The Geographical Journal (Journal of the Royal Geographical Society): Volume XII, No. 2 [‎294v] (91/154)

178
UNITED STATES DAILY ATMOSPHERIC SURVEY.
atmosphere possesses such intense cold at the elevation from which the air is
drawn that, notwithstanding the heat gained by compression in its descent, it is
still far below the normal temperature at the surface of the Earth.
The West Indian hurricanes, always at sea-level and in humid air, and which
are the most violent of all American storms, intrude themselves into the domain of
the United States weather-map at the bend of their parabolic course, at about
latitude 30°. They have for years furnished a fruitful theme for the thoughts of
the investigator.
For twenty-seven years the forecasters of the Weather Bureau have studied the
inception, development, and progression of these different classes of atmospheric
disturbances. From a knowledge personally gained by many years’ service as an
official forecaster, I do not hesitate to express the opinion that we long since
reached the highest degree of accuracy in the making of forecasts possible to be
attained with surface readings. It is patent that we are extremely ignorant of the
mechanics of the storm, of the operations of those vast yet subtle forces in free
air which give inception to the disturbance, and which supply the energy necessary
to continue the same. Long having realized this, I determined at once, on coming
to the control of the United States Weather Bureau, to systematically attack the
problem of upper-air exploration, with the hope ultimately of being able to con
struct a daily synoptic weather-chart from simultaneous readings taken in free air
at an altitude of not less than 1 mile above the earth. Prof. Marvin was assigned'
to the difficult task of devising appliances and making instruments, and I am
pleased to say that we have improved on kite-flying to such an extent that
apparatus is now easily sent up to a height of 1 mile in only a moderate wind.
We have made an automatic instrument which, while weighing less than two
pounds, will record temperature, pressure, and wind-velocity. By January next
we hope to have not less than twenty stations placed between the Rocky mountains
and the Atlantic ocean, taking daily readings at an elevation of 1 mile or more.
We shall then construct a chart from the high-level readings obtained at these
twenty stations, and study the same in connection with the surface chart made at
the same moment; being thus able to map out the vertical gradients of temperature,,
pressure, and wind-velocity, as well as the horizontal distribution of these forces, it
is hoped to better understand the development of storms and cold-waves, and
eventually improve the forecasts of their future course, extent, and rate of
movement.
In exceptional cases we have flown the kites to a height of 1^ mile. From
daily readings at only one kite station, at Washington, we have derived information
as to the force and direction of the wind above the 1-mile level, which has greatly
assisted us in estimating the future direction of a storm-centre when our surface
chart gave but negative indications. It will be a fascinating study to note the
progress of cold-waves at this high level, and to determine if the changes in
temperature do not first begin above. The readings at Washington indicate that
contending equatorial and polar winds may be more potent in the formation of
storm-eddies than heated and ascending convectional currents.
I am anxious to know the difference in temperature between the surface and
the upper stratum in the four quadrants of the cyclone and in the four quadrants
of the anti-cyclone, especially when the storm and cold-wave conditions are intense.
At an elevation of 5 miles but little effect remains of diurnal temperature variation.
At this altitude the atmosphere is free from.the disturbing influence of immediate
surface radiation, and consequently there is but little change between the tem
perature of midday and midnight. The vertical distribution of temperature in the
several quadrants of the cold-wave or rain-storm areas may give a clue to the future