Each year the low point in Arctic ocean sea ice occurs in late summer/early fall, normally in the month of September. As the pace of global warming accelerates (especially in the Northern hemisphere, and most especially in the arctic) in which upcoming year will the Arctic ocean be essentially ice free?
Since even many experts have been surprised by record breaking melt of late, I'm going to guess that Earth's permanent northern polar ice cap will be gone in 2026.
Bruce
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sun Nov 17, 2019 9:46 pm
by neufer
BDanielMayfield wrote: ↑Sun Nov 17, 2019 5:13 pm
Each year the low point in Arctic ocean sea ice occurs in late summer/early fall, normally in the month of September. As the pace of global warming accelerates (especially in the Northern hemisphere, and most especially in the arctic) in which upcoming year will the Arctic ocean be essentially ice free? Since even many experts have been surprised by record breaking melt of late, I'm going to guess that Earth's permanent northern polar ice cap will be gone in 2026.
2036 (depending upon Trump's reelection).
Monthly averages from January 1979 - January 2014. Data source via the Polar Science Center (University of Washington). Data visualisation by Andy Lee Robinson.
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sun Nov 17, 2019 10:33 pm
by Chris Peterson
BDanielMayfield wrote: ↑Sun Nov 17, 2019 5:13 pm
Each year the low point in Arctic ocean sea ice occurs in late summer/early fall, normally in the month of September. As the pace of global warming accelerates (especially in the Northern hemisphere, and most especially in the arctic) in which upcoming year will the Arctic ocean be essentially ice free?
Since even many experts have been surprised by record breaking melt of late, I'm going to guess that Earth's permanent northern polar ice cap will be gone in 2026.
Models seem to place it between 2020 and 2040. My guess is that it's likely to be closer to the former, as our models seem to pretty consistently underestimate warming, ice cover, and other factors stemming from global warming. 2026 wouldn't surprise me.
Re: Predict When Earth Loses Northern Polar Ice Cap
BDanielMayfield wrote: ↑Sun Nov 17, 2019 5:13 pm
Each year the low point in Arctic ocean sea ice occurs in late summer/early fall, normally in the month of September. As the pace of global warming accelerates (especially in the Northern hemisphere, and most especially in the arctic) in which upcoming year will the Arctic ocean be essentially ice free?
Since even many experts have been surprised by record breaking melt of late, I'm going to guess that Earth's permanent northern polar ice cap will be gone in 2026.
Models seem to place it between 2020 and 2040. My guess is that it's likely to be closer to the former, as our models seem to pretty consistently underestimate warming, ice cover, and other factors stemming from global warming. 2026 wouldn't surprise me.
Models also seem to pretty consistently underestimate Greenland glacial feedback from global warming:
This rare footage has gone on record as the largest glacier calving event ever captured on film, by the 2016 Guiness Book of World Records.
On May 28, 2008, Adam LeWinter and Director Jeff Orlowski filmed a historic breakup at the Ilulissat Glacier in Western Greenland. The calving event lasted for 75 minutes and the glacier retreated a full mile across a calving face three miles wide. The height of the ice is about 3,000 feet, 300-400 feet above water and the rest below water.
<<Born in Flanders, the great cartographer Gerhard Mercator spent most of his adult life in Duisburg, Germany, where he died in December 1594. The next year his son Rumold published the last of the three parts of his famous atlas, which contains this map. It is the first full map of the Arctic, an expansion of Mercator's inset of the area in his world map of 1569, here showing recent Northwest and Northeast Passage discoveries. In the east, S. Hugo Willoughbes land is named for Sir Hugh Willoughby (d. 1554), who, leading the English Company of Merchant Adventurers' three-ship expedition in 1553, became locked in the ice off the coast near Murmansk with two of his ships; Russian fishermen found the boats with their corpses the next year. Willem Barentsz (ca. 1550-1597), the Dutch navigator, while commanding three expeditions in search of a navigable passage to eastern Asia across the top of Europe and Russia, reached Novaya Zemlya and discovered Spitsbergen (1596). Fretum Forbosshers and Fretum Dauis, in the west, refer to discoveries of the Englishmen Martin Frobisher and John Davis in the 1570s and 1580s. The roundels in the corners contain the title and maps of the Shetland Islands, the mythical island of Frisland, and the Faeroe Islands. But the interesting feature, of course, is Mercator's depiction of the North Pole as a large magnetic rock, surrounded by four mountainous islands which are separated by four major rivers converging upon it. Mercator explained the source for his cartography in a 1577 letter to John Dee, an English mathematician and astrologer:
In the midst of the four countries is a Whirl-pool . . . into which there empty these four indrawing Seas which divide the North. And the water rushes round and descends into the earth just as if one were pouring it through a filter funnel. It is four degrees wide on every side of the Pole, that is to say eight degrees altogether. Except that right under the Pole there lies a bare rock in the midst of the Sea. Its circumference is almost 33 French miles, and it is all of magnetic stone. . . . This is word for word everything that I copied out of this author years ago. [E. G. R. Taylor, "A Letter Dated 1577 from Mercator to John Dee," in Imago Mundi 13 (1956), p. 60.]
