Showing posts with label snow. Show all posts
Showing posts with label snow. Show all posts

Wednesday, February 9, 2022

Accelerating loss of global snow and ice cover


Ocean heat is at record levels. As a result, global sea ice extent was only 16.23 million km² on February 9, 2022, the third lowest extent on record. What makes this even more worrying is that we're currently in the depth of a persistent La Niña.


Antarctic sea ice at lowest extent on record since start satellite measurements

Ocean heat is a huge threat for Antarctica at the moment. The image below shows that Antarctic sea ice extent was only 2.091 million km² on February 16, 2022, the lowest on record since the start of satellite measurements.


Ocean heat is reducing the sea ice around Antarctica and is getting underneath floating sea ice. 

The Thwaites Glacier, which is on a retrograde slope, is especially vulnerable to collapse. 

The Thwaites Glacier contains enough ice to raise global sea levels by 65 cm (25.59 inches) if it were to completely collapse.

The animation on the right, created with images from Climate Reanalyzer, shows the retreat of the Antarctic snow and ice cover from January 5 to February 18, 2021. 

The animation underneath, by navy.mil, shows sea ice thickness over 30 days up to February 17, 2022 (with 8 days of forecasts added).

Another danger of a rapid loss of the snow and ice cover on Antarctica is release of methane. Jemma Wadham warned about this in a 2012 study, as discussed at the post methane hydrates. More recently, Jemma Wadham said: “We are sleepwalking into a catastrophe for humanity.”

The Thwaites Glacier is often called the Doomsday Glacier because if it collapses it would lead to vast sea level rise, and scientists believe it is likely to fail within a few years, says Cliff Seruntine (the Naturalist) in the video below. 


A recent study concludes that mountain glaciers may hold less ice than previously thought. Their disappearance means less water for drinking and agriculture, and faster temperature rises due to albedo loss. While the study found that the Himalayas contain more water than thought, another recent study, Mt. Everest’s highest glacier is a sentinel for accelerating ice loss, describes how human-induced climate change has a huge impact on the highest reaches of the planet.

The outlook for the Arctic is most threatening, as the post methane hydrates also concluded back in 2013, as described in numerous post here at Arctic-news and as discussed in the video below by Jim Massa.


A huge temperature rise threatens to unfold soon


Above image indicates that the difference between the top of El Niño and the bottom of La Niña could be more than half a degree Celsius.

As said, we're currently in the depth of a persistent La Niña, which suppresses temperatures. As the temperature keeps rising, ever more frequent strong El Niño events are likely to occur, as discussed in an earlier post. 

A 2019 study analyzes how tipping the ENSO into a permanent El Niño can trigger state transitions in global terrestrial ecosystems.

Currently, the temperature rise is additionally suppressed by low sunspots. Within a few years time, sunspots can be expected to reach the peak of their current cycle and observed sunspots are looking stronger than predicted. 

In the image below on the right, adapted from NOAA, the solar cycle is represented as the number of sunspots (top) and F10.7cm radio flux (bottom). 

In a recent communication, James Hansen repeats that, as reductions take place in the sulfate aerosols that are currently co-emitted by traffic, transport and industry, this is causing the current temperature rise to accelerate and could cause further rapid global warming, referred to in a 2021 presentation as a termination shock.

Furthermore, in addition to a huge temperature rise resulting from sulfate aerosols falling away, there could be a further rise in temperature as a result of releases of other aerosols with a net warming impact, such as black and brown carbon, which can increase dramatically as more wood burning and forest fires take place.

In summary, while the temperatures are accelerating, we'll soon be moving into the next El Niño, with sunspots moving toward a peak, with sulfate aerosols causing a termination shock and with other aerosols further driving up the temperature rise. 

Stop the deception!

In a giant scheme of deception, the temperature rise is all too often presented with images of people playing on the beach on a 'warm' day, as if 'global warming' was making life more 'comfortable'. 

