Temperature Rise

Record High Temperatures in 2014

The year 2014 was the warmest year across global land and ocean surfaces since records began in 1880, writes NOAA, adding the graph below. This graph illustrates that temperatures have risen even when focusing on a relatively short recent period with a linear trendline starting in 1998, which was an El Niño year, whereas 2014 wasn't.

Source: NOAA Global Analysis - Annual 2014

Most Appropriate Trendline

While the purple 1998-2014 trendline serves the useful purpose of dispelling the myth that warming had halted recently, it isn't the most appropriate trendline, since extending this trendline backward to 1880 would leave too many data too remote from the trendline, as is further illustrated by the animated image below.

What about the blue linear trendline that is based on data for all the years from 1880 to 2014? By that same logic, the appropriateness of this trendline must also be questioned. Temperatures in recent years have been well above this trendline. A polynomial trendline seems a much better fit, as illustrated by the image below.

Above image also extends the trendline forward, showing that 2 degrees Celsius warming looks set to be exceeded in 2038, based on the same data.

And while this is a frightening scenario, the picture may well be much too optimistic, because the heat is felt most in the Arctic Ocean, the very location where some of the most terrifying feedbacks are accelerating local warming, as further explained below.

Feedbacks in the Arctic

As NOAA writes, much of the record warmth for the globe can be attributed to record warmth in the global oceans, which reached the highest temperature among all years in the 1880–2014 record.

As above image shows, ocean heat reached a record high in 2014. In other words, it was ocean heat that pushed the combined ocean and land temperature to a record high. Anomalies were especially high in the Arctic Ocean, as illustrated by the image below.

Waters close to Svalbard reached temperatures as high as 63.5°F (17.5°C) on September 1, 2014 (green circle). Note that the image below shows sea surface temperatures only. At greater depths (say about 300 m), the Gulf Stream is pushing even warmer water through the Greenland Sea than temperatures at the sea surface.

Since the passage west of Svalbard is rather shallow, a lot of this very warm water comes to the surface at that spot, resulting in an anomaly of 11.9°C. The high sea surface temperatures west of Svalbard thus show that the Gulf Stream can carry very warm water (warmer than 17°C) at greater depths and is pushing this underneath the sea ice north of Svalbard.

Planetary energy imbalance (0.6 W/m2) equals the amount of energy in exploding 400,000 Hiroshima atomic bombs per day, 365 days/year (J. Hansen, 16 Jan. 2015).

Planetary imbalance now is 0.6 W/m². This has made the rise in ocean heat (up to 2000 m deep) more than double over the past decade. Data from 2005 through to 2014 contain a polynomial trendline that points at a similar rise by 2017, followed by an even steeper rise.

What could cause such non-linear rise?

The answer is feedbacks. Arctic snow and ice loss alone may well cause over 2 W/m² warming, warns Prof. Peter Wadhams. Another such feedback is methane erupting from the ocean floor, as methane hydrates get destabilized due to higher temperatures.

As illustrated by the graph below, most of this excess heat is absorbed by oceans and ice. Some of the heat is consumed by the process of melting ice into water, and 93.4% of this excess heat ends up warming up the oceans.

Graph by Sceptical Science based on study by by Nuccitelli et al.

As the Gulf Stream keeps carrying ever warmer water into the Arctic Ocean, methane gets released in large quantities, as illustrated in the images below showing high methane levels over the East Siberian Arctic Shelf (red oval left) and over Baffin Bay (red oval right) with concentrations as high as 2619 ppb.

click on image to enlarge

The images below show methane levels on Jan 25 (top), and Jan 26, 2015 (bottom).

The threat is that huge amounts of methane will erupt from the seafloor of the Arctic Ocean over the coming decades, as illustrated by the image below.

For more on this image, see this post and this page.

Demise of the Arctic sea ice and snow cover is another terrifying feedback. The image below features a NASA/Goddard Space Flight Center Scientific Visualization Studio screenshot showing decline of multi-year Arctic sea ice area over the years.

Below is a video by Nick Breeze who interviews Professor Peter Wadhams on multi-year Arctic sea ice.

