Ocean Heat Invades Arctic Ocean

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NOAA analysis shows that, on land, it now is about 1°C (1.8°F) warmer than the 20th century average.

July 2015 was the warmest month ever recorded for the globe. The combined average temperature over global land and ocean surfaces for July was the all-time highest monthly temperature in the 1880-2015 record – it was 16.61°C (61.86°F), i.e. 0.81°C (1.46°F) above the 20th century average. 

Sea surfaces were very warm as well, in particular the North Pacific, which on August 22, 2015, was exactly 1°C (1.8°F) warmer than it was compared to the period from 1971 to 2000 (see Climate Reanalyzer image right).

The July globally-averaged sea surface temperature was the highest temperature for any month in the 1880-2015 record. In July 2015, the sea surface on the Northern Hemisphere was 0.87°C (1.57°F) warmer than it was in the 20th century, as illustrated by the NOAA graph below. 

As the image below shows, the July data for sea surface temperature anomalies on the Northern Hemisphere contain a trendline pointing at a rise of 2°C (3.6°F) before the year 2030. In other words, if this trend continues, the sea surface will be 2°C (3.6°F) warmer in less than 15 years time from now.

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Such a temperature rise would be a catastrophe, as there are huge amounts of methane contained in the form of hydrates and free gas in sediments under the Arctic Ocean seafloor. A relatively small temperature rise of part of these sediments could cause a huge abrupt methane eruption, which could in turn trigger further eruptions of methane.

As illustrated by the image below, high methane levels are already showing up over the Arctic.

Methane levels as high as 2565 parts per billion were recorded on August 18, 2015

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Loss of Arctic sea ice could speed up such a development. The image on the right shows that, on August 20, 2015, Arctic sea ice extent was at a record low for the time of the year except for the years 2007, 2011 and 2012.

The situation today is even worse than one might conclude when looking at sea ice extent alone. Thick sea ice is virtually absent compared to the situation in the year 2012 around this time of year, as illustrated by the image below that compares sea ice thickness on August 20, 2012 (left) with August 20, 2015 (right).

The comparison below further illustrates this. The left panel shows how thick sea ice is anchored to the north-east tip of Greenland on July 7, 2015. The right panel shows how, on August 20, 2015, this ice has been fractured and shattered into pieces. All this ice looks set to soon flow down Fram Strait and melt away in ever warmer water.

The image below shows sea surface temperature anomalies on August 21, 2015.

On the image below, the green circle at the top of each globe indicates a location where sea surface temperature was 17°C (62.6°F) on August 21, 2015, an anomaly of 11.9°C (21.4°F). This is where warm water is entering the Arctic Ocean from the Atlantic Ocean. At the same time, warm water is entering the Arctic ocean through the Bering Strait from the Pacific Ocean.

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There still are a few weeks to go before sea ice can be expected to reach its minimum, at around half September 2015, while sea currents will continue to carry warmer water into the Arctic Ocean for months to come. More open water increases the chance that storms will develop that will push the last remnants of the sea ice out of the Arctic Ocean, as discussed in earlier posts such as this one, while storms can also mix warm surface waters all the way down to the seafloor, as discussed in this earlier post.

Typhoons increase this danger. The Climate Reanalyzer image below shows typhoons in the Pacific.

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Typhoons developing in the Pacific Ocean are getting stronger as the oceans warm. One of the typhoons visible on above map, Typhoon Goni, has just claimed ten lives in the Philippines.

Stronger typhoons come with an increased chance that they will bring strong winds and warm air and water into the Arctic.

Typhoon Goni and the larger Typhoon Atsani are both moving north and look set to move into the direction of the Arctic Ocean, as illustrated by the forecast for the situation on August 26, 2015, on the right.

Atsani was the twelfth typhoon and sixth super typhoon of the year in the western North Pacific—numbers that meteorologists say put the season on a record-breaking track. The NASA image below gives an idea of the size of Typhoon Atsani.

[ Typhoon Atsani - NASA image ]

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

July data for sea surface temperature anomalies on the Northern Hemisphere contain a trendline pointing at a rise of 2°C...
Posted by Sam Carana on Friday, August 21, 2015

Antarctica linked to Arctic

Waters in the Arctic Ocean continue to warm up. Very warm waters from the North Atlantic and Pacific Ocean are invading the Arctic Ocean.