Forest fires are called 'wildfires', biomass burning and associated deforestation is referred to as 'renewable biofuel', fracking-induced earthquakes are called 'natural' disasters and methane eruptions are called seeps and bubbles of 'natural' gas from 'natural' sources such as wetlands. 

This gives the false impression that this was somehow 'natural' as if human activities had nothing to do with it, and as if owning beach-front property was becoming ever more attractive.


Let's stop this deception! In reality, human-caused emissions have a huge short-term impact on temperature and their combination with genuinely natural variability such as El Niño and sunspots can act as a catalyst, causing numerous feedbacks to kick in with ever greater ferocity. 

This can result in collapse of global sea ice and permafrost, resulting in albedo loss and eruption of huge quantities of carbon dioxide, methane and nitrous oxide, further driving up the temperature rise abruptly, as described at the extinction page. Further feedbacks are also described at the feedbacks page. 

Conclusion

The situation is dire and calls for the most comprehensive and effective action, as described at the Climate Plan.


Links

• Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions - by Lijing Cheng et al. 
https://link.springer.com/article/10.1007%2Fs00376-022-1461-3

• Ocean heat is at record levels, with major consequences - by Kevin Trenberth

• Arctic Data archive System - Vishop extent

• NSIDC: Charctic Interactive Sea Ice Graph

• IPCC: Marine Ice Sheet Instability

• Climate Reanalyzer
https://climatereanalyzer.org/wx/DailySummary/#seaice-snowc-topo

• Antarctica CICE ice thickness

• Antarctica’s ‘doomsday’ glacier: how its collapse could trigger global floods and swallow islands 
https://theconversation.com/antarcticas-doomsday-glacier-how-its-collapse-could-trigger-global-floods-and-swallow-islands-173940

• Methane hydrates (2013)

• Potential methane reservoirs beneath Antarctica - by Jemma Wadham et al. (2012) 
https://www.nature.com/articles/nature11374

• A new frontier in climate change science: connections between ice sheets, carbon and food webs (2021) 

• Ice velocity and thickness of the world’s glaciers - by Romain Millan et al. 
https://www.nature.com/articles/s41561-021-00885-z

• Mountain glaciers may hold less ice than previously thought – here’s what that means for 2 billion downstream water users and sea level rise 
https://theconversation.com/mountain-glaciers-may-hold-less-ice-than-previously-thought-heres-what-that-means-for-2-billion-downstream-water-users-and-sea-level-rise-176514

• Mt. Everest’s highest glacier is a sentinel for accelerating ice loss - by Mariusz Potocki et al. 

• Human-induced climate change impacts the highest reaches of the planet — Mount Everest
• Ocean Heat Content Update 1 - 2022 - Science Talk with Jim Massa
https://www.youtube.com/watch?v=pctkg_LDqcU

• NOAA - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• NOAA - Monthly Temperature Anomalies Versus El Niño 
• Human Extinction by 2022? 

• Tipping the ENSO into a permanent El Niño can trigger state transitions in global terrestrial ecosystems - by Mateo Duque-Villegas et al. (2019) 
https://esd.copernicus.org/articles/10/631/2019

• James Hansen - The New Horse Race

• Climate Impact of Decreasing Atmospheric Sulphate Aerosols and the Risk of a Termination Shock - by Leon Simons, James Hansen and Yann duFournet (2021) 

• NOAA - Solar Cycle Progression

• Aerosols

• Feedbacks

• Extinction




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Sunday, June 5, 2016

High Temperatures In Arctic

0-2000 m Global Ocean Heat Content
Ocean heat content is rising, as illustrated by the image on the right. Where the sea ice declines, this is causing high air temperatures in the Arctic.

This year (from January to April 2016) on the Northern Hemisphere, oceans were 0.85°C or 1.53°F warmer than the 20th century average.

The image below illustrates that temperatures look set to be high in Siberia for the coming week. The panel on the right shows anomalies at the top end of the scale in Eastern Siberia on June 5, 2016, while the panel on the right shows a forecast for June 12, 2016.


