Showing posts with label anomaly. Show all posts
Showing posts with label anomaly. Show all posts

Friday, January 19, 2024

Potential temperature trends

[ click on images to enlarge ]

The above image shows potential temperature trends. Four of the trends are global ones and one trend is based on Arctic (64°North-90°North) data:

  • The red line is a polynomial trend based on 15 years of Arctic data (2009-2023).
  • The green line is a linear trend based on 1880-2023 global data.
  • The yellow line is a linear trend based on 2009-2023 global data.
  • The light blue line is a 10-year moving average (trailing), based on global data.
  • The dark blue line is a polynomial trend, based on 2015-2023 global data, showing global temperatures catching up with the Arctic rise in temperature.

Note that the above image uses annual anomalies from 1951-1980. Recent posts show that, when adjustments are made for an earlier base, for ocean air temperatures and for higher polar anomalies, the 2023 anomaly could be as high as 2.5°C from pre-industrial and when using monthly data, the anomaly could be as high as 2.73°C from pre-industrial. 

Temperature rise hits Arctic most strongly 

Due to feedbacks such as sea ice loss, the temperature rise is felt most strongly at higher latitudes North, as illustrated by the three images below, again using a 1951-1980 baseline.

The image below shows the December 2023 temperature anomaly. 

The image below shows the 2023 temperature anomaly. 

The image below shows how the temperature rise has unfolded from 2000.  

[ Arctic Ocean hit most strongly by temperature rise ]

Over the next few years, the temperature rise in the Arctic could accelerate even more strongly as a result of crossing of two tipping points, i.e. the Latent Heat Tipping Point and the Seafloor Methane Tipping Point, as illustrated by the image below, from an earlier post.

[ increasing ocean heat ]
Note again that annual data are used in the above image. An earlier analysis using monthly data shows that the seafloor methane tipping point was reached in August 2023.

Arctic sea ice extent

Arctic sea ice extent in 2024 was larger than many expected. One of the reasons for this is that Greenland ice has been melting faster than previously thought, as pointed out by a recent study that also includes retreat of glaciers that already lie mostly below sea level. More melting of ice on Greenland has resulted in a larger south-bound flow of icebergs and meltwater, contributing to cooling of the North Atlantic sea surface and slowing down of the Atlantic meridional overturning circulation (AMOC), and in turn contributing to suppress temperatures in the Arctic. As a result, loss of Arctic sea ice extent has been less than would otherwise have been the case. Yet, the temperature rise may soon overwhelm this suppression.

Cold freshwater lid at surface of North Atlantic

[ ocean stratification, from earlier post ]

Slowing down of AMOC and cooling due to heavier melting of Greenland's ice is causing less ocean heat to reach the Arctic Ocean, while a huge amount of ocean heat is accumulating in the North Atlantic, as it did in 2023. A large part of this heat in the North Atlantic can also be present underneath the sea surface.

These developments occur at the same time as ocean stratification increases (see above image) as temperatures rise, as more freshwater enters the ocean as a result of more meltwater and of runoff from land and from rivers, and as more evaporation takes place and more rain falls further down the path of the Gulf Stream, all of which can contribute to formation and growth of a cold, freshwater lid at the surface of the North Atlantic.

[ cold freshwater lid on North Atlantic ]

Furthermore, storms can get stronger as temperatures rise and as changes take place to the Jet Stream. Strong wind can temporarily speed up currents that carry huge amounts of ocean heat with them toward the Arctic Ocean, as discussed in earlier posts such as this one. Much of the ocean heat in the North Atlantic can therefore be pushed abruptly underneath this freshwater lid and flow into the Arctic Ocean.

The danger is that huge amounts of ocean heat can abruptly get pushed into the Arctic Ocean and that the influx of ocean heat will destabilize hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane.

