Abrupt High PM Concentration in an Urban Calm Cavity Generated by Internal Gravity Waves and a Shallow Coastal Atmospheric Boundary Layer with the Influence of the Yellow Dust from China

Using GRIMM-1107 aerosol sampler, GOES-9 DCD satellite images, HYSPLIT model of backward trajectory and 3D-meteorological WRF-3.6 model, high particulate matter concentrations were investigated at Gangneung city in the Korean east coast which consists Mt. Taeglyung its west East Sea on 00:00LST March 26~00:00 LST 4 April 2004. During a Yellow Dust period, maximum PM10 (PM2.5 PM1) concentration was about 3.3 (1.1 1.01) times higher than one non-dust period. After transported dust from Gobi Desert Nei-Mongo by strong northwesterly wind passed over Taegulyang moved down toward city. Then trapped inside calm cavity generated confront internal gravity waves (IGW) eastward movement is prohibited easterly onshore Sea, further combined with gaseous emitted road vehicles heating boilers 09:00LST, 30 (beginning time office hours), causing PM concentrations. On mid-day, as due to daytime sufficient thermal convection rises up top boundary layer (TIBL) 300 m depth mountain, ground-based are much lower 15:00LST thickness TIBL 09:00LST. At night, particulates many after end hours residential could combine both falling uplifted ground surface during day, they IGV under shallower stable nocturnal inversion TIBL, more be accumulated near showing 20:00 LST.