Simulation of Mt. Pinatubo Volcanic Aerosol with the Hamburg Climate Model ECHAM4
Simulation of Mt. Pinatubo Volcanic Aerosol with the Hamburg Climate Model ECHAM4
复制标题
使用汉堡气候模型 ECHAM4 模拟皮纳图博山火山气溶胶
DOI：
10.1007/s007040050076
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发表时间：
1999
影响因子：
3.4
通讯作者：
J. Feichter
中科院分区：
文献类型：
--
作者：
C. Timmreck;H. Graf;J. Feichter
总结我们研究的三维输运山。 皮纳图博火山云与气候模式ECHAM 4。为了获得与观测值相当的模型结果，应用了牛顿松弛技术，该技术迫使预测模型变量接近观测值。模拟的气溶胶分布与卫星数据的比较显示，火山爆发后的头几个月的一致性很好。然而，该模式无法模拟1992年的热带气溶胶最大值，也高估了垂直向下和向北输送的气溶胶。通过380 K等熵层减少平流垂直输运的引入实现了实质性的改善。在线计算了火山爆发后前半年的加热率和大气顶通量，结果均在观测范围内。三个不同的垂直ECHAM 4版本（ECHAM 4 L19，ECHAM 4 L39，MA/ECHAM 4）之间的皮纳图博模拟的比较表明，在对流层顶区域的垂直分辨率为10700米是足够的，实际上减少通过对流层顶的垂直输送。考虑到MA/ECHAM 4模式中布鲁尔多布森环流的上分支，改进了火山云的地理分布。松弛技术的应用可以进一步减少标准气候模式平流层模拟的主要缺点。然而，在所有三种模式中，全球迁移特征中仍有一些关键点尚未得到充分理解。
Summary We study the three-dimensional transport of Mt. Pinatubo volcanic cloud with the climate model ECHAM4. In order to obtain model results comparable with observations a Newtonian relaxation technique was applied, which forces prognostic model variables towards the observations. A comparison of the simulated aerosol distribution with satellite data reveals good agreement for the first months after the eruption. The model, however, is unable to simulate the tropical aerosol maximum in 1992 and also overestimates the vertical downward and northward transport of aerosols. Substantial improvement was achieved with the introduction of reduced advective vertical transport through the 380 K isentropic layer. Heating rates and top of the atmosphere fluxes, which were calculated online for the first half year after the eruption, are in the observed range. A comparison of Pinatubo simulations between three different vertical ECHAM4 versions (ECHAM4 L19, ECHAM4 L39, MA/ECHAM4) indicates that a vertical resolution of ≈ 700 m in the tropopause region is sufficient to realistically reduce the vertical transport through the tropopause. Consideration of the upper branch of the Brewer Dobson circulation in the MA/ECHAM4 model improves the geographical distribution of the volcanic cloud. The application of a relaxation technique can further reduce major shortcomings of stratospheric simulations with the standard climate model. There remain, however some critical points in the global transport characteristics in all three models which are not fully understood.