[ click on images to enlarge ]

This danger is further illustrated by the above compilation image, showing forecasts for January 27, 2024 of:
(1) surface wind and temperature (-3.6°C or 25.4°F at the North Pole)
(2) surface wind
(3) wind at 700 hPa
(4) wind at 250 hPa (Jet Stream) and
(5) ocean currents at surface and wave height.

The image below shows that temperatures are forecast to be above freezing near the North Pole on January 26, 2024 20:00 UTC (downloaded January 26, 2024 06:00 UTC). 


Ominously, the North Atlantic sea surface was much hotter in early 2024 than it was in early 2023.


And ominously, the daily sea surface temperature reached a record high on January 31, 2024, when the daily sea surface temperature reached 21.10°C, higher than the peak of 21.09°C reached in August 2023 and much higher than the 20.99°C peak reached in March 2016.


As latent heat buffer shrinks, Arctic sea ice could melt away quickly

As illustrated by the image below, sea ice was very thin near the North Pole on January 24, 2024, indicating there is very little left of the latent heat buffer constituted by the sea ice to consume incoming heat. 
And even more ominously, Arctic sea ice thickness declined dramatically in a few days time, as indicated by the compilation image below, with images from the University of Bremen. 


For the time of year, Arctic sea ice extent is currently still extensive, compared to earlier years, which is a reflection of more water vapor in the atmosphere and more precipitation. While sea ice extent is relatively large, Arctic sea ice volume now is among the lowest of all years on record for the time of year, as illustrated by the image below. Volume = extent x thickness, so low volume and relatively large extent means that sea ice is very thin. 
As more sunlight starts reaching the Northern Hemisphere, in line with seasonal changes, Arctic sea ice extent can be affected dramatically and abruptly, as illustrated by the image below.

Furthermore, much of the thicker sea ice is located off the east coast of Greenland, as illustrated by the image below. This means that this sea ice is likely to melt away quickly as temperatures rise in line with seasonal changes.
Without the buffer constituted by thicker sea ice, such an influx of ocean heat could destabilize hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane. 
[ The buffer is gone - Latent Heat Tipping Point crossed ]

Given methane's very high immediate global warming potential (GWP), this could push up temperatures dramatically and rapidly. 

[ potential methane rise, from earlier post ]

[ from the Extinction page ]
The above image shows a polynomial trend added to NOAA globally averaged marine surface monthly mean methane data from April 2018 to November 2022, pointing at 1200 ppm CO₂e (carbon dioxide equivalent) getting crossed in 2027.

A rise in methane concentrations alone may suffice to cause the Clouds Tipping Point, at 1200 ppm CO₂e, to get crossed. The resulting clouds feedback could on its own cause the temperature to rise by a further 8°C. 

When further forcing is taken into account, crossing of the Clouds Tipping Point could occur even earlier than in 2027.

The image on the right illustrates how a huge temperature could unfold and reach more than 18°C above pre-industrial by 2026.

With such a rise, the temperature is likely to keep rising further, with further water vapor accumulating in the atmosphere once the water vapor tipping point gets crossed, as discussed in an earlier post and at Could Earth go the same way as Venus? 

As a rather sobering footnote, humans will likely go extinct with a 3°C rise and most life on Earth will disappear with a 5°C rise, as illustrated by the image below, from an earlier post.
[ from earlier post ]

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

• NASA - Goddard Institute for Space Studies (GISS) Surface Temperature Analysis
https://data.giss.nasa.gov/gistemp

• Ubiquitous acceleration in Greenland Ice Sheet calving from 1985 to 2022 - by Char Greene et al. https://www.nature.com/articles/s41586-023-06863-2
discussed at facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161223121909679

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• Latent Heat
https://arctic-news.blogspot.com/p/latent-heat.html

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• Could Earth go the same way as Venus?

Thursday, February 13, 2020

January 2020 Temperature Anomaly


Above image shows NOAA Land+Ocean monthly temperature anomalies from the 20th century average. A trend has been added, based on the Jan.1880-Jan.2020 data. The trend shows that data in the early 1900s were some 0.28°C below the 20th century average.