An exponential trendline based on sea ice volume observations shows that sea ice looks set to disappear in 2019, while disappearance in 2015 is within the margins of a 5% confidence interval, reflecting natural variability. In other words, extreme weather events could cause Arctic sea ice to collapse as early as 2015, with the resulting albedo changes further contributing to the acceleration of warming in the Arctic and causing further methane eruptions from the seafloor of the Arctic Ocean.

click on image to enlarge

As the Arctic continues to warm, the temperature difference between the equator and the Arctic declines, resulting in changes to the jet streams and polar vortex.

One such change is a slowing down of the speed at which the jet streams and polar vortex circumnavigate the globe, as discussed in a recent post.

The image on the right shows that the jet streams on the Northern Hemisphere reached speeds as high as 410 km/h (255 miles per hour) on January 9, 2015. Also note the jet stream crossing the Arctic Ocean, rather than staying between 50 and 60 degrees latitude, where the polar jet streams used to be.

The image below shows winds on January 11, 2015, at several altitudes, i.e. at 10 hPa | ~26,500 m (16.5 mile), high in stratosphere, polar vortex (left, at 250 hPa | ~10,500 m (6.5 mile), jet stream (center), and at 700 hPa | ~3,500 m (2.2 mile), high in planetary boundary layer.

click on image to enlarge

As a result, extreme weather events such as heatwaves and storms can be expected to occur with greater frequency and intensity, as also discussed in a recent post. Heatwaves can heat up the water in the North Atlantic, as it flows into the Arctic Ocean, driven by the Gulf Stream, while heatwaves can also warm up the water in rivers that end up in the Arctic Ocean. Heatwaves can also hit the sea ice in the Arctic Ocean directly, causing rapid sea ice melting, while storms can make the ice break up and be driven out of the Arctic ocean,

Demise of the sea ice and snow cover in the Arctic results in further acceleration of warming, not only due to less sunlight getting reflected back into space, but also due to loss of the buffer that currently absorbs huge amounts of heat as it melts in summer. With the demise of this latent heat buffer, more sunlight will instead go into heating up the water of the Arctic Ocean. For more on the latter, see the page on latent heat.

Above image illustrates some of the self-reinforcing feedback loops that have been highlighted in this and earlier posts. Further feedbacks are pictured in the image below.

from the Feedbacks page

Runaway Global Warming

Above feedbacks are already pushing the temperature rise in the Arctic through the 2°C guardrail.

Based on existing temperature data, global warming on land looks set to exceed 2°C (3.6°CF) warming by the year 2034, but methane eruptions from the seafloor of the Arctic Ocean could push up global temperature rise even faster, in a runaway global warming scenario.

click to enlarge image

This raises the specter of human extinction. With no action taken, there appears to be a 55% risk that humans will be extinct by the year 2045, while taking little action will only postpone near-term human extinction by a few years. Only with rapid implementation of comprehensive and effective action may we be able to avoid this fate.

Comprehensive and Effective Action

In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog at climateplan.blogspot.com and as illustrated by the image below.

Record June–August Global Ocean Surface Temperature

August 2014 record high land and ocean temperature

The combined average temperature across global land and ocean surfaces for August 2014 was record high for the month, at 0.75°C (1.35°F) above the 20th century average of 15.6°C (60.1°F).

June–August 2014 record high land and ocean temperature

June–August 2014, at 0.71°C (1.28°F) higher than the 20th century average, was the warmest such period across global land and ocean surfaces since record keeping began in 1880.

August 2014 record high sea surface temperature

The August global sea surface temperature (SST) was 0.65°C (1.17°F) above the 20th century average of 16.4°C (61.4°F). This record high departure from average not only beats the previous August record set in 2005 by 0.08°C (0.14°F), but also beats the previous all-time record set just two months ago in June 2014 by 0.03°C (0.05°F).

June–August 2014 record high sea surface temperature

The June–August global ocean surface temperature was 0.63°C (1.13°F) above the 20th century average, the highest on record for June–August. This beats the previous record set in 2009 by 0.04°C (0.07°F).

John Davies comments: 

This was the warmest August on record, primarily due to very high Sea Surface Temperatures in the Northern Hemisphere.

There is no El Nino event in this period, but some sort of event - hopefully an event not a climate shift - is taking place. If this is an event, the situation will become more normal when it ends, which will be in less than a years time at worst. If it is a climate shift, we are in desperate trouble, though I think it is an event.

