Arctic News: heat

Showing posts with label heat. Show all posts

Sunday, February 9, 2020

Why stronger winds over the North Atlantic are so dangerous

The image below shows high temperatures over Antarctica. News reports show that temperatures as high as 18.3°C or 65°F were recently recorded on Antarctica. The image also shows high temperatures for the time of year over the North Atlantic, with strong winds along the path of the Gulf Stream.

Wind and temperature on February 8, 2020 at 18:00 UTC, near sea level (~100m, at 1000hPa)

The image below shows that wind speeds as high as 430 km/h or 267 miles per hour (mph) were recorded (at 250 hPa, jet stream, at green circle).

Wind on February 8, 2020 at 18:00 UTC, at 250 hPa (jet stream)

Above image also shows that Instantaneous Wind Power Density at the time was as high as 330.1 kW/m² (at the green circle). This is almost as strong as the wind was in 2015. Then, the Jet Stream at a nearby location reached a similar speed while Instantaneous Wind Power Density was slightly higher, at 338.3 kW/m².

So, why are stronger winds over the North Atlantic so dangerous?

Emissions by people heat up the air, which heats up oceans and makes winds stronger, in turn speeding up global ocean currents.

A recent study found increased kinetic energy in about 76% of the upper 2,000 meters of global oceans, as a result of intensification of surface winds since the 1990s.

As oceans heat up, more water evaporates from the sea surface. This evaporation will cool the sea surface somewhat, thus making that the sea surface can be colder than the water underneath the sea surface. Some of the water vapor will return to the ocean in the form of precipitation, but for each degree Celsius of warming, the atmosphere will hold 7% more water vapor, so much of the water vapor will remain in the atmosphere.

More water vapor in the atmosphere will further speed up global heating, since water vapor is a potent greenhouse gas.

Much of the water vapor will also get blown further along the path of the Gulf Stream in the direction toward the Arctic before precipitating, thus contributing - along with meltwater - to the formation of a cold freshwater lid at the surface of the ocean.

Stronger winds along the path of the Gulf Stream can make huge amounts of warm, salty water travel underneath this cold freshwater lid toward the Arctic, pushing up temperatures and salinity levels at the bottom of the Arctic Ocean and threatening to destabilize methane hydrates that are contained in sediments at the seafloor of the Arctic Ocean.

In summary, stronger winds can trigger huge eruptions of methane. Another recent study found that Arctic permafrost thaw plays a greater role in climate change than previously estimated. All this should be reason to take strong action to reduce this danger.

Emissions keep rising

Sadly, emissions show no sign of decline. The daily average CO₂ level at Mauna Loa, Hawaii was 416.08 ppm on February 10, 2020, higher than it has been for millions of years.

Since the annual peak is typically reached in May, even higher levels can be expected soon.

During the Paleocene–Eocene Thermal Maximum (PETM), about 55.5 million years ago, massive amounts of carbon dioxide were released into the atmosphere. The period lasted for some 200,000 years and global temperatures increased by 5–8°C. From the way emissions are rising now, it looks like we could reach even higher CO₂e forcing soon.

Indeed, the situation at Barrow, Alaska, doesn't look better, as illustrated by the image below, showing CO₂ levels up to February 13, 2020.

Very worrying is the rise in methane levels, as illustrated by the image below.

The image below shows methane levels at Barrow, Alaska, up to February 13, 2020.

High methane levels were recorded over the East Siberian Arctic Shelf (ESAS) by the MetOp-2 satellite on February 10 & 11, 2020, pm at 469 mb.

In the video below, recorded January 3, 2020, Guy McPherson and Josef Lauber discuss the track we're on.

Below is a video of an earlier discussion (February 25, 2019) between Guy McPherson and Josef Lauber.

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

Links

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

• News release: Global ocean circulation is accelerating from the surface to the abyss
https://www.eurekalert.org/pub_releases/2020-02/aaft-goc020320.php

• Deep-reaching acceleration of global mean ocean circulation over the past two decades - by Shijian Hu et al.
https://advances.sciencemag.org/content/6/6/eaax7727

• Arctic permafrost thaw plays greater role in climate change than previously estimated
https://www.colorado.edu/today/2020/02/03/arctic-permafrost-thaw-plays-greater-role-climate-change-previously-estimated

• The Arctic’s thawing ground is releasing a shocking amount of dangerous gases
https://www.nationalgeographic.com/science/2020/02/arctic-thawing-ground-releasing-shocking-amount-dangerous-gases

• Cold freshwater lid on North Atlantic

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

• Carbon release through abrupt permafrost thaw - by Merritt Turetsky et al.
https://www.nature.com/articles/s41561-019-0526-0

• NOAA Global CH4 Monthly Means
https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4

Tuesday, December 17, 2019

Extinction in 2020?

