Monday, November 9, 2015

Ocean Heat

Sea Surface Temperatures

Sea surface temperatures were as high as 15.8°C or 60.4°F near Svalbard on November 7, 2015, a 13.7°C or 24.7°F anomaly. Let this sink in for a moment. The water used to be close to freezing point near Svalbard around this time of year, and the water now is warmer by as much as 13.7°C or 24.7°F.

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Above image further shows that sea surface temperature anomalies as high as 6.7°C or 12.1°F were recorded on November 7, 2015, off the coast of North America, while anomalies as high as 6°C or 10.9°F were recorded in the Bering Strait.

NOAA analysis shows that the global sea surface in September 2015 was the warmest on record, at 0.81°C (1.46°F) above the 20th century average of 16.2°C (61.1°F). On the Northern Hemisphere, the anomaly was 1.07°C (1.93°F).

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How did temperatures get so high near Svalbard? The answer is that ocean currents are moving warm water from the Atlantic Ocean into the Arctic Ocean. The ocean is warmer underneath the sea surface and at that location near Svalbard warm water from below the surface emerges at the surface.

Ocean Heat

The oceans are warming up rapidly, especially the waters below the sea surface. Of all the excess heat resulting from people's emissions, 93.4% goes into oceans. Accordingly, the temperature of oceans has risen substantially over the years and - without action - the situation only looks set to get worse.

NOAA's ocean heat content figures for 0-2000 m are very worrying, as illustrated by the image below.


The image below was created with data for January through to March, while adding non-linear trendlines for ocean heat at depths of 0-700 m and 0-2000 m. For growth of ocean heat content for 0-700 m, a polynomial trend is added, while for growth of ocean heat content for 0-2000 m an exponential trend is added.

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The image below shows a polynomial trend based on all available quarterly data for ocean heat content from 0 to 2000 m. The trendline shows even faster growth.


The danger is that, as ocean heat continues to grow, ocean currents will keep carrying ever warmer water from the Atlantic and Pacific Oceans into the Arctic Ocean.

Merely watching temperatures at the surface of the ocean may underestimate the warming that is taking place below the sea surface. At the sea surface, evaporation takes place that cools the water. Furthermore, melting of sea ice and glaciers will make that a layer of cold freshwater spreads at the surface, preventing much transfer of heat from the ocean to the atmosphere, as discussed at this earlier post. The blue-colored areas on the Northern Hemisphere on the top image are partly the result of this meltwater. There is another reason why these areas are relatively cool, i.e. sulfates, as further discussed in the section below.

Aerosols

Particulates, in particular sulfate, can provide short-term cooling of the sea surface. Large amounts of sulfate are emitted from industrial areas in the east of North America and in East Asia. On the Northern Hemisphere, the Coriolis effect makes that such emissions will typically reach areas over the nearby ocean to the east of such industrial areas, resulting in the sea surface there being cooled substantially, until the particulates have fallen out of the sky. Since the sulfate is emitted on an ongoing basis, the cooling effect continues without much interruption.

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This sulfate has a cooling effect on areas of the sea surface where ocean currents are moving warm water toward the Arctic Ocean. Because the sea surface gets colder, there is less evaporation, and thus less heat transfer from the ocean to the atmosphere during the time it takes for the water to reach the Arctic Ocean. As a result, water below the sea surface remains warmer as it moves toward the Arctic Ocean.


Similarly, as illustrated by above image, sulfur dioxide emitted in industrial areas in North America and East Asia can extend over the oceans, cooling the surface water of currents that are moving water toward the Arctic Ocean.

Methane

The image below shows that atmospheric methane levels in 2014 were 1833 parts per billion (WMO data) or 254% the pre-industrial level. WMO data are for 1984-2014 and are marked in red, while IPCC data (AR5) are for the years 1755-2011 and are marked in blue.


The image below shows the rise of methane levels from 1984 created with World Metereological Organization (WMO) data. The square marks a high mean 2015 level, from NOAA's MetOp-2 satellite images, and it is added for comparison, so it does not influence the trendline, yet it does illustrate the direction of rise of methane levels and the threat that global mean methane levels will double well before the year 2040.


The image below illustrates the danger that large amounts of methane will erupt from the Arctic Ocean, particularly in East Siberian Arctic Shelf, where the sea is quite shallow, so much of the methane can reach the atmosphere without being broken down by microbes on the way up through the water column.


The video below shows how methane concentrations start to rise close to sea level, and how concentrations strengthen at higher altitudes, and to eventually get lower at even higher altitudes.



The Threat

Ocean heat threatens to increasingly reach the seafloor of the Arctic Ocean and unleash huge methane eruptions from destabilizing clathrates. Such large methane eruptions will then warm the atmosphere at first in hotspots over the Arctic and eventually around the globe, while also causing huge temperature swings and extreme weather events, contributing to increasing depletion of fresh water and food supply, as further illustrated by the image below, from an earlier post.

[ click on image at original post to enlarge ]

The image below gives an indication of the ocean heat that is pushed by the Gulf Stream toward the Arctic Ocean. Note that this image shows the situation on November 15, 2015. Water off the east coast of North America is even warmer at the peak of the Northern Hemisphere summer and it is this water that is now arriving in the Arctic Ocean.


