-3-

y

a

One

of the major coces that was moci-ied !s sarHew lh), its gurpose 135 to

adjust voserved winds, using variational anaivsis methocs, so as to conserve M33
rrom eell to cell.

After modification, all observed uoper air wind data from 19m to

33 xm were entered as input. This ‘vas done for four time periods, using winds for
one to three onserving stations for each time. The oovious advantages of this code
(over most other fallout codes) is that mass is not permitted to accumulate in any of
the cells and winas are available for each 3-D cell intersection for four times.
Tne MATHEWwinds are used then by the modified appicl’! particle-in-eell
code

to calculate

source.
allowing

the transport,

diffusion,

and

deposition

of an

instantaneous

Modifications required of ADPIC, to handle the Bravo test, consisted of
more

upper

air

input

than

is

used

in

tvpical

ARAC

assessments.

Furthermore, since particles falling from the stratosohere undergo a larga increase *
in air density, it was necessary to add a turoulent wake correction to the larger
;
.
.
(4
oarticles; this correction follows the method set forth by AleDonald.

Other

modifieations were to incorporate a tropical atmosphere into the fall velocity
calcuations and to make the particle activity increase as the cube of particle
cacius.

Finally, time-integrated deposition was acded; this allows calculation of the

total dose from detonation time to evacuation.

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