Global modeling of tropospheric chemistry with assimilated meteorology: Model description and evaluation
Global modeling of tropospheric chemistry with assimilated meteorology: Model description and evaluation
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DOI：
10.1029/2001jd000807
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发表时间：
2001-10-16
影响因子：
4.4
通讯作者：
Schultz, MG
中科院分区：
文献类型：
--
作者：
Bey, I;Jacob, DJ;Schultz, MG
我们提出了第一个描述和评估的全球三维（3-D）模式的对流层化学驱动的同化气象观测从戈达德地球观测系统（GEOS）的美国宇航局数据同化办公室（DAO）。该模型适用于1994年对流层臭氧-NOx-碳氢化合物化学的1年模拟，并与1994年和其他年份的观测结果进行了评价。它再现的臭氧浓度通常在10 ppb以内，是从世界范围的臭氧探测仪数据网络观测到的。它正确地模拟了不同地区和海拔高度的臭氧浓度的季节性阶段和幅度，但往往低估了北方中纬度地区的季节性幅度。在飞机活动中观察到的NO和过氧乙酰硝酸盐（PAN）的观测浓度通常在2倍内重现，并且通常要好得多。在遥远的对流层HNO 3的浓度通常被高估了2-3倍，这是全球模型中的一个常见问题，可能反映了模型未解决的降水清除不足和气体-气溶胶分配的组合。该模型产生的大气寿命的甲基氯仿（代理全球OH）的5.1年，相比之下，最好的估计从5.5 +/- 0.8年的观测，并模拟H2 O2浓度从飞机观测到显着的区域差异，但没有全球偏见。OH浓度比我们以前的全球3-D模型高出20%，其中包括紫外线吸收气溶胶。模型往往低估了CO的浓度，通常为10-30 ppb，这可能反映了过量的OH（模型OH减少20%可以通过甲基氯仿约束）和低估CO来源（特别是生物源）的组合。该模型低估了观察到的丙酮浓度在南太平洋秋季的一个因素的3;失踪的来源，从海洋可能牵连。
We present a first description and evaluation of GEOS-CHEM, a global three-dimensional (3-D) model of tropospheric chemistry driven by assimilated meteorological observations from the Goddard Earth Observing System (GEOS) of the NASA Data Assimilation Office (DAO). The model is applied to a 1-year simulation of tropospheric ozone-NOx-hydrocarbon chemistry for 1994, and is evaluated with observations both for 1994 and for other years. It reproduces usually to within 10 ppb the concentrations of ozone observed from the worldwide ozonesonde data network. It simulates correctly the seasonal phases and amplitudes of ozone concentrations for different regions and altitudes, but tends to underestimate the seasonal amplitude at northern midlatitudes. Observed concentrations of NO and peroxyacetylnitrate (PAN) observed in aircraft campaigns are generally reproduced to within a factor of 2 and often much better. Concentrations of HNO3 in the remote troposphere are overestimated typically by a factor of 2-3, a common problem in global models that may reflect a combination of insufficient precipitation scavenging and gas-aerosol partitioning not resolved by the model. The model yields an atmospheric lifetime of methylchloroform (proxy for global OH) of 5.1 years, as compared to a best estimate from observations of 5.5 +/- 0.8 years, and simulates H2O2 concentrations observed from aircraft with significant regional disagreements but no global bias. The OH concentrations are similar to 20% higher than in our previous global 3-D model which included an UV-absorbing aerosol. Concentrations of CO tend to be underestimated by the model, often by 10-30 ppb, which could reflect a combination of excessive OH (a 20% decrease in model OH could be accommodated by the methylchloroform constraint) and an underestimate of CO sources (particularly biogenic). The model underestimates observed acetone concentrations over the South Pacific in fall by a factor of 3; a missing source from the ocean may be implicated.