TABLE B.29
SAMPLE CALCULATIONS OF PARTICLE TRAJECTORIES
AVAILABLE DATA, SHOT ZUNI
1.
Altitude
Time
feet
10,000
16,000
25,000
30,006
40,000
50,000
80,000
2.
H-3,
H-3,
H-3,
H-3,
H-3,
H-3,
H-3,
H+9,
Ht9,
H+9,
H+9,
H+9,
H+9,
H+9,
H+21,
H+21,
H4#21,
H4+21,
H+21,
H+21,
H+21,
(2) Chart 2, H—3 hours, 40,000 feet, 12° 02’ N, 165° 41'
H+33
H+33
H+33
H+33
H+33
H+33
H+33
.
OLZ
Time
hours
H-3,
H-3,
H-3,
H-3,
H-3,
H-3,
H+3,
H+3,
H+3,
H4+3,
H+3,
H+3,
H+9,
H+9,
H+9,
H+9,
H+9,
H+9,
H416,
H+16,
H+16,
H+i5,
H+15,
H+16,
H+21,
H+21,
H+21,
H+2i,
H+21,
H+21,
H+27,
H+27,
H+27,
H+27,
H+27,
H+27,
H+ 33
H+33
H+ 33
H+ 33
H+ 33
H+33
Measured winds aloft at Bikini, Eniwetok, and Rongerik Atolls, Reference 70.
COMPUTATION OF PARTICLE TRAJECTORIES
1.
Considering time-and-space variation of the wind Meld:
a. Shot Zuni: particle size, 75y; originating altitude, 60,000 feet; assume 3-hbr persistence of wind Held.
b. Latitude and longitude of particle: 11° 30' N 165° 22° E at 0 time.
c.
Time to fall 5,000 feet (60,000 to 55,000): 1.16 hours.
d. 5,000-foot zonal wind (60,000 to 66,000), (time and apace variation insignificant),
160 degrees, 17 knots.
e. Compute trajectory projection of particle through layer (used plotting device,
Reference 68).
{.
E: wind 240 degrees,
37 knots.
Vertical-motion charts of the wind field (computed values), Reference 71.
2,000
10,000
20,000
30,000
40,000
60,000
Interpolation for time-and-space variation of winds from constant level charts:
(1) Chart 1, H-—3 hours, 50,000 feet, 12° 02" N, 165° 41" E : wind 250 degrees,
38 knots.
hours
Altitude
feet
3.
n.
Conastant-level charts of the wind fleld (isogon-isotach analysis), Reference 70.
Plot Vector 1 (used plotting device).
g- Latitude and longitude of particle at 55,000 feet: 11°47" N 166° 14' E.
h. Timeto fall 5,000 feet (56,000 to 50,000): 1.16 hours.
ft. 5,000-foot zonal wind (55,000 to 60,000), (time and space variation insignificant),
240 degrees, 25 knots.
,
J. Compute trajectory projection of particle through layer (used plotting device).
k. Add Vector 2 to end of vector 1 on plot (used plotting device).
1, Latitude and longitude of particle at 60,000 foets 12° o2' N 166° 41° E.
m. Time to fall 5,000 feet (60,000 to 48,000): 1.21 hours.
(3) Interpolated value of wind in layer 50,000 to 45,000 feet: 245 degrees, 38 knots
at H —3 hours (to nearest 5 degrees).
(4) Chart 3, H+9 hours, 50,000 feet, 12°02" N, 165° 41' E : wind 235 degrees,
30 knota.
(5) Chart 4, H+9 hours, 40,000 feet, 12° 02' N, 165° 41" E : wind 210 degrees,
40 knots.
oa
(6) Interpolated value of wind in layer 50,000 to 45,000 feet: 230 degrees, 32
knots at H+ 9 hours (to nearest 5 degrees).
(7) Final interpolated value of wind in layer 50,000 to 45,000 feet: 240 degrees,
37 knots at H+ 3 hours (to nearest 5 degrees).
o. Compute trajectory projection of particle through layer using final wind in N-7 (used
plotting device).
p. Add Vector 3 to end of vector 2 on plot (used plotting device).
q. Continue the above computations until particle reaches surface.
2.
Considering time-and-space variation of the wind field as well as vertical motions:
a. Shot Zunl; particle size, 75y, originating altitude, 60,000 feet, assume 3-hour perslstence of wind field.
b.
Latitude and longitude of particle: 11° 30' N, 165° 22' E at 0 time.
c. From computed vertical motion charts, determine by interpolation, the value of the
vertical wind through the 5,000-foot tayer (60,000 to 55,000) at H+0 hours and 11° 30° N, 165°
22' E: -19.5 cm/sec.
d.
From measured Bikini winds, obtain 5,000-foot zonal wind (60,000 to 55,000) at H+0
hours: 160°degrees, 17 knots.
e. Compute timeto fall, 5,000 feet in stlll atmosphere (60,000 to 55,000): 1.16 hours.
f. Compute corrected time to fall by considering vertical motiona (60,000 to 55,000),
0.76 hour.
g-
Compute effective wind speed through layer by considering corrected timeto fall,
63 percent increase in falling speed or 53 percent decrease in wind speed:
knots.
160 degrees, 11
bh. Using effective wind speed and atill air time to fall 5,000 feet, compute trajectory
projection of particle through layer. (This reverse approach was used to implement plotting
with plotting device. )
1. Plot Vector i (used plotting device).
.
j. Continue this process interpolating for vertical motions and wind velocity from charts,
asa function of time, space, and altitude, until particle reaches surface.