MEAN SEA LEVEL FWCTUATIONS OFF ALEXANDRIA COAST

MEAN SEA LEVEL FWCTUATIONS OFF ALEXANDRIA COAST
FAMMY M. EID
Faculty of Science Alexandria University, Alexandria, Egypt.
ABSTRACT
The effect of etmospherlc pressure on the fluctuations of
“””,thly lIlI!etl ..e level (“Sl) oft Alexendrle coe.t for the
period frOlll 1962 to 1978 Is Investlgeted by different weys.
It Is found thet the see level height Is generelly
decree.I”lI with tncreesl”ll etmospherlc pressur’ especlelly
6.Jrl”ll ………r. Also. the power end cross-power spectrel
deMltles of “””,thly “Sl end etmospherlc pressure ere
investlgeted for the frequency ra”lle between 0.014 and 0.50
cycles per “””‘th. It Is found thet mo.t of the power Is
centered at low frequencies particularly at emuel end
seml.nnual cycles. There Is soms coherence between IIlOl’lthly
“Sl R et””,spherlc pressure et certeln low frequencies,
while It Is moderste to poor .t “”,st high frequencies.
“oreover. the pressure correction on lllaan see 1…..1 Is
cslcul.ted.
In .dclltlon. the effect of weter density on se. level
oscillstions for the period frOlll July 1977 to June 1978 Is
studied. The densitY cheng.. off Alexandrle co.st showed s
significant effect on the se. level fluctuettons.
Finally the Isost.tlc deperture In s•• level Is
detel1lllned on the besis of the v.rtetlon In etmospherlc
pressure R wster density. The -.”\hly “SL correspond In
silln R relatively In IIIIlgnltude with the Isost.tlc
departure except elIrlng winter when It strongly dl fters
either In sign or tn IIlIlllnttude.