The following is a quick description of our 2011 climatology.

We have merged ozone profile data from 22 years (1988-2010) of ozonesonde measurements
with data from Aura MLS (2004-2010) into monthly 10 degree latitude bands.

OZONE DATA FILES:
ML_ppmv_table.dat
  the ozone mixing ratio table is in units of PPMV (parts per million by volume)
ML_ppmv_stats.dat
  the mixing ratio standard deviations are also in PPMV
ML_du_table.dat
  the table of ozone layer amounts is in Dobson Units per layer (DU = milli-atm-cm)
ML_umkehr.dat
  ozone amounts in Umkehr layers are also in Dobson Units

ML_climo.xlsx
  all forms of the climatology are also given in this Excel spreadsheet

sonde add-on table 2011.txt
  ozone amount to be added to a sonde profile for total ozone calculation


ALTITUDE SCALE:
The climatological tables are in altitude units of Z* (0-65 km).
 (Z* is in units of km but is actually a pressure scale)

Zstar is defined as:

        Z* = 16 x log(1013/P)

 where P is pressure in hPa
    (and the log is base 10)


SONDE DATA:
Over 54,000 sondes from 1988-2010 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 & Ny Alesund have equal weights in December
even though Ny Alesund has 3 times as many sondes as Resolute for that month).



MLS DATA:
Only data from the Aura MLS instrument are used. No data from UARS MLS.
Data are from the version 3.3 processing.

             >>>> note: in an earlier version of this file we accidently switched the latitude regions for the MERGE areas  <<<<

MERGING OF PROFILES:
  40N - 90N: Merged between 320-101hPa  (zstar 8-16)
  40S - 40N: Merged between 156-49hPa   (zstar 13-21)
  90S - 40S: Merged between 320-101hPa  (zstar 8-16)

example: for 60-70N, the profile between the ground and Z*=8 km
         (pressure level 320 hPa) is an average of balloon sonde profiles
         from 3 stations, Sodankyla, Lerwick, and Churchill.
         From Z*=16km to 65 km (pressure level 101 hPa to 0.09 hPa)
         the profile is a zonal average of MLS profiles.
         In the merge zone between 8 km and 16 km the climatology goes
         linearly from 100% sonde at 8 km to 100% MLS at 16 km.