VIDEO :: Methane Concentrations from HIPPO I
Watch and listen as Steve Wofsy, HIPPO Principal Investigator, explains the methane findings during HIPPO I.
Global Methane Concentrations
This panel of figures shows the observations from HIPPO, which is shown in this panel.
And three models - a European model over here, a Japanese model over here and an American model over there. What you have plotted here is latitude, this is southern hemisphere over there, this is northern hemisphere over here, and this is altitude. So it’s a slice right down the middle of the atmosphere, which is basically the main product of the HIPPO mission.
These lines that are drawn on the figures represent so called potential temperature, you can think of them as density. The air parcels can move along these lines without adding or subtracting any heat, so you tens to see concentrations of pollutants become uniform in uniform bands inside these contours. And that’s exactly what you see here in the observations.
You notice that there is more methane in the northern hemisphere than in the southern hemisphere, and there’s sort of a gradient there, and you notice that these things are laying up along the lines of constant potential temperature, until you get to the tropics and then they don’t respect potential temperature at all, we’ll get back to that in a minute.
If I go down here to the GOES Chem model, a Harvard model actually, using NASA assimilated winds. They do a pretty good job on representing where the sources are and how they get distributed throughout the northern hemisphere. They actually don’t do a particularly good job on the gradient between the northern hemisphere and southern hemisphere, and they’re quite a bit off on that.
If we look at the Japanese model, it’s actually doing pretty well on all those measures, so if there was a derby, I guess the Japanese model wins it!
Local Methane Concentrations
So this image shows cross sections of methane concentrations in the atmosphere that we observed during the first two flights of the first HIPPO deployment, starting in Broomfield, going through central Canada, so you can where we are going here through central Canada, coming to Anchorage, and then we fly up almost to the North Pole and come back again.
The little red splotches on here are sort of a color code that shows you where we hit very high levels of methane. And you can see that there are two such locations.
This one over here is in the fossil fuel extraction region of Canada where they are mining coal and gas, and such. And this one over here is from something else. And we’ll talk about this one in a minute.
So you can notice that during the winter time the emissions that come from the surface are held close to the surface, and that’s because the air near the surface is very cold and dense and just kind of sits there and traps the emissions. So it makes for a nice sort of way for us to record what is happening in terms of the emissions accumulating in the atmosphere, to see the build up near the source regions.
This stuff here is no big surprise when we look at the other pollutants that we measure on HIPPO, we see that they are associated with the industrial extraction activities.
This one over here is a little different. We see a lot of methane in the lower atmosphere, but we don’t see any other types of pollutants. And so this appears to be associated with methane being released from the sub-surface in the Arctic Ocean. We can’t really prove that, but it certainly has been a source of concern as the climate warms up and the surface ocean in the Arctic warms up we may see release of trapped methane that sits down in the shallow sediments.
It’s kind of hard to tell when you see methane in the atmosphere whether it’s coming from that process or maybe it’s coming from release from the oil fields and gas fields of Prudhoe Bay, which is right down here. But in fact, it looks like this material here is very much coming from non-extraction type of activity and so we think it could be due to this much talked about release of methane that’s trapped in the Arctic as the climate warms up.