Explanatory note from Emmanuel Lellouch (29/11/96)
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This continuum model for Uranus accounts for the tropospheric CH4. It 
provides the best fit of the radiometric measurements that are summarized 
in Figure 5 of Conrath et al.'s chapter ("Thermal structure and energy 
balance of Uranus") of the "Uranus" book (1991, University of Arizona Press).

 In particular, the max brightness temperature (Tb) around 48 mu is 61.3 K, 
which nicely fits the measurements. There is a discrepancy with the 
radiometric measurements at 50-150 cm-1, but there the uncertainty is large 
(the plot below in this web page shows 1-sigma error bars).

Also included is the flux in Jy, for a 3.6" Uranus size, and compared to the
SWS measurements. The model underestimates the data by 20-25 % throughout,
except near 30 mu. The Tb as inferred from SWS is also given in this table.  
The maximum difference is a very large 2.7 K near 44 mu.

Concerning the accuracy of the model, it fits the earlier measurements 
accurately, but very poorly the SWS data, the question is to know
whether these earlier measurements should be regarded as more reliable than
SWS. There is the possibility of time variations - i.e.  Uranus now could be
indeed warmer than it was 10 years ago - but 2.7 K seems to be a lot, for a
disk average.

For the time being , it is conservative to adopt the difference
between SWS and this model as an indicator of the uncertainties. So, I
would say the model can be trusted within 20 %.