The main component concentrations
of fine particulate were measured at 17 sites by 24-hr
sampling for two weeks by JCAP (Japan Clean Air Program)
in the winter of 1999. The following results were obtained
by multivariate data analysis using the data sets.
(1) The ratio of fine particulate to SPM was about
2/3 and a large difference between the observation
points was not observed although some low values were
indicated in the clean region.
(2) The fluctuation factor and Max/Min of Cl- concentration
for space variation were the highest and those of
SO42- were the lowest among
the six components.
(3) The deviations of space variation for Cele (elemental
carbon) and NO3- concentrations
were larger than for SO42- concentrations.
The peak concentration of Cele and NO3-
for a site sometimes appeared at different dates.
The fluctuation factor of space variation for the
SO42- concentrations was smaller
than that of time variation. SO42-
concentration is thought to change similarly in a
wide mesoscale area.
(4) Three factors were extracted by factor analysis
of all data. Factor 1 is representative of the ammonium
salt that is the main component of the secondary formatted
inorganic particulate. Factor 2 is representative
of the combustion source including vehicle exhaust
and the secondary formatted organic particulate. Factor
3 is representative of sea salt and fine soil particulate.
JCAP (Japan Clean Air Program) は1999年冬季に微小粒子中の主要成分濃度を関東地域の17地点において，1日毎に2週間測定した。このデータセットを用いて多変量解析を行い，次のことを明らかにした。
(1) 微小粒子のSPMに対する質量濃度比は約2/3であり，清浄地域はわずかに小さい値を示したものの，都市域と大差はなかった。
(2) 測定期間中の各成分の平均値を地点別に求めると，地点間の振動係数と最大値／最小値は6主要成分中Cl-
が最も大きく，SO42- は最も小さい値を示した。
(3) Cele ( 元素状炭素 )とNO3- の日平均濃度の空間変動はSO42-
のそれよりも大きかった。同じ測定局でもCeleとNO3-
の極大値は日付の異なる場合があった。SO42- の空間変動は明らかに時間変動よりも小さく，メソスケール内でかなり同じ濃度レベルで変化すると予測される。
(4) 全測定データを用いた因子分析により，3因子を抽出した。第1因子は無機イオンの二次生成を，第2因子は自動車排気粒子を含む燃焼系発生源と有機二次粒子を，第3因子は海塩粒子と土壌粒子の微小粒径区分をそれぞれ代表することがわかった。
