We happened to choose a moan conditicn for continental po

air over

Burope. You will notice that there is about ten thousand

of dif-

ference in these tvo casos and to scue extent we can say

that this corres-

ponds to the change in tha height of the tropopause, bocaush

this does act

as & very Ltiportent if, but actually ‘m this case it never] aid reach the /

tropopause, end 89 ve can't rely entirely, particularly for|the low yield
bombs, on saying that tropopause ils the height at vhich it
I mentiomed cariier that one of the reasons we vere

qo.

Row

concarnpd with thie

question of heights was because wa felt that it was Lape

az to determine -

what part of the cloud could be scavenged by rain. These biuesdash lines _
represent the height to vhich the rain ia rain-bearing c ot

usually

-

goes -- the muximm height to which it goca in summer, and fhe implication
is obvious, I think, if you accept cur data, that if wa gotia beab of more

than about § KT under Hevada conditions, that all of the defris

will go

above the mucimum height of the rain in rain-bearing clauis] and therefore |

ve wouldn"t expect it to be rained out initially, we'd havd to wait for
it to come back dovn by some other mechanism before it could

be rained.

The next thing vhich we vanted to take into account was the|transport of

the debris, beth horigontally and vertically, after the

clofd stabilised.

7 y

rm

Ths gross transport is due to the wind end { think mecteprolegists can umally
provide good iInfammtion on vhere the cloud will go for thelfirst few hours,

based on upper air winds. Me can also tell how 1t will go dn the averages,

vecause we have &

arrthrenoaae :

tty good backlog

of data on upper air

effect is, of course, the shear in the atmosphere.

nds.

Another

This isla little bit

One has

mi

herder to get at, bezause it is not usually observed directly.

as

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