Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/26447
Title: | Mesospheric CO2 ice clouds on Mars observed by Planetary Fourier Spectrometer onboard Mars Express | Authors: | Aoki, Shohei GIURANNA, MARCO Sato, Yuki Nakagawa, Hiromu Sato, Takao M. WOLKENBERG, PAULINA MARIA Murata, Isao Kasaba, Yasumasa |
Issue Date: | 2016 | Journal: | GEOPHYSICAL RESEARCH ABSTRACTS | Volume: | EGU General Assembly Conference Abstracts | First Page: | EPSC2016-8330 | Abstract: | We investigate mesospheric CO2 ice clouds on Mars detected by the Planetary Fourier Spectrometer (PFS) onboard Mars Express (MEx). The relatively high spectral resolution of PFS allows firm identification of the clouds' reflection spike. A total of 279 occurrences of the CO2 ice clouds features has been detected at the bottom of 4.3 μm CO2 band from the MEx/PFS data during the period from MY27 to MY32. 115 occurrences out of them are also confirmed by simultaneous observations by MEx/OMEGA imaging spectrometer. The spatial and seasonal distributions of the CO2 ice clouds observed by PFS are consistent with the previous studies: the CO2 ice clouds are only observed between Ls=0° and 140° at distinct longitudinal corridors around the equatorial region (±20°N). The CO2 ice clouds are preferentially detected at local time between 15-17h. The relatively high spectral resolution of PFS allows us to investigate the spectral shape of the CO2 ice clouds features. The CO2 ice clouds reflection spike is peaked between 4.24 and 4.29 μm, with no evidence of the secondary peak at 4.32-4.34 μm observed by MEx/OMEGA (Määttänen et al., 2010). In most of the cases (about 75%), the peak is present between 4.245 and 4.255 μm. Moreover, small secondary peaks are found around 4.28 μm (about 15 occurrences). These spectral features cannot be reproduced by the synthetic spectra with the assumption of a spherical particle shape in our radiative transfer model (DISORT). This can be due to the fact that the available CO2 ice reflective indexes are either inaccurate or inappropriate for the mesospheric temperatures, or that the particle shape is not spherical. Accurate measurements of the reflective index depending on temperature and detailed comparison with the model taking into account non-spherical shapes will give a clue to solve this issue. | Conference Name: | EGU General Assembly Conference Abstracts | Conference Place: | Vienna, Austria | Conference Date: | 17-22 aprile, 2016 | URI: | http://hdl.handle.net/20.500.12386/26447 | URL: | https://www.egu2016.eu/ https://www.geophysical-research-abstracts.net/egu2016.html |
ISSN: | 1029-7006 | Bibcode ADS: | 2016EGUGA..18.8330A | Fulltext: | open |
Appears in Collections: | 3.02 Abstract in Atti di convegno |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
EGU2016-8330.pdf | Abstract | 46.46 kB | Adobe PDF | View/Open |
Page view(s)
60
checked on Apr 25, 2024
Download(s)
13
checked on Apr 25, 2024
Google ScholarTM
Check
Items in DSpace are published in Open Access, unless otherwise indicated.