Unambiguous detection of mesospheric CO2 clouds on Mars using 2.7 μm absorption band from the ACS/TGO solar occultations

IF 2.5 2区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Icarus Pub Date : 2024-08-22 DOI:10.1016/j.icarus.2024.116271
{"title":"Unambiguous detection of mesospheric CO2 clouds on Mars using 2.7 μm absorption band from the ACS/TGO solar occultations","authors":"","doi":"10.1016/j.icarus.2024.116271","DOIUrl":null,"url":null,"abstract":"<div><p>Mesospheric CO<sub>2</sub> clouds are one of two types of carbon dioxide clouds known on Mars. We present observations of mesospheric CO<sub>2</sub> clouds made by Atmospheric Chemistry Suite (ACS) onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO). We analyzed 1663 solar occultation sessions of Thermal InfraRed (TIRVIM) and Middle InfraRed (MIR) channels of ACS covering more than two Martian years that contain spectra of 2.7 μm carbon dioxide ice absorption band<strong>.</strong> That allowed us to unambiguously discriminate carbon dioxide ice aerosols from mineral dust and water ice aerosols, not relying on the information of atmospheric thermal conditions. CO<sub>2</sub> clouds were detected in eleven solar occultation observations at altitudes from 39 km to 90 km. In five cases, there were two or three layers of CO<sub>2</sub> clouds that were vertically separated by 5–15 km gaps. Effective radius of CO<sub>2</sub> aerosol particles is in the range of 0.1–2.2 μm. Spectra produced by the smallest particles indicate a need for a better resolved CO<sub>2</sub> ice refractive index. Nadir optical depth of CO<sub>2</sub> clouds is in the range 5 × 10<sup>−4</sup>–4 × 10<sup>−2</sup> at both 2.7 μm and 0.8 μm. Asymmetrical diurnal distribution of detections observed by ACS is potentially due to local time variations of temperature induced by thermal tides. Two out of five cases of carbon dioxide cloud detections made by the TIRVIM instrument reveal the simultaneous presence of CO<sub>2</sub> ice and H<sub>2</sub>O ice aerosols. Temperature profiles measured by the Near InfraRed (NIR) channel of ACS are used to calculate CO<sub>2</sub> saturation ratio <em>S</em> at locations of carbon dioxide clouds. Supersaturation S &gt; 1 is detected in only 6 out of 19 cases of CO<sub>2</sub> cloud layers; extremely low values of S &lt; 0.1 are found in 9 out of 19 cases.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Icarus","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0019103524003312","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0

Abstract

Mesospheric CO2 clouds are one of two types of carbon dioxide clouds known on Mars. We present observations of mesospheric CO2 clouds made by Atmospheric Chemistry Suite (ACS) onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO). We analyzed 1663 solar occultation sessions of Thermal InfraRed (TIRVIM) and Middle InfraRed (MIR) channels of ACS covering more than two Martian years that contain spectra of 2.7 μm carbon dioxide ice absorption band. That allowed us to unambiguously discriminate carbon dioxide ice aerosols from mineral dust and water ice aerosols, not relying on the information of atmospheric thermal conditions. CO2 clouds were detected in eleven solar occultation observations at altitudes from 39 km to 90 km. In five cases, there were two or three layers of CO2 clouds that were vertically separated by 5–15 km gaps. Effective radius of CO2 aerosol particles is in the range of 0.1–2.2 μm. Spectra produced by the smallest particles indicate a need for a better resolved CO2 ice refractive index. Nadir optical depth of CO2 clouds is in the range 5 × 10−4–4 × 10−2 at both 2.7 μm and 0.8 μm. Asymmetrical diurnal distribution of detections observed by ACS is potentially due to local time variations of temperature induced by thermal tides. Two out of five cases of carbon dioxide cloud detections made by the TIRVIM instrument reveal the simultaneous presence of CO2 ice and H2O ice aerosols. Temperature profiles measured by the Near InfraRed (NIR) channel of ACS are used to calculate CO2 saturation ratio S at locations of carbon dioxide clouds. Supersaturation S > 1 is detected in only 6 out of 19 cases of CO2 cloud layers; extremely low values of S < 0.1 are found in 9 out of 19 cases.

查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
利用 ACS/TGO 太阳掩星的 2.7 μm 吸收波段明确探测火星中间层二氧化碳云层
中间层二氧化碳云是火星上已知的两种二氧化碳云之一。我们介绍了欧空局-俄罗斯航天局ExoMars痕量气体轨道器(TGO)上的大气化学套件(ACS)对中间层二氧化碳云的观测。我们分析了ACS的热红外(TIRVIM)和中红外(MIR)通道的1663次太阳掩星,时间跨度超过两年,其中包含2.7微米二氧化碳冰吸收波段的光谱。这使我们能够明确地将二氧化碳冰气溶胶与矿物尘埃和水冰气溶胶区分开来,而不依赖于大气热条件的信息。在海拔 39 千米至 90 千米的 11 次太阳掩星观测中,我们探测到了二氧化碳云。其中有五次观测发现了两层或三层二氧化碳云,这些云在垂直方向上相距 5-15 千米。二氧化碳气溶胶粒子的有效半径在 0.1-2.2 μm 之间。最小颗粒产生的光谱表明需要更好地解析二氧化碳冰的折射率。在 2.7 μm 和 0.8 μm 处,二氧化碳云的昼夜光学深度在 5 × 10-4-4 × 10-2 之间。由 ACS 观测到的不对称昼夜分布可能是由于热潮引起的局部温度时变造成的。在 TIRVIM 仪器探测到的五次二氧化碳云中,有两次发现同时存在二氧化碳冰和一氧化二氮冰气溶胶。利用 ACS 的近红外(NIR)通道测量的温度曲线计算二氧化碳云所在位置的二氧化碳饱和度比 S。在 19 个二氧化碳云层案例中,只有 6 个案例检测到超饱和度 S > 1;在 19 个案例中,有 9 个案例检测到 S < 0.1 的极低值。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
Icarus
Icarus 地学天文-天文与天体物理
CiteScore
6.30
自引率
18.80%
发文量
356
审稿时长
2-4 weeks
期刊介绍: Icarus is devoted to the publication of original contributions in the field of Solar System studies. Manuscripts reporting the results of new research - observational, experimental, or theoretical - concerning the astronomy, geology, meteorology, physics, chemistry, biology, and other scientific aspects of our Solar System or extrasolar systems are welcome. The journal generally does not publish papers devoted exclusively to the Sun, the Earth, celestial mechanics, meteoritics, or astrophysics. Icarus does not publish papers that provide "improved" versions of Bode''s law, or other numerical relations, without a sound physical basis. Icarus does not publish meeting announcements or general notices. Reviews, historical papers, and manuscripts describing spacecraft instrumentation may be considered, but only with prior approval of the editor. An entire issue of the journal is occasionally devoted to a single subject, usually arising from a conference on the same topic. The language of publication is English. American or British usage is accepted, but not a mixture of these.
期刊最新文献
Baroclinic waves observed on Mars from InSight data Three-dimensional modeling of Ganymede’s Chapman–Ferraro magnetic field and its role in subsurface ocean induction New astrometric positions for six Jovian irregular satellites using Gaia DR3 in 2016 — 2021 Changes in the longitude polarization dependence of Jupiter's moon Io as evidence of the long-term variability of its volcanic activity NAROO program: Analysis of USNO Galilean observations 1967–1998
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1