Watts Up With That?

Recently we’ve been discussing products from the AIRS satellite instrument (Atmospheric InfraRed Sounder) onboard the Aqua satellite. There has been quite a bit of interest in this because unlike the satellite temperature record that goes back to 1979, until now we have not had a complementary satellite derived CO2 record. We are about to have one, and much more.

Click image to see a slide show with this graphic in it (PDF)

I wrote to the AIRS team to inquire about when the satellite data on CO2, and other relevant products might be made public. All that has been released so far are occasional snippets of data and imagery, such as the short slide show above.

Here is the response I got from them:

Thank you for your interest in the AIRS CO2 data product.

We are still in the validation phase in developing this new product.
It will be part of the Version 6 data release, but for now those of us
working on it are intensively validating our results using in situ
measurements by aircraft and upward looking fourier transform IR
spectrometers (TCCON network and others).

The AIRS CO2 product is for the mid-troposphere. For quite some time
it was accepted theory that CO2 in the free troposphere is
“well-mixed”, i.e., the difference that might be seen at that altitude
would be a fraction of a part per million (ppmv). Models, which
ingest surface fluxes from known sources, have long predicted a smooth
(small)variation with latitude, with steadily diminishing CO2 as you
move farther South. We have a “two-planet” planet – land in the
Northern Hemisphere and ocean in the Southern Hemisphere. Synoptic
weather in the NH can be seen to control the distribution of CO2 in
the free troposphere. The SH large-scale action is mostly zonal.

Since our results are at variance with what is commonly accepted by he
scientific community, we must work especially hard to validate them.
We have just had a paper accepted by Geophysical Research Letters that
will be published in 6-8 weeks, and are preparing a validation paper.

We have global CO2 retrievals (day and night, over ocean and land, for
clear and cloudy scenes) spanning the time period from Sept 2002 to
the present. Those data will be released as we satisfactorily
validate them.

I suggest you Google “Carbon Tracker” for some interesting maps
generated using model atmospheres and data for CO2 sources. It shows
the CO2 weather in the lowest part of the atmosphere.

The big picture is that CO2 sources and sinks are in the planetary
boundary layer. Global circulation of CO2 occurs in the free
troposphere. Thus, PBL is local whereas free troposphere is
international.

———-
AIRS Team

With the suggestion of using the Google “Carbon tracker”, some readers might look at this response as a “dodge”. I don’t see it that way at all. Why? Because they are actively engaged in proving the instrument by doing a series of aircraft based measurements to validate the data the instrument on the spacecraft is seeing.

For example, read this paper from them:

First Satellite Remote Sounding of the Global Mid-Tropospheric CO2

These graphics show how hard they are working to validate the data from in situ measurements using airborne flask samples sent to a lab spectrometer: Read the rest of this entry »