Above image depicts how humans could go extinct as early as 2020. The image was created with NASA LOTI 1880-Nov.2019 data, 0.78°C adjusted to reflect ocean air temperatures (as opposed to sea surface temperatures), to reflect higher polar temperature anomalies (as opposed to leaving out 'missing' data) and to reflect a 1750 baseline (as opposed to a 1951-1980 baseline), with two trends added. Blue: a long-term trend based on Jan.1880-Nov.2019 data. Red: a short-term trend, based on Jan.2009-Nov.2019 data, to illustrate El Niño/La Niña variability and how El Niño could be the catalyst to trigger huge methane releases from the Arctic Ocean.

How was above image created? Let's first look at the baseline. The NASA default baseline is 1951-1980. The added trend in the image below shows early 1900s data to be well below this 1951-1980 baseline. In this analysis, a 0.28°C adjustment was therefore used to reflect this, and to reflect a 1750 baseline, a further 0.3°C was used, adding up to a 0.58°C baseline adjustment.

Furthermore, the NASA Land+Ocean temperature index (LOTI) uses sea surface temperatures, but ocean air temperatures seem more appropriate, which adds a further 0.1°C adjustment. Also, when comparing current temperatures with preindustrial ones, it's hard to find data for the polar areas. Treating these data as 'missing' would leave important heating out of the picture. After all, the polar areas are heating up much faster than the rest of the world, and especially so in the Arctic region. Therefore, a further 0.1°C adjustment was used to reflect higher polar temperature anomalies, resulting in the above-mentioned 0.78°C adjustment.

Finally, the red trend illustrates El Niño/La Niña variability. As discussed in a recent post, an El Niño is forecast for 2020 and this could be the catalyst to trigger huge methane releases from the Arctic Ocean.

The image below shows El Niño/La Niña variability going back to 1950, added to the NOAA monthly temperature anomaly.

As said, the Arctic region is heating up much faster than the rest of the world. There are several reasons why this is the case. Decline of the sea ice makes that less sunlight gets reflected back into space and that more sunlight is reaching the Arctic Ocean. This also causes more water vapor and clouds to appear over the Arctic Ocean. Furthermore, Arctic sea ice has lost most of the thicker multi-year ice that used to extend meters below the surface, consuming huge amounts of ocean heat entering the Arctic Ocean along ocean currents from the North Atlantic and the North Pacific oceans.

[ created with NOAA Arctic Report Card 2019 image ]

Above-mentioned feedbacks (albedo changes and more water vapor and clouds) contribute to higher temperatures in the Arctic. Furthermore, as the temperature difference between the North Pole and the Equator narrows, the jet stream changes, which can lead to further Arctic heating, i.e. higher temperatures of the atmosphere over the Arctic Ocean and over land around the Arctic Ocean, which in turn causes higher temperatures of the water flowing into the Arctic Ocean from rivers.

Furthermore, jet stream changes can also cause additional heating of parts of the Pacific Ocean and the Atlantic Ocean.

[ click on images to enlarge ]

Above image shows that sea surface temperature anomalies off the East Coast of North America as high as 13.6°C or 24.4°F were recorded on December 18, 2019.

Ocean currents can bring huge amounts of heat into the Arctic Ocean, and this can be amplified due to cyclones speeding up the inflow of water from the Atlantic Ocean and the Pacific Ocean into the Arctic Ocean.

As above image shows, the temperature rise of the oceans on the Northern Hemisphere is accelerating. This constitutes a critical tipping point, i.e. there are indications that a rise of 1°C will result in most of the sea ice underneath the surface to disappear. This sea ice used to consume the inflow of warm, salty water from the Atlantic Ocean and the Pacific Ocean. So, while there may still be sea ice left at the surface, since low air temperatures will cause freezing of surface water, the latent heat buffer has gone.

As long as there is sea ice, this will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.

The danger is that, as Arctic Ocean heating accelerates further, hot water will reach sediments at the Arctic Ocean seafloor and trigger massive methane eruptions, resulting in a huge abrupt global temperature rise. As discussed in an earlier post, a 3°C will likely suffice to cause extinction of humans.

Earlier this year, an Extinction Alert was issued, followed by a Stronger Extinction Alert.

In a rapid heating scenario:

a strong El Niño would contribute to
early demise of the Arctic sea ice, i.e. latent heat tipping point +
associated loss of sea ice albedo,
destabilization of seafloor methane hydrates, causing eruption of vast amounts of methane that further speed up Arctic warming and cause
terrestrial permafrost to melt as well, resulting in even more emissions,
while the Jet Stream gets even more deformed, resulting in more extreme weather events
causing forest fires, at first in Siberia and Canada and
eventually also in the peat fields and tropical rain forests of the Amazon, in Africa and South-east Asia, resulting in
rapid melting on the Himalayas, temporarily causing huge flooding,
followed by drought, famine, heat waves and mass starvation, and
collapse of the Greenland Ice Sheet.

