課題名

B-5　二酸化炭素の大気・海洋間交換の解明に関する研究

課題代表者名

杉村行勇（気象庁気象研究所）

研究期間

昭和62年度〜平成2年度

合計予算額

2年度当初予算額11,973千円

研究体制

（１）広域における二酸化炭素の大気・海洋間交換の研究（気象庁）

研究概要

The purpose of this study is to clarify the role of ocean for stabilizing the CO₂ concentration in the atmosphere in the global climate system.  Since 1987, measurements of pCO₂ in air and surface sea water in wide area of the Pacific Ocean were made on research vessels to estimate CO₂ flux between the atmosphere and the ocean.  The exchange coefficient was also conducted by a experimental method.

The concentrations of atmospheric CO₂ over the Pacific Ocean show a seasonal variation and a increase year by year. The ¹³C/ ¹³C of C0₂ in air suggestes the importance of exchange process between air and sea for the temporal variation of atmospheric CO₂ in the equatorial Pacific. On the other hand, a significant difference in the distribution of pCO₂ in surface sea was observed in the equatorial Pacific between 1987 (EI Nino Period) and 1989 (La Nina period). On the basis of these results,CO₂ fluxes between air and sea for 1987 and 1989 were estimated to be 0.48 Gt-C/yr and 1.0 Gt-C/yr in the equatorial Pacific, respectively.

In the laboratory on land, experiments of CO₂ exchange between air and sea water were carried out using the circular wind eater tunnel.  The exchange coefficient clearly depends on the wind speed.