Simulating the impacts of chronic ozone exposure on plant conductance and photosynthesis, and on the regional hydroclimate using WRF/Chem
Simulating the impacts of chronic ozone exposure on plant conductance and photosynthesis, and on the regional hydroclimate using WRF/Chem
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使用 WRF/Chem 模拟长期臭氧暴露对植物电导和光合作用以及区域水气候的影响
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
P. Hyde
中科院分区：
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作者：
Jialu Li;A. Mahalov;P. Hyde
对WRF/Chem中的Noah多参数化陆面模式进行了修正，使之包含了长期臭氧暴露对植物电导率和光合作用的影响。基于修正的WRF/Chem，COE对区域水文气候的影响已经在美国大陆进行了研究。我们的研究结果表明，该模型在其当前配置的修改/不修改可以重现的观测和再分析数据的降雨和温度模式，虽然它低估了在中部大平原和高估它在东部沿海各州的降雨。关于COE效应的实验测试包括设定不同的环境臭氧浓度（[O3]）阈值，并使用不同的线性回归来量化五氯苯酚与COE的关系。与WRF/Chem对照运行（即，在不考虑COE影响的情况下，在不同的实验设置下，修改后的模型改善了德克萨斯州和紧邻北部地区的降雨和温度的模拟估计。2007-2012年6月、7月和8月的模拟表明，在德克萨斯州及周边地区，地表[O3]使潜热通量（LH）减少10-27 W m−2，地表气温（T2）增加0.6 °C-2.0 °C，降雨量减少0.9-1.4 mm d−1，径流量减少0.1-0.17 mm d−1，所有这些都高度依赖于精确的实验装置，特别是[O3]阈值。产生这些结果的机制是COE减少LH和增加感热通量，这反过来又增加了鲍文比和空气温度。同时，LH的降低也导致对流位能的降低，最终导致对流降水的减少。在任何高[O3]地区采用这种修改后的WRF/Chem模型可以提高植被，气象，化学/排放和作物生产力的相互作用的理解。
The Noah-Multiparameterization land surface model in the Weather Research and Forecasting (WRF) with Chemistry (WRF/Chem) is modified to include the effects of chronic ozone exposure (COE) on plant conductance and photosynthesis (PCP) found from field experiments. Based on the modified WRF/Chem, the effects of COE on regional hydroclimate have been investigated over the continental United States. Our results indicate that the model with/without modification in its current configuration can reproduce the rainfall and temperature patterns of the observations and reanalysis data, although it underestimates rainfall in the central Great Plains and overestimates it in the eastern coast states. The experimental tests on the effects of COE include setting different thresholds of ambient ozone concentrations ([O3]) and using different linear regressions to quantify PCP against the COE. Compared with the WRF/Chem control run (i.e., without considering the effects of COE), the modified model at different experiment setups improves the simulated estimates of rainfall and temperatures in Texas and regions to the immediate north. The simulations in June, July and August of 2007–2012 show that surface [O3] decrease latent heat fluxes (LH) by 10–27 W m−2, increase surface air temperatures (T2) by 0.6 °C–2.0 °C, decrease rainfall by 0.9–1.4 mm d−1, and decrease runoff by 0.1–0.17 mm d−1 in Texas and surrounding areas, all of which highly depends on the precise experiment setup, especially the [O3] threshold. The mechanism producing these results is that COE decreases the LH and increases sensible heat fluxes, which in turn increases the Bowen ratios and air temperatures. This lowering of the LH also results in the decrease of convective potential and finally decreases convective rainfall. Employing this modified WRF/Chem model in any high [O3] region can improve the understanding of the interactions of vegetation, meteorology, chemistry/emissions, and crop productivity.