Detonated:    28 January 1951    

Time:     1352    GMT

TYPE OF DETONATION:     Airburst    
 
ALTITUDE OF DETONATION:     330    m (above ground) 
 
REPORTED YIELD:     8     kilotons 
 
RADIOIODINE (I-131) PRODUCED:   1.3 x 10E6 Curies 
 
STABILIZED CLOUD HEIGHT:  Top  10.7  km msl;  
 
                          Base  No Report   
 
MEASUREMENTS AVAILABLE FROM GUMMED FILM COLLECTORS:  No      
 
 
RADIOIODINE IN COUNTIES WITHOUT GUMMED FILM COLLECTORS  
     ESTIMATED BY:    Meteorological Model   
 
CLOSE-IN FALLOUT PATTERN AVAILABLE:   No 
             Trajectory and Fallout Characteristics 
 
 
                               Ranger, Baker. 
 
Close-In Fallout. 
 
     No close-in fallout data have been located for this test. 
 
Town Data Base 
 
     No Town Data Base records have been located for this test. 
 
County Data Base 
 
     No County Data Base fallout estimates were made for this test. 
 
Upper-Air Trajectories. 
 
 
     Four upper air trajectories were started from the Nevada Test Site at the 
time of detonation (Fig.RA/1/T). The 3.0 km trajectory, not included in the 
Machta et al (1957) analysis, was computed especially for this report.  Initial 
trajectory movements were toward east through southeast. The highest three 
trajectories moved eastward at 15 to 26 m s-1 then just east of the Oklahoma 
panhandle they gradually turned toward east-north-east and accelerated to 28 to 
38 m s-1.  
 
     Although directional shears were minimal among the four trajectories, 
considerable speed shears were exhibited.  The 12.2 km trajectory reached the 
east coast of Maine in only 30 hours, while the 9.1 and 5.5 km trajectories 
required 1 1/2 days to reach the coast, exiting over Cape Cod and northern New 
Jersey, respectively.  The much slower 3.0 km trajectory required 3 full days to 
exit over the east coast of Maine.  This trajectory lay somewhat to the north of 
the higher-level trajectories early but it moved along the north edge of the 
envelope of the higher trajectories from mid-continent eastward.      
 
     The deposition of radioiodine (I-131) across the United States was estimated 
by the Meteorological Transport and Deposition Model described in the 
introduction of this Annex, in Chapter 3, and in Appendix 1.  This is because no 
ground-level collection system for detecting radioactivity had been established 
for the Ranger tests, as mentioned above.  Fallout was distributed along the 
trajectory tracks nearly continuously from the Nevada Test Site to eastern Maine 
in a fairly narrow band as shown in Fig. RA/1/F.  The heaviest depositions were 
close to the detonation site but moderate amounts were found eastward and 
northeastward from northeast Oklahoma across Indiana and northeastward to 
Massachusetts. The occurrence of more rain in the eastern half of the country 
caused the moderate fallout to persist within the trajectory envelope across the 
eastern half of the U. S. Lesser amounts are shown near the borders of the 
trajectory envelope.       
  Reference 
 
 
Machta, L., H.L. Hamilton, Jr., L.F. Hubert, R.J. List, and K.M. Nagler, 1957: 
Airborne measurements of atomic debris. Journal of Meteorology, 14(4): 165-175.  
 
Figure RA/1/T. Estimated trajectories, at several altitudes, of the radioactive cloud resulting 
               from the test BAKER of 28 January 1951.  Numbers indicate the position of each 
               trajectory at 0000 GMT for several days following the explosion. 
 
Figure RA/1/F. 
Figure RA/1/CD.