Observed Similarity In Satellite Derived Total Column Ozone Data And Ground Based Dobson And Ozonesonde Over Nairobi Kenya

Abstract

This study sought comparison of satellite total column Ozone data from 1985 to 2003 against ground based Dobson spectrophotometer and Ozonesonde data. The area of study was Nairobi and the main objective was to ascertain the similarity of the three total column ozone data sets. The inter-comparison was carried out by paring two data sets of corresponding Julian day. The root mean square (RMS) error, bias and percentage difference were used in order to achieve the objectives of the study. The RMS error for Dobson/satellite was between 0% and 26%, percentage difference with Dobson as reference ranged from -6% to 20%. Satellite/Ozonesonde and Ozonesonde/Dobson data sets showed variable RMS error and percentage difference. Bias was positive on average ranging between 2du to 12du in all the three data sets. Dobson/satellite results showed small differences of RMS error, bias and percentage difference hence were comparable. The ozonesonde data had some discrepancies partly because of vertical dynamics of Ozone and that of the balloon carrying Ozone sensors.