It is worth noting that these very high Sea Surface Temperatures are likely to lead to high land temperatures soon, as normally land temperatures in the Northern hemisphere can be expected to exceed Sea Surface Temperatures.

The drought affecting California and the whole of the west of North America, Central America, and large parts of the Brazilian rainforest, though preceding this event was almost certainly down to changes which started before this event but ultimately caused it.

Despite the record high combined average temperature across global land and ocean surfaces for August, the global economy will continue as normal and no specific action can be expected to be taken to curb emissions. This will change, if global temperatures continue to rise. Temperatures are high enough to cause global concern, however. More later.

Note: NOAA's most recent (Sep 4, 2014) prediction puts the chance of El Niño at 60-65% during the Northern Hemisphere fall and winter.

Sea surface temperatures (SST) can be expected to remain high in the Arctic Ocean, as SST anomalies are high in the North Atlantic (+1.65°C, image left) and high temperatures are forecast over the Arctic for at least the next seven days (anomalies as high as +2.87°C, image right). For a comparison with October 3 temperatures, see this earlier post.

Additionally, an increasing amount of heat has been going into the deeper parts of the ocean, and the Gulf Stream will for month to come continue to transport water into the Arctic Ocean, and this water will be warmer than the water already there, threatening to unleash ever larger eruptions of methane from the seafloor of the Arctic Ocean, as discussed in this earlier post.

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


References

- NOAA National Climatic Data Center, State of the Climate: Global Analysis for August 2014.
http://www.ncdc.noaa.gov/sotc/global/2014/8

- EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION, issued by:
Climate Prediction Center/NCEP/NWS and the International Research Institute for Climate and Society, 4 September 2014
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

- ENSO: Recent Evolution, Current Status and Predictions
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

- ClimateReanalyzer.org
http://climatereanalyzer.org

Post by Sam Carana.

The Threat of Storms Wreaking Havoc in the Arctic Ocean

Arctic sea ice extent is close to a record low for the time of the year, as the image below shows.

Furthermore, the current decline in sea ice extent is much steeper than it used to be for this time of the year, raising the specter of sea ice hitting an absolute record low later this year. Moreover, a total collapse of sea ice may occur if storms continue to develop that push the remaining ice out of the Arctic Ocean into the Atlantic Ocean.

The threat posed by storms is illustrated by the track projected to be followed by Hurricane Arthur (above NOAA image, July 4), renamed as Post-Tropical Cyclone Arthur (NOAA image below, July 5).

The path followed by Arthur is influenced by the current shape of the jet stream. As the animation below illustrates, the jet stream looks set to prevent Hurrican Arthur from moving to the east and instead make it move into the Labrador Sea to the west of Greenland and - partly due to the high mountains on Greenland - continue to wreak havoc in Baffin Bay further north.

[ Note: this animation is a 1.87 MB file that may take some time to fully load ]

As described in an earlier post, post-tropical cyclone Leslie made landfall with hurricane-force winds in Newfoundland in September 2012. The large extratropical low pressure system continued to move rapidly northeastward across eastern Newfoundland at a forward speed of near 45 kt, and merged with a much larger extratropical low over the Labrador Sea.

Recent research by NOAA-affiliated scientists suggests that - over the years - the latitude where hurricanes, typhoons, and cyclones reach their maximum intensity on the Northern Hemisphere has shifted closer to the North Pole.

Such storms can bring lots of heat and moisture into the Arctic, and they can also increase the height of waves. All this can have devastating impact on the sea ice. The many ways in which storms can increase the dangerous situation in the Arctic is described in the post Feedbacks in the Arctic.

Last month, the June heat record broke in Greenland. Very high temperatures are currently recorded all over North America, as the image below shows.

Furthermore, sea surface temperature anomalies in the Arctic are currently very high, as the image below shows.

Additionally, the sea ice is currently very thin, as shown by the Naval Research Laboratory animation below.

The above animation further shows that there now is very little sea ice left in Baffin Bay, making it easier for storms to cause very high waves that could enter the Arctic Ocean and break the sea ice north of Greenland and Canada.

Arctic sea ice volume minimum is typically reached around halfway into September. This is still months away, but the prospect of an El Niño event striking this year now is 90%, according to predictions by the European Centre for Medium-range Weather Forecasts.

