Estimating the multi-year average air-sea CO_(2) flux over a large area usually involves the use of monthly mean variables from the atmosphere and ocean.Ignoring sub-monthly processes will blur the oceanic carbon cycl...Estimating the multi-year average air-sea CO_(2) flux over a large area usually involves the use of monthly mean variables from the atmosphere and ocean.Ignoring sub-monthly processes will blur the oceanic carbon cycle,especially when the synoptic and sub-seasonal scale processes are significant,like in the South China Sea(SCS).Based on an empirical relationship between the partial pressure of CO_(2) in water and the sea surface temperature(SST),we recalculated the air-sea CO_(2) flux of the SCS with daily products of atmospheric reanalysis and SST.Our results show that the sub-monthly process contributes 10%of the total CO_(2) flux of the SCS and can even alter the sign of the CO_(2) flux in the spring.In the near-surface coupling process,intramonthly variations in surface winds play the dominant role,except in regions with significant ocean eddies.The co-spectrum analysis of SST and wind speed reveals the most essential oscillation of>20 days.Therefore,a product of the sea surface environment for 10-day intervals can better estimate the air-sea CO_(2) flux over the SCS than monthly data.展开更多
Air–sea exchange plays a vital role in the development and maintenance of tropical cyclones（TCs）. Although studies have suggested the dependence of air–sea fluxes on surface waves and sea spray, how these processe...Air–sea exchange plays a vital role in the development and maintenance of tropical cyclones（TCs）. Although studies have suggested the dependence of air–sea fluxes on surface waves and sea spray, how these processes modify those fluxes under TC conditions have not been sufficiently investigated based on in-situ observations.Using continuous meteorological and surface wave data from a moored buoy in the northern South China Sea,this study examines the effects of surface waves and sea spray on air–sea fluxes during the passage of Typhoon Hagupit. The mooring was within about 40 km of the center of Hagupit. Surface waves could increase momentum flux to the ocean by about 15%, and sea spray enhanced both sensible and latent heat fluxes to the atmosphere,causing Hagupit to absorb 500 W/m^2 more heat flux from the ocean. These results have powerful implications for understanding TC–ocean interaction and improving TC intensity forecasting.展开更多
在全球气候变暖的背景下,准确估计海-气界面CO_2通量显得非常重要。海-气界面CO_2通量通常利用块体公式,由气体交换速率与大气和海洋的CO_2分压差(ΔpCO_2)的乘积来计算。影响气体交换速率的因素很多,但一般经验性地与风速相联系,其测...在全球气候变暖的背景下,准确估计海-气界面CO_2通量显得非常重要。海-气界面CO_2通量通常利用块体公式,由气体交换速率与大气和海洋的CO_2分压差(ΔpCO_2)的乘积来计算。影响气体交换速率的因素很多,但一般经验性地与风速相联系,其测量方法通常有物质平衡法和涡相关法,后者给出的结果比前者大。基于前人的两类观测数据,提出了一个以风速为函数的气体交换速率新方案。在此基础上,基于最新的SOCATv2(Surface Ocean CO_2Atlas version 2)的ΔpCO_2数据集,计算了1982—2011年海洋对CO_2的净吸收量及其年变化,发现2001年海洋净吸收量存在一个最小值,2001年之后,海洋净吸收量迅速增加,而这一年变化特征主要由ΔpCO_2的年变化特征所决定,风速的影响可以忽略。展开更多
基金supported by the National Key Research and Development Program of China (Grant No. 2023YFF0805502)the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (Grant No. SML2022SP401)+1 种基金the Ocean Negative Carbon Emissions (ONCE) Programthe National Natural Science Foundation of China (Grant No. 42305078)
文摘Estimating the multi-year average air-sea CO_(2) flux over a large area usually involves the use of monthly mean variables from the atmosphere and ocean.Ignoring sub-monthly processes will blur the oceanic carbon cycle,especially when the synoptic and sub-seasonal scale processes are significant,like in the South China Sea(SCS).Based on an empirical relationship between the partial pressure of CO_(2) in water and the sea surface temperature(SST),we recalculated the air-sea CO_(2) flux of the SCS with daily products of atmospheric reanalysis and SST.Our results show that the sub-monthly process contributes 10%of the total CO_(2) flux of the SCS and can even alter the sign of the CO_(2) flux in the spring.In the near-surface coupling process,intramonthly variations in surface winds play the dominant role,except in regions with significant ocean eddies.The co-spectrum analysis of SST and wind speed reveals the most essential oscillation of>20 days.Therefore,a product of the sea surface environment for 10-day intervals can better estimate the air-sea CO_(2) flux over the SCS than monthly data.
基金Zhejiang Provincial Natural Science Foundation of China under contract No.LR15D060001the National Program on Global Change and Air-Sea Interactions under contract No.GASI-IPOVAI-04the National Natural Science Foundation of China under contract Nos 41476021,41706034 and 41321004
文摘Air–sea exchange plays a vital role in the development and maintenance of tropical cyclones（TCs）. Although studies have suggested the dependence of air–sea fluxes on surface waves and sea spray, how these processes modify those fluxes under TC conditions have not been sufficiently investigated based on in-situ observations.Using continuous meteorological and surface wave data from a moored buoy in the northern South China Sea,this study examines the effects of surface waves and sea spray on air–sea fluxes during the passage of Typhoon Hagupit. The mooring was within about 40 km of the center of Hagupit. Surface waves could increase momentum flux to the ocean by about 15%, and sea spray enhanced both sensible and latent heat fluxes to the atmosphere,causing Hagupit to absorb 500 W/m^2 more heat flux from the ocean. These results have powerful implications for understanding TC–ocean interaction and improving TC intensity forecasting.
文摘在全球气候变暖的背景下,准确估计海-气界面CO_2通量显得非常重要。海-气界面CO_2通量通常利用块体公式,由气体交换速率与大气和海洋的CO_2分压差(ΔpCO_2)的乘积来计算。影响气体交换速率的因素很多,但一般经验性地与风速相联系,其测量方法通常有物质平衡法和涡相关法,后者给出的结果比前者大。基于前人的两类观测数据,提出了一个以风速为函数的气体交换速率新方案。在此基础上,基于最新的SOCATv2(Surface Ocean CO_2Atlas version 2)的ΔpCO_2数据集,计算了1982—2011年海洋对CO_2的净吸收量及其年变化,发现2001年海洋净吸收量存在一个最小值,2001年之后,海洋净吸收量迅速增加,而这一年变化特征主要由ΔpCO_2的年变化特征所决定,风速的影响可以忽略。
