Record High Methane Levels

Record High Methane Levels

anomaly Arctic Bering Strait heating methane ocean sea surface SST temperature warming

Unknown 8/07/2015 Add Comment

[ click on images to enlarge ]

As the top image shows, sea surface temperature anomalies in the Bering Strait on August 4, 2015, were as high as 8.7°C (15.6°F). Such high anomalies are caused by a combination of ocean heat, of heatwaves over Alaska and Siberia extending over the Bering Strait, and of warm river water run-off.

As the image on the right shows, sea surface temperatures in the Bering Strait were as high as 20.5°C (69.1°F) on August 4, 2015.

As warm water flows through the Bering Strait into the Arctic Ocean, it dives under the sea ice and becomes harder to detect by satellites that typically measure water temperatures at the surface, rather than below the surface.

The image below shows sea surface temperature anomalies from 1971 to 2000, for August 6, 2015, as visualized by Climate Reanalyzer.

Climate Reanalyzer applies a mask over sea-ice-covered gridcells, reducing anomalies in such cells to zero.

Below is a NOAA image, for August 5, 2015, also with anomalies from 1971 to 2000.

Below is another NOAA image, showing anomalies for August 6, 2015. Because the base period is 1961 to 1990, the anomalies are higher. Nonetheless, the yellow areas that feature around the North Pole on above image do not show up on the image below.

In other words, looking at sea surface temperatures alone may lead to underestimations of the temperatures of the water underneath the sea ice. Keeping that in mind, have a look again at the high anomalies on the image below.

The danger is that further decline of the sea ice will lead to rapid warming of the Arctic Ocean, while the presence of more open water will also increase the opportunity for strong storms to develop that can mix high sea surface temperatures all the way down to the seafloor, resulting in destabilization of sediments and triggering releases of methane that can be contained in such sediments in huge amounts.

The image below shows that global mean methane levels as high as 1840 parts per billion (ppb) were recorded on August 4, 2015. Peak methane levels that day were as high as 2477 ppb.

This peak level of 2477 ppb isn't the highest recorded the year. As the image below shows and as discussed in a previous post, methane levels as high as 2845 ppb were recorded on April 25, 2015. The average of the daily peaks for this year up to now is 2355 ppb. Very worrying about the above image are the high levels of methane showing up over the Arctic Ocean.

As above image also shows, the mean methane level of 1840 ppb is in line with expectations, as methane levels rise over the course of the year, to reach a maximum in September. This mean level of 1840 ppb is higher than any mean level since records began.

The image below shows all the World Meteorological Organisation (WMO) annual means that are available, i.e. for the period 1984 through to 2013.

As above image shows, a polynomial trendline based on these WMO data (for the period 1984 through to 2013) points at a doubling of mean global methane levels by about 2040. The added NOAA data are the highest mean in 2014, i.e. 1839 ppb recorded on September 7, 2014, and the above-mentioned level of 1840 ppb recorded on August 4, 2015.

As said, mean global methane levels last year reached its peak in September and the same is likely to occur this year. In other words, this new record is likely to be superseded by even higher levels soon.

The image on the right shows the steady rise of the highest mean daily methane levels that have been recorded recently, indicating that a continued rise can be expected that would put another highest mean level for 2015 on the trendline of above image soon.

Again, the danger is that a warming Arctic Ocean will trigger further methane releases from the seafloor, leading to rapid local warming that in turn will trigger further methane releases, in a vicious cycle of runway warming.

As illustrated by the image on the right, at a 10-year timescale, the current global release of methane from all anthropogenic sources exceeds all anthropogenic carbon dioxide emissions as agents of global warming.

Over the next decade or so, methane emissions are already now more important than carbon dioxide emissions in driving the rate of global warming, and this situation looks set to get worse fast.

Unlike carbon dioxide, methane's GWP does rise as more of it is released. Higher methane levels cause depletion of hydroxyl, which is the main way for methane to be broken down in the atmosphere.

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

The image shows all the World Meteorological Organisation (WMO) annual means that are available, i.e. for the period...
Posted by Sam Carana on Friday, August 7, 2015

Fracturing of the Jet Stream

Fracturing of the Jet Stream

Arctic Bering Strait fracturing heat jet stream methane ocean sea ice SST thickness warming

Unknown 7/08/2015 Add Comment

Earlier this month, the jet stream was forecast to move over the Arctic Ocean north of Siberia on July 8, 2015, 12:00 UTC, in one, strong, long stream of wind, as discussed in the previous post and depicted below.