The identity of the author cited by Mercator, a "Jacobus Cnoyen of Herzogenbusch," has never been established. Jodocus Hondius acquired the printing plates in 1604; later editions of the Hondius version of the map show the separation of Greenland and the re-drawing of polar coastlines, particularly in the Spitsbergen and Novaya Zemlya areas, as the demythologizing of the Arctic continued by explorers and whalers.>>
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sat Apr 04, 2020 4:39 pm
by BDanielMayfield
With the slowdown in aviation (and other human activities) due to the covid-19 pandemic will arctic sea ice melting be enhanced? I suspect that it will, since solar insolation reduction due to jet aircraft contrail creation will be much reduced this summer. This could cause 2020 to become the year in which the point of essentially no sea ice in in the Arctic Ocean is reached.
Bruce
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sat Apr 04, 2020 7:04 pm
by neufer
BDanielMayfield wrote: ↑Sat Apr 04, 2020 4:39 pm
With the slowdown in aviation (and other human activities) due to the covid-19 pandemic will arctic sea ice melting be enhanced?
I suspect that it will, since solar insolation reduction due to jet aircraft contrail creation will be much reduced this summer.
<<NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994. According to Patrick Minnis, a senior research scientist at NASA’s Langley Research Center in Hampton, Va., there has been a one percent per decade increase in cirrus cloud cover over the United States, likely due to air traffic. Cirrus clouds exert a warming influence on the surface by allowing most of the Sun’s rays to pass through but then trapping some of the resulting heat emitted by the surface and lower atmosphere. Using a general circulation model, Minnis estimates that cirrus clouds from contrails increased the temperatures of the lower atmosphere by anywhere from 0.36 to 0.54°F per decade. Minnis’s results show good agreement with weather service data, which reveal that the temperature of the surface and lower atmosphere rose by almost 0.5°F per decade between 1975 and 1994.
This enhanced infrared image from the Moderate Resolution Imaging Spectroradiometer (MODIS), aboard NASA’s Terra satellite, shows widespread contrails over the southeastern United States during the morning of January 29, 2004. Such satellite data are critical for studying the effects of contrails. The crisscrossing white lines are contrails that form from planes flying in different directions at different altitudes. Each contrail spreads and moves with the wind. Contrails often form over large areas during winter and spring.>>
Re: Predict When Earth Loses Northern Polar Ice Cap
BDanielMayfield wrote: ↑Sat Apr 04, 2020 4:39 pm
With the slowdown in aviation (and other human activities) due to the covid-19 pandemic will arctic sea ice melting be enhanced?
I suspect that it will, since solar insolation reduction due to jet aircraft contrail creation will be much reduced this summer.
<<NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994. According to Patrick Minnis, a senior research scientist at NASA’s Langley Research Center in Hampton, Va., there has been a one percent per decade increase in cirrus cloud cover over the United States, likely due to air traffic. Cirrus clouds exert a warming influence on the surface by allowing most of the Sun’s rays to pass through but then trapping some of the resulting heat emitted by the surface and lower atmosphere. Using a general circulation model, Minnis estimates that cirrus clouds from contrails increased the temperatures of the lower atmosphere by anywhere from 0.36 to 0.54°F per decade. Minnis’s results show good agreement with weather service data, which reveal that the temperature of the surface and lower atmosphere rose by almost 0.5°F per decade between 1975 and 1994.
