“Well mixed” Carbon Dioxide Part 2: Sources and Sinks

Following from Part 1 (North vs South), this post looks at current sources and sinks for CO2.

Here are some images of surface CO2 concentration for today (June 26 in Australia) from nullschool.

Darker areas show lower CO2, lighter areas are higher.  I recommend the nullschool site!

Europe:

The industrialised Ruhr valley appears to have the highest CO2 concentration.  Paris Berlin and London are difficult to identify however.

South America (Argentina):

The high concentration appears to be from Buenos Aires- perhaps the satellite image of the CO2 is 200 km off target?

China, Korea, and Japan:

The highest concentration appears to be close to Japan’s larger cities.  Eastern China, including Shanghai and Beijing, is around 402ppm.

Southern Africa:

Kinshasa and Johannesburg are close to the high concentrations, but dry season fires could also be the cause.

Indochina:

Oddly, the high concentration is to the south west and west of Hanoi in a rural region.

USA:

A large part of the USA seems to be one vast carbon sink at the moment.  New York and Chicago areas could be associated with some higher CO2, and there are those two areas in California, one of which I identified as Los Angeles in the previous post.  Now I’m not so sure.  More later.

Kamchatka yesterday:

And today:

The Kamchatka Peninsula features many active volcanoes and that’s what I think we are seeing here.  Yesterday afternoon the concentration peaked at 509ppm and today is down a lot but the “hot spots” are still distinct.

Australia:

Again inland eastern Australia is a carbon sink with large areas under 390ppm.  Melbourne may be the cause of a 408ppm area, but where is Sydney? Brisbane? Perth? Adelaide?

Southern California:

Note San Francisco does not appear to have over high CO2.  One of the high areas is indeed over the Los Angeles area, but the other is in the mountains to the north:  Kern County to be precise, where a bushfire has broken out.  The other ‘haze’ appears to be from the Santa Barbara fire.  See this map of fire locations.

It seems to me that it is hard to identify strong sources of CO2 associated with the world’s large cities and industrial areas.  However, it is the weekend, so perhaps this will change during the coming week.  We shall see.

On the other hand, very strong sources of CO2 can be traced to volcanoes and bushfires, and also decaying vegetation in the dry season.  Sinks as we have seen are clearly associated with rapidly growing crops, grasslands, and forests.

And today the Equatorial Pacific sink appears to match the cooler water being pushed westwards by the strengthening trade winds.  See for yourself at nullschool.

I will continue to monitor these sources and sinks as the seasons progress.

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“Well Mixed” Carbon Dioxide Part 1: North vs South

This post addresses the question: How “well mixed” is carbon dioxide in Earth’s atmosphere?

Here are some images of surface CO2 concentration for yesterday (June 23 in Australia) from nullschool.

Darker areas show lower CO2, lighter areas are higher.  Very nifty.

Fig. 1:  Northern Hemisphere CO2:

The dark areas with low CO2 are the northern forests and farm land, now growing strongly.  Note the cold, dry North Pole has high CO2.

Fig. 2: Southern Hemisphere:

Cold, dry Antarctica has high CO2, whereas a broad area of inland Eastern Australia, which recently has had some decent rain, has lower CO2.

Fig. 3:The East:

Fig. 4: The West:

The contrast in South America is interesting!

Fig. 5:  The Pacific (a hemisphere on its own):

Note the northern Pacific (north of 5 degrees north) is predominantly above 400ppm, while a broad band from about 5 degrees north to about 20 degrees south is about 395ppm.

Note also a tiny area in southern California pluming into the Pacific with a very high reading of 437ppm.  Los Angeles.

The IPCC and climate scientists generally refer to data from Mauna Loa in Hawaii.  The CSIRO in Australia also measures CO2 concentration at Cape Grim in Tasmania.  The next few charts compare Cape Grim data with that of Mauna Loa.

Fig. 6:  Comparison Mauna Loa and Cape Grim CO2 1976-2016

Here is a closer look at the most recent years:

Fig. 7:  Comparison Mauna Loa and Cape Grim CO2 2010-2016

There are several points to note:

Cape Grim CO2 concentration is increasing at the same rate as Mauna Loa.

There are massive swings in Mauna Loa’s data, while Cape Grim fluctuates gently.  In 2016 there was no “bottom” at all.

Cape Grim is much lower- in fact the annual high points are at about the same level as Mauna Loa’s low points.

