-3- One of the major coces that was mocitied ts watHen?), itS Qurpose 1s to agiust observed winds, using variational analysis methods, so as to conserve muss from cell to cell. After modification, all observed uoper air wind data from 1) mto 33 Km were entered as input. This vas done for four time periods, using winds for one to three observing stations for each time. The oovious advantages of this code (over most other fallout codes) is that mass is not permitted to accumulate in anv of the cells and wings are available for each 3-D call intersection for four times. J Tne MATHEWwinds are used then by the modified appicl? particle-in-cell code to calculate the transport, diffusion, and deposition of an source. allowing instantaneous Modifieations required of ADPIC, to handle the Bravo test, consisted of more upper air input than is used in typical ARAC assessments. furthermore, since particles falling from the stratosohere undergo a larga increase in air density, it was necessary to add a turdulent wake correction to the larger . . . [. Oarticles; this correction follows the method set forth by MeDonala!? modifications were to incorporate a tropical atmosphere into the fall | Other velocity caleuations and to make the particle activity increase as the cube of particle radius. Finally, time-integrated ceposition was added; this allows calculation of the total cose from cetonation time to evacuation.