This enhanced infrared image from the Moderate Resolution Imaging Spectroradiometer (MODIS), aboard NASA’s Terra satellite, shows widespread contrails over the southeastern United States during the morning of January 29, 2004. Such satellite data are critical for studying the effects of contrails. The crisscrossing white lines are contrails that form from planes flying in different directions at different altitudes. Each contrail spreads and moves with the wind. Contrails often form over large areas during winter and spring.>>
But what do you really think Art? Just a few days ago you quoted this contradictory consensus pov from wikipedia:
https://en.wikipedia.org/wiki/Contrail# ... pact_study
The grounding of planes for three days in the United States after September 11, 2001, provided a rare opportunity for scientists to study the effects of contrails on climate forcing. Measurements showed that without contrails, the local diurnal temperature range (difference of day and night temperatures) was about 1 °C (1.8 °F) higher than immediately before;[21] however, it has also been suggested that this was due to unusually clear weather during the period.[22]
Condensation trails have been suspected of causing "regional-scale surface temperature" changes for some time.[23][24] Researcher David J. Travis, an atmospheric scientist at the University of Wisconsin-Whitewater, wrote in the science journal Nature that the effect of the change in aircraft contrail formation during the three days after the September 11 attacks was observed in surface temperature change, measured across over 4,000 reporting stations in the continental United States.[23] His research documented an "anomalous increase in the average diurnal temperature change".[23] The diurnal temperature range (DTR) is the difference in the day's highs and lows at any weather reporting station.[25] Travis observed a 1.8 °C (3.2 °F) departure from the two adjacent three-day periods to 11–14 September.[23] This increase was the largest recorded in 30 years, more than "2 standard deviations away from the mean DTR".[23]
The September 2001 air closures are deeply unusual in the modern world, but similar effects have provisionally been identified from World War II records,[26][27] when flying was more tightly controlled. A 2011 study of climate records in the vicinity of large groups of airbases found a case where contrails appeared to induce a statistically significant change in local climate, with a temperature variance around 0.8 °C
Re: Predict When Earth Loses Northern Polar Ice Cap
BDanielMayfield wrote: ↑Sat Apr 04, 2020 4:39 pm
With the slowdown in aviation (and other human activities) due to the covid-19 pandemic will arctic sea ice melting be enhanced?
I suspect that it will, since solar insolation reduction due to jet aircraft contrail creation will be much reduced this summer.
https://earthobservatory.nasa.gov/images/4435/aircraft-contrails wrote:
Minnis’s results show good agreement with weather service data, which reveal that the temperature of the surface and lower atmosphere rose by almost 0.5°F per decade between 1975 and 1994.
This enhanced infrared image from the Moderate Resolution Imaging Spectroradiometer (MODIS), aboard NASA’s Terra satellite, shows widespread contrails over the southeastern United States during the morning of January 29, 2004. Such satellite data are critical for studying the effects of contrails. The crisscrossing white lines are contrails that form from planes flying in different directions at different altitudes. Each contrail spreads and moves with the wind. Contrails often form over large areas during winter and spring.>>
BDanielMayfield wrote: ↑Sun Apr 05, 2020 8:14 am
But what do you really think Art? Just a few days ago you quoted this contradictory consensus pov from wikipedia:
https://en.wikipedia.org/wiki/Contrail#September_11,_2001,_climate_impact_study wrote:
The grounding of planes for three days in the United States after September 11, 2001, provided a rare opportunity for scientists to study the effects of contrails on climate forcing. Measurements showed that without contrails, the local diurnal temperature range (difference of day and night temperatures) was about 1 °C (1.8 °F) higher than immediately before; however, it has also been suggested that this was due to unusually clear weather during the period.
The September 2001 air closures are deeply unusual in the modern world, but similar effects have provisionally been identified from World War II records, when flying was more tightly controlled. A 2011 study of climate records in the vicinity of large groups of airbases found a case where contrails appeared to induce a statistically significant change in local climate, with a temperature variance around 0.8 °C
A local diurnal (difference between day & night temperatures) temperature range
increase of about 1.8 °F during the airline shutdown in 2001 is not inconsistent
with a 0.5°F temperature increase per decade between 1975 and 1994.
Very cold mornings in winter/spring polar regions
are mitigated by the combined infrared blankets of:
Modern increases in carbon dioxide, methane & jet contrail cirrus clouds are all contributing to preventing those very cold Arctic winter/spring mornings of 50 years ago and, thereby, making for large expanses of ice free Arctic Ocean to warm further during long summer polar days.
(Ozone hole cooling and CFC warming tend to cancel each other out to some extent.)
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sun Apr 05, 2020 3:43 pm
by Chris Peterson
BDanielMayfield wrote: ↑Sat Apr 04, 2020 4:39 pm
With the slowdown in aviation (and other human activities) due to the covid-19 pandemic will arctic sea ice melting be enhanced? I suspect that it will, since solar insolation reduction due to jet aircraft contrail creation will be much reduced this summer. This could cause 2020 to become the year in which the point of essentially no sea ice in in the Arctic Ocean is reached.