Adjustment

When using a 1750 baseline, the data need to be adjusted even more than that 0.28°C, since it was even colder in 1750. The total baseline adjustment may well be 0.58°C, as discussed in an earlier post. Furthermore, ocean data in above image are sea surface temperatures. To reflect air temperatures, a further 0.1°C adjustment is applied. Finally, an extra 0.1°C adjustment is applied to reflect higher polar temperatures (as opposed to leaving out missing data). Altogether, this adds up to a 0.78°C adjustment, which implies that the temperature in January 2020 was 1.92°C above pre-industrial.

Which trend is most applicable?

How much and how fast could temperatures keep rising? That question looks even more important than this 0.78°C adjustment. Indeed, the trend added to even the unadjusted data (in above image) points at temperatures crossing 2°C average by 2026.

The image below shows a blue trend, similar to the trend in above image. In the image below, this blue trend points at temperatures crossing 3°C above pre-industrial by 2026.


As discussed in an earlier post, a 3°C temperature rise may well drive humans into extinction, while the rise could continue to exterminate all life on Earth.

As the image shows, the January 2020 anomaly is well above the blue trend. As discussed in an earlier post, a 2020 El Niño could be the catalyst to trigger feedbacks, including huge methane releases from the Arctic Ocean seafloor. While these feedbacks are already active in many ways, a 2020 El Niño could make them start kicking in much more strongly.

A short-term trend (in red) has therefore been added as well, to illustrate El Niño/La Niña variability and to highlight this danger. Ominously, the January 2020 anomaly is above this red trend as well. This is even more the case when the same analysis is done with NASA data, which produces similar results while the January 2020 adjusted temperature anomaly gets even higher, i.e. 1.96°C above pre-industrial.

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


Links

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• 2020 El Nino could start 18°C temperature rise
https://arctic-news.blogspot.com/2019/11/2020-el-nino-could-start-18-degree-temperature-rise.html


Saturday, August 24, 2019

Cyclone over Arctic Ocean - August 24, 2019


As illustrated by above map, Arctic heating is accelerating, with temperatures showing up in the Arctic that are up to 4.41°C hotter than the average global temperature during 1880-1920.

The image below shows two plots. On the left-hand side is the temperature plot associated with above map, had a monthly mean been selected. To smooth the data, a 4-year running mean was chosen, and the plot on the right-hand side shows the associated global mean anomalies. Note that, due to this smoothing, only data from 1882 to August 2017 are displayed in the plot of the right-hand side.


It is appropriate to adjust the data by 0.5°C, as follows:
  1. An adjustment of 0.3°C to reflect a pre-industrial baseline (heating occurred due to people's emissions before 1880-1920);
  2. An adjustment of 0.1°C to reflect air temperatures over oceans (as opposed to sea surface temperatures);
  3. An adjustment of 0.1°C to better include polar temperatures (the top and bottom of the image at the top shows large polar areas that should not be excluded, the more so since the Arctic has the highest temperature anomalies).
The image below shows both adjusted and unadjusted data as dark blue lines, with a light-blue polynomial trend added over the adjusted data.

Such a trend can further smooth out seasonal differences and El Niño/La Niña variability.

Such a trend can also show the potential for further temperature rise in the near future, which can constitute an important warning.

This is particularly important as the trend shows that we could be crossing the 2°C guardrail this year, i.e. the threshold that was too dangerous to be crossed.

What is the danger? Arctic heating is accelerating, as the image at the top shows, and this could make global temperatures skyrocket in a matter of years. Where Arctic sea ice disappears, hot water emerges due to albedo changes and loss of the buffer that has until now been consuming heat as part of the melting process. This is illustrated by the image below showing the sea surface temperature difference from 1961-1990 in the Arctic at latitudes 60°N - 90°N on August 23, 2019.


