East Asia and Western Pacific METEOROLOGY AND CLIMATE

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eastward. In addition to maintaining monitoring sections south of Japan, the
Japanese oceanographers also pay close attention to both the area where the
Kuroshio exits the East China Sea and the shelf areas north and east of the
Changjiang river mouth.
The working group which coordinates this bilateral program has recognized the
deficiency of the research collaboration aspect and has taken steps to strengthen
it. In 1988 two joint research projects have been initiated, one on the Tsushima
current and the other on the circulation on both sides of the Ryukyus. This year
joint research projects have expanded to other disciplines/ including one on
micro- and meso-scale air-sea interaction to be conducted over the East China Sea.
4. AIR-SEA INTERACTION ASPECT
Since the start of JRK the Japan Meteorological Agency has been conducting
observations over the East China Sea to study, via indirect means, the energy and
momentum transfer across the sea surface. Vertical profiles of physical
characteristics of the maritime atmospheric boundary layer have also been measured
with tethered ballon and aerological observations. On the Chinese side, so far
research attention on air-sea interaction has been focussed on carbon dioxide and
aerosol measurements. Preliminary findings by the Chinese scientists are as
follows-. (1) Both the concentration and size spectrum of aerosol have apparent
seasonal characteristics, reflecting the difference in the transport of terrestial
substances under different weather systems; (2) The partial pressure of carbon
dioxide in maritime atmosphere was found to be around 350 ppmv, about the same as
the global average value. The corresponding value in ocean is in general higher
than the atmospheric value by 20 to 25 ppmv. There are targe variations in the
oceanic value, with a maxumum difference of more than 100 ppiv; (3) In the East
China Sea, the total inorganic carbon concentration in the Kuroshio water was
found to be around 1.8-2.0 lol/kg and the total inorganic alkali 2.2-2.4 mol/kg.
The winter values are higher than the summer values; (4) A one-dimensional air-sea
coupled boundary layer model which takes both convection and entrainment into
account shows promising agreement with results measured by the Japanese scientists.
As commented earlier, a joint resarch project on micro- and meso-scale
air-sea interaction will be conducted over the East China Sea later this year.
Tentative subthemes of this project are (1) characteristics of the maritime
atmospheric convective boundary layer and effects of cloud on this boundary layer,
(2) transfer of momentum and energy across the sea surface, and (3) mechanism of
air mass transformation.