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Fortuin & Kelder ozone climatology

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The Fortuin & Kelder ozone climatology gives for each month the ozone concentration on 19 pressure levels, i.e. ozone profiles, for 17 latitudinal bands of 10 degrees. The climatology gives ozone volumne mixing ratio's in ppm.

Download the climatology data file o3mean.dat (35 kB)
(per month are given: 17 latitudinal columns, each with 19 pressure rows)

For details on the climatology, see
J.P.F. Fortuin and H. Kelder, 1998:
"An ozone climatology base on ozonesonde and satellite measurements",
J. Geophys. Res. vol. 103, 31,709-31,734.
On this page:


 

Pressure levels and latitudinal bands

The 19 pressure levels are:
  pressure [hPa]: 1000  700  500  300  200  150  100   70   50   30
  pressure [hPa]:   20   10    7    5    3    2    1  0.5  0.3

The 17 latitudinal bands are:

        band:     1    2    3    4    5    6    7    8    9
    latitude: -85  -75  -65  -55  -45  -35  -25  -15   -5   +5

        band:     9   10   11   12   13   14   15   16   17
    latitude:  -5   +5  +15  +25  +35  +45  +55  +65  +75  +85

  For latitude L [degrees] the band N is thus:
           N = nint{(L+90.)/10.}
  where nint is the function that rounds the number
  to an integer.
Note that for latitudes below -85 or above +85 the climatology does not provide a value; use for these the value of bands 1 and 17, respectively.


 

Integrate profiles to total columns

The climatology gives ozone volumne mixing ratio's in ppm, so it needs to be converted to Dobson Units [DU] for total columns:
      d N [DU] / d P [mbar] = 0.78914 vmr [ppm]
The integration per month and per latitudinal band is then simply a loop over the nlevels=19
      o3column=0.
      DO il=1,nlevels-1
         dp=pressure(il)-pressure(il+1)
         o3column=o3column+dp*(o3mean(il)+o3mean(il+1))/2.
      ENDDO
      o3column=o3column*0.78914
Download the total column data file o3column.dat (2 kB)
(per month are given: 17 latitudinal values)


 

Convert pressure levels to altitudes

To convert the pressure levels to altitudes, the temperature is needed, and this varies with latitude and season. To give an idea mid-latitude summer temperatures can be used. Rounding the altitude to 0.5 km values, the 19 pressure levels are:
  pressure [hPa]: 1000  700  500  300  200  150  100   70   50   30
   altitude [km]:   0.0  3.0  5.5  9.5 12.0 14.0 16.5 19.0 21.0 24.5

  pressure [hPa]:   20   10    7    5    3    2    1  0.5  0.3
   altitude [km]:  27.0 32.0 34.5 37.0 41.0 44.0 49.5 55.0 59.0
To do is more exact, the following do-loop would be needed:
     altitude(1)=terrainheight
     DO il=2,nlevels
        ilm=il-1
        altitude(il)=altitude(il) +
    #      1.e-3*(Rgas/g0)*temperature(ilm) *
    #      ( log(pressure(ilm)) - log(pressure(il)) )
     ENDDO
where nlevels=19 in this case and terrainheight=0 [km] in general. Furthermore:
   temperature() is a temperature profile
   Rgas = 287.0, the gas constant for dry air [J/kg/K]
   g0 = 9.80665, the gravitational acceleration [m/s^2]


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