Predictions based on cloud properties are devilishly difficult, because clouds provide both positive and negative feedbacks to temperature, have different effects at different latitudes, and have different effects at different heights. As good as our climate models are getting, the impact of clouds remains one of the least developed parts of those models.
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sun Apr 05, 2020 4:31 pm
by neufer
Chris Peterson wrote: ↑Sun Apr 05, 2020 3:43 pm
Predictions based on cloud properties are devilishly difficult, because clouds provide both positive and negative feedbacks to temperature, have different effects at different latitudes, and have different effects at different heights. As good as our climate models are getting, the impact of clouds remains one of the least developed parts of those models.
Cirrus clouds almost always increase average surface temperatures.
Re: Predict When Earth Loses Northern Polar Ice Cap
Chris Peterson wrote: ↑Sun Apr 05, 2020 3:43 pm
Predictions based on cloud properties are devilishly difficult, because clouds provide both positive and negative feedbacks to temperature, have different effects at different latitudes, and have different effects at different heights. As good as our climate models are getting, the impact of clouds remains one of the least developed parts of those models.
Cirrus clouds almost always increase average surface temperatures.
But that's a fairly local response. How it plays to regional climate is much more complex.
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sun Apr 05, 2020 8:03 pm
by BDanielMayfield
Thanks Art and Chris. Complicated issues then. My layman's opinion prior to this discussion would have been that, had the covid 19 pandemic not occurred, there would have been increased trans Arctic flights this summer due to people traveling between Europe and Japan for the Tokyo Olympics, producing greater cloud cover and a cooler Arctic Ocean this summer and reduced melting. But now since there will be much reduced airline trans Arctic traffic I expected increased warming this summer, in both cases as compared to more "normal" summers. Now I'm just puzzled.
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Sun Apr 05, 2020 8:42 pm
by neufer
BDanielMayfield wrote: ↑Sun Apr 05, 2020 8:03 pm
Thanks Art and Chris. Complicated issues then. My layman's opinion prior to this discussion would have been that, had the covid 19 pandemic not occurred, there would have been increased trans Arctic flights this summer due to people traveling between Europe and Japan for the Tokyo Olympics, producing greater cloud cover and a cooler Arctic Ocean this summer and reduced melting. But now since there will be much reduced airline trans Arctic traffic I expected increased warming this summer, in both cases as compared to more "normal" summers. Now I'm just puzzled.
Just think of jet contrail cirrus as yet another modern greenhouse gas that is warming the Arctic Ocean.
Warming of the Arctic Ocean isn't just "local" when it results in a stalled meandering jet stream resulting in both floods & droughts.
Warming of the Arctic Ocean isn't just "local" when it melts long frozen tundra which then releases still more greenhouse gases.
Re: Predict When Earth Loses Northern Polar Ice Cap
BDanielMayfield wrote: ↑Sun Apr 05, 2020 8:03 pm
Thanks Art and Chris. Complicated issues then. My layman's opinion prior to this discussion would have been that, had the covid 19 pandemic not occurred, there would have been increased trans Arctic flights this summer due to people traveling between Europe and Japan for the Tokyo Olympics, producing greater cloud cover and a cooler Arctic Ocean this summer and reduced melting. But now since there will be much reduced airline trans Arctic traffic I expected increased warming this summer, in both cases as compared to more "normal" summers. Now I'm just puzzled.
Just think of jet contrail cirrus as yet another modern greenhouse gas that is warming the Arctic Ocean.
Warming of the Arctic Ocean isn't just "local" when it results in a stalled meandering jet stream resulting in both floods & droughts.
Warming of the Arctic Ocean isn't just "local" when it melts long frozen tundra which then releases still more greenhouse gases.
All points well taken.
Moving beyond less contrails then, what effect is the overall reduction in air pollutants due to this slowdown likely to be, as far as Arctic ice loss is concerned? With a significant reduction in CO2, and less dust/soot to darken ice surfaces, could we see an increase in year over year ice coverage?
Bruce
Re: Predict When Earth Loses Northern Polar Ice Cap
neufer wrote: ↑Sun Apr 05, 2020 8:42 pm
Just think of jet contrail cirrus as yet another modern greenhouse gas that is warming the Arctic Ocean.
Warming of the Arctic Ocean isn't just "local" when it results in a stalled meandering jet stream resulting in both floods & droughts.
Warming of the Arctic Ocean isn't just "local" when it melts long frozen tundra which then releases still more greenhouse gases.
All points well taken.