[ from an earlier post ]

The precautionary principle calls for appropriate action when dangerous situations threaten to develop. How can we assess such danger? Risk is a combination of probability that something will eventuate and severity of the consequences. Regarding the risk, there is growing certainty that climate change is an existential threat, as discussed in a recent post. There's a third dimension, i.e. timescale. Imminence alone could make that a danger needs to be acted upon immediately, comprehensively and effectively. While questions may remain regarding probability, severity and timescale of the dangers associated with climate change, the precautionary principle should prevail and this should prompt for action, i.e. comprehensive and effective action to reduce damage is imperative and must be taken as soon as possible.

The image below gives a visual illustration of the danger.

Polynomial trendlines can point at imminent danger by showing that acceleration could eventuate in the near future, e.g. due to feedbacks. Polynomial trendlines can highlight such acceleration and thus warn about dangers that could otherwise be overlooked. This can make polynomial trendlines very valuable in climate change analysis. In the image below, the green linear trend and the blue polynomial trend are long-term trends (based on Jan.1880-Nov.2019 data), smoothing El Niño/La Niña variability, but the blue polynomial trend better highlights the recent temperature rise than the green linear trend does. The red short-term trend (based on Jan.2009-Nov.2019 data) has the highest R² (0.994) and highlights how El Niño could be the catalyst for huge methane eruptions from the Arctic Ocean, triggering a huge global temperature rise soon.

The image below, from an earlier post, explains the speed at which warming elements can strike, i.e. the rise could for a large part occur within years and in some cases within days and even immediately.

As the image below shows, peak methane levels as high as 2737 parts per billion (ppb) were recorded by the MetOp-2 satellite in the afternoon of December 20th, 2019, at 469 mb. Ominously, a large part of the atmosphere over the East Siberian Arctic Shelf (ESAS) is colored solid magenta, indicating methane levels above 1950 ppb.

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

Monday, October 14, 2019

Arctic Ocean October 2019

Above image shows temperatures north of 80°N. The red line on the image shows the 2019 daily mean temperature up to Oct 13, 2019. The temperature is now well above the 1958-2002 mean (green line). The image also shows the freezing point of fresh water (273.15K, 0°C or 32°F, blue line).

The freezing point for salt water is lower, at around -2°C, or 28.4°F, or 271.2°K. In other words, a rise in the salt content of the water alone can make ice melt, i.e. even when the temperature of the water doesn't rise.

Above combination image shows forecasts for October 26, 2019. The left panel shows that air temperatures (2 m) are forecast to be 5.4°C higher over the Arctic than 1979-2000. Parts of the Arctic Ocean where there is no sea ice are forecast to be especially hot, since this is where heat gets transferred from the Arctic Ocean to the atmosphere. Anomalies are as high as 30°C, the top end of the scale. Temperature anomalies are in line with changes to the Jet Stream, as illustrated by the forecast in the right panel.

As above image shows, there was very little sea ice north of Greenland on October 11, 2019. Arctic sea ice extent is very low. As the image below shows, Arctic sea ice extent was 4.88 million km² on October 13, 2019, the lowest on record for the time of year.

[ click on image to enlarge ]

As the image below shows, the heat rising from the Arctic Ocean is such that sea ice extent is hardly growing.

The image below shows Arctic sea ice extent for the years, 1980,1990, 2010, 2012 and 2019, for the period as indicated.

The image below indicates that Arctic sea ice volume has been at record low levels for the time of year for some time.

Rising temperatures of water in the Arctic Ocean cause the sea ice to melt away from below. The image below, created with NOAA 2007-2019 June-September sea surface temperature data, shows heating of the sea surface on the Northern Hemisphere, with an ominous trend added.

The image indicates that a critical tipping point was crossed this year, with the disappearance of the thick sea ice that hangs underneath the surface.

[ click on image to enlarge ]

The situation is so precarious because hot, salty water keeps flowing into the Arctic Ocean, at a time of year when the sea ice is growing in extent and sealing off the surface of the Arctic Ocean, thus reducing the heat that can get transferred to the atmosphere.

How hot is that water flowing into the Arctic Ocean? The image on the right shows sea surface temperature anomalies. On October 13, 2019, the sea surface near Svalbard at the green circle was 18.3°C or 65°F, i.e. 14.7°C or 26.4°F hotter than 1981-2011.

This is an indication of how hot the water is underneath the sea surface. At the sea surface, water gets colder due to evaporation and rain, resulting in a lid of fresh water at the surface sealing off hot and salty water underneath.

