CFHT Observations of Ion and Neutral Winds in Jupiter's Auroral Thermosphere

AST 0406881Gladstone Dr. G.兰德尔·格拉德斯通将减少和分析1999年和2000年在加拿大-法国-夏威夷望远镜（CFHT）上用傅里叶变换光谱仪（FTS）仪器对木星H3+和H2极光发射的近2微米红外（IR）波长的现有观测。在光谱成像（BEAR）模式下，获得了14个高分辨率的干涉图立方体，其中包含来自北方和南方极光区的明亮的H3+和H2发射线。对这些数据的仔细分析将提供关于木星热层中成分、温度、离子和中性风速度的空间分布的信息。初步估计表明，电喷射型风速高达每秒6公里（显然是超音速，因为预计的热速度为每秒2 - 3公里）。初步得出的温度在北方极光比南方低35%，进一步简化这些数据可以为研究木星高层大气的动力学和能量学提供一个前所未有的窗口，并将为新开发的木星热层大气环流模式（JTGCM）提供急需的约束条件。在过去的十年里，我们对木星上层大气的理解发生了非常迅速的变化，主要是由于地面观测站的大量数据（例如，CFHT、IRTF）、地球轨道观测站（例如，HST，Chandra）和航天器（例如，旅行者号、伽利略号、卡西尼号）。需要像JTGCM这样的模型来帮助理解所有这些数据，但是找到合适的模型约束是相当困难的。CFHT的数据将在这里减少和分析提供的唯一信息的空间分布的木星的高空离子和中性风可预见的未来。 这些观测是由来自巴黎-默东天文台和巴黎天体物理研究所的几位同事参与的国际合作的一部分。***

AST 0406881GladstoneDr. G. Randall Gladstone will reduce and analyze existing observations that were taken with the Fourier Transform Spectrometer (FTS) instrument at the Canada-France-Hawaii Telescope (CFHT) in 1999 and 2000 of Jupiter's H3+ and H2 auroral emissions at infrared (IR) wavelengths near 2 micron. With the FTS in spectroimaging (BEAR) mode, 14 high-resolution interferogram cubes were obtained that contain bright H3+ and H2 emission lines from the northern and southern auroral regions. Careful analyses of these data will provide information on the spatial distribution of composition, temperature, and ion and neutral wind velocities in Jupiter's thermosphere. Preliminary reduction indicates electrojet-type winds of up to 6 km/s (apparently supersonic, since the expected thermal speed is 2-3 km/s). Preliminary derived temperatures are about 35% lower in the northern aurora than in the south, while derived H3+ column densities in the south are about an order of magnitude lower than in the north.Further reduction of these data can provide an unprecedented window on the dynamics and energetics of Jupiter's upper atmosphere and will yield much needed constraints for a newly-developed Jupiter Thermosphere General Circulation Model {JTGCM). Our understanding of the upper atmosphere of Jupiter has changed very rapidly over the last decade, primarily as a result of a great wealth of data from ground-based observatories {e.g., CFHT, IRTF), Earth-orbiting observatories {e.g., HST, Chandra), and spacecraft {e.g., Voyager, Ulysses, Galileo, Cassini). A model such as JTGCM is required to help make sense of all these data, but finding suitable model constraints is quite difficult. The CFHT data to be reduced and analyzed here provide the only information on the spatial distribution of Jupiter's high-altitude ion and neutral winds available for the foreseeable future. These observations were made as part of an international collaboration involving several colleagues from the Observatoire de Paris-Meudon and the Institut d' Astrophysique de Paris. ***