These high air temperatures are causing feedbacks that are in turn further speeding up warming in the Arctic.

Warmer Rivers

Temperatures as high as 28.9°C or 83.9°F were recorded over the Mackenzie River close to the Arctic Ocean on June 13, 2016, at location marked by the green circle.


Below is a satellite image of the Mackenzie River delta on June 11, 2016


The image below shows that temperatures as high as 36.6°C or 97.8°F were forecast for June 13, 2016, over the Yenisei River in Siberia that ends in the Arctic Ocean.


Wildfires

Earlier this month, temperatures in Eastern Siberia were as high as 29.5°C (85°F). This was on June 5, 2016, at a location close to the coast of the Arctic Ocean (green circle).


High air temperatures come with increased risk of wildfires, as illustrated by the image below showing carbon monoxide levels as high as 2944 ppb on June 4, 2016 (at green circle).


The satellite image below zooms into the area with these high carbon monoxide readings, showing wildfires on Kamchatka Peninsula on June 3, 2016.


Albedo Loss

The image on the right shows that, this year, April snow cover on the Northern Hemisphere was the lowest on record. The added trend points at a total absence of snow by the year 2036.

Professor Peter Wadhams, head of the Polar Ocean Physics Group at Cambridge University, says: “My prediction remains that the Arctic ice may well disappear, that is, have an area of less than one million square kilometres for September of this year.”

Warming due to Arctic snow and ice loss may well exceed 2 W per square meter, i.e. it could more than double the net warming now caused by all emissions by people of the world, Peter Wadhams calculated in 2012.

Seafloor Methane

Peter Wadhams further co-authored a study that calculated that methane release from the seafloor of the Arctic Ocean could yield 0.6°C warming of the planet in 5 years (see video interview of Thom Hartmann with Peter Wadhams below).



Combined Impact Of Multiple Feebacks

In conclusion, high air temperatures in the Arctic are very worrying, as they can trigger a number of important feedbacks, i.e. the ones discussed above and further feedbacks such as:
  • Changes to Jet Streams. As the Arctic warms more rapidly than the rest of Earth, changes are occurring to the jet streams. As a result, winds can increasingly bring hot air far to the north, resulting in further loss of the Arctic snow and ice cover, in turn further warming up the Arctic.
  • Warmer Rivers. High air temperatures cause warming of the water of rivers that end up in the Arctic Ocean, thus resulting in additional sea ice decline and warming of the Arctic Ocean all the way down to the seabed.
  • Wildfires. High air temperatures set the scene for wildfires that emit not only greenhouse gases such as carbon dioxide and methane, but also pollutants such as carbon monoxide that depletes hydroxyl that could otherwise break down methane, and black carbon that, when settling on ice, causes it to absorb more sunlight (see under albedo loss), besides being a climate forcer when in the atmosphere.
  • Soil destabilization. Heatwaves and droughts destabilize the soil. Soil that was previously known as permafrost, was until now held together by ice. As the ice melts, organic material in the soil starts decomposing, resulting in emissions of methane and carbon dioxide, while the soil becomes increasingly vulnerable to wildfires.
  • Buffer Loss. Arctic snow and ice cover acts as a buffer, absorbing heat that in the absence of this buffer will have to be absorbed by the Arctic Ocean, as discussed in earlier posts such as this one. 
  • Albedo Loss. Arctic snow and ice cover make that sunlight is reflected back into space. In the absence of this cover, the Arctic will have to absorb more heat.
  • Seafloor Methane. As sediments at the seafloor of the Arctic Ocean warm, hydrates contained in these sediments could be destabilized and release huge quantities of methane.

How much warmer could it be within one decade?

The two feedbacks mentioned by Peter Wadham (albedo and seafloor methane) are are depicted in the image below.

for further discussion, see the feedbacks page
The combined global temperature rise over the next decade due to these two feedbacks (albedo and seafloor methane) alone may be 0.4°C or 0.72°F for a low-rise scenario and may be 2.7°C or 4.9°F for a high-rise scenario.

