18 January 2010

NASA and the case of the incredible falling satellite

Well, it's been explained that Lindzen and Choi's July 2009 paper On the Determination of Climate Feedbacks was wrong because apparently the ERBE 2 satellite decayed in orbit from 1987 to 1993. Who would have known? NASA didn't according to them until 2006. Surprise, surprise the sudden realisation of the error just so happens to accentuate the runaway feedback postulated by the IPCC.  See, if the satellite gets closer to earth it measures more outgoing infra red heat radiation and so inflates the values measured requiring an "adjustment".  This "adjustment" cleverly detracts from the outgoing radiation as measured by Lindzen and Choi and so enhances the notion that all that nasty CO2 is trapping heat down here on earth and not escaping into outer space.
The above graph shows how NASA's whoopsy means that much less longwave (heat) radiation is escaping the earth and therefore staying here on earth to warm us.  Edition 2 is original data, edition 3 is the new "value added" data from NASA to explain to us that global warming is real.  Yes, I'm afraid the greenhouse effect is quite operational and ready to destroy planet earth...

It was raised by melty on Andrew Revkins Dotearth blog.  He gave these links: 1, 2, 3.

There are two main objections. One explored by Roy Spencer on the statistical method used to draw averages.  The second is that the satellite orbit decayed (link above).  It's not for me to judge the statistical merits of averaging the data.  But I find that the claim that the ERBE 2 satellite decayed in orbit without anyone knowing to be implausible. 

From NASA:

"As the altitude dropped over the 15-yr period, the Nonscanner WFOV instrument recorded a small steady increase in satellite altitude fluxes....It was recently discovered that the altitude correction was disabled in the case of a near-circular orbit and therefore did not apply to correct the average spacecraft altitude change that occurred later in the extended ERBS mission. The main effect of this altitude change is a small increase (0.6%) in both TOA outgoing longwave (LW) radiation and reflected shortwave (SW) radiation over the 15-yr period."

So, the algorithm didn't take the decay into account - seems completely unlikely, but what's more unlikely is that the decay itself wouldn't have been noticed earlier.  How could they not know the satellite was moving when altitude is a fundamental parameter of satellite navigation?  If the altitude decreased it would have to be matched by an increase in orbital velocity to compensate for the increased gravitational attraction.

Surely NASA is aware of these issues.  How much of a fool do they take us for?  Navigation must record every relevant parameter and beam them back to base.  They must have been aware of the decay in orbit.

Update 22 January 2009:

Using this orbit calulator the increase in tangential velocity required for a fall from 611 to 590km is 11.39 metres per second.

This extra velocity can be provided by the fall itself however it is complicated by the presence of a very slight atmosphere at that altitude.  This will combine with gravity to decay the orbit and eventually bring the satellite crashing down to earth.

At 590 km the atmosphere will be e^(590/7) = 2.484exp-37 bars.  This is 2.484exp-32 pascals.

1 comment:

  1. Excellent analysis, thanks for posting.

    ~ Smokey