This hot and salty water moves underneath the sea surface in line with the deeper parts of the ocean, to emerge at this area near Svalbard (marker in the image below), as the water at this area becomes more shallow, making the sea current push the water to the surface.

Back in 2011, a study by Micha Ruhl et al. pointed at huge methane releases from clathrates during the end-Triassic mass extinction event, as discussed in an earlier post. The danger is that, in the absence of thick sea ice, hot water with a high salt content will reach the seafloor of the Arctic Ocean, making it easier for ice in cracks in sediments at the seafloor to melt, resulting in huge methane releases.

[ from an earlier post ]

Ominously, methane levels as high as 2961 parts per billion were recorded by the MetOp-2 satellite on October 24, 2019, in the afternoon at 469 mb.

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

• Critical Tipping Point Crossed In July 2019
https://arctic-news.blogspot.com/2019/09/critical-tipping-point-crossed-in-july-2019.html

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

• Arctic Ocean overheating
https://arctic-news.blogspot.com/2019/09/arctic-ocean-overheating.html

• How extreme will it get?
https://arctic-news.blogspot.com/2012/07/how-extreme-will-it-get.html

• Warning Signs
https://arctic-news.blogspot.com/2018/03/warning-signs.html

Saturday, September 14, 2019

Critical Tipping Point Crossed In July 2019

In July 2019, a critical tipping point was crossed. July sea surface temperatures on the Northern Hemisphere were 1.07°C above what they were during the 20th century, as illustrated by above image which has a trend added that points at 5°C above the 20th century by 2033.

Why is 1°C above 20th century's temperature such a critical tipping point for the sea surface on the Northern Hemisphere? Let's first take a look at where global heating is going.

Oceans are absorbing over 90% of global heating, as illustrated by above image. Due to the high greenhouse gas levels resulting from people's emissions, oceans keep on getting hotter, and given oceans' huge heat-absorbing capacity, it has taken many years before this tipping point was crossed.

In July 2016, the tipping point was touched at 0.99°C. In July 2017, the July temperature anomaly was on the tipping point, at exactly 1°C. In July 2018, the sea surface was a bit cooler, and the tipping point was crossed in July 2019 when the temperature anomaly was 1.07°C above the 20th century average.

Arctic sea ice used to absorb 0.8% of global heating (in 1993 to 2003). Ocean heat keeps flowing into the Arctic Ocean, carried by ocean currents, as illustrated by above image. As peak heat arrives in the Arctic Ocean, it melts sea ice from below.

The image below shows sea surface temperatures on August 13, 2019 (left) and on September 9, 2019 (right). The light blue line forms a line indicating the sea surface temperature there is 0°C. That light blue line has moved pole-ward in September, due to rivers that kept adding warm water and also due to more warmer water entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean.

As above image also shows, the sea surface near Svalbard was 20.4°C (or 68.7°F) at the area marked by the green circle on August 13, 2019 (left), and 20.3°C (or 68.5°F) on September 9, 2019 (right), indicating how high the temperature of the water can be underneath the surface, as it moves into the Arctic Ocean. In other words, further ocean heat is still entering the Arctic Ocean.

From mid August 2019, ocean heat could no longer find any sea ice to melt, since the thick sea ice that hangs underneath the surface had already disappeared. A thin layer of sea ice at the surface was all that remained, as air temperatures didn't come down enough to melt it from above.

This indicates that the buffer has gone that has until now been consuming ocean heat as part of the melting process. As long as there is sea ice in the water, this sea ice will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.

The image below, created with NOAA 2007-2019 June-August sea surface temperature data, shows how extra heating of the sea surface on the Northern Hemisphere from 2012 caused the buffer to disappear and the 1°C tipping point to be crossed in 2019.

Once the buffer is gone, further heat arriving in the Arctic Ocean must go elsewhere.

The image below illustrates the difference in extent between the years, as recorded by ads.nipr.ac.jp. On September 13, 1980, Arctic sea ice extent was 7.77 million km². On September 17, 2019, Arctic sea ice extent was 3.96 million km². On September 16, 2012, extent was 3.18 million million km².

Arctic sea ice will soon be growing in extent, sealing off the water, meaning that less ocean heat will be able to escape to the atmosphere.

This situation comes at a time that methane levels are very high globally. Mean global methane levels were as high as 1911 parts per billion on September 3, 2019, as discussed in a recent post. This post, as well as many earlier posts, also discussed the danger that ocean heat will reach sediments at the seafloor of the Arctic Ocean and cause huge methane releases.

Ominously, methane levels at Barrow, Alaska, were very high recently, as illustrated by above image showing methane levels peaking at over 2500 parts per billion. The satellite image below shows the global situation on the afternoon of September 13, 2019, when peak methane levels as high as 2605 ppb were recorded by the MetOp-1 satellite at 586 mb.