Additionally, as temperatures rise, further feedbacks will kick in more strongly, further accelerating the rise in temperature, as also discussed in earlier posts such as this one.

When also including further feedbacks, warming could exceed 10°C (18°F) within one decade, assuming that no geoengineering will take place within a decade, as discussed in earlier posts such as this one.

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.

Links

• Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

• Feedbacks in the Arctic
http://arctic-news.blogspot.com/p/feedbacks.html

• East Siberian Heatwave
http://arctic-news.blogspot.com/2015/07/east-siberian-heat-wave.html

• Wildfire Danger Increasing
http://arctic-news.blogspot.com/2016/05/wildfire-danger-increasing.html

• Albedo changes in the Arctic
http://arctic-news.blogspot.com/2012/07/albedo-change-in-arctic.html

• Three kinds of warming in the Arctic
http://arctic-news.blogspot.com/2016/02/three-kinds-of-warming-in-arctic.html

• Arctic could become ice-free for first time in more than 100,000 years, claims leading scientist
http://www.independent.co.uk/environment/climate-change/arctic-could-become-ice-free-for-first-time-in-more-than-100000-years-claims-leading-scientist-a7065781.html

• Greenhouse gas levels and temperatures keep rising
http://arctic-news.blogspot.com/2016/01/greenhouse-gas-levels-and-temperatures-keep-rising.html

• Arctic Methane Release: "Economic Time Bomb"
http://arctic-news.blogspot.com/2013/07/arctic-methane-release-economic-time-bomb.html

• February Temperature
http://arctic-news.blogspot.com/2016/03/february-temperature.html

• September 2015 Sea Surface Warmest On Record
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Tuesday, July 21, 2015

Ocean Temperatures At Record High

Of all the excess heat that results from people's emissions, 93.4% goes into oceans. Accordingly, ocean heat has strongly increased over the years.

NOAA analysis shows that, for the oceans on the Northern Hemisphere, the June 2015 sea surface temperature was at a record high 0.87°C (1.57°F) above the 20th century average of 16.4°C (61.5°F), as also illustrated by the graph below.


The most recent 12-month period, July 2014–June 2015, also broke the record (set just last month) for the all-time warmest 12-month period in the 135-year period of record. 


As the above image shows, sea surface temperature anomalies around North America are very high, threatening to further raise temperatures of the Arctic Ocean, which already has very high sea surface temperatures, as also illustrated by the image below. 


As the image below shows, sea surface temperatures as high as 19°C (66.2°F) were recorded in the Bering Strait on July 19, 2015.



The snow depth comparison below shows the situation on July 20, 2015, on the left and a forecast for July 27, 2015, on the right. The green lines indicate areas where sea ice is at melting point. Note the decline of snow cover on Greenland and the Himalayas.


As the continued snow decline on Greenland also illustrates, high temperatures can be expected to keep causing further decline of the snow and ice cover for many weeks to come, given that the minimum sea ice extent is typically reached about half September.

As the image below shows, sea surface temperatures as high as 10.1°C (50.1°F) were recorded in Baffin Bay, off the west coast of Greenland, on July 20, 2015.


On July 21, 2015, temperatures as high as 14°C (57.1°F) were recorded east of Svalbard, an anomaly of 9.7°C (17.4°F), as illustrated by the image below, created with nullschool.net images.


The danger is that warm water will enter the Arctic Ocean and cause the Arctic sea ice to collapse, which could make the Arctic Ocean absorb even more heat. This could unleash huge methane eruptions from the Arctic Ocean's seafloor, in turn driving temperatures up even higher and causing more extreme weather events, wildfires, etc.

The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan. 



For the oceans on the Northern Hemisphere, the June 2015 sea surface temperature was at a record high 0.87°C (1.57°F)...
Posted by Sam Carana on Tuesday, July 21, 2015
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Monday, May 25, 2015

Sleeping Giant in the Arctic



Huge amounts of carbon are contained in sediments, soils and vegetation in the Arctic. Rising temperatures in the Arctic threaten to cause much of this carbon to be released to the atmosphere.

