Blue Ocean Event

Blue Ocean Event

A Blue Ocean Event occurs when virtually all sea ice disappears and the surface color changes from white (sea ice) to blue (ocean). According to many, a Blue Ocean Event starts once Arctic sea ice extent falls below 1 million km².

The image on the right shows a trend pointing at zero Arctic sea ice volume by September 2027. Note that the volume data in the image are averages for the month September ⁠— the minimum for each year is even lower. Furthermore, since zero volume implies zero extent, this indicates that a Blue Ocean Event could happen well before 2027. 

Albedo

Without sea ice, less sunlight will be reflected back into space, and will instead be absorbed by the Arctic. 


Sea ice reflects 50% to 70% of the incoming energy, while thick sea ice covered with snow reflects as much as 90% of the incoming solar radiation. The ocean reflects only 6% of the incoming solar radiation and absorbs the rest.

[ Arctic up to 4.1°C warmer than 1951-1980 ]
An analysis by Pistone et al., published 2014, found an additional 6.4 ± 0.9 W/m² of solar energy input into the Arctic Ocean region between 1979 and 2011. Averaged over the globe, this albedo decrease would correspond to a forcing that is 25% as large as that due to the change in CO₂ during this period.

Note of course that this extra heat has not spread equally around the globe, but has especially raised temperatures in the Arctic, as is illustrated by the image on the right, created with a NASA image that shows temperature anomalies of up to 4.1°C (versus 1951-1980) over the Arctic Ocean.

Latent Heat

In addition to albedo loss due to the disappearance of Arctic sea ice, there is the loss of the sea ice acting as a latent heat buffer. 

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.


As the temperature of the ocean rises, ever less sea ice remains in the Arctic. Once the sea ice is gone, further heat arriving in the Arctic Ocean will strongly raise the water temperature and the atmosphere over the Arctic Ocean.

Further changes

Albedo change due to disappearance of the sea ice goes hand in hand with  loss of the latent heat buffer. There are further changes associated with the disappearance of Arctic sea ice, including changes to the Jet Stream, albedo loss due to decline of the terrestrial snow and ice cover and further changes as described below. These changes can jointly raise the global temperature by as much as 1.6°C by 2026 and cause huge amounts of heat to abruptly reach sediments at the seafloor of the Arctic Ocean, resulting in huge releases of methane contained in sediments in the form of hydrates and free gas that could raise the global temperature by a further 1.1°C by 2026.

What is causing sea ice to disappear?

Arctic sea ice is disappearing as rising air temperatures are increasingly causing sea ice to melt and as water from rivers increasingly carries heat from land into the Arctic Ocean.

Furthermore, ocean heat is rising, as illustrated by the image below and as discussed in an earlier post.


The Gulf Stream amplifies the flow of ocean heat into the Arctic Ocean. The image below, from NOAA, shows how ocean heat has increased over the years.

Change in heat content in the upper 2,300 feet (700 meters) of the ocean from 1993-2020.
Between 1993–2019, heat content rose by up to 6 Watts per square meter in parts of the ocean (dark orange).
Some areas lost heat (blue), but overall, the ocean gained more heat than it lost.
The changes in areas covered with the gray shading were not statistically significant.
NOAA Climate.gov image, based on data from NCEI.

The image below, from an earlier post, shows that sea surface temperatures were as much as 14.1°C or 25.3°F higher than 1981-2011 off the North American coast (green circle) on March 5, 2022.


The Gulf Stream, pictured below, is heating up rapidly as temperatures are rising. Particularly, pollution clouds pouring eastwards from the coast of North America are amplifying heating up of the Gulf Stream.

[ Atlantic Ocean currents ]

The Gulf Stream extends to the north as the North Atlantic Current and continues into the Arctic Ocean. The blue color on the maps above below indicates depth (also see scale underneath images).

On the image below, Malcolm Light indicates three areas of concern:
Area 1. Methane hydrates on the slope;
Area 2. Methane hydrates on the abyssal plane;
Area 3. Methane hydrates associated with the spreading Gakkel Ridge hydro-thermal activity (the Gakkel Riidge runs in between the northern tip of Greenland and the Laptev Sea).

In addition, huge amounts of methane are contained in sediments at the bottom of the shallow parts of the Arctic Ocean, in particular the East Siberian Arctic Shelf (ESAS).

Dr. Natalia Shakova warned in 2008 that some 50Gt of carbon in the form of methane can be released at any moment from the East Siberian Arctic Shelf alone, because of the high temperature of the invading Atlantic (Gulf Stream) waters. 
 

Consequences of a Blue Ocean Event

Consequences of a Blue Ocean Event are discussed in the videos below by Paul Beckwith, earlier posted in 2018.


The video below discusses that, 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 have a look at Paul's video below, The Arctic Blue-Ocean-Event (BOE). When? Then What?


Clearly, the rapid decline of the sea ice has grave consequences. When also looking beyond what's happening in the Arctic, there are a number of events, tipping points and feedbacks that are making things worse. 

