PART B - THE EFFECT OF WIND ON CHEMICAL AGENT CLOUD TRAVEL
During the target analysis phase of planning chemical weapons employment,
the effect of the current wind conditions, and the terrain in the target
area must be given proper consideration.
These two influences can mean
the difference between a successful chemical operation and a disaster.
Regardless of who fires the weapon delivering the agent, if the wind or
terrain carries the agent or vapor hazard into friendly position,
unprotected personnel will become casualties.
For this reason, it is
important to know how far and in what direction a chemical cloud will
To determine the distance and direction of travel of a chemical cloud,
you must be able to:
Determine the wind direction,
Determine the wind speed,
Assess the dissipation effect of wind on a chemical cloud.
Determine the Direction the Cloud Will Travel
Army meteorological sections are organic to each division within the
This weather information may come from either artillery
meteorological channels or from Air Force weather sections reporting to
the staff weather officer.
From this data, you will receive the
direction from which the wind is blowing. To determine which direction
the wind is blowing toward, note the given wind direction, and if it is
180, or more, subtract 180. As an example, if the given wind direction
is 240, this is the direction from which the wind is blowing.
determine the direction the wind is blowing to, subtract 180, (240,-180=
60,). Therefore, 60 is the direction the wind is blowing toward.
Determine the Speed the Cloud Will Travel
The staff weather officer will also be able to tell you at what speed the
current surface winds are blowing. Normally, when you receive the wind
speed, it will be given to you in nautical miles per hour (knots per
hour). You must then convert the speed to kilometers. To convert knots
per hour to kilometers per hour, multiply the knots by 1.85.