The situation has meanwhile been adjusted in a more recent forecast. This recent forecast shows the jet stream getting fractured over Siberia on July 8, 2015, 12:00 UTC, resulting in a sequence of vertical wind streams. This is a new development, rather unknown to the forecasting model that works on the basis of the jet stream flowing horizontally in one strong and narrow stream around the globe.

A further forecast has been added in the bottom panel, i.e. for July 12, 2015, 12:00 UTC, showing the jet stream moving well over the Arctic Ocean in two places, over the East Siberian Sea and over the Canadian Archipelago.

Fracturing of the jet stream and alignment along longitude, rather than latitude, is a worrying development. It is the most extreme form of what is described at Feedbacks in the Arctic as the "Open Doors" feedback or feedback #10, a feedback that makes it easier for warm air to move into the Arctic and for cold air move out of the Arctic, each of which will further contribute to a smaller temperature difference between the Equator and the North Pole, thus further changing the jet stream, in a self-reinforcing spiral.

The jet stream used to act as a barrier, keeping cold air in the Arctic and keeping temperate air in the temperate zone. As the jet stream fractures, more extreme weather - including more intense heatwaves - can be expected.

The result is further acceleration of warming in the Arctic, due to direct sunlight, due to warm wind carried north as the jet stream changes, due to warm water from rivers flowing into the Arctic Ocean, due to soot from wildfires settling on the snow and ice, causing their further demise, etc.

The image below illustrates the impact of warm river water. Off the coast of Anadyr, in East Siberia, waters reached a temperature of 15.4°C (59.7°F) on July 5, 2015, a 9.2°C (16.6°F) anomaly.

The image below also shows the impact of warm water from rivers in Alaska. Major melting took place on St Lawrence Island, as evident by the low sea surface temperatures around the Island on July 2, 2015 (left panel), while by July 6, 2015, much of this colder water had mixed with the warmer water moving up the Bering Strait from the Pacific Ocean and with the warm river water from Siberia and Alaska.

The Naval Research Laboratory's 30-day animation below illustrates the dramatic fall in sea ice thickness.

The image below shows sea surface temperatures in the Arctic as at July 7, 2015.

With ocean heat at very high levels, the danger is that, as temperatures keep rising, further methane hydrates will get destabilized and further amounts of methane will be released in the Arctic. High methane levels have already been showing up for years over the Arctic Ocean, indicating that methane releases from the seafloor of the Arctic Ocean are already taking place.

Above image shows that, on July 6, 2015, high methane levels show up north of Greenland (yellow oval). This could be a result of the heavy melting that is taking place on Greenland, exposing methane hydrates contained in the ice there. Hydrate destabilization on Greenland is discussed as feedback#21 at Feedbacks in the Arctic. Loss of ice mass on Greenland has fallen dramatically over the years and looks set to get even worse, as illustrated by the image below.

Dramatic ice mass loss on Greenland looks set to get even worse. See also discussion at the Controversy page.

Over the next few months, waters in the Arctic Ocean can be expected to further warm up and sea ice to further decline, all making that the situation can only be expected to worsen.
The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan.

Sea surface temperatures in the Arctic as at July 7, 2015. http://arctic-news.blogspot.com/2015/07/fracturing-of-the-jet-stream.html
Posted by Sam Carana on Wednesday, July 8, 2015

Persistently High Methane Concentrations over Beaufort Sea

Persistently High Methane Concentrations over Beaufort Sea

anomaly Arctic Beaufort Sea Bering Strait methane Oc ean sea surface temperatures SST temperature

Unknown 8/19/2014 Add Comment

High methane concentrations have been showing up over Beaufort Sea over the past few days, as shown on the image below. This follows the recent high methane concentrations over the East Siberian Sea.

The persistent character of these very high methane concentrations over the Arctic Ocean indicates that methane has started to erupt from clathrates under the seabed, triggered by very warm water reaching the bottom of the Arctic Ocean.

Methane eruptions from hydrates in sediments under the Arctic Ocean helped mean methane levels reach new records, with mean global methane readings as high as 1835 parts per billion recorded at several altitudes on August 17, 2014.

The very high sea surface temperature anomalies that show up on above image give an idea of the inflow of warm water from the Pacific Ocean through the Bering Strait. This is further highlighted by the combination image below.

[ click on image to enlarge ]

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

Post by Sam Carana.