An earlier post mentions tipping points in the following scenario of a rapid temperature rise:
  1. a stronger-than-expected El Niño would contribute to
  2. early demise of the Arctic sea ice, i.e. latent heat tipping point +
  3. associated loss of sea ice albedo,
  4. destabilization of seafloor methane hydrates, causing eruption of vast amounts of methane that further speed up Arctic warming and cause
  5. terrestrial permafrost to melt as well, resulting in even more emissions,
  6. while the Jet Stream gets even more deformed, resulting in more extreme weather events
  7. causing forest fires, at first in Siberia and Canada and
  8. eventually also in the peat fields and tropical rain forests of the Amazon, in Africa and South-east Asia, resulting in
  9. rapid melting on the Himalayas, temporarily causing huge flooding,
  10. followed by drought, famine, heat waves and mass starvation, and
  11. 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.

Shrinking multi-year sea ice

The image below, in the upper left map, shows sea ice age distribution toward the end of the melt season for 1985, while the upper right map shows the end of the 2020 melt season. The bottom time series of different age categories shows the minimum extent for 1985 to 2020.


Rising temperatures

The image below was earlier posted in October 2021 and shows two trends, a red trend and a blue trend.
 

The red trend is based on NASA 1880-Sep.2021 data adjusted by 1.28°C to reflect a 3480 BC base, higher polar anomalies and air temperatures. The red trend indicates that the 2°C threshold could already have been crossed when the Paris Agreement was adopted in 2015, while a 5°C anomaly could be crossed by 2060.

The blue trend based on 2015-Sept. 2021 data. The blue trend is more susceptible to short-term variables, such as El Niño, sunspots and volcanoes that are often also referred to as natural variables (as opposed to what is caused by people). The blue trend illustrates that temperatures are currently suppressed by short-term variables (compared to the red trend).

The blue trend illustrates that there could be a huge temperature rise over the next few years, triggered by short-term variables, in particular an El Niño and sunspots, while changes to the Jet Stream increase the frequency and intensity of extreme weather events such as heatwaves and storms that can push a lot of heat into the Arctic. Furthermore, as emissions by people heat up the air, this heats up the sea surface and makes winds stronger, in turn speeding up global ocean currents. A 2020 study by Hu et al. 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.

Cold Freshwater Lid on North Atlantic

One feedback of rising temperatures is that a cold freshwater lid could be forming at the surface of the North Atlantic.


Stronger winds along the path of the Gulf Stream can speed up sea currents that travel underneath this cold freshwater lid over the North Atlantic. As a result, huge amounts of warm, salty water can travel from the Atlantic Ocean toward the Arctic Ocean, 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 the Arctic Ocean itself, increased flow of freshwater from rivers can also lead to a more extensive freshwater lid at the surface, since freshwater doesn't mix well with the more salty water underneath.

Seafloor methane

The above changes could enable more warm, salty water to travel from the Atlantic Ocean into the Arctic Ocean and reach shallow parts of the Arctic Ocean such as the East Siberian Arctic Shelf (ESAS), pushing up temperatures and salinity levels at the seafloor and threatening to destabilize methane hydrates, resulting in eruptions of methane from these hydrates and from free gas contained in sediments at the seafloor of the Arctic Ocean.

Such eruptions of methane could, on their own, cause the 1200 ppm CO₂e cloud feedback tipping point to be crossed within years, which in turn can cause global temperatures to rise by 8°C, as discussed in an earlier post.
 
Latent heat loss, feedback #14 on the Feedbacks page
Joint impact

Further feedbacks of the rising temperatures can make the situation even more threatening, e.g. more methane over the Arctic would push up temperatures locally over the Arctic Ocean as well as over the permafrost on land. A 2020 study by Turetsky et al. found that Arctic permafrost thaw plays a greater role in climate change than previously estimated. Loss of terrestrial permafrost can result in huge releases of greenhouse gases and in albedo changes that could equal those resulting from sea ice loss. Further feedbacks also include changes to clouds, as discussed at the clouds feedback page. 

[ from the Extinction page ]
A huge temperature rise in the Arctic looks set to unfold, triggered by the combined impact of an upcoming El Niño and a peak in sunspots, resulting in loss of the latent heat buffer and albedo losses due to further sea ice decline. As temperatures keep rising in the Arctic, changes to the Jet Stream look set to intensify, while loss of terrestrial albedo in the Arctic could equal the albedo loss resulting from sea ice decline.

Further feedbacks include permafrost degradation, both terrestrial and on the seafloor of the Arctic Ocean, looks set to cause huge releases of greenhouse gases (particularly CO₂, CH₄ and N₂O), in turn also causing more water vapor to enter the atmosphere, causing a huge rise in temperature, especially in the Arctic, where vast amounts of methane are contained in sediments at the seafloor.

Temperatures looks set to rise further due to the falling away of sulfate aerosols, while there could be a further temperature rise due to releases of other aerosols that have a net warming impact, such as black and brown carbon, which can increase dramatically as more wood burning and forest fires take place.

As the temperature keeps rising, further self-reinforcing feedbacks will kick in with more ferocity such as an increase in water vapor globally combined with a decrease in lower clouds decks, further increasing the temperature, as described at the clouds feedback page.

Altogether, the temperature could rise by more than 18°C above pre-industrial, as illustrated by the image on the right from the Extinction page.

In conclusion, temperatures could rise strongly by 2026, resulting in humans going extinct, making it in many respects rather futile to speculate about what will happen beyond 2026. On the other hand, the right thing to do is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.


Links

• PIOMAS Sea Ice Volume Data, 1979-present
• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Albedo
https://arctic-news.blogspot.com/p/albedo.html

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

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


• Sunspots

• Feedbacks