Dynamic Meteorology at the Photosphere of HD 209458b
Dynamic Meteorology at the Photosphere of HD 209458b
复制标题
HD 209458b 光球层的动态气象学
DOI：
10.1086/444354
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
A. Showman
中科院分区：
文献类型：
--
作者：
C. Cooper;A. Showman
我们使用全球三维大气环流模型计算了近距离凌日系外行星HD 209458 b的气象学。动力学是由这个潮汐锁定行星的一个半球的永久照射驱动的。模拟预测的全球温度对比度~500 K的光球和稳定的超旋转喷流的发展。喷流从赤道延伸到中纬度地区，从顶部模型层在1毫巴下降到10巴的加热区的底部。赤道附近的风速在300毫巴时超过4 km s-1。大气中最热的区域被吹到了亚恒星点下游约60°经度处。我们从这些结果预测的最大和最小观测到的辐射从行星在一个完整的轨道周期，与峰值红外发射的时间之前的第二次日食的~14小时之间的比率~2的因素。
We calculate the meteorology of the close-in transiting extrasolar planet HD 209458b using a global, three-dimensional atmospheric circulation model. Dynamics are driven by perpetual irradiation of one hemisphere of this tidally locked planet. The simulation predicts global temperature contrasts of ~500 K at the photosphere and the development of a steady superrotating jet. The jet extends from the equator to midlatitudes and from the top model layer at 1 mbar down to 10 bar at the base of the heated region. Wind velocities near the equator exceed 4 km s-1 at 300 mbar. The hottest regions of the atmosphere are blown downstream from the substellar point by ~60° of longitude. We predict from these results a factor of ~2 ratio between the maximum and minimum observed radiation from the planet over a full orbital period, with peak infrared emission preceding the time of the secondary eclipse by ~14 hr.