On May 23, 2015, temperatures in Alaska were as high as 91°F (32.78°C), as illustrated by the image below.

[ image credit: US National Weather Service Alaska ]
High temperatures were reached at the city of Eagle, located on the southern bank of the Yukon River, at an elevation of 853 ft (260 m). High temperatures at such a location will cause meltwater, aggravating the situation well beyond the local area.
A bank of permafrost thaws near the Kolyma
River in Siberia. Credit: University of Georgia

Carbon contained in soils will thus become increasingly exposed under the combined impact of rising temperatures and the associated growing amounts of meltwater. The meltwater can additionally cause erosion further downstream, thus making carbon at many locations become more prone to be consumed by microbes and released into the atmosphere in the form of carbon dioxide and methane.

A recent study found that, at a location where the Kolyma river in Siberia carved into the permafrost and exposed the carbon, microbes converted 60% of the carbon into carbon dioxide in two weeks time.

Gary Houser, who recently launched the movie Sleeping Giant in the Arctic, elaborates on the threat of emissions from thawing permafrost:
This immense release would likely feed on itself, raising temperatures that continue melting more and more permafrost in a vicious, frightening, and unstoppable cycle. A tipping point could well be crossed, at which time human intervention is no longer possible. Temperatures across the planet could soar, setting in motion catastrophic levels of drought and food shortage. All life support systems on earth and life forms themselves could be placed under severe stress.

The colossal scale of the danger - and the observation of those factors lining up that could trigger it - demand that humanity exercise the precautionary principle. All political decision-making related to carbon emissions must be based on the understanding that a catastrophic consequence is looming, and the window of time for prevention quickly diminishing.
SLEEPING GIANT IN THE ARCTIC:
Can Thawing Permafrost Cause Runaway Global Heating?
by Gary Houser



Sources: 

US National Weather Service Alaska

University of Georgia

Sleeping Giant in the Arctic


Sleeping Giant in the Arctic http://arctic-news.blogspot.com/2015/05/sleeping-giant-in-the-arctic.html

Posted by Sam Carana on Monday, May 25, 2015
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Friday, August 15, 2014

Heatwave to hit Greenland

A heatwave with temperature anomalies exceeding 36°F (20°C) is expected to hit Greenland between August 16 and 22, 2014, as illustrated by the image on the left and the animation on the right. 

Such heatwaves can be expected to hit the Arctic more frequently and with greater intensity, as temperatures in the Arctic are rising faster than elsewhere on Earth.

Such heatwaves can result in massive melting on Greenland, as persistent heat changes the texture of the snow and ice cover, in turn reducing its reflectivity. This makes that less sunlight is reflected back into space and is instead absorbed. 

The image below illustrates what a difference the presence of sea ice can make.
from: Arctic Warming due to Snow and Ice Demise
As the NSIDC/NOAA graphs below shows, melting on Greenland has been relatively modest this year when compared to the situation in 2012. By July 12, 2012, 97% of the ice sheet surface had thawed, according to this NASA analysis and this NOAA Arctic Report Card.


Melting on Greenland directly affects sea level rise, and melting on Greenland is accelerating due to a number of factors.

Projections of melting on Greenland have long been based on a warming atmosphere only, ignoring the warmer waters that lubricate glaciers and that warm Greenland's bedrock canyons that sit well below sea level.

Furthermore, there are growing quantities of black carbon deposits as a result of burning of fossil fuel and biomass. High temperatures have recently caused ferocious wildfires in Canada that have in turn caused a lot of black carbon to go up high into the atmosphere.

And of course, the atmosphere over the Arctic is warming up much faster than most models had projected. This in turn causes triggers further feebacks, including more extreme weather events such as heatwaves and rain storms that can be expected to hit Greenland with ever more frequency and ferocity. Further feedbacks include methane eruptions from the heights of Greenland, as discussed at the Arctic Feedbacks Page.

