[1] This study is concerned with the quantitative prediction of dust storms in real time. An integrated wind erosion modeling system is used for 24-, 48-, and 72-hour forecasts of northeast Asian dust events for March and April 2002. The predictions are validated with synoptic records from the meteorological network and dust concentration measurements at 12 stations in China, Japan, and Korea. The predicted spatial patterns and temporal evolutions of dust events and the predicted near-surface dust concentrations are found to agree well with the observations. The validation confirms the capacity of the modeling system in quantitative forecasting of dust events in real time. On the basis of the predictions, dust activities in northeast Asia are examined using quantities such as dust emission, deposition, and load. During an individual dust episode, dust sources and intensities vary in space and time, but on average the Gobi Desert, the Hexi (Yellow River West) Corridor, the Chaidam Basin, the Tulufan Basin, and the fringes of the Talimu and Zhunge'er Basins are identified to be the main source regions. The Gobi Desert is the strongest dust source, where the maximum dust emission reaches 5000 mg m À2 s À1 and the net dust emission reaches 16 t km À2 d À1 in March and April 2002. Net dust deposition covers a large area, with the Loess Plateau receiving about 1.6 to 4.3 t km À2 d À1. A zone of high dust load exists along the northern boundary of the Tibet Plateau, with a maximum of around 2 t km À2 situated over the Gobi Desert. The total dust emission, total dust deposition, and total dust load for the domain of the simulation are estimated. The average (maximum) total dust emission is 11.5 Â 10 6 (65.7 Â 10 6 ) t d À1 , the average (maximum) total dust deposition is 10.8 Â 10 6 (51.4 Â 10 6 ) t d À1 , and the average (maximum) total dust load is 5.5 Â 10 6 (15.9 Â 10 6 ) t.

[1] A size-segregated aerosol model that includes most of the major physical processes (generation, transport, and dry and wet deposition) is developed. This model is coupled with a Regional Air Quality Model (RAQM) and is applied to simulate Asian dust storms during the 10-day period of 15-24 March 2002. A nonhydrostatic mesoscale model (MM5) is used to provide meteorological fields. Model results are verified by available observational data including surface weather observations and size-segregated particle concentrations. The validation demonstrates a good capability of this model system in capturing most of the key features of dust evolution and reproducing the particle mass size distribution along the transport pathway of soil dust. An apparent feature has been both observed and reproduced by the model, showing a shift of size range with peak mass concentration from coarse mode to finer mode on the pathway from source regions to distant downwind areas. The maximum dust concentration averaged over 10 days is simulated to be 3000 mg m À3 over the southern China-Mongolia border. Total dry deposition of soil dust for 10 days is up to 30 g m À2 in the Gobi desert along the southern China-Mongolia border. Distribution and magnitude of particle deposition are strongly dependent on both concentration and size-segregated dry deposition velocity and scavenging rate. While dry deposition dominates the removal of dust particles in or in the vicinity of source regions, the influence of wet deposition increases along the transport pathway of soil dust, with high removal efficiency for coarser particles (>2 mm) and very low efficiency for particles in the accumulation mode. Of the total dust emission (43.2 megatons), about 71% is redeposited onto the underlying surface by the dry deposition process, 6% is removed by the wet deposition process, and the remaining 23% is suspended in the atmosphere or subject to long-range transport.

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NOTE 73 al. (2011) detected iodine-131 and cesium-137 in soil samples collected on March 29 in the prefecture using germanium semiconductor detectors. This study focuses on the vertical distributions of the two radionuclides in surface soil. SAMPLES AND METHODS Soil core samples were taken on April 13, 2011 at three sites in Fukushima prefecture: Hiwada in Koriyama-city (Site 1; N 37°28′32″, E 140°23′17″; two cores were obtained in Site 1), Yabuki in Nishi-Shirakawa-county (Site 2; N 37°11′59″, E 140°20′37″), and Iizaka in Fukushimacity (Site 3; N 37°48′50″, E 140°26′34″). The distances of the three sites from the Fukushima Daiichi Nuclear Power Station are 55 km (Site 1) and 65 km (Sites 2 and 3). We selected the three sites to investigate different types of soils. The soil types of the samples for Sites 1-3 were gray lowland soil, andosol, and brown forest soil, respectively. The soil at Site 1 was taken from a field, whereas the soil at Sites 2 and 3 was used to grow fruit trees. A stainless steel pipe with a diameter of 4.7 cm and length of 30 cm was inserted into the soil at each site to recover the soil core sample, which was divided into 8 fractions