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PM_1.0 (fine particles, with diameter < 1 μm), PM_2.5 (fine particles, with diameter < 2.5 μm) and PM₁₀ (coarse particles, with diameter < 10 μm) were measured at 24-hour intervals near a high-traffic road in Hong Kong, from October 2004 to September 2005. Mass concentrations were determined for the three particle fractions, averaging for PM_1.0, PM_2.5 and PM₁₀, respectively, 44.5±18.4, 55.4±25.5 and 81.3±37.7 μg·m^-3. PM_2.5 was 3.7 times the U.S. EPA's annual NAAQS of 15 μg·m^-3. Overall, PM_1.0 accounted for 44 to 69% (average 57%) of PM₁₀, while PM_2.5 accounted for 58 to 82% (average 71%) in this study. The particulate masses showed obvious seasonal patterns with high concentrations in cold seasons and low in warm seasons, especially high concentrations of PM_2.5-10 during the cold seasons. Diurnal variations of mass concentrations of PM_2.5 were determined during July, showing two major peaks in the morning and afternoon rush hours.

Seasonal variation of residual currents in the Meghna Estuary, located at the northern part of the Bay of Bengal, has been investigated through the use of a 3D numerical model. Residual current in the Meghna Estuary appears to be strongly influenced by tidal currents and Coriolis Effect under average meteorological and hydrological conditions of four different seasons considered,. Average seasonal variation of wind speed and direction as well as fresh water inflow does not seem to have significant influence on residual current. Only under the influence of average of maximum wind speeds of different seasons, residual currents in the Meghna Estuary show their dependency on wind stress. In general, at the surface layer northward and northwestward flow is created during the pre-monsoon and monsoon periods and southwest and southeastward flow is created during the post-monsoon and winter periods.