Evening star., 1939-06-01
Of Stars, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study

80 sSsSI .S~SHSASsy
And Study
By Thomas r. Henry.
A stratosphere dawn patrol now guards
the United States from surprise attacks
of cold waves.
The two sentry boxes from which robot
sentinels make their ascents at dawn
each day are the United States Weather
Bureau stations at Fargo, N. OAK, and
Sault Ste. Marie, Mich.
Attached to small, wind-tossed bal
looms these electrically operated wire
brains mount from IL to Is miles above
the earth's surface at speed of about
1000 feet minute and send back by
means of an automatically operating
radio transmitter data on the tenn
perature, humidity, wind direction and
velocity which they encounter on the
way. They are the newest type of radio
sondes" devised for the Weather Bureau
by the United States Bureau of Stand
ards. 1t requires little more than an
hour and half for one of these robots
to complete its journey and send back
adequate data for the daily forecast
upon which the meteorologists start at
7:3O am.
Like hostile Indians about to attack a
frontier settlement, the cold waves hide
behind the rim of the Arctic Circle and
often descend with lightning-like speed
upon the Northern United States A
favorite path is through the hitherto
impossible for such an air mass to get
over the border without being detected
from either Fargo or Sault Ste. Marie.
The latter station is considered a more
essential key position in the Weather
Bureau network.
A common path of the cold waves is
across Canada just east of the Rockies
and generally along the route of the
northWard flowing Mckenzie River. AS
it comes southwark it is likely to veer
to the eastward. Another cold path is by
way of Hudson and James Bays and
across the Great Lakes area.
In the past weather forecasters have
had to depend for their first warning of
such cold wave on ground observations
taken at Canadian stations in the Yukon
or at Fort Churchill in the Hudson Bay
area, but the conditions in the upper air
might not make themselves apparent at
the earth's surface until several hours
after they were well on their way
southwark.
A few years ago dawn airplane patrols
were established at the Fargo and Sault
Ste. Marie stations But it is precisely
at such stations, where cold waves usual
ly are associated with fast action in the
atmospheric flow and can occur with
great and unexpected suddenness that
there is frequently bad flying weather
so that it is necessary to postpone or
cancel airplane soundings. Even in good
weather the pilots seldom went above
5 miles, considerably below the floor of
the stratosphere. Thus they may miss
some OF the most significant data from
the viewpoint of forecasters.
Admittedly, say the Bureau of Stand
ards engineers in describing their latest
improvements on the radio sonde device,
there is some loss of observations such
as may be made by pilot The wire
brain OF the robot can make certain OBJ
servations far more accurately than any
human being but 1t cannot adjust itself
to report conditions for which its me-
chanical nerve cells have not been wired.
1t does not make direct reports, for
example, Of the attitudes of cloud bases
ana tops, haze layers, and layers where
ice formation takes place. Such data
can be deduced indirectly, however, from
the observation it radios back to the
ground station.
One of the outstanding advantages is
In speed, the Bureau of Standards engi-
neers report. 1t takes an airplane an
hour and half to make soundings up
to height of miles. In a few min
utes longer the radio sonde can furnish
almost as much data for threefold that
altitude. Experiments now are under
way, however, which are expected to
double this speed. At present the ascent
must be fairly slow in order for the
wire brain properly to observe changes
nerve pathways are being made for it
which will enable it to make the ascent
in so minutes.
At the same time the bureau engi-
neers have perfected new ultraviolet
meter which will enable the robot senti-
nels to send back much more precise
data on cloud levels
Similar robot dawn patrols now are
being sent out from the Weather Bu-
reau stations at Washington, Nashville,
Oklahoma City, Omaha and Oakland,
Calf. These provide data valuable for
predicting regional changes in weather
but have not the key station significance
of the Sault Ste. Marie observations. Up
to the present more than $500 radio
soundings Of the upper atmosphere have
been made in the course of routine
weather forecasting work.