All this combines into a growing threat that hydrates contained in sediments will destabilize and that huge quantities of methane will be released abruptly from the seafloor of the Arctic Ocean. The risk that this will eventuate is intolerable and calls for parallel lines of action as pictured in the image below.

Climate Plan, July 7, 2014 version, as discussed at this Climate Plan post and at the Climate Plan blog

Related

- Storm enters Arctic region
arctic-news.blogspot.com/2012/09/storm-enters-arctic-region.html

- Huge cyclone batters Arctic sea ice
arctic-news.blogspot.com/2012/08/huge-cyclone-batters-arctic-sea-ice.html

- Hurricane Sandy moving inland
http://arctic-news.blogspot.com/2012/10/hurricane-sandy-moving-inland.html

- Feedbacks in the Arctic
http://arctic-news.blogspot.com/2014/03/feedbacks-in-the-artcic.html

Post by Sam Carana.

CO2 growth highest on record

Despite many promises, global emissions of carbon dioxide (CO₂) continue to grow.

NOAA figures show that 2013 CO₂ level growth was the highest ever recorded, i.e. 2.95 ppm.

The EPA expects U.S. 2013 energy-related CO₂ emissions to be 2% higher than in 2012.

The UC San Diego image below shows CO₂ levels in the atmosphere over the past two years.

Back in September 2013, John Davies warned: “The world is probably at the start of a Runaway Greenhouse Event which will end most human life on Earth before 2040. This will occur because of a massive and rapid increase in the carbon dioxide concentration in the air which has just accelerated significantly. The increasing Greenhouse Gas concentration, the gases which cause Global Warming, will very soon cause a rapid warming of the global climate and a chaotic climate.”

The post featured a graph with a 4th-order polynomial trendline pointing at some 7.5 ppm CO₂ annual growth by 2040. While many welcomed the warning contained in the graph, some argued against using higher-order polynomial trendlines. So, for those who don't feel comfortable with a 4th-order polynomial trendline, the graph below adds both a linear trendline and a 3rd-order polynomial trendline.

The 3rd-order polynomial trendline, based on the recent data, points at CO₂ annual growth of some 7 ppm by 2040, justifying the warning sounded by the 2013 graph.

And what do the recent data say, when a 4th-order polynomial trendline is applied? As the image below shows, they show an even steeper rise, reaching 7 ppm growth per year as early as 2030.

As many posts at this blog have warned, rapid growth in greenhouse gases and numerous feedbacks are threatening to push Earth into runaway global warming. This calls for comprehensive and effective action to - among other things - reduce atmospheric CO₂ levels back to 280 ppm, as illustrated by the image below and as further discussed at the Climate Plan blog.

As continental U.S. freezes, Alaska gets record high temperatures

While much of the continental United States endured several cold snaps in January 2014, record-breaking warmth gripped Alaska. Spring-like conditions set rivers rising and avalanches tumbling. NASA Eartobservatory illustrates the above words with the two images below.

Above map depicts land surface temperature anomalies in Alaska for January 23–30, 2014. Based on data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, the map shows how 2014 temperatures compared to the 2001–2010 average for the same week. Areas with warmer than average temperatures are shown in red; near-normal temperatures are white; and areas that were cooler than the base period are blue. Gray indicates oceans or areas where clouds blocked the satellite from collecting usable data.

A persistent ridge of high pressure off the Pacific Coast fueled the warm spell, shunting warm air and rainstorms to Alaska instead of California, where they normally end up. The last half of January was one of the warmest winter periods in Alaska’s history, with temperatures as much as 40°F (22°C) above normal on some days in the central and western portions of the state, according to Weather Underground’s Christopher Bart. The all-time warmest January temperature ever observed in Alaska was tied on January 27 when the temperature peaked at 62°F (16.7°C) at Port Alsworth. Numerous other locations—including Nome, Denali Park Headquarters, Palmer, Homer, Alyseka, Seward, Talkeetna, and Kotzebue—all set January records.

The combination of heat and rain has caused Alaska’s rivers to swell and brighten with sediment, creating satellite views reminiscent of spring and summer runoff. On January 25, 2014, the Aqua satellite collected this image of sediment flowing into the Gulf of Alaska from numerous rivers along the state’s southeastern coast.