Waters in the North Atlantic and in the North Pacific are very warm, due to a number of reasons.

What is happening in the oceans is very important in this respect. As discussed in earlier posts, most of the extra heat caused by people's emissions goes into the oceans.

The great ocean conveyor belt (Thermohaline Circulation), brings warm water from the southern hemisphere to the northern hemisphere.

The Gulf Stream is the North Atlantic leg of the great ocean conveyor belt, and it brings dense, salty water from the North Atlantic into the Arctic Ocean.

Saltier water is denser than fresher water because the dissolved salts fill interstices between water molecules, resulting in more mass per unit volume.

Very dense ocean water can be found in the North Atlantic because the North Atlantic has high salinity, due to high evaporation rates, while salty water is also coming from the Mediterranean Sea.

As also discussed in an earlier post, this dense, saltier water sinks in the North Atlantic, accumulating in deeper water.

By contrast, much of the Arctic Ocean has low salinity, due to ice melt and river runoff.  As it enters the Arctic Ocean, the warm and dense water from the Atlantic thus dives under the under the sea ice and under the less salty surface water in the Arctic Ocean.

In conclusion, much of the heat resulting from people's emissions accumulates in the North Atlantic and also ends up in the Arctic. This partly explains why surface temperatures are rising much faster at the poles, as illustrated by the NOAA image below.

There are further reasons why surface air temperatures elsewhere (other than at the poles) are rising less rapidly than they did, say, a decade ago. As also discussed by Andrew Glikson in the post No Planet B, the increased amounts of sulphur emitted by the growing number of coal-fired power plants and by the burning of bunker fuel on sea is (temporarily) masking the full wrath of global warming.

Another reason is the growth of the sea ice around Antarctica, as illustrated by the CryosphereToday image on the left.

Melting takes place both in the Arctic and on Antarctica, but more so in the Arctic. Recent research of CryoSat-2 data reveals that Greenland alone is now losing about 375 cubic kilometers of ice annually, while in Antarctica the annual volume loss now is about 125 cubic kilometers.

Currents also distribute ocean heat in ways that make the Arctic warm up more than twice as rapidly as the Antarctic. In a recent paper, John Marshall et al. further suggest that ozone depletion also contributes to this.

All this makes that, while the jet streams on the northern hemisphere are circumnavigating the globe at a slower pace, jet streams on the southern hemisphere are getting stronger, making it more difficult for warm air to enter the atmosphere over Antarctica, while the stronger winds also speed up sea currents on the southern hemisphere. This makes the sea ice around Antarctica grow, and as the sea ice spreads further away from Antarctica, temperatures of surface waters around Antarctica are falling.

Growth of the sea ice around Antarctica makes that more sunlight is reflected back into space. There now is some 1.5 million square kilometers more sea ice around Antarctica than there used to be. The albedo change associated with sea ice growth on the southern hemisphere can be estimated at 1.7 W/sq m, i.e. more than the total RF of all CO2 emission caused by people from 1750 to 2011 (IPCC AR5).

The rapid growth of sea ice on the southern hemisphere alone goes a long way to explain why, over the past three months, surface air temperatures have not been much higher than they used to be, both globally and in the Arctic, as illustrated by above NOAA image. What has also contributed to warmer temperatures around latitude 60 on the northern hemisphere is the fact that methane has accumulated in the atmosphere at that latitude, as discussed in earlier posts.

Arctic SST far exceed anything ever seen in human history

So, does the sea ice on the southern hemisphere constitute a negative feedback that could hold back global warming? It doesn't.

It may temporarily keep surface temperatures close to what they used to be, as the sea ice reflects lots of sunlight back into space, but at the same time ocean temperatures are rising strongly, as the sea ice also prevents heat from radiating out of the waters around Antarctica.

The latter also helps explaining the colder surface temperatures over those waters.

Much of this additional ocean heat has meanwhile been transported by the great ocean conveyor belt to the northern hemisphere.

No time before in human history has such a huge amount of ocean heat accumulated in the North Atlantic and the North Pacific. This heat is now threatening to invade the Arctic Ocean and trigger huge temperature rises due to methane eruptions from the seafloor.

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

Smoke Blankets North America

A thick layer of smoke blankets large parts of North America, as also illustrated by the animation below based on images from July 15 to 18, 2014, from Wunderground.com.