Below is a radio version of this post, roughly as read by Debba Kale Earnshaw at this episode and the next episode of extinctionradio.org



Malcolm Light comments:
To a geologist-oceanographer, the increasing rate of heat gain in the deep water seems obvious. Massive quantities of heat are generated in the earth's interior by radioactivity and find their way to the surface in rising convection systems to erupt along mid-ocean ridges as basaltic lava flows, pushing the plates apart. Under normal circumstances, prior to the arrival of civilized man, the plates cooled as they expanded by passing their heat into the oceans, which then was radiated into space.

Now, with the fast evolving atmospheric greenhouse Arctic methane global warming veil. the heat is simply being reflected back into the oceans and onto the land. Therefore, just like a pressure cooker, the Earth's interior heat is becoming trapped more and more and of course the end result will be a final blow-out. The more than 400 thousand years of ice core data show that we can expect a massive atmospheric methane peak caused by destabilization of the Arctic subsea methane hydrates very soon (8 to 16 years away) and it will produce a Permian style extinction event with a temperature increase of some 8 to 10 degrees C.


Climate Plan

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

Sea surface temperatures were as high as 15.8°C or 60.4°F near Svalbard on November 7, 2015, a 13.7°C or 24.7°F anomaly....
Posted by Sam Carana on Monday, November 9, 2015

8 comments:

  1. This is really out of any current scenario from the IPCC. And worst, in Paris they will discuss fairy tail scenarios that put the bulk of the issue around 3 generations from now... conveniently...

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  2. Hottest October on record by a country mile in south east Australia. The world could hit 1C by years end. Aerosols have a dimming effect in the mid latitudes of the northern hemisphere equal to the best part of a degree. Ice loss in the Arctic will take over CO2 as the main driver of climate change soon. Then methane steps in as a rapid amplifier. The ice is still accumulating in the Antarctic as it has for 10,000 years but at a decreasing rate. The AMOC is slowing which will confound the climates along its length. This is one of the most intricate and engaging problems I have ever come across. How it is possible to construct predictive models given the complex interplay of feedbacks is beyond me.

    Thank you for maintaining this blog. Its one of the few places where a layman get a big picture of whats going on. Most other sites are more reductive. They're useful too but in a diferent way.

    Our conversation in the west is dominated by sea level rise. Most people know nothing about feedbacks or food security or looming droughts or the massive changes in ocean ecology and how this impacts on our daily lives or the future of all species on this planet.

    Thanks

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    1. Matthew wrote: "Ice loss in the Arctic will take over CO2 as the main driver of climate change soon."

      I'm interested to know the source for this claim, and hopefully this time the moderator will let this comment through. The latest paper I know about in this regard is

      K. Pistone, I. Eisenman, and V. Ramanathan (2014). Observational determination of albedo decrease caused by vanishing Arctic sea ice. Proc Natl Acad Sci USA 111, 3322-3326.
      http://eisenman.ucsd.edu/papers/Pistone-Eisenman-Ramanathan-2014.pdf

      which found that the albedo decrease from Arctic sea ice between 1979 and 2011 corresponds "to an additional 6.4 ± 0.9 W/m2 of solar energy input into the Arctic Ocean region since 1979. Averaged over the globe, this albedo decrease corresponds to a forcing that is 25% as large as that due to the change in CO2 during this period."

      Has there been research published since this paper that shows this is now approaching 100%? I'm dubious.

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    2. David, note that the estimate by Pistone et al, refers to the period between 1979 and 2011. Furthermore, note that it refers to Arctic sea ice loss only. Flanner et al. earlier concluded that snow and ice on the Northern Hemisphere was reflecting 0.45 watts less energy per square meter in 2008 than it did in 1979, with nearly equal contributions from changes in land snow cover and sea ice.

      The combined impact of TOTAL loss of ice and snow cover in the Arctic could be well over 2 W/sq m globally, as Prof. Peter Wadhams concluded back in 2012. By comparison, this would more than double the radiative forcing resulting from the emissions caused by all people of the world, which at that time was estimated by the IPCC at a net 1.6 W/sq m.

      So, it makes sense to say that the combined loss of snow and ice cover in the Arctic could soon contribute more to global warming than CO2 emitted by people. Moreover, decline of snow and ice cover is just one of multiple feedbacks in the Arctic, with methane releases looming as an even larger threat.

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    3. What is the citation to Wadham's paper?

      Note that 0.45 W/m2 is nowwhere near CO2's RF of about 1.7 W/m2?

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    4. Peter Wadhams' calculation was made in 2012. The link to the respective post is included in above comment. That post compares the radiative forcing impact of albedo changes to the figure of a NET 1.6 W/sq m warming due to people's emissions, which incorporates the masking effect of aerosols and the cumulative impact of all CO2 emissions from 1750, estimated by the IPCC at ~2000 Gt CO2 by 2011. By comparison, global CO2 emissions from fossil fuel combustion and cement and metal production in 2013 was 35.3 Gt. So, when only looking at the current CO2 emissions, their impact will clearly be a lot lower than the joint impact of the all CO2 emissions since 1750. Also, as said, Flanner's 0.45 W/m2 figure refers to the period 1979-2008, so the figure for the impact of albedo changes in the Arctic now will be higher than that.

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  3. Second to Matthew Peterson. Much appreciate your blog.

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  4. Excellent question David and thanks for picking up the thread Sam Carana.

    I read things then forget where I read them.

    I think more people should be aware that albedo and methane drivers are about to overtake CO2.

    This is conjecture but I think thats the point that we watch it all slip away. I cannot think of a technology or policy that could turn thst around. We would have to reduce CO2 in the atmosphere to very low levels and wait 1000's of years for a signal.

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