Some Ideas For Future Reanalysis Efforts
John Lanzante
Current Limitations
- The LKS adjusted data are limited to 87 stations for the nominal time period of
1948-1997. The adjustment process is tedious and very time consuming, with a
subjective component. It is not practical to apply this methodology to other
stations or even to extend the existing ones beyond 1997. There is no other
proven, general-purpose method which can be applied to radiosonde station data. - It is very likely that LKS did not adjust enough (i.e., failed to adjust enough
stations/vertical levels) so that the spurious cooling bias is even larger than
estimated. This statement is supported by three independent pieces of evidence:- By design, LKS selected only the most obvious potential inhomogeneities
for consideration; more ambiguous cases were not scrutinized. - Even after homogeneity adjustment, the LKS radiosonde temperatures
have a non-trivial spurious cooling trend relative to the
Christy/Spencer MSU data. - The new Wentz et al. MSU temperature products have a considerably
larger warming trend than the comparable Christy/Spencer products.
- By design, LKS selected only the most obvious potential inhomogeneities
- In summary, current radiosonde temperature time series (LKS as well as
all other such products) are sub-standard both in their own right for
climate monitoring and for use as input to the next~ 50-year Reanalysis.