When also taking into account the accelerating impact of such factors on melting in Greenland, sea levels could rise much faster than anticipated, as illustrated by the image below.

from: more than 2.5m sea level rise by 2040? 

Note that sea level rise is only one of the many dangers of global warming, as discussed in the 2007 post Ten Dangers of Global Warming.

The image on the right shows a temperature forecast for August 16, 2014, with parts of Greenland changing in color from blue into green, i.e. above the melting point for snow and ice.

Such high temperatures are now hitting locations close to the North Pole ever more frequently, due to the many feedbacks that are accelerating warming in the Arctic, as discussed at this Feedbacks page.

One of the most dangerous feedbacks is a sudden eruption of huge quantities of methane from the seafloor of the Arctic Ocean, as discussed in a recent post.

The impact of such feedbacks can be accumulative and interactive, resulting in self-reinforcing feedbacks loops that can escalate into runaway warming.

Below is another forecast by ClimateReanalyzer for August 16, 2014, showing the remarkable ‘greening’ of Greenland, as well as the very high temperatures reaching the higher latitudes of North America.


Also see the very high sea surface temperatures around Greenland on the image below, created with ClimateReanalyzer.

Sea surface temperature anomalies on August 15, 2014. 
In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog. 


Post by Sam Carana.
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Saturday, February 15, 2014

Extreme weather strikes around the globe - update

As the weather gets more extreme, disaster strikes around the globe. The Guardian reports three people killed as storms continue to batter southern UK. The Vancouver Sun reports that a U.S. Northeast snowstorm kills 25. And the Sacramento Bee reports Six dead and 1,000 injured in fresh Japan snow storm.

What is the story behind these extreme weather events? The image below tells the story. The Arctic has been much warmer than it used to be, due to numerous feedbacks that accelerate warming in the Arctic. This reduces the temperature differential between the Arctic and lower latitudes, which changes the Jet Stream and Polar Vortex, in turn making the weather at many places ever more extreme.

 earlier forecasts by cci-reanalyzer.org
Above image illustrates the situation, showing an Arctic Ocean that is warmer than the higher latitudes of the Asian and North American continents.

Arctic sea ice has meanwhile reached record lows, as illustrated by the image below.


The situation can be expected to get even worse. The image below shows sea ice extent, as measured by the NSIDC, which is one day ahead compared to above image.


Below, two regular contributors to the Arctic-news blog comment on the situation.

Read more »
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Monday, February 10, 2014

Extreme weather strikes around the globe

  Editorial note: this post has meanwhile been updated as
Extreme weather strikes around the globe update.


As the weather gets more extreme, disaster strikes around the globe.

Here's a snapsnot from today's news. In London, the BBC reports, flooded homes along the River Thames are being evacuated and thousands more are at risk. In Japan, reports Reuters, eleven people died, more than a thousand were injured and tens of thousands lost power when the worst snowstorm in decades hit Tokyo and areas around the Japanese capital before heading north to blanket the tsunami-hit Pacific coast. Many countries in the Middle East were hit by snow. The BBC reports that heavy snow in northern Iran has left around 480,000 homes without power and some towns and villages cut off.

What is causing these extreme weather events? The image below tells the story. While at times it has been cold at many places around the world, when averaged over the past 30 days, temperatures around the globe have actually been several degrees higher than they used to be. The Arctic has been hit hardest, with anomalies as high as 21°C over this 30 day period. This affects the Jet Stream and Polar Vortex, which in turn is making the weather ever more extreme.



The situation is further illustrated by the cci-reanalyzer.org forecasts below.



And while the sea ice didn't look too bad at the start of the year, growth has meanwhile stopped, as illustrated by the image below.


Added below are two videos by Paul Beckwith, further discussing the situation.





Editor's note: Reanalysis of temperature anomaly Jan 12 - Feb 10, 2014.
Meanwhile, I've added another image (above), created with NOAA's reanalysis, which compares temperatures to a larger dataset, and the colors look a lot different, so NOAA may indeed have mixed the colors up somewhat in the initial image, as Albert suggested at the Facebook discussion (click on image below).

