56 U. S. COAST AND GEODETIC SURVEY. 



that component. The numerical value at the right of each term 



fives its maximum value in the foot unit. Term {B)^^, although 

 aving a larger theoretical value than some of the lunar terms which 

 were retained in (100), is usually neglected in the solar tide. Term 

 (B) 59 is a constant and therefore does not affect the rising and falling 

 of the tide but does cause a permanent deformation of the earth's 

 surface. Term (B) go has a period of an anomalistic year which differs 

 very little from a tropical year, the latter being the period of the 

 meteorological component Sa, to which later reference will be made. 

 The coefficients and arguments of the terms of (215) are free from 

 the quantities depending upon the longitude of the moon's node. 

 The k's of the arguments of the solar tides may therefore be consid- 

 ered as zero, and as all the coefficients are constant the factor F of 

 reduction will be unity for each. 



It will be noted that the general coefficient of each group of terms of 

 (215) differs from the corresponding general coefficients of (100) by 



S /c V 

 the factor 'jr \~) ' ^^ order that the coefficients of the individual 



terms of the solar and lunar tides may be more conveniently compared 



S /c V 

 with each other, this factor -r? ( ) is usually transferred from the 



general coefficient of the solar tide to each of the individual terms, thu« 

 leaving the general coefficients the same for both formulas. For 

 brevity this factor is represented by G in Table 3. 



17. LUNISOLAR K^ AND Kg TIDES. 



Comparing (100) and (215), we find that the terms iA)^^ and {A)^^ 

 have the same speeds as {B)^y and (5)^2, respectively, the small ine- 

 qualities represented by 2v and v not affecting the mean speeds of 

 the terms in which they occur. In the analysis and predictions of 

 the tides the components of equal speeds are combined into single 

 components, known as the lunisolar tides, and designated as K^ 

 for the diurnal component and Kj for the semidiurnal component. 



For brevity in the following discussion let 



C=3/2^(^Ja (216) 



C,= C sin 2\ (217) 



C2 = Ccos='X (218) 



«-^(0 ^'''^ 



^ = (1/4 + 3/8 e^) (220) 



^i = ^sin2/ (221) 



A2 = Asm'I (222) 



B={l/^ + SI8e,') G (223) 



5i = Bsin2co (224) 



B^^Bsin'o} (225) 



