The following is a quick description of our climatology:


We have merged data from 15 years (1988-2002) of ozonesonde measurements
and SAGE (version 6.1) and/or UARS-MLS into monthly 10 degree latitude bands.


The units are PPMV and the altitude scale is zstar- defined as:
zstar=16xlog(1013/P)
where zstar=0 to 60 which is "about" 1 km per layer.
The climatological tables are in altitude units of Z (0-60).


SONDE DATA:
Over 23,400 sondes from 1988-2002 have been used in this climatology.
Data have been "filtered" i.e. all obvious bad data points have been removed.
Balloons that burst below 250 mb are discarded. Data from bouncing balloons
were sorted by pressure.
****No total ozone correction factor (TOMS or Dobson) filtering was used*****


We average the stations equally for each band so that we do not introduce any
longitudinal biases (e.g. Resolute & Nyalesund have equal weights in December
even though Ny Alesund has 3 times as many sondes than Resolute for that month).


SAGE & MLS DATA:


SAGE Version 6.1 data was used 1988-2001
SAGE Data have been "filtered" for bad retrievals (via the Stacey Frith filter)
MLS (1991-1999) Version 5 data was used.


SAGE data was used at all latitudes EXCEPT for the following:
80-90 North  All MLS
70-80 North  All MLS
60-70 North  October-February & May --> MLS
50-60 North  November-January & May --> MLS



80-90 South  All MLS
70-80 South  All MLS
60-70 South  January, April-November  -->MLS
50-60 South  January  -->  MLS   (bad sage coverage)



Everything else--> SAGE


Merging of profiles:
Where SAGE data was being used:
Average profiles from sondes & SAGE are merged between z layers 10 & 18 (240-76 mb).
Weighted averages are used (i.e. at layer 10 it is 95% sonde & 5% sage, then at
layer 11 it is 84/16, then 72/28, etc)


Where MLS data was used:
Average profiles from sondes & MLS are merged between z layers 20 & 28 (50-20mb).
Weighted averages are used as described above


Statistics are available for each z layer (stand dev in PPMV) for
both sondes (layers 0-32) and SAGE (layers 15-60).


Problems:
The MLS zonal mean for 80-90 North & South is not a true representation
of the 10 degree band since the measurements are biased. The MLS only measures
from 80-83 degrees while the sone only represents the pole.


The southern hemisphere high latitudes have the added problem that
in Sept-Nov the sondes (0-24km) tend to be weighted toward ozone
"hole" conditions and are not a true representation of the zonal
ozone values.  Be careful here!!


The highest layers (z > 55) may have a slight error due to sunrise/sunset differences
in SAGE.  Depending on latitude and time of year the measurements may be biased
due to a large quantity of one measurement over the other.


Gordon Labow
labow@chapman.gsfc.nasa.gov