[ note that this animation is a 2.3MB file that may take some time to fully load ]

The are also extensive wildfires throughout the boreal forest and tundra zones of Central Siberia in Russia.

Such wildfires can send huge amounts of carbon dioxide, methane, soot, dust and volatile organic compounds into the atmosphere. Much of this gets deposited at higher latitudes, discoloring land, snow and ice, and thus speeding up warming by absorbing more sunlight that was previously reflected back into space.

Soils at higher latitudes can contain huge amounts of carbon in the form of peat, as described in the earlier post The Threat of Wildfires in the North. There are further conditions that make the situation in the Arctic so dangerous.

Temperature anomaly March-April-May-June 2014 (JMA)

The Arctic is particularly vulnerable to warming due to geographics. Seas in the Arctic Ocean are often shallow and covered by sea ice that is disappearing rapidly. Largely surrounded by land that is also rapidly losing its snow and ice cover, the Arctic Ocean acts like a trap capturing heat carried in by the Gulf Stream, which brings in ever warmer water. Of all the heat trapped on Earth by greenhouse gases, 90% goes into oceans, while a large part of the remaining 10% goes into melting the snow and ice cover in the Arctic, as described in an earlier post. Such basic conditions make that the Arctic is prone to warming.

Then, there are huge amounts of methane held in sediments under the Arctic Ocean, in the form of hydrates and free gas. Unlike methane releases from biological sources elsewhere on Earth, methane can be released from the seafloor of the Arctic Ocean in large quantities, in sudden eruptions that are concentrated in one area.

Until now, permafrost and the sea ice have acted as a seal, preventing heat from penetrating these methane hydrates and causing further destabilization. As long as there is ice, additional energy will go into melting the ice, and temperatures will not rise. The ice also acts as a glue, keeping the soil together and preventing hydrate destabilization from pressure changes and shockwaves resulting from seismic activity. Once the ice is gone, sediments become prone to destabilization and heat can more easily move down along fractures in the sediment, reaching hydrates that had until then remained stable.
 

Temperature anomaly March-April-May 2014 (NASA)

When methane escapes from the seafloor of the Arctic Ocean and travels through waters that are only shallow, there is little opportunity for this methane to be broken down in the water, so a lot of it will enter the atmosphere over the Arctic Ocean. The Coriolis effect will spread the methane sideways, but latitudes over the Arctic are relatively short, making the methane return at the same spot relatively quickly, while the polar jet stream acts as a barrier keeping much of the methane within the Arctic atmosphere. In case of large methane eruptions, the atmosphere over the Arctic will quickly become supersaturated with methane that has a huge initial local warming potential.

Hydroxyl levels in the atmosphere over the Arctic are very low, extending the lifetime of methane and other precursors of stratospheric ozone and water vapor, each of which have a strong short-term local warming potential. In June/July, insolation in the Arctic is higher than anywhere else on Earth, with the potential to quickly warm up shallow waters, making that heat can penetrate deep into sediments under the seafloor.

created by Sam Carana, part of AGU 2011 poster

The initial impact of this methane will be felt most severely in the Arctic itself, given the concentrated and abrupt nature of such releases, with the danger that even relatively small releases of methane from the seafloor of the Arctic can trigger further destabilization of hydrates and further methane releases, escalating into runaway warming.

This danger is depicted in the image on the right, showing how albedo changes and methane releases act as feedbacks that further accelerate warming in the Arctic, eventually spiraling into runaway global warming.

The currently very high sea surface temperature anomalies are illustrated by the two images below.

As the image below right shows, sea surface temperatures as high as 18 degrees Celsius (64.4 degrees Fahrenheit) are currently recorded in the Arctic.

Albedo changes and methane releases are only two out of numerous feedbacks that are accelerating warming in the Arctic.

Also included must be the fact that Earth is in a state of energy imbalance. Earth is receiving more heat from sunlight than it is emitting back into space. Over the past 50 years, the oceans have absorbed about 90% of the total heat added to the climate system, while the rest goes to melting sea and land ice, warming the land surface and warming and moistening the atmosphere.

In a 2005 paper, James Hansen et al. estimated that it would take 25 to 50 years for Earth’s surface temperature to reach 60% of its equilibrium response, in case there would be no further change of atmospheric composition. The authors added that the delay could be as short as ten years.

