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

CFHT 对木星极光热层中离子风和中性风的观测

• 批准号: 0406881
• 负责人: G. Randall Gladstone
• 金额: --
• 依托单位: Southwest Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-15 至 2009-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0406881&HistoricalAwards=false
• 关键词: CFHT; Observations; Ion; Neutral; Winds

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. ***

AST 0406881 gladstonedr。G. Randall Gladstone将对1999年和2000年加拿大-法国-夏威夷望远镜（CFHT）上的傅立叶变换光谱仪（FTS）观测到的木星H3+和H2在红外（IR）波长接近2微米处的极光辐射进行分析。利用光谱成像（BEAR）模式下的FTS，获得了14个高分辨率干涉图立方体，其中包含来自南北极光区域的明亮H3+和H2发射线。对这些数据的仔细分析将提供木星热层中成分、温度、离子和中性风速的空间分布信息。初步估算表明，电喷型风高达6公里/秒（显然是超音速，因为预计热速度为2-3公里/秒）。北极光的初步推导温度比南极光低约35%，而南极光的H3+柱密度比北极光低约一个数量级。进一步减少这些数据可以为了解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环流模型（JTGCM）提供急需的约束条件。在过去十年中，我们对木星上层大气的认识发生了非常迅速的变化，这主要是由于来自地面观测站的大量数据的结果。（CFHT， IRTF），地球轨道观测站{例如；， HST，钱德拉)和航天器{例如。、旅行者号、尤利西斯号、伽利略号、卡西尼号)。需要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。这里将对CFHT数据进行简化和分析，提供了在可预见的未来木星高空离子风和中性风空间分布的唯一信息。这些观测是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。＊＊＊