Mars global atmospheric oscillations - Annually synchronized, transient normal-mode oscillations and the triggering of global dust storms
Mars global atmospheric oscillations - Annually synchronized, transient normal-mode oscillations and the triggering of global dust storms
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火星全球大气振荡 - 每年同步的瞬态常模振荡和全球沙尘暴的触发
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发表时间：
1988
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通讯作者：
J. Tillman
中科院分区：
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作者：
J. Tillman
对火星表面的大气压力进行了几个火星年的观测和分析，发现了异常性质的日常压力变化中的瞬变事件。这些事件只持续几个太阳日（火星日），似乎每年重复几个太阳日，似乎在同一个太阳日或至少在几个太阳日内覆盖半球的大部分，在某些情况下成对发生，分离20个太阳日，与年压力最小值一致（即，南半球二氧化碳的最大浓度），并且由接近于并且有时在频率上与周日谐波和半日谐波相同的光谱分量组成。这表明，这些事件是开尔文，正常模式，瞬态，全球振荡。对1977 A、1977 B和1982 A全球沙尘暴爆发过程的研究表明，沙尘暴爆发过程中存在着假日振荡和有时候的假半日振荡，这些振荡可能与长周期环流引起的风一起触发全球沙尘暴。在1977年B全球沙尘暴之前，周日谐波消失，取而代之的是1.1周/日的振荡。如果缺乏典型的日潮表明对流受到抑制，这可能部分解释了1977 B风暴的缓慢发展。日平均压力在短暂的季节，提前全球沙尘暴季节的近四分之一的一年，表现出不同的行为在全球沙尘暴年比在非沙尘暴年。这意味着在这些情况下，全球环流必须有很大的不同，并且可能与某一年晚些时候全球沙尘暴的存在或不存在有关。这些分析表明，一个几乎昼夜和几乎半日，高频率的全球振荡，不同于经典的太阳驱动的潮汐，可能是相当常见的火星上。
Observation and analyses of the atmospheric pressure at the surface on Mars for several Martian years has led to the discovery of transient events in the daily pressure variations of an unusual nature. These events last only a few sols (Mars days), appear to repeat on an annual basis to within a few sols, appear to cover a large portion of the hemisphere on the same sol or at least within a few sols, occur in pairs with separations of 20 sols in some instances, are coincident with the annual pressure minimum (i.e., the maximum concentration of carbon dioxide in the southern hemisphere), and consist of spectral components near to, and sometimes identical in, frequency to the diurnal and semidiurnal harmonics. It is suggested that these events are Kelvin, normal-mode, transient, global oscillations. Examination of the initiation of the 1977A, 1977B, and 1982A global dust storms indicate that pseudo-diurnal and some-times pseudo-semidiurnal oscillations exist during the initiation phase and might be involved in triggering the global dust storms, possibly in conjunction with winds due to longer-period circulations. The diurnal harmonic disappears prior to the 1977B global dust storm and is replaced by an oscillation at 1.1 cycles/sol. If the lack of a classical diurnal tide indicates the suppression of convection, this might partially explain the slow growth of the 1977B storm. The daily average pressure during the transient season, which precedes the global dust storm season by almost one fourth of a year, exhibits a different behavior during the global dust storm years than during the nonglobal dust storm years. This implies that the global circulation must differ significantly in these cases and may be related to the presence or absence of global dust storms later in a given year. These analyses suggest that an almost diurnal and an almost semidiurnal, high-frequency global oscillation, different from the classical solar-driven tides, may be quite common on Mars.