Disappearance of Arctic sea ice comes with numerous feedbacks that further speed up the heating, as described in the recent post Arctic Sea Ice Gone By September 2019?. Heatwaves can strongly heat up the water that gets carried by rivers into the Arctic Ocean. As the image below shows, the water was as hot as 10.7°C or 51.3°F at green circle on August 20, 2019, i.e. 9.4°C or 16.9°F hotter than 1981-2011.


As the Arctic is heating up faster than the rest of the world, the Jet Stream gets more and more distorted. A cyclone is forecast over the Arctic Ocean for August 24, 2019, pulling hot air over the Arctic Ocean, resulting in temperatures at the green circle as high as 10.4°C or 50.6°F at 1000 hPa and 7.4°C or 45.2°F at surface level, as the image below shows.


The image below illustrates the distortion of the Jet Stream, moving over the Arctic Ocean on August 24, 2019.


Such a cyclone can pull huge amounts of hot air over the Arctic Ocean, while it can also devastate the sea ice with the destructive power of winds, rain and hail.


As above animation shows, Arctic sea ice is very thin and vulnerable at the moment. The cyclone also looks set to batter the sea ice at a time when huge amounts of ocean heat are entering the Arctic Ocean from the Atlantic and Pacific Oceans. More ocean heat looks set to be on the way. As the image below shows, sea surface temperatures around North America were as high as 33°C or 91.4°F on August 21, 2019.


The image below shows the worrying rise of Northern Hemisphere sea surface temperature anomalies from the 20th century average, with the added trend illustrating the danger that this rise will lead to Arctic sea ice collapse and large methane eruptions from the seafloor of the Arctic Ocean, further accelerating the temperature rise.

[ from an earlier post ]
The image below shows the cyclone over the Arctic Ocean on August 26, 2019.


The image below shows a close-up of the sea ice just north of the North Pole, on August 26, 2019.


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


Links

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

• Arctic Sea Ice Gone By September 2019?
https://arctic-news.blogspot.com/2019/07/arctic-sea-ice-gone-by-september-2019.html

• July 2019 Hottest Month On Record
https://arctic-news.blogspot.com/2019/08/july-2019-hottest-month-on-record.html


Monday, April 2, 2018

How much warmer is it now?

The IPCC appears to be strongly downplaying the amount of global warming that has already occurred and that looks set to eventuate over the next decade or so, according to a leaked draft of the IPCC 'Special Report on 1.5°C above pre-industrial'. The 'First Order Draft of the Summary for Policy Makers' estimates that the global mean temperature reached approximately 1°C above pre-industrial levels around 2017/2018.

Let's go over the numbers step by step, by following the image below line by line (click on the image to enlarge it).

NASA's data for the two most recent years for which data are available (2016/2017) show a warming of 0.95°C when using a baseline of 1951-1980 and a warming of 1.23°C when using a baseline of 1890-1910 (left map on image below). In other words, using this earlier baseline results in an additional 0.28°C rise. When using an even earlier baseline, i.e. 1750 or preindustrial, it could be 1.53°C warmer, as discussed in an earlier post.


In other words, merely changing the baseline to preindustrial, as agreed to at the Paris Agreement, can show that we're already above the 1.5°C guardrail that the Paris Agreement had pledged we should not cross.

There's more! As a recent publication points out, most methods that calculate the global temperature use sea surface temperatures. However, doesn't it make more sense to calculate the temperature of the air just above the sea surface? Measuring air temperature at the surface is done in the case of temperatures over land, where one doesn't measure the temperature of the soil or rocks when telling people how warm it is. Since air surface temperatures are slightly higher than sea surface temperatures, the result of looking at air surface temperatures across the globe would be a temperature that is approximately 0.1°C warmer. Furthermore, many areas in the Arctic may not have been adequately reflected in the global temperature, e.g. because insufficient data were available. Since the Arctic has been warming much faster than the rest of the world, inclusion of those areas would add another 0.1°C to the rise. Adding this to the above 1.53°C rise makes that it's already 1.73°C (or 3.11°F) warmer than preindustrial.

