A Blue Ocean Event looks set to occur in the Arctic when there will be virtually no sea ice left. At first, the duration of this event will be a few weeks in September, but as more heat accumulates in the Arctic, the event will last longer each year thereafter.
Indeed, a Blue Ocean Event will come with accumulation of more heat, due to loss of latent heat, as a dark (blue) ocean absorbs more sunlight than the reflective ice, etc. Consequences will extend far beyond the Arctic, as shown on the image below that features Dave Borlace's Blue Ocean Top Ten Consequences.
A Blue Ocean Event could happen as early as September 2019. The image below shows that Arctic sea ice extent on April 7, 2019, was 12.97 million km², a record low for measurements at ads.nipr.ac.jp for the time of year. By comparison, on May 28, 1985, extent was larger (13.05 million km²) while it was 51 days later in the year.
In the video below, Paul Beckwith also discusses the rapid decline of the sea ice and the consequences.
Clearly, the rapid decline of the sea ice has grave consequences. When also looking beyond what's happening in the Arctic, there are further events, tipping points and feedbacks that make things worse. An earlier post contains the following rapid warming scenario:
a stronger-than-expected 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.
Importantly, depicted above is only one scenario out of many. Things may eventuate in different order and occur simultaneously, i.e. instead of one domino tipping over the next one sequentially, many events reinforcing each other. Further points should be added to the list, such as falling away of sulfate cooling due to economic changes, ocean stratification and stronger storms that can push large amounts of warm salty water into the Arctic Ocean.
Global sea ice extent is also at a record low for the time of year. Global sea ice extent on April 8, 2019, was 17.9 million km². On April 8, 1982, global sea ice extent was 22.32 million km², i.e. a difference of 4.42 million km². That constitutes a huge albedo loss.
As discussed in an earlier post, this all adds up to further global warming that may eventuate very rapidly. The image below shows how a total rise of 18°C or 32.4°F from preindustrial could eventuate by 2026.
The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.
• Jet Stream Center-of-Rotation to Shift 17 degrees Southward from North Pole to Greenland with Arctic Blue Ocean Event - by Paul Beckwith https://www.youtube.com/watch?v=bFme3C9e-cs
On March 30, 2019, Arctic sea ice extent was 13.42 million km², a record low for the measurements at ads.nipr.ac.jp for the time of year.
[ click on images to enlarge ]
As the Arctic warms up faster than the rest of the world, the temperature difference between the North Pole and the Equator narrows, making the jet stream wavier, thus enabling warm air over the Pacific Arctic to move more easily into the Arctic.
The image on the right shows that, on March 31, 2019, the Arctic was 7.5°C or 13.5°F warmer than 1979-2000.
The earlier forecast below shows a temperature anomaly for the Arctic of 7.6°C or 13.68°F for March 31, 2019, 12:00 UTC and in places 30°C or 54°F warmer. The inset shows the Jet Stream moving higher over the Bering Strait, enabling air that has been strongly warmed up over the Pacific Ocean to move into the Arctic.
A wavier Jet Stream also enables cold air to more easily move out of the Arctic. The inset shows the Jet Stream dipping down over North America where temperatures lower than were usual were recorded.
The later forecast below shows a temperature anomaly for the Arctic of 7.7°C or 13.86°F for March 31, 2019, 12:00 UTC.
The image below shows that El Niño can be expected to push temperatures up higher in 2019 during the Arctic sea ice retreat.
A warmer sea surface can cause winds to grow dramatically stronger, and they can push warm, moist air into the Arctic, while they can also speed up sea currents that carry warm, salty water into the Arctic Ocean.
Rivers can also carry huge amounts of warm water from North America and Siberia into the Arctic Ocean, as these areas are getting hit by ever stronger heatwaves that are hitting the Arctic earlier in the year.
With Arctic sea ice at a low, it won't be able to act as a buffer to absorb heat for long, with the danger that an influx of warm, salty water will reach the seafloor and trigger methane eruptions.
As warmer water keeps flowing into the Arctic Ocean and as air temperatures in the Arctic are now starting to rise on the back of a strengthening El Niño, fears for a Blue Ocean Event in 2019 are rising, which would further accelerate the temperature rise as less sunlight gets reflected back into space.
The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.
Blue Ocean Event as part of four Arctic tipping points
What will be the consequences of a Blue Ocean Event, i.e. the disappearance of virtually all sea ice from the Arctic Ocean, as a result of the warming caused by people?
Paul Beckwith discusses some of the consequences in the video below. As long as the Arctic Ocean has sea ice, most sunlight gets reflected back into space and the 'Center-of-Coldness' remains near the North Pole, says Paul. With the decline of the sea ice, however, the 'Center-of-Coldness' will shift to the middle of Greenland. Accordingly, we can expect the jet streams to shift their center of rotation 17° southward, i.e. away from the North Pole towards Greenland, with profound consequences for our global weather patterns and climate system, for plants and animals, and for human civilization, e.g. our ability to grow food.
Also see Paul's video below, The Arctic Blue-Ocean-Event (BOE). When? Then What?
Changing Winds
As global warming continues, the additional energy in the atmosphere causes stronger winds and higher waves.
As the Arctic warms up faster than the rest of the world, the jet streams are getting more out of shape, exacerbating extreme weather events.
The image on the right shows the jet stream crisscrossing the Arctic Ocean on September 10, 2018, with cyclonic wind patterns all over the place.
On the image below, Typhoon Mangkhut is forecast to cause waves as high as 21.39 m or 70.2 ft on September 14, 2018.
The inset on above image shows Typhoon Mangkhut forecast to cause winds to reach speeds as high as 329 km/h or 205 mph at 700 hPa (green circle), while Hurricane Florence is forecast to hit the coast of North Carolina, and is followed by Hurricane Isaac and Hurricane Helene in the Atlantic Ocean.
