24 








Table 29. Harmonic coefficients of diurnal waves of air temperature, Carnegie, 1928-29 
Latitude range and number of days of record 
METEOROLOGICAL RESULTS OF LAST CRUISE OF CARNEGIE 





35°N-25°N, | 25°N-15°N, 








Desig- 65°N-55°N, | 55°N-45°N, | 45°N-35°N, 
nation 6 days, 21 days, 26 days, | ieee med oe CANE: 
July-Aug. July-Aug. June-Sep. Aug.-Oct. Aug.-Nov. Aa Nay 





Coefficients, °C 
ay -0.460 -0.143 -0.369 -0.486 -0.441 -0.725 
ag +0.097 +0.129 +0.100 +0.205 +0.165 +0.280 
a3 -0.022 -0.014 +0.054 +0.058 +0.007 +0.008 
a4 +0.021 +0.033 +0.035 -0.024 -0.030 -0.026 
by -0.444 -0.159 + 0.384 -0.266 -0.201 -0.176 
bg + 0.044 +0.192 +0.095 +0.101 +0.021 +0.002 
b3 +0.049 -0.001 +0.015 -0.023 +0.008 +0.014 
b4 -0.061 +0.019 -0.047 -0.027 +0.025 -0.022 
Amplitude, °C 
cl 0.639 0.213 0.533 0.554 0.484 0.746 
c2 0.106 0.231 6.138 0.228 0.166 0.280 
c3 0.054 0.014 0.056 0.062 0.011 0.016 
c4 0.064 0.038 0.059 0.036 0.039 0.034 
Phase angle, ° 
$1 226.0 222.0 223.9 241.2 245.5 256.4 
$2 65.6 33.9 46.5 63.8 82.8 89.6 
$3 335.8 265.9 74.5 111.6 41.2 29.7 
$4 161.0 60.1 143.3 221.6 309.8 229.8 













5°S-15°S, 15°S-25°S, ° ° ° ° 
Pai 38 days, 31 days, | “Segara” | odars.” |-15°N-15°S, 
Nov. and Nov. and Nov. -jan. Dae 117 days, 


Jan.-Apr. 
Jan.-Mar. 



Coefficients, °C 
al -0.517 -0.678 -0.598 -0.791 -0.631 -0.640 4 
a2 +0.167 +0.252 + 0.226 +0.158 +0.098 + 0.233 2 
a3 +0.027 -0.026 -0.016 +0.062 +0.032 + 0.003 2 
a4 -0.034 +0.001 -0.035 -0.008 -0.036 -0.0202 
bi -0.140 -0.139 -0.187 -0.245 -0.285 -0.1524 
b2 +0.017 +0.034 -0.015 + 0.037 +0.037 +0.0182 
b3 +0.014 + 0.039 +0.030 + 0.004 + 0.005 +0.022 2 
b4 +0.014 +0.009 +0.002 + 0.026 +0.009 0.0002 
Amplitude, °C 
cy 0.536 0.692 0.627 0.828 0.693 0.657 
co 0.168 0.254 0.226 0.162 0.105 0.234 
C3 0.030 0.047 0.034 0.062 0.032 0.022 
C4 0.037 0.009 0.035 0.027 0.037 0.020 
Phase angle, ° 
oy 254.8 258.4 252.6 252.8 245.7 256.6 
$92 84.2 82.3 93.8 76.8 69.3 85.6 
63 62.8 326.3 331.9 86.3 81.1 7.8 
$4 292.4 6.3 273.3 342.9 284.0 270.0 
' 2 These are means for latitude zones 15° N-5° N, 5° N, 5°N-5° S, and 5° S-15° S, and 
from these amplitudes, c, and phase angles, ¢, were determined. 
apply certain corrections to these coefficients since, as 
has been brought out in the discussion of the measure- 
ment of air temperature on board ship (p. 13), the air 
temperatures recorded in the Stevenson screen on deck 
are probably too high during daylight hours to represent 
correctly temperature conditions within the free air at 
Similar heights above the sea (3.6 meters). In order 
partially to offset this effect, the corrections to the air- 
temperature data (from the diurnal variability of the 
differences between dry-bulb at deck and crosstrees) 
have been arranged according to ranges of latitude, cor- 
rected for noncyclic change, and subjected to harmonic 
analysis. The coefficients, a and b, have then been sub- 
tracted from similar values of the original analyses, and 
the corrected amplitudes, c and ¢, computed. These 
corrected temperatures and amplitudes, cj and cQ, are 
shown in figure 20. Corrections were not determined 
for c3 andc4. Using these corrected values we findthat 
between latitudes +20°,,the 24-hour term averages four 
times larger than the 12-hour term. One cannot claim 
great reliability for these corrected values (table 30), 
though they more nearly represent the actual unaffected 
air temperatures, and demonstrate the necessity for ob- 
taining true values before drawing conclusions regarding 
relations between the diurnal oscillations of pressure 
and temperature. Correcting the Fourier coefficients of 
