1060 
ship observations. For this purpose a sampling has 
been made of the extensive hourly sea and air tempera- 
ture data obtained on the last Carnegie Expedition 
[11]. In order to test the diurnal variation of ( — 
tz) under conditions such that radiation effects should 
be at a maximum, the analysis was limited to hourly 
temperature data collected on 103 days when the Car- 
negie was in the tropics or, during summer months, 
when it was at the higher latitudes. The hourly values 
for (t. — t), when ¢ was uncorrected for radiation 
effects (see Table II), varied from a maximum of 
+0.90C between the hours of 0200 and 0400 LMT 
to a minimum of —0.24C at 1200 LMT, giving an 
extreme range of 1.14C. When ¢, data corrected for 
radiation effects were used (see [11] for discussion of 
correction method), the time and magnitude of the 
maximum values for (¢, — tz.) remained unchanged, but 
the hour of occurrence of the minimum was shifted to 
MARINE METEOROLOGY 
observations are used, particular care should be exer- 
cised to remove the diurnal effects from the (¢) — f,) 
data which represent ocean areas from about 60°W 
eastward to 90°H. (See Table II.) 
One of the principal objections to the use of the 
Bowen ratio for establishing Q;, is that it requires both 
extensive humidity observations and observed or calcu- 
lated evaporation rates. Neither of these two classes of 
data are available for the Southern Hemisphere nor do 
such data exist in any quantity for the higher latitude 
oceans. A more direct method for determining the 
sensible heat flux between sea and atmosphere would 
be desirable, preferably one which does not involve the 
use of either humidity or evaporation data. 
In a recently published article, Miyazaki [15] pre- 
sents monthly values of Q; within five restricted areas 
“along the Tusima warm current’? (Sea of Japan). 
The results have been obtained through use of an equa- 
TasiE II]. Mean Hourty Vaues or ty — ta (CC) OvER THE OCEANS FROM A SAMPLING OF THE “CARNEGIE”? DaTa 
ours (EMD) nn sec ae ne cache casls Sas eee a tarees 0 1 2 4 5 6 i 8 9 10 11 12 
Meridian equivalent to GM noon................... 180°W | 165°W | 150°W | 135°W | 120°W | 105°W | 90°W | 75°W 60°W 45°W 30°W 15°W 0 
(Conmectedid aan (@) eee eee eee 0.82) 0.89} 0.90) 0.90 | 0.90 | 0.87 | 0.81 | 0.66 | 0.43 | 0.28 | 0.21} 0.41) 0.36 
Uncorrected data (0).................. 0.82) 0.89! 0.90) 0.90 | 0.90 | 0.87 | 0.81 | 0.65 | 0.40 | 0.16 |—0.05|—0.15/—0.24 
Difference (a) minus (6)............... 0.00) 0.00) 0.00) 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.03 | 0.07 | 0.26) 0.56} _ 0.60 
(SOM (IUIN OL) swawnwrcn ees aap eaowaote Saupe AtoudaoS 13 14 15 17 18 19 20 21 22 23 
Mean all hours 
Meridian equivalent to GM noon................... 15°E 30°E 45°E 60°E 75°E 90°E | 105°E | 120°E | 135°E | 150°E | 165°E 
Correctedidatan (@) eee eee eee eee 0.23) 0.38) 0.35) 0.42 | 0.53 | 0.67 | 0.74 | 0.74 | 0.77 | 0.75 0.77 0.62 
Uncorrected data (6).................. —0.23)—0.17/—0.09} 0.13 | 0.30 | 0.50 | 0.66 | 0.73 | 0.77 | 0.75 | 0.77 0.46 
Difference (a@) minus (0)............... 0.46) 0.55; 0.44) 0.29 | 0.23 | 0.17 | 0.08 | 0.01 | 0.00 | 0.00 | 0.00 0.16 
(a) ta corrected for radiation effects. 
(b) ta uncorrected for radiational heating and cooling of ship and instruments. 
1000 LMT and the previous negative value raised to 
+0.21C, giving a corrected range of 0.69C. If it is as- 
sumed that the method of correcting the Carnegie data 
for radiational effects is valid, these differences indicate 
that about 40 per cent of the apparent diurnal variation 
in (t» — tz) is brought about by daytime heating of 
ship and instruments. 
From the standpoint of the effects of the diurnal 
variation of (¢, — ft) upon the published results for 
Qn, it appears that the time error should be significant 
only in those regions where Q, is small or negative and 
where the temperature observations were obtained dur- 
ing daylight hours. Fortunately this effect was notice- 
able on the author’s charts only in the eastern and 
southern North Atlantic where (ft) — t.) is small or 
negative and where the observations were recorded 
during the late forenoon. On the charts for Q, this cor- 
rection would serve to restrict the negative areas in 
the North Atlantic, giving slight positive values to 
the peripheral portions of those areas which at present 
indicate negative values. None of the values for the 
North Pacific should be noticeably affected. In future 
computation of Q@,, when Greenwich Meridian noon 
tion developed by Kuzmin and Saito [12] in which 
only the quantities (¢. — tf.) and W., the wind velocity 
at height a, are needed.’ However, the validity of the 
method is not established by the computation nor is 
any attempt made to adjust the formula to fit the type 
of observational materials which were used. 
Burke [4] has developed a method for determining 
the changes in the heat content of continental polar air 
as it moves out over a warm sea surface. The technique 
requires a knowledge of the initial air temperature, the 
initial lapse rate in the air mass, and the distance the 
air mass has traveled over a sea surface exhibiting a 
3. The final equation which was used for the computations 
is 
4.15 (ty — ta)Wa 
- cal one day, (8) 
= 2 
Qi = 5749 E (aa + 0.16Wa 
Zo 
where 2 is the roughness parameter (given as a function of 
wind speed after Kriimmel and increasing from 0.25 cm at 
W. = 100 em sec to 27.00 cm at Wa = 2000 cm sec). The 
thickness of the laminar boundary layer is assumed constant 
at 0.16 cm. 