The records are out of phase.  Mauna Loa peaks in northern spring and bottoms out in northern autumn, whereas Cape Grim peaks in southern Spring and “bottoms out” in southern Summer.

Now I look at the seasonal change in concentration.

Fig. 8:  Seasonal rises and falls at Cape Grim

Fig. 9:  Seasonal rises and falls at Mauna Loa

Notice at Mauna Loa the annual rises from bottoms to peaks are getting larger, but so are the falls, while at Cape Grim there are slower rises but falls are lessening.  I compare rises and falls separately in the next two plots:

Fig. 10:  Seasonal increases compared

Fig. 11:  Seasonal decreases compared

I would interpret this as follows:

As emissions increase, carbon dioxide sinks (mainly growing plants) consume more and more.  However this is not enough to remove all of the additional CO2, so each year the growth continues.

In the Northern Hemisphere, sinks completely overwhelm sources in summer.

In the Southern Hemisphere there is a much less pronounced annual peak in spring, perhaps because there is less land, especially from 30 to 70 degrees south, and much of it is dry.  CO2 concentration has increased to the level at which vegetation CO2 sinks are becoming unable to make an impression (at least in El Nino years).

The bulk of CO2 increase originates in the Northern Hemisphere.  In northern winter as the Inter-Tropical Convergence Zone shifts south of the Equator, the north east trade winds move CO2 to the Southern Hemisphere where it is gradually mixed.  In northern summer (now), the ITCZ is north of the Equator, and the image of the Pacific in Figure 5 above shows trade winds crossing the Equator with less CO2 concentration than just to the north.

We know there are large changes to CO2 concentration following ENSO events.  This may be due to the changing circulation over the tropical Pacific as more or less CO2 is shifted by trade winds north and south. Or perhaps changing ocean currents, upwelling, or downwelling warm or cool large ocean areas.

Drier areas of the globe (deserts, Polar regions) have higher CO2 concentration than wetter areas.  Few growing plants, more CO2.  More and greener plants, less CO2.

And finally: CO2 is not “well mixed” globally, and an average concentration is as elusive as an average temperature.  There is a range of concentrations between areas of sources and sinks approaching 80ppm.

The Pause Update: May 2016

The complete UAH v6.0 data for May were released on today.  I present all the graphs for various regions, and as well summaries for easier comparison.  The Pause still refuses to go away, despite all expectations.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 6 months long- 450 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are May 2016.

 [CLICK ON IMAGES TO ENLARGE]

Globe:

The 12 month mean to May 2016 is +0.46C.  The Pause is still an embarrassing reality! However, it may “disappear” soon with a small positive trend.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies, which shows that The Pause is over by my rather strict criterion:

+0.27C/100 years since December 1997- not exactly alarming.  The Pause will return sooner with monthly anomalies than 12 month means of course.

Northern Hemisphere:

The Northern Hemisphere Pause has “disappeared” as expected.  Note the not very alarming warming of 0.14+/- 0.1C per 100 years for half the record compared with 1.35C for the whole period.

Southern Hemisphere:

The pause has shortened by one month.  For well over half the record the Southern Hemisphere has zero trend.

Tropics:

The Pause has shortened dramatically with the El Nino influence, but is still over half the record.

Tropical Oceans:

The Pause has shortened by 19 months.

Northern Extra Tropics:

The Pause by this criterion has ended in this region, however note that the slope since 1998 is +0.23 +/- 0.1C per 100 years compared with +1.58C for the whole period.  That’s still embarassingly slow warming.

Southern Extra Tropics:

The Pause has lengthened by another month.

Northern Polar:

The Pause has decreased by 2 months.

Southern Polar:

The South Polar region has been cooling for the entire record.

USA 49 States:

No change.

Australia:

The Australian Pause has lengthened rapidly.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

Note that the Pause has ended by my criteria in the Northern Extra Tropics and the Northern Hemisphere, but apart from the North Polar region, all other regions have a Pause of 18 years 9 months or longer- well over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

The only region to show strong warming for this period (18 years) is the North Polar region: the Northern Extra Tropics and the Northern Hemisphere have very mild warming but all other regions are Paused or cooling. In fact “global” warming since June 1998 is limited to that part of the globe north of 20 degrees North.  And the lower troposphere over Australia has had strong cooling for the past 18 years.

12 month means will continue to grow for the next few months, so the Pause as  here defined may disappear shortly, and may not reappear until early 2018.  The impact of the coming La Nina will be worth watching.  Unless temperatures reset at a new, higher level and continue rising, very low trends will remain.