08

100

90;

~ FLIGHT 2488 (Il OCTOBER I960)

BOF

70

T

ALTITUDE (THOUSANDS OF FEET)

FLIGHT 2468 ( 7JUNE 1960)

60
50

40:

TROPOPAUSE

30

20

lO

20

1

L

30

40

1

50

L

=~ 60

PB ACTIVITY (yc /10° FT, AMBIENT)

4

-70

al.

-60

i

-50

4

-40

|

-30

TEMPERATURE(°C)

Fig, 1 -- Impactor-filter flights, Minneapolis, Minn.

-20

Select target paragraph3