Moving beyond less contrails then, what effect is the overall reduction in air pollutants due to this slowdown likely to be, as far as Arctic ice loss is concerned? With a significant reduction in CO2, and less dust/soot to darken ice surfaces, could we see an increase in year over year ice coverage?
Effects on the environment will be as short lived as the slowdown itself.
Re: Predict When Earth Loses Northern Polar Ice Cap
neufer wrote: ↑Sun Apr 05, 2020 8:42 pm
Just think of jet contrail cirrus as yet another modern greenhouse gas that is warming the Arctic Ocean.
Warming of the Arctic Ocean isn't just "local" when it results in a stalled meandering jet stream resulting in both floods & droughts.
Warming of the Arctic Ocean isn't just "local" when it melts long frozen tundra which then releases still more greenhouse gases.
All points well taken.
Moving beyond less contrails then, what effect is the overall reduction in air pollutants due to this slowdown likely to be, as far as Arctic ice loss is concerned? With a significant reduction in CO2, and less dust/soot to darken ice surfaces, could we see an increase in year over year ice coverage?
Effects on the environment will be as short lived as the slowdown itself.
True enough. But, it's not going to be short, from a human standpoint.
Re: Predict When Earth Loses Northern Polar Ice Cap
neufer wrote: ↑Mon Apr 06, 2020 1:58 pm
Effects on the environment will be as short lived as the slowdown itself.
True enough. But, it's not going to be short, from a human standpoint.
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Tue Apr 07, 2020 12:52 am
by Doum
Hello all,
Long time no see. About the polar ice cap. Having it melting, it mean that many fossil or freeze remnant of ancient animal might appear to the naked eye. Those wont stay intact in the atmosphere and will degrade with the weather. Any of you know if advice had been given to any expedition that go there each years to look for those a bit. It is an opportunity to do it i think. I know it has nothing to do with when the polar ice cap will melt. Just a thought.
Re: Predict When Earth Loses Northern Polar Ice Cap
Posted: Tue Apr 07, 2020 2:49 pm
by neufer
Doum wrote: ↑Tue Apr 07, 2020 12:52 am
About the polar ice cap. Having it melting, it mean that many fossil or freeze remnant of ancient animal might appear to the naked eye. Those wont stay intact in the atmosphere and will degrade with the weather. Any of you know if advice had been given to any expedition that go there each years to look for those a bit. It is an opportunity to do it i think. I know it has nothing to do with when the polar ice cap will melt. Just a thought.
Long time no see. About the polar ice cap. Having it melting, it mean that many fossil or freeze remnant of ancient animal might appear to the naked eye. Those wont stay intact in the atmosphere and will degrade with the weather. Any of you know if advice had been given to any expedition that go there each years to look for those a bit. It is an opportunity to do it i think. I know it has nothing to do with when the polar ice cap will melt. Just a thought.
There are no fossils or ancient animals trapped in the polar ice cap, which is just sea ice, none of it very old. It is material on arctic land, especially Siberia, that is likely to be lost to warming.
Re: Predict When Earth Loses Northern Polar Ice Cap
Doum wrote: ↑Tue Apr 07, 2020 12:52 am
About the polar ice cap. Having it melting, it mean that many fossil or freeze remnant of ancient animal might appear to the naked eye. Those wont stay intact in the atmosphere and will degrade with the weather. Any of you know if advice had been given to any expedition that go there each years to look for those a bit. It is an opportunity to do it i think.
There are no fossils or ancient animals trapped in the polar ice cap, which is just sea ice, none of it very old. It is material on arctic land, especially Siberia, that is likely to be lost to warming.
Ah....NOW who's being picky?
An ice free Arctic ocean leads to melting Siberian permafrost.
Re: Predict When Earth Loses Northern Polar Ice Cap
Doum wrote: ↑Tue Apr 07, 2020 12:52 am
About the polar ice cap. Having it melting, it mean that many fossil or freeze remnant of ancient animal might appear to the naked eye. Those wont stay intact in the atmosphere and will degrade with the weather. Any of you know if advice had been given to any expedition that go there each years to look for those a bit. It is an opportunity to do it i think.
There are no fossils or ancient animals trapped in the polar ice cap, which is just sea ice, none of it very old. It is material on arctic land, especially Siberia, that is likely to be lost to warming.
Ah....NOW who's being picky?
An ice free Arctic ocean leads to melting Siberian permafrost.
Monthly averages from January 1979 - January 2014. Data source via the Polar Science Center (University of Washington). Data visualisation by Andy Lee Robinson.
