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Compare to surface heating of basin surrounded by only mountains, the
transportation of accumulated sensible heat flux from the mountain toward
the low atmosphere over the sea cannot cause sea waters to be much warmed
up, but it can greatly warm up air and soil. Because one thousand times
higher energy is required to warm up sea water masses than air masses. At
this time, air temperature near ground surface of Kangnung city was 35 C,
which well matches calculated value, but air temperature on the sea surface
is 28 Cless7 C than one in the inland coast.
3.2. Wind and air temperature distribution — night
At 00:00 LST, August 15, as nighttime radiative cooling of the ground sur-
face due to no solar radiation increases, synoptic south-westerly wind over
the top of Mt. Taeguallyung moves down along the eastern slope toward the
coast and is associated with mountain wind generated by air temperature
difference between the mountain and the plain surfaces, resulting in down-
slope wind. Then, the downslope wind is further intensified by land breeze
due to horizontal air temperature difference between the coastal inland and
the sea surfaces, becoming strong downslope wind storm (Figs. 3(a)-(c)).
As the downslope wind storm reaching the bottom of the eastern slope
is too strong, a hydraulic jump motion of air occurs near the ground surface
of Kangnung downtown, bounding up to the 1 km height over the coastal
sea and causes the generation of lee-side internal gravity waves. Maximum
speed of wind storm on the lee slope of the mountain reaches 15 m/s, but
nighttime surface wind speed of 2 m/s near Kangnung city beneath of the
internal gravity waves is much weaker than daytime one of 5 m/s, under
the sea breeze.
Turbulent diffusion coecients for heat of 1 m 2 /s exists near the ground
surface and indicates occurrence of a thin shallow nocturnal surface inver-
sion layer (NSIL). Although its thickness is within the height of about 150 m
over the ground in the west of the mountain, no inversion layer due to the
destruction of the inversion by strong downslope windstorm is found along
the eastern slope and shallow surface inversion layer exists in the coast
(Fig. 3(d)). Over the sea surface, marine inversion layer (MIL) forms with
a thickness of about 250 m.
The thickness of the marine inversion layer is slightly larger than one of
the inland NSIL, because the cooling of sea surface is much smaller than
that of the ground surface. At 00:00 LST, surface air temperature at Kang-
nung city is 29 C, which is over than 25 C and this temperature continues
to be until next day morning. If air temperature over 25 C persists for
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