transport from south to north
ropopause gap must be rather
“not exceeding a week.
rpretation of the observed proa is possible if a sudden tem> of vertical mixing or convection
for instance, there is a sudden
K profile from type A to type B
2 supply of fresh Rn™ from the
the stratosphere is interrupted.
low turbulence rate in this layer,
j Rn™ in the lower stratosphere
until it decays. A fraction of the
ie tropopause will diffuse down-
troposphere or upward into the
here. Since the mixing rate is
tropopause than in the lower
he Rn™ content decreases more
; tropopause than in the layer
|
2
WN,
WO.
:
\
5}
r
™
se
c
8
5
3
: o
; &
.
the Po™®*/Rn™ ratio.
of the disturbed layer depends on
e within the boundary layer. For
=
E
i
2
os
7
\
\
i
!
&
— | Alaska series (May 1961)
2
|
one } Hawaian Series (June 1961)
r
[
Calculated:
=--- with K protile A
dprowe nth
a"
“
(| Tropopause}
pg
2
4
st
4
2}
Profiles
4
7
ar
B
‘
‘
‘
"
\
a
0
e
SN
5 107°
O°
|
\
ct
Rn-Profiles
from MACHTA a. LUCAS (1962):
:
\
.
a)
i
\
\
3 10
=
4
\
2
¥
2
4
Vy
>
c
5
5
-A___-
co
~
€ 10otoa ~ \ \‘
3
|
'
5
‘g
at
D
~_
=
6
86
0
2
4
Altitude (km)
6
8 20
|
a
7
2b
ye
tt
“o2z46801246
Altitude (km)
Fig. 5. Comparison of observed Rnprofiles in the upper troposphere and lower stratosphere
over Hawaii and Alaska with theoretical profiles (A, B) calculated with the A profiles on the
rig
2
/Rn™ ratios are nearly equal but
|
‘
© ia
B10)
time scale for the processes in-
- decreases with increasing height
level. At a given height the Pb™/
SY
¥
‘atosphere. The main reason for
rather short half-life of 3.8 days,
sted for steady-state conditions.
4
—°
yossible contaminations of the air
gure.
Tote i Rn
“
Calculated with K-profile:
QB
wk
leet
2
Specific activity (dps/cm?)
?n'* decay products. For the de0" (ty = 3.05 min), Pb™ (ti
nd Bi™(tj. = 19.7 min), the theexpected, radioactive equilibrium
pt in surface air. In the boundary
oactive equilibrium is disturbed
deposition of decay products at
face which results in a downward
vithin the boundary layer.
yws the vertical profiles of Po™,
* (Po™) in the boundary layer,
Iculated with the aid of the K
n Figure 1. In all cases a lack of
y products with respect to Rn™
Tas A
SA
NB
tt
“
7
OSTate
210
ntration with altitude above the
cate the value of Rn™ as a tracer
yf the exchange between tropo-
see UN
7
10°
7
~~
2
_
result is a temporary, slow in-
rther measurements are necessary
ese preliminary results. In any
3807
INTERNATIONAL SYMPOSIUM ON TRACE GASES AND RADIOACTIVITY
et
cotsseeee [WN
Po mencernen eee
QA
——~— WNN —-— SSN
aeesenenendernnenenesncttttien
—
eo weer Oa
wee
42
aeprn ne reeetnaseeEte
POeee
pees”
TFT
ayeent”
ae
ae ,
= mee
410°
wee
aoe
2hae=
=
ee
——
Rn
cee
ro
218
-5
10
ee
Le
_-_=
—
aan
—
———
a
*
£
u
_ eb an rtta
Rn~. Bi
31
pin 1 yr
nl = =
Fig. 6.
na §
~ ~~t--
ee
=
p78
“ss
See, ~~.
Po—— eee eee==
ON
ppo!4
Pee er
ticm
75
NNN
10cm
poul8 ppc!
5
piel4
== SSSSSS st
im
Altitude
10m
see ee ee ee
100m
Calculated vertical profiles of radon and its short-lived decay products in the boundary
layer near ground level (£xo = 1 Rn atom/em’sec).
10