Center, Card Deck No. 144. To these data were 

 added the sea surface temperatures measured 

 weekly at Johnston Island for BCF, Honolulu. 

 At Christmas Island, meteorological observa- 

 tions are made three times dally and the sea 

 surface temperature ismeasured dailyfor BCF. 

 The sea surface temperatures and the 1800 

 G.m.t. synoptic meteorological observations 

 from the two islands (0800 local time, Christ- 

 mas Island, and 0700 local time, Johnston Is- 

 land) have been combined with the surface ma- 

 rine data. 



At the time of the initial sorting, derived prop- 

 erties and heat exchange processes were also 

 computed. Thus the data tape referred to in the 

 introduction contains in chronological order by 

 day and by 1° square the sea surface tempera- 

 ture, the dry and wet bulb air temperatures, 

 the sea level atmospheric pressure, the cloud 

 cover, the sea-air vapor pressure difference, 

 the vapor pressure of the air, the wind speed 

 and direction, the zonal and meridional com- 

 ponents of the wind velocity, the radiation from 

 sun and sky, the effective back radiation, the 

 heat of evaporation, and the conduction of sensi- 

 ble heat. 



I planned originally to summarize the mete- 

 orological data for periods of, possibly, 5 days 

 and then, by summation, obtain values for the 

 monthly sea-air interaction processes. The 

 spatial and temporal distribution of marine sur- 

 face observations, however, proved inadequate 

 to permit this procedure; I had to use the tradi- 

 tional climatic approach. 



PROCESSING OF DATA 



The meteorological data were initially sorted 

 chronologically by day and by 1° square units of 

 area. When more than one set of observations 

 occurred in a 1° square per day, the meteoro- 

 logical properties, including the wind speeds and 

 the zonal and meridional components of the wind 

 velocity, were averaged. In consequence only 

 one set of meteorological observations can occur 

 per day in any 1° square. 



Quality control over the large number of data 

 proved to be a major task. In the initial sorting 

 process, "flagging" values that fell outside the 

 climatic limits proved unsuccessful. This pro- 

 cedure had been used in the preparation of the 

 Indian Ocean meteorological atlas (Ramage, 

 Miller, and Jefferies, in press). Too many ob- 

 servations that were consistent with surrounding 

 data fell outside the climatic limits during the 



2 years of this study. An initial listing of the 

 data was therefore inspected without computer 

 aid. Only obviously erroneous values, deter- 

 mined by comparison with values in the same 

 geographic region and within a few days, were 

 eliminated. 



Of the original marine surface and island 

 decks, I sorted only those meteorological data 

 that enter into the computation of large-scale, 

 sea-air interactions: the dry and wet bulb air 

 temperatures; the sea-air temperature differ- 

 ence; the sea-level atmospheric pressure; the 

 speed and direction of wind; and the total cloud 

 cover. 



The meteorological properties were, there- 

 fore, summarized by 5° square units of area and 

 by months and are presented in table A. The 

 summaries for each property contain the mean 

 value, the highest and lowest values observed, 

 the standard deviation if there were more than 

 four observations, and the number of observa- 

 tions. In addition, the summary also includes 

 the mean location of observations. 



Smoothed charts of the sea surface temper- 

 ature, the air temperature, the vapor pressure 

 of the air, the cloud cover, and the wind speed 

 were obtained by contouring the summarized 

 data plotted at the mean location of the obser- 

 vations. This procedure had been used in the 

 preparation of the Indian Ocean meteorological 

 atlas (Ramage et al., in press). In turn, the 

 smoothed charts were used to obtain interpo- 

 lated values at the center of each 5° square, and 

 to compute the radiation from sun and sky, the 

 effective back radiation, the heat of evapora- 

 tion, the conduction of sensible heat, and the net 

 heat exchange across the sea surface. Table B 

 presents both the interpolated values and the 

 derived heat exchange processes. 



When table B is used in combination with ta- 

 ble A, it is possible to judge the reliability of 

 the results in any area and month covered by 

 this report. 



HEAT EXCHANGE COMPUTATIONS 



Sea-air interaction processes cannot, in gen- 

 eral, be measured directly except for the radi- 

 ative energy exchange. Radiation measurements 

 over the oceans, however, are scarce. Quanti- 

 tative evaluation of these processes, therefore, 

 depends on computations in which empirically 

 derived formulas are used. These formulas 

 were reviewed by Laevastu (1960) and the more 

 general subject of large-scale, sea-air inter- 