At 850 hPa, Typhoon Mangkhut reaches Instant Wind Power Density as high as 196.9 kW/m² on September 13, 2018, as illustrated by above image.
The situation is likely to get worse over the next few months, as this is only the start of the hurricane season and El Niño is strengthening, as illustrated by the image on the right.
The image below shows how the occurrence and strength of El Niño has increased over the decades.
Four Arctic Tipping Points
There are numerous feedbacks that speed up warming in the Arctic. In some cases, there are critical points beyond which huge changes will take place rather abruptly. In such cases, it makes sense to talk about tipping points.
1. The albedo tipping point
As Arctic sea ice gets thinner and thinner, a Blue Ocean Event looks more imminent every year. A Blue Ocean Event means that huge amounts of sunlight won't get reflected back into space anymore, as they previously were. Instead, the heat will have to be absorbed by the Arctic.
At the other hemisphere, the sea ice around Antarctica is at its lowest extent for the time of the year, as illustrated by above image. Global sea ice extent is also at its lowest for the time of the year, as illustrated by the image below.
A Blue Ocean Event will not only mean that additional heat will have to be absorbed in the Arctic, but also that wind patterns will change radically and even more dramatically than they are already changing now, which will also make that other tipping points will be reached earlier. This is why a Blue Ocean Event is an important tipping point and it will likely be reached abruptly and disruptively.
2. The latent heat tipping point
Disappearance of the sea ice north of Greenland is important in this regard. The image on the right shows that most sea ice at the end of August 2018 was less than 1 meter thick.
The image below shows how the sea ice has been thinning recently north of Greenland and Ellesmere Island, an area once covered with the thickest multi-year sea ice. Disappearance of sea ice from this area indicates that we're close to or beyond the latent heat tipping point, i.e. the point where further ocean heat can no longer be consumed by the process of melting the sea ice.
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. Without sea ice, additional ocean heat will have to go somewhere else.
Above image shows how much sea surface temperatures in the Arctic have warmed, compared to 1961-1990. The image also shows the extent of the sea ice (white). In the image below, a large area has changed from sea ice to water twelve days later, showing how thin and fragile the sea ice is and how easily it can disappear as the water continues to warm.
As the Arctic is warming faster than the rest of the world, changes have been taking place to the jet streams on the Northern Hemisphere that make it easier for warm air and water to move into the Arctic. This means that warm water is increasingly entering the Arctic Ocean that can no longer be consumed by melting the sea ice from below.
Arctic sea ice extent has remained relatively large this year, since air temperatures over the Arctic Ocean have been relatively low in June and July 2018. At the same time, ocean heat keeps increasing, so a lot of heat is now accumulating underneath the surface of the Arctic Ocean.
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3. Seafloor Methane Tipping Point
As said above, Arctic sea ice has been getting thinner dramatically over the years, and we are now near or beyond the latent heat tipping point.
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This year, air temperatures over the Arctic Ocean were relatively low in June and July 2018, and this has kept Arctic sea ice extent larger than it would otherwise have been. As a result, a lot of heat has been accumulating underneath the surface of the Arctic Ocean and this heat cannot escape to the atmosphere and it can no longer be consumed by melting. Where will the heat go?
As the temperature of the Arctic Ocean keeps rising, more heat threatens to reach sediments at its seafloor that have until now remained frozen. Contained in these sediments are huge amounts of methane in the form of hydrates and free gas.
Melting of the ice in these sediments then threatens to unleash huge eruptions of seafloor methane that has been kept locked up in the permafrost for perhaps millions of years. Seafloor methane constitutes a third tipping point.
The image on the right features a trend based on WMO data. The trend shows that mean global methane levels could cross 1900 ppb in 2019.
Ominously, methane recently reached unprecedented levels. Peak levels as high as 3369 ppb on August 31, 2018, as shown by the image below on the right.
The next image on the right below shows that mean global levels were as high as 1905 ppb on September 3, 2018.
The third image below on the right may give a clue regarding the origin of these unprecedented levels.
More methane will further accelerate warming, especially in the Arctic, making that each of the tipping points will be reached earlier.
Less sea ice will on the one hand make that more heat can escape from the Arctic Ocean to the atmosphere, but on the other hand the albedo loss and the additional water vapor will at the same time cause the Arctic Ocean to absorb more heat, with the likely net effect being greater warming of the Arctic Ocean.
Additionally, more heat is radiated from sea ice into space than from open water (feedback #23).
How much warming could result from the decline of snow and ice cover in the Arctic?
As discussed, there will be albedo changes, there will be changes to the jet streams, and there will be further feedbacks, adding up to 1.6°C of additional global warming that could eventuate due to snow and ice decline and associated changes in the Arctic.
A further 1.1°C of warming or more could result from releases of seafloor methane over the next few years.
4. Terrestrial Permafrost Tipping Point
Additional warming of the Arctic will also result in further warming due to numerous feedbacks such as more water vapor getting into the atmosphere. Furthermore, more intense heatwaves can occur easier in the Arctic due to changes to jet streams. All this will further accelerate melting of the ice in lakes and in soils on land that was previously known as permafrost. This constitutes a fourth tipping point that threatens to add huge amounts of additional greenhouse gases to the atmosphere. Until now, the permafrost was held together by ice. As the ice melts, organic material in the soil and at the bottom of lakes starts to decompose. The land also becomes increasingly vulnerable to landslides, sinkholes and wildfires. All his can result in releases of CO₂, CH₄, N₂O, soot, etc., which in turn causes further warming, specifically over the Arctic.
In total, a temperature rise of 10°C threatens to occur in as little as a few years time.
The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.
