The objective standard for Asian Dust determination using the instrument in the Republic of Korea

SEONG-HEON KIM, HYUK-JE LEE, JAE-YOUNG KIMObservational Technology and Management Division, Korea Meteorological Administration

E-mail : shkim@kma.go.kr

Asian Dust Monitoring Network

Instrument

Future Plan

PM10

Recently Global Warming and Industrialization makes rapid progress of the desertification in East Asia. The intensity and occurrence of Asian dust have gradually increased since 2000 in Korea . A severe Asian dust event was observed 2-3 times per year in 2000s and affecting public health and industry. KMA built quantitative Asian Dust Monitoring Network for preventing damage from Asian dust and established Warning System for Asian dust in 2002.

ReferenceYoung-Gon Lee and C.-H. Cho, 2007 : Characteristics of Aerosol Size Distribution for a Severe Asian Dust Event Observed at Anmyeon, Korea in April 2006. Journal of the Korean Meteorological Society, 43, 87-96.

Asian Dust Monitoring Network

LIDAR

KMA LIDAR system Time series of extinction coefficient and depolarization ratio displayed in the KMA intranet

Warning System

Alarm - Alarm is issued when an hourly averaged dust concentration(PM10) is expected to exceed 300 ㎍ / ㎥ for over 2 hours Advisory - Advisory is issued when an hourly averaged dust concentration(PM10) is expected to exceed 400 ㎍ / ㎥ for over 2 hours Warning - Warning is issued when an hourly averaged dust concentration(PM10) is expected to exceed 800 ㎍ / ㎥ for over 2 hours

Objective standard for Asian Dust

KMA is using PM10 and LIDAR for observing the quantitative Asian dust, but the Asian dust is being determined from measuring with observer eyes. Hence, there is a difference of observer opinion and shortage of objectivity. Especially, it is need to improve the determination criterion of Asian dust observation using the instruments in the case of weak Asian dust.

Background

The present situation Asia dust is measured with the eye when PM10 concentration is less than 300 ㎍ / ㎥ . - Asian dust is determined from the brown dust and sky muddiness measured with the observer eyes.

Baengnyeongdo

GanghwaGwanaksan

Bukgyegryelbido

Gwangdeoksan

Anmyundo

Chuncheon

Gunsan

CheonanCheongwon

Chupungnyeong

Jinju

Daegu

Andong

Yeongdeok

Yeongwol

UlleungdoDaegwallyeong

Sokcho

Gudeoksan

Gosan

Heuksando

Gwangju

Munsan

Seoul

Cheonju

Suwon

Ulsan

Jindo

PM10 station : 28

Lidar station : 4

Asian Dust determination of weak Asian Dust (less than 300 ㎍ / ㎥ ) Monitoring Asian dust

- Using statistics to distinguish between Asian dust and other dust events Asian dust determination - Asian dust is determined through observed APS(Aerodynamic Particle Sizer) as PM10 concentration is more than statistics.

Local Stationmonth BaengnyeongDo Kanghwa Kwangduk Kwanak

1 130 170 110 1702 140 170 110 1603 160 180 170 1704 150 150 140 1605 150 160 130 1606 90 130 120 170

[ ㎍ / ㎥]

Table for statistic analysis (example)

Asian Dust Non-Asian DustVolume

Concentration change

Increasing the volume concentration of the coarse particle (more than 1.5 ㎛ )

Increasing the volume concentration of the fine particle (less than 1.5 ㎛ )

Volume Concentration Distribution

High volume concentration (more than 100 ㎛ 3/ ㎝ 3) around 2~5 ㎛

High volume concentration (more than 100 ㎛ 3/ ㎝ 3) less than 1 ㎛

Volume Concentration Max. Peak around 3 ㎛ Peak less than 1 ㎛

Criteria by using APS

• Type-1(Asian Dust)

Time series of PM10 data displayed in the KMA intranetKMA PM10 system

The Instrument measuring the number density of particles with the diameter of 10 ㎛ or less KMA is using PM10 because the diameter of Asian dust particles is mainly 2~6 ㎛ . The observed data is collected every 5 minutes, instantly displayed on Combined Meteorological Information System(COMIS), and used in quantitative Asian dust forecast.

Dual-polarization LIDAR system including polarization analyzer can get the information about the shape and vertical profile of aerosol particles since it observe depolarization and extinction coefficient though the analysis of lager pulse(532nm) holding specific polarization in atmosphere. Generally, polarization is easily broken in non-globular shaped particles. Therefore, Asian dust observation based on depolarization is useful because aerosol like Asian dust is a not-globular shape. The observed data is collected every 15 minutes, instantly displayed in Combined Meteorological Information System(COMIS), and used in quantitative Asian dust forecast.

• Type-2(Asian Dust & Pollution)

• Type-3(Pollution) • Type-4(Sea Fog or Haze)

Studying the objective standard for Asian Dust determination by using the instrument Applying to forecasting the weak Asian Dust