Another question is over what period measurements should be taken when assessing whether thresholds have been crossed. When focusing on temperatures during specific months, the rise could be much higher than the annual average. So, does it make more sense to look at a monthly peak rather than at a long-term average?

When building a bridge and when calculating what load the bridge should be able to handle, it makes sense to look at peak traffic and at times when a lot of heavy trucks happen to be on the bridge. That makes a lot more sense than only looking at the average weight of cars driving over the bridge during a period of - say - one, two or thirty years.


Accordingly, the right panel of the top image shows numbers for February 2016 when temperature anomalies were particularly high. When looking at this monthly anomaly, we are already 2.37°C (or 4.27°F) above preindustrial, i.e. well above the 2°C guardrail that the Paris Agreement had pledged we should definitely not cross.

Should the temperature rise be calculated using a longer period? The IPCC appears to have arrived at its temperature rise estimate by using an extrapolation or near term predictions of future warming so that the level of anthropogenic warming is reported for a 30 year period centered on today.

The image below, from an earlier post, shows global warming for a 30-year period centered on January 2018, using NASA 2003 to January 2018 LOTI anomalies from 1951-1980, adjusted by 0.59°C to cater for the rise from preindustrial to 1951-1980, and with a polynomial trend added.


If above trendline is adjusted by a further 0.2°C, by shifting to air temperatures instead of sea surface temperatures, and by better reflecting Arctic temperatures, then the trendline looks set to cross the 2°C guardrail in 2018. So, will Earth cross 2°C in 2018?


Above images illustrate the importance of what's going to happen next. The temperature rise up until now may well be dwarfed by what's yet to come and the outlook may well be even worse than what most fear will eventuate. The image below, from an earlier post, shows a steep rise from 2016 to 2026, due to the combined impact of the warming elements listed in the left box of the image below.


Meanwhile, the rise in carbon dioxide levels appears to be accelerating, as illustrated by the images below.


Indeed, despite pledges made at the Paris Agreement to limit the temperature increase to 1.5°C above pre-industrial, the rise in CO₂ since preindustrial, i.e. 1750, still appears to be accelerating.


On March 18, 2018, the sea surface temperature near Svalbard (at the green circle) was 16.7°C or 62.1°F, i.e. 14.7°C or 26.4°F warmer than the daily average during the years 1981-2011.


On March 30, 2018, methane levels as high as 2624 parts per billion were recorded.


On April 1, 2018, methane levels as high as 2744 parts per billion were recorded.



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


Links

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

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• IPCC seeks to downplay global warming
https://arctic-news.blogspot.com/2018/02/ipcc-seeks-to-downplay-global-warming.html

• 2016 well above 1.5°C
https://arctic-news.blogspot.com/2017/01/2016-well-above-1.5c.html

• Interpretations of the Paris climate target, by Andrew Schurer et al.
https://www.nature.com/articles/s41561-018-0086-8


Sunday, December 24, 2017

Winds keep changing as warming continues

November 2017 was 0.87 degrees Celsius warmer than the mean 1951-1980 November temperature, as above image shows. The last three Novembers — 2015, 2016, and 2017 — are the three warmest in the entire modern record. The warmest month of November happened in 2015 (+1.03°C) when there was a strong El Niño, while we're currently in a La Niña period.

On the image below, cyclonic winds on December 21, 2017, are visible near the Philippines and Vietnam. Near the Philippines, 3-hour precipitation accumulation was as high as 121.6 mm or 4.79 in (at green circle). As a BBC report describes, Tropical Storm Tembin made landfall in the southern Philippines on December 22, 2017, causing flash flooding and mudslides. More than 180 people are reported to have been killed, as the tropical storm swept through Mindanao island, with dozens more missing.


A week earlier, Tropical Storm Kai-Tak hit the central Philippines, killing dozens. The region is still recovering from Typhoon Haiyan, which killed more than 5,000 people and affected millions in 2013.


