The PM10 concentration data is useful for indentifying intensity and a transport way

of Asian dust. However, it is difficult to identify them properly due to the limited spatial

resolution and coverage. Therefore, a methodology to estimate PM10 concentration using

visibility data obtained from synoptic observation was developed. To derive the converting

function, correlation between visibility and PM10 concentration is investigated using visibility

and PM10 concentration data observed at 20 stations in Korea from 2005 to 2009. To minimize

bias due to atmospheric moisture, data with higher relative humidity over a critical value were

eliminated while deriving PM10-visibility relationship. As a result, an exponentially decreasing

function of visibility is obtained under the condition that relative humidity is less than 82%.

Verification of the visibility converting function to PM10 concentration was carried out for the

dust cases in 2010. It was found that spatial distributions of PM10 calculated by visibility are in

good agreement with the observed PM10 distribution, especially for the strong dust cases in 2010.

And correlation between the derived and observed PM10 concentration was 0.63. We applied the

function to obtain distributions of PM10 concentration over North Korea, in which concentration

data are not available, and compared them with satellite derived dust index, IODI distributions

for dust cases in 2010. It is shown that the visibility function estimates quite similar patterns of

dust concentration with IODI image, which suggests that it can contribute for prediction by