Earth's waters act as a buffer, delaying the rise in land surface temperatures that would otherwise occur, but this delay could be shortened. Much of that extra ocean heat may enter the atmosphere much sooner, e.g. as part of an El Niño event. Another buffer, Arctic sea ice, could collapse within years, as illustrated by the image below.

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The demise of sea ice comes with huge albedo changes, resulting in more heat getting absorbed by the Arctic Ocean, in turn speeding up warming of the often shallow waters of the Arctic Ocean. This threatens to make heat penetrate subsea sediments containing huge amounts of methane. Abrupt release of large amounts of methane would warm up the Arctic even more, triggering even further methane releases in a spiral of runaway warming.

Particularly worrying is the currently very warm water that is penetrating the Arctic Ocean from the Atlantic Ocean and also from the Pacific Ocean, as illustrated by the image further above and the image on the right.

The danger is that the Arctic will warm rapidly with decline of the snow and ice cover that until now has acted as a buffer absorbing heat, with more sunlight gets absorbed due to albedo changes and as with additional emissions, particularly methane, resulting from accelerating warming in the Arctic.

The numerous feedbacks that accelerate warming in the Arctic are pictured in the image below.

[ from: climateplan.blogspot.com/p/feedbacks.html ]

Furthermore, the necessary shift to clean energy will also remove the current masking effect of aerosols emitted when burning fuel. One study finds that a 35% – 80% cut in people's emission of aerosols and their precursors will result in about 1°C of additional global warming.

In the video below and the video further down below, Guy McPherson discusses Climate Change and Human Extinction.

from: http://fossilfreeri.org/2014/07/13/guy-mcphersons-climate-change-the-end-part-4/

This is further illustrated by the image below, showing how surface temperature rises are accelerating in the Arctic compared to global rises, with trendlines added including one for runaway global warming, from How many deaths could result from failure to act on climate change?

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

Hat tip to Jim Kirkcaldy for pointing at the wildfire development at an early stage.

Post by Sam Carana.

Has the descent begun?

On March 9, 2014, Arctic sea ice area was at a record low for the time of the year, at only 12.88731 square kilometers.

Sea ice extent shows a similar descent, as illustrated by the NSIDC image below.

NSIDC update: The image below shows that Arctic sea ice extent was 14.583 square kilometers on March 11, 2014 (light green line), a record low for this time of the year and smaller than it was in 2006 (magenta line) and 2011 (orange line) at this time of the year.

The situation is dire, given that methane concentrations have risen strongly following an earthquake that hit the Gakkel Ridge on March 6, 2014, as illustrated by the image below.

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Huge amounts of methane have been released from the seafloor of the Arctic Ocean over the past half year, and the resulting high methane concentrations over the Arctic will contribute to local temperature rises.

The image below shows that sea surface temperatures are anomalously high in the Arctic Ocean and off the east coast of North America, from where warm water is carried by the Gulf Stream into the Arctic Ocean.

The prospect of an El Niño event makes the situation even more dire. NOAA recently issued an El Niño Watch. This follows a conclusion by an international research team that found a 75% likelyhood of an El Niño event in late 2014.

The consequences of sea ice collapse would be devastating, as all the heat that previously went into transforming ice into water will be asbsorbed by even darker water, from where less sunlight will be reflected back into space. The danger is that further warming of the Arctic Ocean will trigger massive methane releases is unacceptable and calls for comprehensive and effective action as discussed at the Climate Plan blog.

M4.5 Earthquake hits Gakkel Ridge

The above image shows recent large methane release over the Gakkel Ridge, the faultline that crosses the Arctic Ocean between the northern tip of Greenland and the Laptev Sea (red line on map). Methane readings were as high as 2395 ppb at 586 mb, an altitude that often shows high methane readings originating from the Arctic Ocean.

An earthquake with a magnitude of 4.5 hit the Gakkel Ridge at a depth of 2 km on March 6, 2014, at 11:17.17.0 UTC. The location is shown on the map below.

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The image below shows more recent methane readings, around March 8, 2014.

The image below is a Naval Research Laboratory forecast of sea ice thickness for March 8, 2014, run on March 3, 2014.

Meanwhile, the sea ice is close to record lows (for the time of the year), as illustrated by the images below. The image directly below shows sea ice area.

The image below shows sea ice extent.

The image below, by Wipneus, shows sea ice volume.

The image below, by Andy Lee Robinson, offers a different way of looking at sea ice volume, the Arctic Death Spiral.