The winds are fueled by high sea surface temperatures. Above image shows that, on December 21, 2017, sea surface temperatures were as high as 31.7°C or 89°F north of Australia. In line with rising temperatures caused by global warming, sea surface temperature anomalies are high across the oceans, as the image below illustrates.


As above image also shows, the sea surface was relatively cold at locations indicative for El Niño (depicted as four El Niño regions on the right).

The image below shows El Niño forecast plumes indicating that we're currently in a La Niña period, and that temperatures are on the rise.


In conclusion, just like the rise in temperatures is currently masked by a La Niña period, the return to a new El Niño period will further strengthen the rise.


This strengthening of winds is what can be expected in a warmer world. Above image shows a wavy Northern Polar Jet Stream combine with the Northern Subtropical Jet Stream to reach speeds as high as 401 km/h or 249 mph.

As the jet stream becomes more wavy and extends over the Arctic, more warm air and water gets carried into the Arctic, further speeding up warming, as also discussed at The Arctic is changing the Jet Stream - Why This Is Important.

The importance of Arctic warming was also discussed in the recent post Warming is accelerating. Changes to the Jet Stream can cause a lot more heat to be brought into the Arctic, through both the Bering Strait and the Fram Strait. This image below shows wind through the Bering Strait reaching speeds as high as 135 km/h or 84 mph.


The combination image below shows the Jet Stream extending over the Arctic Ocean and remaining in place for days, reaching speeds as high as 206 km/h or 128 mph. Such 'blocking' patterns can cause a lot of heat to be brought into the Arctic atmosphere, as well as into the water of the Arctic Ocean. The image in the left-hand panel indicates that temperature anomalies over the Arctic Ocean could be as high as 30°C or 54°F.

[ click on images to enlarge ]
As the temperature difference between the North Pole and the Equator decreases, the Jet Stream becomes more wavy, at times extending deep over the continents and bringing cold air to the south. This further increases the (already high) temperature difference between land and ocean, further speeding up cyclonic winds that move over the oceans toward the North Pole and that carry warm water and air toward the Arctic Ocean. The image below shows a forecast for January 1, 2018.


As sea ice keeps declining, ever less sunlight gets reflected back into space. The image below shows the decline in global sea ice area over the years.


The image below shows the average year-to-date Arctic sea ice volume (PIOMAS data).


This further confirms the updated trend analysis of the NASA temperature anomaly below.


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

Links

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

• Warming is accelerating
https://arctic-news.blogspot.com/2017/11/warming-is-accelerating.html

• The Arctic is changing the Jet Stream - Why This Is Important
https://arctic-news.blogspot.com/2017/10/the-arctic-is-changing-the-jet-stream-why-this-is-important.html

• NASA: November 2017 temperature news release
https://data.giss.nasa.gov/gistemp/news/20171218

• BBC: Philippines Tropical Storm Tembin kills 180 on Mindanao
https://www.bbc.com/news/world-asia-42464644

• NOAA: Four El Niño regions
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/nino_regions.shtml

• ECMWF: El Niño forecast plumes
https://www.ecmwf.int/en/forecasts/charts/catalogue/seasonal_system5_public_nino_plumes

• 10°C or 18°F warmer by 2021?
https://arctic-news.blogspot.com/2017/04/10c-or-18f-warmer-by-2021.html

• Abrupt Warming - How Much And How Fast?
https://arctic-news.blogspot.com/2017/05/abrupt-warming-how-much-and-how-fast.html

• Accelerating growth in CO₂ levels in the atmosphere
https://arctic-news.blogspot.com/2017/02/accelerating-growth-in-co2-levels-in-the-atmosphere.html

• High methane levels over the Arctic Ocean on January 14, 2014
https://arctic-news.blogspot.com/2014/01/high-methane-levels-over-the-arctic-ocean-on-january-14-2014.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Methane Erupting From Arctic Ocean Seafloor
https://arctic-news.blogspot.com/2017/03/methane-erupting-from-arctic-ocean-seafloor.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html