostarchive.org/archive/Z5ypj https://archive.is/nkILZ https://archive.is/nkILZ

dredmorbius 5y ago
#TIL GhostArchive. https://ghostarchive.org/index.html https://ghostarchive.org/index.html

dredmorbius 5y ago

It's worth noting that the record here extends back 32 years, to 1989. And that the weather station isn't equipped with rain guages, as those were seen as not useful. The story also mentions that the liquid precipitation should form a distinctive ice layer which will be preserved in the snowpack, and detecatable in future ice cores. For those curious about any previous liquid precipitation events, that ice record might give some indication of when those might have occurred. According to the article, "ice core data shows that the last time melting occurred at the ice cap top dates to the 1880s." Which suggests not within at least 130-ish years. This is a reminder that the duration of direct observations of meterological conditions is limited in both time and geography. Similarly for satellite observations: very comprehensive in territorial coverage, but beginning only in the 1960s and making great strides in each decade since. Paleometerological records are limited in location to places where weather events can be reliably recorded, and often it's only a specific set of characteristics which are (ice cores, pollen samples, isotopic characteristics, etc.). But they do provide a view across a broad span of time. Both temporal and spatial aspects have enormous significance.

mzs 5y ago
"ice core data shows that the last time melting occurred at the ice cap top dates to the 1880s." That could have been melting instead of rainfall though, right?
- dredmorbius 5y ago
  Correct. It's the most recent possible occurence, or candidate occurrence. Not the most recent definite occurrence. We do know that it has not rained at that location for at least 130 years, at least sufficient to leave an ice-core trace. We do NOT know when it did rain most recently, previously, based on the information in the article.
dalbasal 5y ago
Any larger, perennial or otherwise noteworthy deeper in those ice cores?

cozzyd 5y ago

Hah I was up there up until about a month ago. We did not design our equipment to be resistant to rain. Oops, apparently.

echelon 5y ago
Totally unrelated question. Greenland has so few people, yet so much land. I get that this is on account of the temperatures, but would it be possible to build large cities there if there were demand? Or are the geography and natural resources insufficient to support cities of scale?
- bpodgursky 5y ago
  I mean, it's 98% ice, miles of it. It's certainly possible for people to live on ice if there's demand and energy, but there are a lot of other open areas of the earth for people to build cities on.
- cozzyd 5y ago
  If you're talking about building on the ice sheet, building on ice is very difficult, the snow is constantly drifting and requires a lot of maintenance (lifting or moving buildings every few years, etc.). And only the 109th national guard operates ski-equipped C-130's that can bring supplies. Smaller planes can come (Baslers or Twin Otters) but those can't carry nearly as much. They used to have a traverse from the air force base at Thule but they stopped due to difficulty getting on the ice sheet from there. On the coast it would be more reasonable to build a city, though the topography is rough and getting enough food would be expensive. The only place I've been on the coast is Kangerlussuaq (the main commercial airport for Greenland, and also a base for the 109th ANG which is how I got to Greenland and to Summit). You can explore on street view what it looks like: https://www.google.com/maps/@67.0035567,-50.6859212,3a,75y,316.76h,95.51t/data=!3m7!1e1!3m5!1sYEdICDsdM12SPe9kTsPHMg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DYEdICDsdM12SPe9kTsPHMg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D160%26pitch%3D-20%26thumbfov%3D100!7i13312!8i6656 https://www.google.com/maps/@67.0035567,-50.6859212,3a,75y,3... . It actually has the largest road network in Greenland and a seaport. But... there isn't that much room to build if you wanted to and I think that's more or less the story everywhere in Greenland. For example, ere is Nuuk, the capital and largest city: https://www.google.com/maps/@64.1770542,-51.7239805,3a,75y,42.76h,99.55t/data=!3m6!1e1!3m4!1sSHD_drWAczdQeYU1nFWVkA!2e0!7i13312!8i6656 https://www.google.com/maps/@64.1770542,-51.7239805,3a,75y,4... Not great terrain for city building...

irrational 5y ago

Yesterday I noticed that on July 2nd someone left a review for a movie that said in part "They did have to put in Climate change nonsense. Wonder if that is a requirement with funding so AL gore can get billions of more tax dollars. 1168 people found this helpful." It is incredible to me that climate change is still considered to be nonsense by so many people.

SubiculumCode 5y ago
I used to assume that people, on the whole, were rational and reasonable. I now understand that most people can maintain rationality only for the domains in which they have first-hand experience or education, and otherwise will resort to hearsay, fantastical speculations, conspiratorial thinking, and propaganda of all sorts. It is becoming ever more clear to me that the potential genius of a representative system of government is the chance for citizens to put their trust into informed and reasoned individuals to make decisions in their name. We should elect reasoned people, and review their record, not day to day, but bi-yearly, so that our ignorance does not impede their work. Of course, when the representative system has been distorted as it has, we do not trust or respect our representatives.
anonymousiam 5y ago
Yes, and many of those people are scientists. Skepticism is (or should be) a normal part of the scientific method. Controls and reproducible results need to happen before results can be considered conclusive. I understand that sometimes this is impossible in climate science. Climate change is a fact. Humans being responsible for increasing CO2 levels is a fact. Whether the consequences of raising CO2 levels will be more detrimental than beneficial is yet to be seen. There is little that the western world can do to slow CO2 emission growth. Raising taxes doesn't accomplish much. Also, accurate observations of Greenland (present day and historical) are available here: http://polarportal.dk/en/greenland/surface-conditions/ http://polarportal.dk/en/greenland/surface-conditions/
- gamegoblin 5y ago
  Even setting aside warming affects of CO2, it’s well-understood that increasing atmospheric carbon leads to ocean acidification which is much more inarguably a massive net negative.

ChrisArchitect 5y ago

more discussion yesterday already: https://news.ycombinator.com/item?id=28240552 https://news.ycombinator.com/item?id=28240552