净生态系统碳通量（NEE）的计算对于准确模拟区域碳通量和大气CO2浓度的时空变化至关重要。本文利用中尺度大气—温室气体耦合模式WRF-GHG（Weather Research and Forecasting Model with Greenhouse Gases Module），对2010年7月28日至...净生态系统碳通量（NEE）的计算对于准确模拟区域碳通量和大气CO2浓度的时空变化至关重要。本文利用中尺度大气—温室气体耦合模式WRF-GHG（Weather Research and Forecasting Model with Greenhouse Gases Module），对2010年7月28日至2010年8月2日期间影响长江三角洲地区大气CO2浓度及时空分布的各种过程进行了详尽模拟。结果表明，植被光合呼吸模型（VPRM）能模拟不同植被下垫面 NEE 的日变化；WRF-GHG模拟的大气CO2浓度日变化与观测相吻合，但低估了大气CO2浓度5～15 ppm（ppm表示10？6），这可能与人为排放源的低估、VPRM参数的不确定性以及气象场模拟的不准确性有关。太湖和植被覆盖较好的地区如浙江北部山区是该地区的主要碳汇，而城市为CO2的主要排放源。太湖和陆地生态系统对区域内碳循环起到一定的调节作用，减缓区域大气 CO2浓度的升高。此外，局地气象条件如湖陆风对太湖周边地区大气 CO2浓度有显著影响。展开更多
Carbon dioxide(CO2) is an important greenhouse gas that influences regional climate through disturbing the earth’s energy balance. The CO2concentrations are usually prescribed homogenously in most climate models and ...Carbon dioxide(CO2) is an important greenhouse gas that influences regional climate through disturbing the earth’s energy balance. The CO2concentrations are usually prescribed homogenously in most climate models and the spatiotemporal variations of CO2are neglected. To address this issue,a regional climate model(RegCM4) is modified to investigate the non-homogeneous distribution of CO2and its effects on regional longwave radiation flux and temperature in East Asia. One-year simulation is performed with prescribed surface CO2fluxes that include fossil fuel emission, biomass burning, air-sea exchange, and terrestrial biosphere flux. Two numerical experiments(one using constant prescribed CO2concentrations in the radiation scheme and the other using the simulated CO2concentrations that are spatially non-homogeneous) are conducted to assess the impact of non-homogeneous CO2on the regional longwave radiation flux and temperature. Comparison of CO2concentrations from the model with the observations from the GLOBALVIEW-CO2network suggests that the model can well capture the spatiotemporal patterns of CO2concentrations. Generally, high CO2mixing ratios appear in the heavily industrialized eastern China in cold seasons, which probably relates to intensive human activities. The accommodation of non-homogeneous CO2concentrations in the radiative transfer scheme leads to an annual mean change of -0.12 W m-2in total sky surface upward longwave flux in East Asia. The experiment with non-homogeneous CO2tends to yield a warmer lower troposphere.Surface temperature exhibits a maximum difference in summertime, ranging from -4.18 K to 3.88 K, when compared to its homogeneous counterpart. Our results indicate that the spatial and temporal distributions of CO2have a considerable impact on regional longwave radiation flux and temperature, and should be taken into account in future climate modeling.展开更多
文摘净生态系统碳通量（NEE）的计算对于准确模拟区域碳通量和大气CO2浓度的时空变化至关重要。本文利用中尺度大气—温室气体耦合模式WRF-GHG（Weather Research and Forecasting Model with Greenhouse Gases Module），对2010年7月28日至2010年8月2日期间影响长江三角洲地区大气CO2浓度及时空分布的各种过程进行了详尽模拟。结果表明，植被光合呼吸模型（VPRM）能模拟不同植被下垫面 NEE 的日变化；WRF-GHG模拟的大气CO2浓度日变化与观测相吻合，但低估了大气CO2浓度5～15 ppm（ppm表示10？6），这可能与人为排放源的低估、VPRM参数的不确定性以及气象场模拟的不准确性有关。太湖和植被覆盖较好的地区如浙江北部山区是该地区的主要碳汇，而城市为CO2的主要排放源。太湖和陆地生态系统对区域内碳循环起到一定的调节作用，减缓区域大气 CO2浓度的升高。此外，局地气象条件如湖陆风对太湖周边地区大气 CO2浓度有显著影响。
基金Supported by the National Natural Science Foundation of China(41575145,41621005,and 91544230)National Key Basic Research and Development Program of China(2016YFC0203303 and 2014CB441203)EU 7th Framework Marie Curie Actions IRSES Project:REQUA(PIRSES-GA-2013-612671)
文摘Carbon dioxide(CO2) is an important greenhouse gas that influences regional climate through disturbing the earth’s energy balance. The CO2concentrations are usually prescribed homogenously in most climate models and the spatiotemporal variations of CO2are neglected. To address this issue,a regional climate model(RegCM4) is modified to investigate the non-homogeneous distribution of CO2and its effects on regional longwave radiation flux and temperature in East Asia. One-year simulation is performed with prescribed surface CO2fluxes that include fossil fuel emission, biomass burning, air-sea exchange, and terrestrial biosphere flux. Two numerical experiments(one using constant prescribed CO2concentrations in the radiation scheme and the other using the simulated CO2concentrations that are spatially non-homogeneous) are conducted to assess the impact of non-homogeneous CO2on the regional longwave radiation flux and temperature. Comparison of CO2concentrations from the model with the observations from the GLOBALVIEW-CO2network suggests that the model can well capture the spatiotemporal patterns of CO2concentrations. Generally, high CO2mixing ratios appear in the heavily industrialized eastern China in cold seasons, which probably relates to intensive human activities. The accommodation of non-homogeneous CO2concentrations in the radiative transfer scheme leads to an annual mean change of -0.12 W m-2in total sky surface upward longwave flux in East Asia. The experiment with non-homogeneous CO2tends to yield a warmer lower troposphere.Surface temperature exhibits a maximum difference in summertime, ranging from -4.18 K to 3.88 K, when compared to its homogeneous counterpart. Our results indicate that the spatial and temporal distributions of CO2have a considerable impact on regional longwave radiation flux and temperature, and should be taken into account in future climate modeling.
