북태평양에서 일산화탄소의 연직분포 및 일변화 : 모형 연구

Abstract

Carbon monoxide (CO) which is formed by photochemical reaction with dissolved organic matter, is one of the useful tracers for understanding the physical, chemical, and biological phenomena in the ocean. We developed a CO module and integrated it into ERSEM (European Regional Seas Ecosystem Model) in order to investigate the CO dynamics occurring in the complex marine ecosystem. The CO module consists main processes of CO dynamics in the upper ocean photochemical production, microbial oxidation, and air-sea gas exchange. Physical mixing in the upper ocean is relied on GOTM (General Ocean Turbulence Model). Setting up a 1-D model by coupling ERSEM with GOTM we examined the CO module by simulating the observations conducted for 24 hours at two hydrocasting stations, NP06 (47.38°N, 160.69°E) and NP11 (62.50°N, 174.00°W) in 2012 as a SHIPPO (SHIpborne Pole-to-Pole Observations) project. Not only did the 1-D model effectively reproduce the typical sinusoidal variation of CO at the surface but also the vertical structure of exponential decrease of dissolved CO with depth which is shown in the observations. This implies that the photochemical production occurring within the euphoticzone during daytime and the microbial oxidation occurring in the entire water column at all the time were properly implemented in our module. Analysis of length scales relevant to the aforementioned processes based on the model simulationsted it into ERSEM (European Regional Seas Ecosystem Model) in order to investigate the CO dynamics occurring in the complex marine ecosystem. The CO module consists main processes of CO dynamics in the upper ocean photochemical production, microbial oxidation, and air-sea gas exchange. Physical mixing in the upper ocean is relied on GOTM (General Ocean Turbulence Model). Setting up a 1-D model by coupling ERSEM with GOTM we examined the CO module by simulating the observations conducted for 24 hours at two hydrocasting stations, NP06 (47.38°N, 160.69°E) and NP11 (62.50°N, 174.00°W) in 2012 as a SHIPPO (SHIpborne Pole-to-Pole Observations) project. Not only did the 1-D model effectively reproduce the typical sinusoidal variation of CO at the surface but also the vertical structure of exponential decrease of dissolved CO with depth which is shown in the observations. This implies that the photochemical production occurring within the euphoticzone during daytime and the microbial oxidation occurring in the entire water column at all the time were properly implemented in our module. Analysis of length scales relevant to the aforementioned processes based on the model simulations