AEROGRAPHER'S MATE 3 & 2 



With the preceding rules in mind, the fol- 

 lowing procedure is suggested for completing 

 the SST analysis: Place the plotted chart over 

 the history chart. Next, locate the most pre- 

 dominant or most persistent feature on the 

 historical chart (Gulf Stream, Kuroshio Cur- 

 rent, etc.). If there are no major features, 

 start in the area of the most dense data. This 

 area or feature is outlined with a standard 

 isotherm using the corresponding isotherm on 

 the history map as a guide. 



NOTE: Standard isotherm spacing is either 

 2°C or 5°F. However, in areas of weak hori- 

 zontal gradients it may be necessary to analyze 

 to the nearest 1° or even 1/2°. 



If a report is noticed which does not fit 

 and appears to be in error, it should be circled. 

 In areas of few or no reports, copy the pre- 

 vious isotherms unless for some specific reason 

 a change is indicated. When one isotherm is 

 completed, take the next value in sequence 

 and sketch it in while using history as a guide. 

 Continue with ihis procedure until the chart 

 is completed. 



The final step in completing the sea sur- 

 face temperature analysis is to harden in the 

 isotherms, using either ink pen, felt tip pen, 

 or soft pencil. 



Label the chart type, date (if a composite 

 chart, the date is the day of the latest data), 

 and the name of the analyst. 



SEA CONDITION ANALYSIS. — An important 

 factor which must be considered in oceanographic 

 forecasting is the physical condition of the sur- 

 face of the sea. This refers to the height and 

 direction of movement of the waves of which 

 the surface is composed. The forecasting of 

 these sea surface characteristics for fleet op- 

 erations, rescue work, etc., is one of the more 

 important responsibilities of the Aerographer's 

 Mate. 



As with any of the other parameters which 

 describe the ocean environment, an analysis of 

 the sea condition must be accomplished before 

 a reliable forecast can be made. 



Analysis Techniques. — Values of wave 

 heights, periods and direction are plotted on the 

 sea condition chart. Significant wave heights 

 (average of 1/3 highest waves observed) in 



feet are indicated by solid isopleths and direc- 

 tions of wave trains are shown by arrows as 

 indicated in figure 11-24. 



The periods are not analyzed, primarily due 

 to the inaccuracy of visual observations. These 

 charts do not differentiate between sea and 

 swell, but show the effective reported wave 

 value height, whether the wave is sea, swell 

 or a combination of both. An important dis- 

 advantage which must be remembered is that 

 waves are not nearly as conservative as sea 

 surface temperatures or layer depths, thus re- 

 sulting in deterioration in the value of the chart 

 over a relatively short period of time. 



RADIOACTIVE FALLOUT 



The radioactive fallout from nuclear weap- 

 ons exploded on or near the surface of the 

 earth creates serious hazards in large areas 

 outside the area of structural damage. In pre- 

 dicting the fallout area, information must be at 

 hand with respect to location of burst, the 

 yield of the weapon, and the atmospheric wind 

 structure. Except for experimental tests, only 

 the last mentioned can be available before the 

 detonation. The procedures explained in this 

 chapter provide for the preparation of a gen- 

 eralized RADFO plot to be available for tactical 

 purposes in reacting to low-yield and high- 

 yield nuclear explosions. 



In the event of a nuclear detonation, radio- 

 logical fallout may be of great significance to 

 the conduct of naval operations. This chapter 

 provides Aerographer's Mates with the infor- 

 mation necessary to enable them to determine 

 areas which are potentially hazardous because 

 of fallout following a nuclear explosion. 



Procedures to be utilized by the operating 

 forces of the Navy are contained in Nuclear 

 Fall-Out Forecasting and Warning Organization 

 ATP 25 (NAVY) (AIR) and, NAVWEASERVCOM 

 INST. 3441.1. 



FALLOUT MESSAGES 



To aid in the evasion of fallout from nu- 

 clear explosions, two types of messages are 

 disseminated to Naval units. One is used in 

 case of an actual detonation of a nuclear device, 

 while the second is a prediction type mes- 

 sage that can be used for planning prior to 

 a nuclear detonation. Both types are given in 

 Table 11-3 along with their symbolic form and 



222 



