PRODUCT/VERSION: URAP 1998 O3 BASELINE STANDARD

DATA SOURCE: MLS (Version 4), HALOE (Version 18), and SAGE-II (Version 5.96) 

TIME PERIOD FOR AVERAGING OF DATA: April 1992 to March 1993

ALTITUDE RANGE: 420K to 2100K

LATITUDE RANGE: 80S to 80N

DESCRIPTION:

Monthly mean O3 baseline values are expressed on isentropic and 
equivalent latitude surfaces. Ozone profiles along with reported 
temperature data from MLS, HALOE and SAGE were first interpolated
to 14 predefined isentropic surfaces. These levels ranging from
420K to 2100K are used to approximate the UARS levels between 100
and 0.68 mb. On the same theta surfaces the potential vortivcities
and equivalent latitudes can be calculated from UKMO data. The PV
and corresponding equivalent latitudes then can be interpolated to
ozone measurement latitudes and longitudes. Final O3 baseline values
are based on average of all three measurements as described for the
pressure surface averaging. Detailed description can be found in a
paper being submitted to JGR.

The chief features of the data are:   
(1) Monthy mean ozone variances in winter seasons are smaller than 
    those in pressure and latitude surfaces.

WARNINGS:

(1) Bad (or missing) data values are set to 999.0 if there are any.

(2) Interpolation was necessary at some latitudes; these data are flagged
    negative.

(3) NO day time or night time ozone measurements are separated in 
    the final ozone climatology. 


REFERENCES:


CONTACTS
Originator: Ray H.J. Wang, Derek Cunnold
URAP co-ordinator: John Remedios