Anyway, the point made in the post remains, i.e. that as global warming continues, warming in the Arctic accelerates more rapidly than at lower latitudes, which weakens the polar vortex and jet stream in a self-reinforcing feedback that causes the Arctic to warm up even further compared with lower latitudes.

As said, the situation calls for comprehensive and effective action, as discussed at the Climate Plan blog.

Read more »
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Thursday, September 12, 2013

Temperature Rise

Surface Temperature Rise

How much have temperatures risen over the past 100 years or so? In the image below, Peter Carter points at the aerosols from volcanic eruptions and fossil fuel combustion that temporarily delay the full impact of global warming.


Temperature Rise hits Arctic most strongly

In above image, temperature anomalies are compared to a 3-decade base period from 1951 to 1980. To highlight the full wrath of global warming, it is more informative to compare anomalies with an earlier base period. Furthermore, a short running mean better shows how high peaks can reach.



NASA typically compares temperature change relative to 1951-1980, because the U.S. National Weather Service uses a three-decade period to define "normal" or average temperature. The NASA GISS analysis effort began around 1980, so the most recent 30 years at the time was 1951-1980.1

But as said, it is more informative to use a 30-year base period that starts earlier. To show Gobal & Arctic Temperature Change, James Hansen and Makiko Sato used a 1951-1980 base period next to a 1880-1920 base period. For this post, a 1883-1912 base period was selected to create the above image, and this same base period was selected to create the image below.


Above image shows that the Arctic is hit most strongly by the temperature rise. Note that the anomalies in above image are visualized by latitude, but are averaged by longitude globally, masking even higher anomalies that can be experienced at specific longitudes. At times, some areas in the Arctic do already experience anomalies of over 20°C, as shown in the animation below, based on NOAA data for the period December 7, 2011 - January 21, 2012.

Read more »
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Thursday, January 10, 2013

Dark Snow Project - Research into soot on Greenland

Fossil fuel combustion creates carbon emissions that increase atmospheric thickness, warming climate. The occurrence of wildfire increases with climate warming, increasing soot loading of the atmosphere. Some of this soot is transported through the atmosphere and is deposited on glaciers, lowering their reflectivity, increasing solar energy absorption, increasing melt rates.
image from DarkSnowProject.org

In parts of Greenland where winter snow loss during each melt season exposes impurity-rich bare ice, the surface reflectivity drops from 85% to 30%. Consequently, most of the 24-hour sunlight goes into ice melt. In this Dark Zone, the impact of soot manifests strongest in a self-reinforcing feedback loop that research by Jason Box has shown to have doubled melt rates in the past decade.

High on the inland ice sheet where melting is rare, satellite data show surface darkening making the researchers suspect that wildfire and industrial soot are to blame. Darkening here promotes snowpack heating, bringing earlier melt, keeping melt going longer. Here is where this feedback is changing the ice sheet in surprising ways, leading to complete surface melting in year 2012.



To measure the extent to which soot particles enhance melting, Jason Box is organizing a Greenland ice sheet expedition for 2013. The Dark Snow Project expedition is to be the first of its kind, made possible by crowd-source funding.



References

- Fire and Ice: Wildfires Darkening Greenland Snowpack, Increasing Melting (News Release from Byrd Polar Center)
http://bprc.osu.edu/~jbox/DS/20121205_news_release_CALIPSO_etc.pdf

- The DarkSnowProject
http://darksnowproject.org

-Video: Sampling Greenland, the Dark Snow Project, by Peter Sinclair, produced at Greenman Studio, Midland, MI.
http://www.youtube.com/watch?v=vT6H7HPWkqU

- Where there’s fire there’s smoke - Blog by Jason Box, the Meltfactor.org


Further reading

- Greenland is melting at incredible rate
http://arctic-news.blogspot.com/2012/07/greenland-is-melting-at-incredible-rate.html

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