Rain impacts on CO₂ exchange in the western equatorial Pacific Ocean

Abstract

The ocean plays a major role in the global carbon cycle through the atmosphere‐ocean partitioning of atmospheric carbon dioxide. Rain alters the physics and carbon chemistry at the ocean surface to increase the amount of CO 2 taken up by the ocean. This paper presents the results of a preliminary study wherein rain measurements in the western equatorial Pacific are used to determine the enhanced transfer, chemical dilution and deposition effects of rain on air‐sea CO 2 exchange. Including these processes, the western equatorial Pacific CO 2 flux is modified from an ocean source of +0.019 mol CO 2 m −2 yr −1 to an ocean sink of −0.078 mol CO 2 m −2 yr −1 . This new understanding of rain effects changes the ocean's role in the global carbon budget, particularly in regions with low winds and high precipitation.