군산지방의 황사특성 분석 : 2005-2007년

Abstract

The annually spring asian dusts are increasingly coming from China and Mongolia to South Korea as the invasion of a natural phenomenon, but recently two or three times attacks of severe asian dust events seriously affected the awareness of public health and huge industrial damages over the Korean peninsula. In this study, the characteristics of asian dust events was analyzed and classified over Gunsan, Jeollabuk Prov., korea for 2005-2007. World Meteorological Organization recommends the way of the phenomenon of dust and sandstorms, as there exists any distinction between the reports. There is no quantitative criteria and observations of the asian dust phenomenon, but in the East Asian region, the strength of a variety of asian dusts uses and reports, with the intensity of asian dusts in the country in accordance with 0, 1 and 2 separated sky status and visibility, yes or no, except for the yellow sand phenomenon. However, the results are of visual observation asian dusts largely dependent on the subjectivity by observer, and it also applies for a prediction even though this is very difficult observations by measuring equipment and materials linked to the quantification desperately needs. Accordingly, quantitative observations of the asian dusts to Gunsan in the last three years to the day of PM10 concentrations observed by the three types of cases which form by selecting observer. Climate data, weather chart, the PM10, asian dust Lidar, wind profiler using materials use to derive a result of the investigation and some conclusions. First, the asian dusts origin of Gobi Desert, Mongolia, barren plateau etc, are located on the path one or more of observation points, that were observed the PM10 concentrations extremes 9,000㎍/㎥ more than the seven cases of the six cases, and 3,000㎍/㎥ more than seven case except for case. That is one point of the asian dusts originates PM10 concentrations extremes 9000㎍/㎥ or more, when duststorm symptoms appeared in Gunsan. Second, the PM10 concentrations extremes observed only 400㎍/㎥ more than 2-7 km from the lidar's depolarization ratio of 0.15 or more has been destroyed, and in case 400㎍/㎥ below if the upper-level depolarization ratio not appear, one kilometer or less was increased depolarization ratio, that you know already Aerosol during the wait patiently on the ground. That is depolarization ratio appeared 0.15 and later the lidar's near of the 2-7 km , which will appear the PM10 concentration of 400㎍/㎥ more than in Gunsan, we are likely to have asian dust special advisor to the announcement should be polite watchlist. Third, the PM10 concentrations extremes the 800㎍/㎥ for more than two cases of depolarization ratio by 2-7 km near 0.15 or more observations after 1km below the ground after 2 hours on pm10 extremes is found to 3 hours, 400-800㎍/㎥ two cases of depolarization ratio by 2-7 km from the 0.3 and later observed in a relatively short period of time is 2 hours or less. Fourth, the current Asian dusts of his observations are subjective depending on visual observation is determined, but the wind profiler's character winds of fall (-) Airstream to the Asian dusts at the start time of 6 cases and 7 cases match, and PM10 concentrations are extremes 800㎍/㎥ If more than 30 to 60kts, it is also the movement of Asian dusts at the start observers can determine the time when the wind profiler is difficult to determine the character of the horizontal wind, wind + viewed deserve consideration. Fifth, the depolarization ratio by 1km below ground patiently increasing value is 0.2 or later when the wind profilers noise ratio is 30dB or more observations, and depolarization ratio increases also increase tends to noise ratio. Asian dusts are also asymmetric spectrum observations (+) value of 1 to 5 km near the extensive observations and the PM10 extremes visual observations of the 3 cases and 7 cases match. We should have to collect and analyze more severe asian dust events with PM10 and Lidar, wind profilers, including optical particle counter(OPC), ceilometer observation equipment, etc. using a variety of Asian dusts with improving the ability of analysis and conditions of asian dusts and also collect direct information from the origin of asian dust events with the emission of dust concentration and weather condition on the near real time basis. We also should improve the accuracy of prediction model for asian dusts further.