Long‐term measurements of free‐tropospheric sulfate at Mauna Loa: Comparison with global model simulations
Long‐term measurements of free‐tropospheric sulfate at Mauna Loa: Comparison with global model simulations
复制标题
莫纳罗亚火山自由对流层硫酸盐的长期测量：与全球模型模拟的比较
DOI：
10.1029/2000jd900627
复制
发表时间：
2001
影响因子：
--
通讯作者：
C. Land
中科院分区：
文献类型：
--
作者：
B. Huebert;C. A. Phillips;L. Zhuang;E. Kjellström;H. Rodhe;J. Feichter;C. Land
我们在此报告了三种模式，即全球大气通用示踪剂输送模式（MOGUNTIA，简称MOG）、欧洲中心/汉堡（GCM模式）3 （ECHAM3，简称E3）和欧洲中心/汉堡（GCM模式）4 (ECHAM4，简称E4)，与夏威夷莫纳罗亚天文台（MLO）十年来的硫酸盐气溶胶测量（Obs）进行了比较。根据四个标准对观测结果进行分类，以消除当地火山的任何污染。E3运行了8年，E4运行了5年，以评估年际变化。在气候平均浓度方面，E3 （51 pmol mol−1）与Obs （53 pmol mol−1）非常接近，而MOG （33 pmol mol−1）和E4 （134 pmol mol−1）预测的浓度不同。Obs年平均年际变率略大于E3和E4。值得注意的是年际变率较大；这表明多年时间序列对于与气候模式进行比较是必不可少的。E3将《Obs》的季节性循环复制得非常好。E4预测的浓度要高得多，尽管季节振幅是合理的。MOG表现出的季节变异性要小得多，这表明从大陆到偏远地区的大部分运输可能是由随机过程（没有被气候模式描述）造成的。使用标记源，E4发现东南亚的城市/工业源和火山是MLO中大部分硫酸盐的来源。Obs、E3和E4每个月的年际变化相似。当E4以微推模式运行1年（以便它倾向于再现实际气象）并与Obs逐日比较时，R2为0.73。因此，尽管存在显著的量级差异，E4清楚地再现了导致自由对流层硫酸盐浓度每天变化的许多特征。当我们将E4连续5-8 km的火山源移至较低海拔时，大的高估值被降低，但没有消除，这表明仅靠高海拔释放不能解释E4预测的高浓度。缺失的过程和垂直交换和清除的参数化是模拟之间差异的可能原因。虽然观测值与E4之间的差异表明我们首先要寻找E4硫处理的缺点，但我们不能排除E3的补偿误差导致其与观测值更好地吻合的可能性。
We report here on a comparison of three models, Model of the Global Universal Tracer Transport in the Atmosphere (MOGUNTIA, abbreviated here as MOG), European Center/Hamburg (GCM Model) 3 (ECHAM3, here E3), and European Center/Hamburg (GCM Model) 4 (ECHAM4, here E4), with a decade-long time series of sulfate aerosol measurements (Obs) from the Mauna Loa Observatory (MLO), Hawaii. The observations were sorted with four criteria to eliminate any contamination from the local volcanoes. E3 was run for 8 years, and E4 was run for 5 years to assess interannual variability. In terms of the climatological average concentration, E3 (51 pmol mol−1) was very close to Obs (53 pmol mol−1), while MOG (33 pmol mol−1) and E4 (134 pmol mol−1) predicted different concentrations. The interannual variability of the annual average was somewhat larger in Obs than in E3 and E4. The large interannual variability is noteworthy; it demonstrates that multiyear time series are essential for comparison with climatological models. The seasonal cycle of Obs was reproduced surprisingly well by E3. E4 predicted much higher concentrations, although the seasonal amplitude was reasonable. MOG showed much less seasonal variability, which suggests that stochastic processes (which are not described by climatological models) may be responsible for much of the transport from continents to remote regions. Using tagged sources, E4 found that urban/industrial sources in SE Asia and volcanoes were responsible for most of the sulfate at MLO. The interannual variability of each month was similar for Obs, E3, and E4. When E4 was run in a nudged mode for 1 year (so that it tended to reproduce the actual meteorology) and compared day-by-day to Obs, the R2 was 0.73. Thus, in spite of significant magnitude differences, E4 clearly reproduces many of the features that cause free-tropospheric sulfate concentrations to vary from day-to-day. When we moved the continual 5–8 km volcanic source in E4 to lower altitudes, the large overestimate was reduced but not eliminated, suggesting that the high-altitude releases alone cannot explain the high concentrations predicted by E4. Missing processes and the parameterizations of vertical exchange and scavenging are among the possible reasons for the differences between the simulations. While the discrepancy between the observations and E4 suggests that we first look for shortcomings in E4's sulfur processing, we cannot exclude the possibility that compensating errors in E3 cause its better agreement with the observations.