All of the heat, moisture, and melting snow has elevated the risk of avalanches. A series of extremely large avalanches in late January sent snow and debris crashing onto the Richardson Highway, blocking the road and cutting the port town of Valdez off from highway access. The avalanches dumped a mound of snow 100 feet (30 meters) tall and up to 1,500 feet (460 meters) long on the highway.

Below are two videos with forecasts for the period from February 4, 2014, to February 11, 2014. The top video shows temperature forecasts and the bottom video shows temperature anomaly forecasts.

No Planet B

By Andrew Glikson
Earth and paleo-climate science, Australian National University
IPCC Reviewer

The global CO₂cide 400 ppm milestone

Figure 1. Mouna Loa Month ending May 1, 2013, from:  http://keelingcurve.ucsd.edu/

Figure 2. CO2 levels over the past 800,000,000 years, from:  http://keelingcurve.ucsd.edu/

Figure 3. Mouna Loa CO2 level 29 April, 2013 keelingcurve.ucsd.edu/ 

On the 29 April, 2013, NOAA recorded a CO2 level of 399.50 ppm, while some readings in April 2013 exceeded 400 ppm (Figures 1, 2 and 3, from: http://keelingcurve.ucsd.edu/), signifying a return to atmosphere conditions of the Pliocene (5.2 – 2.6 million years ago).

This followed a rise from 394.45 ppm to 397.34 ppm (March 2012 – 2013) at a rate of 2.89 ppm per year, unprecedented in the recorded geological history of the last 65 million years (Figure 4).

Pliocene temperatures - about 2 – 3 degrees C warmer than pre-industrial temperatures, resulted in an intense hydrological cycle, ensuing in extensive rain forests, lush savannas (now occupied by deserts), small ice caps and sea levels about 25 meters higher than at present (Figure 5).

Figure 4. CO2 rise rates vs Temperature rise rates for the Cainozoic (65 Ma to the present). 

Figure 5. The Pliocene Earth compared to the modern Earth 
http://www.giss.nasa.gov/research/features/199704_pliocene/page2.html
Note (1) the lower albedo in the Pliocene poles signifying the smaller
size of the ice caps and (2) the high albedo of the modern Sahara and
Gobi deserts signifying the a larger extent of Holocene deserts.

Life abounded during the Pliocene. However, regular river flow conditions such as allowed cultivation and along river valleys since about 7000 years ago, and temperate Mediterraneantype climates allowing extensive farming, could hardly exist under the intense hydrological cycle and heat wave conditions of the Pliocene.

Gradual to intermittent advents of Pleistocene ice ages over the last 2 million years allowed many species to adapt to changing conditions. Abrupt warming events, such as the DansgaardOeschger cycles, occurred during glacial periods (Figure 4). Extreme shifts in state of the climate exceed the rate to which many species can adapt.

The basic laws of atmospheric physics and chemistry and the behavior of past atmospheres indicate changes in the level of atmospheric greenhouse gases constitute a key parameter determining the current trend of the terrestrial climate. Concomitant rates of SO2 release, mainly from coal burning, have regulated changes in temperature.

Increases in SO2 release about 1950 and 2001 are responsible for slow-down of temperature rise (Figure 6).

Figure 6. Comparison of the rate of warming and variations in SO2 levels.
Temperature from GISS/NASA (http://data.giss.nasa.gov/gistemp/); SO2 levels after
http://www.atmos-chemphys.net/11/1101/2011/acp-11-1101-2011.html.
          Note the overlap between slow-down of overall temperature rise rates and increase in SO2 emissions
(http://www.atmos-chem-phys.net/11/1101/2011/acp-11-1101-2011.html) around 1950 and 2001. 

The current CO2 ppm/year rise rate of ~3 ppm/year surpasses any recorded since the last 65 million years of Earth history. High CO2 and temperature rises occurred about ~55 Ma ago. At that stage release of methane drove a CO2 rise of near-1800 ppm and a temperature rise of about 5 degrees C over 10,000 years, namely a rate of 0.18 ppm/year and 0.0005 degrees C/year (Zachos et al. 2008; http://www.nature.com/nature/journal/v451/n7176/full/nature06588.html).

