3:30 PM - 5:00 PM
[PCG19-P12] Spectral Simulations Assuming Submillimeter-wave Band Limb Sounding Observations of the Venusian Atmosphere
Keywords:Terahertz, Venusian Atmosphere, Limb Sounding, Atmospheric chemistry, Atmospheric dynamics, Satellite
Venus is a non-magnetized terrestrial planet covered by a CO2 atmosphere, and study the physical and chemical environment of the atmosphere there is important for understanding the universal nature of the atmosphere of terrestrial exoplanets. Atmospheric minor constituents and the Doppler velocity above the cloud altitudes of Venus have been discussed by submillimeter-wave band observations using ground based single dish telescopes and interferometers such as ALMA, which allow us to study the atmospheric photochemistry and dynamics.
The submillimeter-wave band is less affected by dust absorption. In addition, on Venus, trace molecules such as carbon monoxide, sulfide, chloride, water, and their isotopes is observable in the day and night regions and with or without a background light source such as the sun. From the spectral profile, their altitude distributions can also be derived by retrieval analysis.
While ground-based submillimeter-wave telescopes have difficulty in observing molecules that are abundant in the Earth's atmosphere, such as water, limb sounding from a satellite orbiter can observe the altitude distribution of trace molecules including water from cloud top altitude to about 140 km with a high S/N ratio, even with a low consumption and room temperature Schottky barrier diode mixer detector. Direct observation of the wind velocity field in the east-west direction and meridional circulation with high accuracy is also a strong advantage of rim sounding observations by a satellite orbiter.
Since submillimeter-wave band observations of the Venusian atmosphere have been carried out with ground-based telescopes, the potential of submillimeter-wave band observations from a satellite orbiter has not been fully investigated. Therefore, refering the data set of the Venus Climate Databese (LMD/IPSL), Sandor et al. Icarus 290,156,2017, Mahieux et al, PSS, 113, 264, 2015, Belyaev et al. Icarus, 294, 58, 2017, Krasnopolsky, 218,230, 2012, the SO and SO2 data observed with the ALMA telescope in 2017, and the CO data observed with SPART from 2011 to 2021, we performed spectral radiative transfer calculations for such as water, sulfide, chloride, and their isotopic molecules assuming limb soundings and nadir observations with a terahertz band heterodyne spectrometer on a Venus orbitor. In this meeting, the results will be discussed.
The submillimeter-wave band is less affected by dust absorption. In addition, on Venus, trace molecules such as carbon monoxide, sulfide, chloride, water, and their isotopes is observable in the day and night regions and with or without a background light source such as the sun. From the spectral profile, their altitude distributions can also be derived by retrieval analysis.
While ground-based submillimeter-wave telescopes have difficulty in observing molecules that are abundant in the Earth's atmosphere, such as water, limb sounding from a satellite orbiter can observe the altitude distribution of trace molecules including water from cloud top altitude to about 140 km with a high S/N ratio, even with a low consumption and room temperature Schottky barrier diode mixer detector. Direct observation of the wind velocity field in the east-west direction and meridional circulation with high accuracy is also a strong advantage of rim sounding observations by a satellite orbiter.
Since submillimeter-wave band observations of the Venusian atmosphere have been carried out with ground-based telescopes, the potential of submillimeter-wave band observations from a satellite orbiter has not been fully investigated. Therefore, refering the data set of the Venus Climate Databese (LMD/IPSL), Sandor et al. Icarus 290,156,2017, Mahieux et al, PSS, 113, 264, 2015, Belyaev et al. Icarus, 294, 58, 2017, Krasnopolsky, 218,230, 2012, the SO and SO2 data observed with the ALMA telescope in 2017, and the CO data observed with SPART from 2011 to 2021, we performed spectral radiative transfer calculations for such as water, sulfide, chloride, and their isotopic molecules assuming limb soundings and nadir observations with a terahertz band heterodyne spectrometer on a Venus orbitor. In this meeting, the results will be discussed.