READ ME file for the v4.06.01 point release of CRU TS CLD (cloud cover)

CRU TS v4.06 was released on 26 May 2022. Not long after, users began
reporting irregular patterns in CLD, particularly in South America.

Upon investigation, it was found that new observations had been
assimilated without range confirmation; this resulted in maximum cloud
values (100%) in many more cases than would usually occur in that part
of the world.

We withdrew CRU TS v4.06 CLD on 16 June, corrected the assimilations,
and produced a revised 'point release' for CLD (v4.06.01) which should
be used instead of v4.06 CLD. No other variables were affected.

More stringent error exclusion (using the regression errors) has also
been introduced. This does not necessarily remove excessive values,
it eliminates uncertain ones (becasue they are synthesised from DTR
with a poor-performing regression).

The run ID for v4.06.01 was #2206161921

The comparison plots for v4.06 vs v4.05 have been replaced for CLD with
v4.06.01 vs v4.05. Additional comparison plots between 4.06 (withdrawn)
and 4.06.01 (published) CLD have also been added.

All comments in the main v4.06 Read Me file regarding CLD remain valid.

Ian Harris
NCAS-Climate
Climatic Research Unit
School of Environmental Sciences
University of East Anglia
Norwich
NR4 7TJ

i.harris@uea.ac.uk