in East Asia and West Pacific Ocean M.Yamada(NU), T.Nagatani(NU) D.Zhang(PUK), T.Shibata(NU)

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1 Dust Particle Distribution in Free Troposphere in East Asia and West Pacific Ocean Y.Iwasaka (NU), G.-Y.Shi (IAP) Z.Zhen (CAREERI), Y.S.Kim (HU/NU) A.Matsuki(NU),D.Trochkine(IWEP/NU) M.Yamada(NU), T.Nagatani(NU) D.Zhang(PUK), T.Shibata(NU)

2 Aircraft borne measurements in Japan (%) Spring mean >4km Summer mean >4km % etc Sea Salt Soil Spring mean <4km Summer mean <4km % Observed seasonal change in the vertical structure of coarse (D>1µm) aerosols over Japan. Relative seasonal change in the total number of coarse particles is shown as 100% being the mean value for spring. Fractions by different particle types are superimposed. (Matsuki et al., JGR 2003)

3 Observations of Aerosols over Taklamakan Desert Observational Periods: Aerosol concentration, size, morphology and chemistry Lidar Balloon-borne Optical Particle Counter Electron-microscopic experiments of particles collected directly in free troposphere over Taklamakan desert

4 Lidar Measurements Aerosol Concentration Scatt. Ratio = [B1 + B2]/B1 Where B1 and B2 are backscattering coefficient of air molecules and aerosols, respectively. Nonspherisity Depolar. Ratio = P cross/p parallel where P cross and P parallel are cross and parallel component of backscattering power

5 Vertical Profiles of Aerosols Measured by Lidar at Dunhuang Upper Boundary At About 6km

6 Large Depolarization Ratio From near the boundary to about 6km Existence of Nonspherical Shape Particles

7 Clear Boundary at about 6km In Spring and Summer Characterizing Vertical Distribution of Aerosols over Dunhuang (possibly Taklamakan Desert)

8 Existence of Mineral Particles deduced from electron-microscopic experiments of particles collected over Dunhuang summer of 2002 and spring of 2003 Collection of particulate matter with a Balloonborne impactor (JGR 2003 Iwasaka et al.) (this symposium M. Yamada et al.)

9 Balloon-train Positioning of sampler is made by GPS

10 (B) Fine particles also were collected (b) (a) (a) (b) C* C* X-ray Counts O* S Ni* X-ray Counts O* S Ni* X-ray Emission (kev) X-ray Emission (kev) Electron micrograph of individual particles collected in the free troposphere between about 3km and 5km over Dunhuang, China. Both fine particles (a) and (b) are ammonium sulfate.

11 (a) Typical electron micrograph of collected particles in spring in the range of 3-7km. (a) Si-rich particle, (b) Ca-rich particle. The Ni* peak is due to the Ni grid used inside the collection surface C* 5μm X-ray counts O* Al Si Ni* K Ni* X-ray emission (kev) (b) C* 10μm X-ray counts Ca O* Ni* Al Si Ca Ni* X-ray emission (kev)

12 Measurements of aerosol size and concentration with an Optical Particle counter show large decrease in concentration of particles with all size ranges near 5km

13 Particle concentration measured with a balloon borne OPC at Dunhuang 27August, >0.3μm >0.5μm >0.8μm >1.2μm >3.6μm Coarse mode particles well mixed in near surface ~ 6km Altitude, m (Y.S.Kim et al., JGR,2004) Number Conc. cm -3

14 The trajectories of balloons suggest noticeable westerly above about 5km and sometimes north-easterly below about 5km

15 2003/3/ m 7000m 5000m 3000m 8min 6min 7min Launching point 48km Landing point 2002/8/ m 6852m 3min launching 5172m 5min 3179m 6min 12km landing Trajectories of Balloon-borne sampler

16 Westerly becomes clear above about 5km

17 Combination of wind system and geographical situation causes outflow of particles even in summer above 5km According to Sun et al. north-easterly dominates near surface

18 Summary Coarse dust particles were frequently observed in summer in the free troposphere Above about 5-6km westerly dominates even in summer Taklamakan desert can play as dust pool and source in summer Long range transport of dust particles in summer is important from view point of radiative contribution of particles and chemistry on surface of dust In future systematic field studies of dust particles (weak KOSA) impact in summer season

19 Thank You