Travelers Research Center Contract 



A contract was executed with Travelers in February 1^62 to make a 

 feasibility study for determining by machine methods a surface wind 

 field over the North Atlantic Ocean. The input data for the work done 

 on this contract consisted of the following: 



1. Digitized sea-level pressure grid data on magnetic tape for 

 the Worth Atlantic Ocean within the time period April 1955 through 

 March I96O obtained from the U. S. Air Force Project ^33L. 



2. Digitized surface to "JOO-mh mean temperature grid data on 

 magnetic tape for the same period, also from Project 433L. 



3. Ocean Station Vessel surface synoptic weather data on punched 

 cards for the same period for ship locations B, C, D, and E. 



h. Seasonal charts of air-sea temperature difference distribution 

 for the North Atlantic Ocean. 



5. Monthly charts of mean sea-surface temperatures for the North 

 Atlantic Ocean. 



6.- North Atlantic sirrf ace-weather ship reports for 15 December 

 through 27 December 1959. 



The U. S. Air Force Project 4331- data consist of manually-read 

 sea-level pressure values and pressure height and teraperatiare data for 

 the 700-mb level on a diamond grid network at the JIWP gridpoints for 

 which points i and j are both odd or both even. The data were ex- 

 tracted from subjective synoptic weather map analyses by the U. S. 

 Weather Bureau. Travelers checked all the data for errors^ made 

 corrections^ and, by interpolation from the diamond grid, computed 

 values for all the standard JNWP gridpoints. The data in corrected 

 form are on IBM 7^90 magnetic tapes for the period April 1955 through 

 March I96O. 



Two methods were investigated by Travelers for the development of 

 a wind- specification technique. The first method used the screening- 

 regression technique to generate wind- specification equations of which 

 six equations (Table l) using ^9 different variables (Table 2) were 

 generated and tested. Winds from these equations are regression winds 

 in this report. The second method, which was much more difficult to 

 obtain, was undertaken to try for improvement of the regression winds. 

 It consisted of an objective analysis of winds using the regression 

 winds as an initial guess and then actual ship wind observations 

 (assuming them to be correct) for correcting the initial guess. These 

 wind estimates are called objective-«.nalysis winds in this report. In 

 addition, geostrophic and gradient winds were computed and evaluated 

 for comparison with the regression winds. 