High methane levels over the Arctic Ocean on February 17, 2014

Above image shows IASI methane readings over the last day or so, when levels as high as 2223 ppb were recorded.

Where does the methane come from?

On above image, methane shows up prominently along the faultline that crosses the Arctic Ocean from the northern tip of Greenland to the Laptev Sea. This indicates that the methane originated from the depths of the Arctic Ocean, where sediments contain large amounts of methane in the form of free gas and hydrates, which have become destabilized.

High methane concentrations have persistently shown up over the Arctic Ocean since October 1, 2013. On January 19, 2014, levels as high as 2363 ppb were recorded over the Arctic Ocean, as illustrated by the image below, from an earlier post.

[ from earlier post, click on image to enlarge ]

Below is a comparison of methane readings for the week from February 9 to 16, 2014, compared to the same period in 2013.

[ from earlier post, click on image to enlarge ]

The above comparison shows that there is a lot of methane over the Arctic Ocean that wasn't there last year. 

Furthermore, high methane readings show up where currents move the sea ice out of the Arctic Ocean, in areas such as Baffin Bay. This indicates that methane that is released from the seafloor of the Arctic Ocean appears to be moving underneath the ice along with exit currents and entering the atmosphere where the sea ice is fractured or thin enough to allow the methane to pass through. 

Also note that more orange areas show up on the southern hemisphere in 2014, indicating that more methane from the northern hemisphere is now spreading south beyond the equator. This in addition to indications that more methane is rising and building up at higher altitudes, as discussed in an earlier post.

Causes

What made these high releases from the seafloor of the Arctic Ocean persist for so long? At this time of year, one might have thought that the water in the Arctic Ocean would be much colder than it was, say, on October 1, 2013.

Actually, as the combination image below shows, sea surface temperatures have not fallen much at the center of the Arctic Ocean between early October, 2013 (left) and February 17, 2014 (right). In the area where these high methane concentrations occured, sea surface temperatures have remained the same, at about zero degrees Celsius.

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The above comparison image shows that, while surface temperatures in the Atlantic Ocean may have fallen strongly with the change of seasons, surface temperatures in the Arctic Ocean have changed only little.

In this case of course, what matters more than surface temperatures are water temperatures at greater depth. Yet, even here temperatures in the Arctic Ocean will have decreased only slightly (if at all) compared to early October 2013, since the Gulf Stream has continued to push warmer water into the Arctic, i.e. water warmer than the water in the Arctic Ocean, so the heating impact of the Gulf Stream continues. Also, sea surface temperature anomalies along the path of the Gulf Stream continue to be anomalously high, as the image below shows.

The situation looks even more grim on the Climate Reanalyzer image below, showing sea surface temperature anomalies that are far more profound in the Arctic Ocean.

Note also that, as the sea ice extent increased, there have been less opportunities for the heat to evaporate on the surface and for heat to be transferred from the Arctic Ocean to the air.

Finally, what matters a lot is salinity. The combination image below compares salinity levels between October 1, 2013 (left), and February 17, 2014 (right).

[ click on image to enlarge ]

Salinity levels were low on October 1, 2013, as a lot of ice and snow had melted in the northern summer and rivers had carried a lot of fresh water into the Arctic Ocean. After October 1, 2013, little or no melting took place, yet the Gulf Stream continued to carry waters with higher salt levels from the Atlantic Ocean into the Arctic Ocean.

Annual mean sea surface salinity

Seawater typically has a salinity level of over 3%; it freezes and melts at about −2°C (28°F). Where more saline water from the Atlantic Ocean flows into the Arctic Ocean, the water in the Arctic Ocean becomes more saline. The freezing and melting point of fresh water (i.e. zero salinity) is 0°C (or 32°F). More salinity makes frozen water more prone to melting, i.e. at temperatures lower than 0°C, or as low as −2°C.

As the salinity levels of the water on the seafloor of the Arctic Ocean increased, the ice that had until then held the methane captive in hydrates on the seafloor of the Arctic Ocean started to melt. Indeed, the areas in the Arctic Ocean where the high methane releases occurred on January 14, 2014 (top image) show several practical salinity units (psu) increase since October 1, 2013.

Higher salinity levels are showing up closer to the faultline that runs through the Arctic Ocean from the top of Greenland to the Laptev Sea.