by a confluence of the southward flowing Oyashio Current and the northward flowing 

 Kuroshio Current, both of which have been discussed in connection with previous 

 cases. ) Upon reaching the American mainland, it divides into (1) the southward 

 flowing California Current, and (2) the Alaska Current which curves counter-clockwise 

 past the Gulf of Alaska and then follows the Alaskan Peninsula. It is suggested 

 that the elongated warm pattern which, in Figure 5-7, extends across the area from 

 east to west may represent the northern-most branch of the Alaska Current at the 

 longitude where it again recurves southward. 



5. 3. 3 Indian Ocean Case 



The third series selected in this set of tests was located in that portion of 

 the Indian Ocean just off the northwest coast of Australia. This area was one of 

 generally clear skies throughout the period 6 August through 8 August 1963, as 

 evidenced by both nephanalyses from TIROS TV passes, and conventional weather 

 maps. This was also one of the few occasions in this investigation when it seemed 

 relatively safe to assume clear skies during a nighttime pass. Two passes were 

 selected for analysis; one from TIROS VII, Pass 706, on the 6th of August 1963 

 at 0348Z or 1148 local time; and the other 2-1/2 days later from TIROS VII, 

 Pass 744, on 8 August at 1655Z (or 0055 on 9 August local time). 



The first of these analyses is shown in Figure 5-8. As indicated previously, 

 the area is largely isothermal, with only a slight increase in temperature toward 

 the north (equatorward). The cloud mass shown in the western portion was deter- 

 mined using a 10 % albedo threshold applied to the Channel 5 listings. The satellite 

 was in alternating-open mode in both cases, so the data as originally plotted were 

 somewhat noisy, particularly in view of the small over-all gradients. Much of this 

 problem disappeared when the data were re-plotted as averages over 1 squares. 



Figure 5-9 shows the corresponding night-time analysis from Pass 744. With 

 the exception of the relatively cool waters along the Australian coast, the pattern 

 looks quite different, although the absolute temperatures are not drastically changed. 

 The area of the warmest waters in Figure 5-9 was largely cloud covered at the time 

 of Pass 706 (Fig. 5-8). The cooler temperatures indicated in the northwest corner 

 of the Pass 744 data seem out of place, and may well be the result of some cloudi- 

 ness. Of course Channels 3 and 5 provide no information as to .the cloudiness of an 

 area in night-time passes. The periodic variation of Channel 2 degradation with the 

 orbit-sun phase geometry is relatively steady during this period, and hence cannot 

 account for the generally warmer temperatures found in the second case. 



31 



