Geoscience Reference
In-Depth Information
If cloud droplets fall down toward the ground with air temperature
greater than 0
◦
C like 3
◦
C at 18:00 LST December 8, they become rain. As
the cloud droplets of ice phase close to the ground surface of the city, the
phase of snow was changed into the phase of rain, through melting process
of ice crystal to be water due to air temperature over than 0
◦
C. However,
when the distance between the cloud base and the ground is very close,
snow phase of droplets still remains snow phase, but when the distance is
far, snow phase is changed into rain phase.
A relative humidity band of 100% near the ground surface lay along
the coast from south-east to north-west and coincided with rainfall amount
band along the coast (Figs. 5 and 6). Simultaneously, these two kinds of
bands also coincided with minimum values of sensible heat fluxes near the
surface (Fig. 7).
In the open sea, sensible heat flux was very big with a maximum value of
320 W/m
2
, which implied a great amount of water vapor to be evaporated
from the sea surface into the atmosphere, due to the temperature difference
between sea water (about 8
◦
C) and air temperature (about 2-3
◦
C) near the
sea surface. The sensible heat fluxes became smaller closing to the coast.
In the coastal inland, the fluxes were zero or negative value, due to very
small temperature difference between air temperature and ground surface
temperature, implying the cooling of air masses by the cold ground surface.
Thus a great amount of moisture driven by easterly wind from the sea
into the inland basin and further the mountain side should be cooled down
Fig. 5. (a) Relative humidity (%) at 10 m height over the ground surface at 18:00 LST,
December 7, 2002 and (b) 18:00 LST, December 8. T and K denote Mt. Taegulyung and
Kangnung city.
