hot area was the sector from surface to 60,000 feet
(18.30 km) and the cool area was that area enclosed by
bearing lines from winds at 60,000 to 90,000 feet
(18.30 to 27.40 km).
The long-range (24-hour) fallout
plot was drawn to show its location relative to native
atolls and populations and was presented in conjunction with the surface radex area.
Seventy-two-hour airborne particle trajectoryforecast.
The airborne particle trajectory forecast (constructed
by Weather Central) was used to evaluate contamination
on air routes and to extend the surface radex area beyond H+6.
Air radex area.
The air radex area normally did not
affect the shot decision, and it was not directly used
at briefings unless requested.
(This radex area was
Plotted and kept displayed at the Radsafe Office.)
Radiation hazard outlooks.
The following specific
potential hazards were evaluated at each briefing:
-- Bikini and Enewetak.
The outlook was determined
from the forecast hodograph for the shot atoll.
-- Ujelang.
Both the long-range fallout plot and shot
atoll hodographs were used to evaluate the outlook
for Ujelang.
-- Native atolls in the southeast quadrant.
Both the
fallout plot and shot atoll hodographs were used to
evaluate the outlook for native atolls in the southeast quadrant.
-- Aircraft control destroyer.
The shot atoll hodograph was used to recommend safe positioning of the
control destroyer for at least 6 hours and retirement in the most favorable direction in the event
fallout was experienced.
-- Fleet tugs (ATFs) and YAGs.
This was presented to
indicate the major activity (drone liberty ships,
Project 6.4) taking place within or near the surface radex area, and within close range of the
armed device prior to H-hour.

~~ Air routes through Wake and Kwajalein.

The impact

on the air routes was determined by the 72-hour

airborne particle trajectory forecast. The trajectories at 10,000, 20,000, and 30,000 feet (about 3,

6, and 9 km) were considered to have the major impact on these routes between H-hour and H+24.

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