oe
.
@
nl @®
,
~1
2° Saye es Usay
mf
sate,A1200/ES
“SUBJ: -The Relationship Between Energy and Rate of Cloud Rise
“S70; Dee Me De Urry
«PRO We Allen
|
“DATEs Al Dec 520
40M.
<As you suggested last week, I have gone ever all avaliable datz on the
le
|
- gates of rise of clouds from U.S. atomic testes and have plotted values for the
Sy in BiTe #8 show Ain the sooompanying graphy Sogethe:
sapetes of risa agai
‘welth the empirical
on of rélationsiiip.
2s
the rate of rise changes with time, increasing to a maximum during the
@*#€ixet wirute end decreasing thereafter to essentially zero afters about 10 minutes.
aihe data available to us are not good enoughtoshow the maxim rate die to post
whiuding and infrequent measurements, but may be used to obtain the average rete off
qarlee over a period of mimtes, he sverege over the initial 3 minutes is used on
Mathis graph.
In all cases axcept IVY Mike the clouds were still rising rapidly
gmand were still in the troposphere after the third alnute, The Mike cloud ws
=
Skgeated in a special manner es indicated below.
4
“It is weasoneble to believe there to be acme dependency of Frise rate én
shah lapse of ambient alr temperature with altitude. the effect of inversions and
_watable layers will, however, be « minimum in the earliest seconds of rise, increasing
> jain importance ao the temperature difference decreases between Cloud and surreunding
“getmosphere. -Mhen the cloud reaches ambient air temperature, further vertical motion
ie damped out. It 46 therefore preferable to measure the rate of rise st the earlies’
‘appossible time, and the maxim rate of rise should be more indicative ef energy thar
. tthe mean Sainte rate weed hore.
|
4
"Since the mean apse rate of temperature is markedly different in the
‘SBtratoephers than in the troposphere, it 4s preferable to make all measurements in
withe troposphere until adequate sarrections gan be made for this.
| B+ Rate Of rive data are available fron the following sources:
oye
‘qarhee and dispersion @f the SANDSTONE €]
= in an AFSHP publication, “Classified
.
,MBolentific Metearolegical Information, Operation SANDSTONE," His data were obtained
aby theodolite and aze reasonably accurate over at least the first few minmtes of riw.
De
~Qpexation GREENHOUSE.
The rise of the GREENHOUSE elouds were @&:
sefained from an unpublished report on “Cloud Physics", Proj. 4,6, by Dr. W.W.Kellogg,
*Rand Carp. -Motion picture photography were analyzed fcr cloud sise and ¢loud
‘wiimensions, and the ra tes of rise over the first 4 or 5 minutes are probably good,
walthough weather clouds obscured parts of the etaxic clouds.
The maximm altitudes
“Of the Dog and George clouds are etill in doubt since the tops of these elouis were
“Rot visible from the camars positions,
ie
.
QosratinBUSTERSJANGLE. Two sources of cloud rise data are
savallable tor”these operstions, one being that taken by myself (with your help fin a
|
(5)
--Incl
coe:
paFoD
13
3
.
oe
.
a
, The
.
2258
—
wen
.
4
oe
bet
‘4
Consists a >
Pr ~,
we
we
ee, eee Se
Tris Decuncer
Po
ey
ah
OF: