Simulation of spontaneous and variable global dust storms with the GFDL Mars GCM
Simulation of spontaneous and variable global dust storms with the GFDL Mars GCM
复制标题
使用 GFDL Mars GCM 模拟自发和可变的全球沙尘暴
DOI：
10.1029/2005je002660
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
A. Ingersoll
中科院分区：
文献类型：
--
作者：
S. Basu;John I. B. Wilson;M. Richardson;A. Ingersoll
我们报道了在大气环流模式中对全球沙尘暴的成功模拟。模拟的风暴在多年模拟中自发发展，并表现出显著的年际变化。模拟的风暴导致大气沙尘、全球平均气温和大气环流强度急剧增加，这与观测结果一致。与观测到的全球风暴一样，模式中的风暴自发启动发生在南部春季和夏季，风暴发展具有显著的年际变化：没有风暴的年份夹杂着大小不一的风暴和特定的季节性启动日期。我们的结果支持这样的观点，即当沙尘注入机制涉及一个激活阈值时，全球沙尘暴行为可以从周期性强迫系统(唯一的强迫是昼夜和季节循环)中出现。在我们的模拟中，地面风应力与分解的大范围(>；300公里)风系统有关，引发了风暴。这些风一般与季节性迁移的CO_2帽边界和希腊盆地倾斜的地形、热潮和行波有关。数量非常有限的大风暴开始于沿与北半球行波相关的锋区上升。全球范围的爆炸性增长是由于哈德利环流的加强和次级扬尘中心的激活。
We report on the successful simulation of global dust storms in a general circulation model. The simulated storms develop spontaneously in multiyear simulations and exhibit significant interannual variability. The simulated storms produce dramatic increases in atmospheric dustiness, global-mean air temperatures, and atmospheric circulation intensity, in accord with observations. As with observed global storms, spontaneous initiation of storms in the model occurs in southern spring and summer, and there is significant interannual variability in storm development: years with no storms are interspersed with years with storms of various sizes and specific seasonal date of initiation. Our results support the idea that variable and spontaneous global dust storm behavior can emerge from a periodically forced system (the only forcing being the diurnal and seasonal cycles) when the dust injection mechanism involves an activation threshold. In our simulations, surface wind stresses associated with resolved, large-scale (>300 km) wind systems initiate the storms. These winds are generally associated with the seasonally migrating CO_2 cap boundary and sloping topography of the Hellas basin, thermal tides, and traveling waves. A very limited number of large storms begin with lifting along the frontal zones associated with traveling waves in the northern hemisphere. Explosive growth to global scales results from the intensification of the Hadley circulation and the activation of secondary dust-lifting centers.