The K-T asteroid impact of 65 Ma-ago resulted in a rise of more than 2000 ppm CO2 within about 10,000 years, namely ~0.2 ppm /year. This triggered a temperature rise of about 7.5 degrees C, namely 0.00075 degrees C per year (Beerling et al. 2002 http://www.pnas.org/content/99/12/7836.full) (Figure 4). Calculations by these authors suggest a release of approximately 4500 billion tons of carbon from impacted carbonates and shale, ignited bushfires and ocean warming.

The consequences of the current rise in greenhouse gases is manifested by enhancement of the hydrological cycle, with ensuing floods and of heat waves (http://www.ipcc-wg2.gov/SREX/ ; http://www.aph.gov.au/Parliamentary_Business/Committees/Senate_Committees?url=ec_ctte/extreme_weather/index.htm).

Open-ended combustion of known fossil fuel reserves (Figure 7) would lead to atmospheric CO2 levels of ~800 to 1000 ppm CO2, high degree to total melting of the polar ice caps, sea level rise on the scale of tens of meters and disruption of the biosphere on a scale analogous to recorded mass extinctions (http://www.astrobio.net/interview/2553/under-a-green-sky).

Figure 7. CO2 emissions by fossil fuels (1 ppm CO2 ~ 2.12 GtC). 
Alternative estimates of reserves and potentially recoverable resources are from EIA (2011) and GAC (2011).
We are headed toward 800 to 1,000+ ppm, which represents the near-certain destruction of modern civilization
as we know it -- as the recent scientific literature makes chillingly clear. 
(http://thinkprogress.org/climate/2012/01/28/413955/james-hansen-on-cowards/). 

Carbon emissions may be self-limiting. It is likely that, before atmospheric CO2 reach 500 ppm, disruption of fossil fuel-combusting systems by extreme weather events would result in reduction of emissions. On the other hand the extent to which amplifying feedback processes (methane release from permafrost and Arctic sediments, bushfires, warming oceans) would continue to add greenhouse gases to the atmosphere is uncertain.

Preoccupied with short-term economic forecast, daily A$ exchange rates, share market fluctuations and, sports results, with some exceptions (http://www.theage.com.au/national/greenhouse-gases-in-new-danger-zone-20130428-2imjm.html) the accelerating rate of atmospheric CO2 seems to hardly rate a mention on the pages of the global media.

There are few signs the extreme danger the terrestrial biosphere and the oceans are driving the global community to undertake the urgent large-scale measures required to attempt to arrest current trends.

In Australia the language has changed, from “the greatest moral issue of our generation” (http://www.youtube.com/watch?v=CqZvpRjGtGM) to hit-pocket controversy over a “carbon tax”, a meningless 5 percent reduction in local emissions which overlook the export of hundreds of million tons of coal, ending up in the same atmosphere.

There is no evidence the recent IPA celebration (http://www.crikey.com.au/2013/04/05/abbottbolt-rinehart-fawn-in-the-ipa-court-of-king-murdoch/), attended by the likely next prime minister, the world’s media moguls and mining magnates, as well as an archbishop, was concerned with the future of the Earth’s climate.

In professor Hans Joachim Schellnhuber’s words stated in Doha “overriding everything else the 1st Law of Humanity: Don’t kill your children!” (http://www.pik-potsdam.de/news/inshort/files/Schellnhuber-keynote-COP18-state-dinner-Doha.pdf).

There is no planet B.

Record Methane in Arctic early March 2013

The image below, produced by Dr. Leonid Yurganov, shows methane levels for the first ten days of March 2013.

Methane levels for this period are at record highs in the Barents and Norwegian Seas, i.e. the highest levels ever recorded by IASI, which is is short for Infrared Atmospheric Sounding Interferometer, a Fourier transform spectrometer on board the European EUMETSAT Metop satellite that has supplied data since 2007.

The record levels are indicated on the image below at the top right, while the geographical location of the four domains distinguished in the image are illustrated on the image further below.

The image at the top of this post displays average methane levels for the period March 1 to 10, 2013, at 600 mb. On individual days and on specific locations, methane levels could be much higher, as illustrated by the NOAA image below showing methane levels reaching a high of 2237 ppb on March 6, 2013, at 742 mb. The empty image further below is added to help distinguish land contours.

The earlier post Dramatic increase in methane in the Arctic in January 2013 showed that high methane levels lined up closely with the contours of land and sea ice. The same is the case for the record levels of methane in early March, as illustrated by the animation below.