Author's Name:	Ahmed F. Hassoon & Basim I. Wahab
Subject Area:	Science and Engineering
Subject	Other
Section	Research Paper

atmospheric visibility, air pollution, multiple linear regression, hourly data.

Atmospheric visibility in Baghdad city is estimated at 2012 depending on air pollutants concentration such as CO, NO2, NOX, O3 that recorded continuously at daytime (every half-hour) from ambient air quality monitoring AL-Waziriya station-Baghdad this station recorded also meteorological parameters such as air temperature (T), wind speed (WS) and direction (WD) these data is compared with atmospheric visibility that recorded at the same time taken from National Environment Satellite data and information service ( NESDIS) for Baghdad station. All these data is analysis basically to hourly and daily. Statistical methods such as simple and multiple linear correlation coefficient is used to correlated these atmospheric variability (atmospheric elements + air pollutant gasses) with visibility, where empirical equations is put to these visibility based on these hourly and daily data. Daily data don’t given a clear relationship between the calculated and observed visibility but hourly comparison is significant .The effect of polluted concentration on calculated visibility is tested from decreases gas concentration about 50% and see what its effect on the increases or decreases calculated visibility at different months and seasons, for example decreases of CH4 concentration would have great increases in the calculated visibility in months May and December where there is increases about 200% in May and 150% in December , while ozone concentration have small effect on the visibility study show that decreases of half in O3 will not increases the visibility in most the months and seasons of 2012 .