TY - JOUR
T1 - Thermal structure of the Venusian atmosphere from the sub-cloud region to the mesosphere as observed by radio occultation
AU - Ando, Hiroki
AU - Imamura, Takeshi
AU - Tellmann, Silvia
AU - Pätzold, Martin
AU - Häusler, Bernd
AU - Sugimoto, Norihiko
AU - Takagi, Masahiro
AU - Sagawa, Hideo
AU - Limaye, Sanjay
AU - Matsuda, Yoshihisa
AU - Choudhary, Raj Kumar
AU - Antonita, Maria
N1 - Funding Information:
We appreciate the careful readings and helpful comments of anonymous reviewers. Our study could not have been possible without the efforts of the ESA Venus Express Science and Mission Operation teams, the VEX Flight Control Team and the ESA ESTRACK ground station crews. The VeRa Experiment has benefited greatly from the continuous support of the NASA Deep Space Network. The data obtained in Venus Express radio occultation experiments are open to the public via the ESA’s Planetary Science Archive (PSA) (ftp://psa.esac.esa. int/pub/mirror/VENUS-EXPRESS/VRA/). The data obtained by Akatsuki radio occultation measurements are available in JAXA’s data archive (https://doi.org/10.17597/ISAS.DARTS/VCO-00015). The data from Magellan radio occultation are located on NASA’s Planetary Data System (PDS) (https://ode.rsl.wustl.edu/mars/pagehelp/ quickstartguide/index.html?mgn_rss_rocrtp.htm). Our study was partly supported by JSPS KAKENHI Grants 16H02225, 17H02961, 19H00720, 19H01971 and 19H05605 and NASA Grant NNXAC1679G. We are grateful to the operating staff of Akatsuki spacecraft, Usuda Deep Space Center, and India Deep Space Network ground stations. Figures were produced using the GNUPLOT and GFD-DENNOU Library. We also thank Glenn Pennycook, MSc, from Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - We present distributions of the zonal-mean temperature and static stability in the Venusian atmosphere obtained from Venus Express and Akatsuki radio occultation profiles penetrating down to an altitude of 40 km. At latitudes equatorward of 75°, static stability derived from the observed temperature profiles is consistent with previous in-situ measurements in that there is a low-stability layer at altitudes of 50–58 km and highly and moderately stratified layers above 58 km and below 50 km, respectively. Meanwhile, at latitudes poleward of 75°, a low-stability layer extends down to 42 km, which has been unreported in analyses of previous measurements. The deep low-stability layer in the polar region cannot be explained by vertical convection in the middle/lower cloud layer, and the present result thus introduces new constraints on the dynamics of the sub-cloud atmosphere. The Venusian atmosphere is in striking contrast to the Earth’s troposphere, which generally has a deeper low-stability layer at low latitudes than at mid- and high latitudes.
AB - We present distributions of the zonal-mean temperature and static stability in the Venusian atmosphere obtained from Venus Express and Akatsuki radio occultation profiles penetrating down to an altitude of 40 km. At latitudes equatorward of 75°, static stability derived from the observed temperature profiles is consistent with previous in-situ measurements in that there is a low-stability layer at altitudes of 50–58 km and highly and moderately stratified layers above 58 km and below 50 km, respectively. Meanwhile, at latitudes poleward of 75°, a low-stability layer extends down to 42 km, which has been unreported in analyses of previous measurements. The deep low-stability layer in the polar region cannot be explained by vertical convection in the middle/lower cloud layer, and the present result thus introduces new constraints on the dynamics of the sub-cloud atmosphere. The Venusian atmosphere is in striking contrast to the Earth’s troposphere, which generally has a deeper low-stability layer at low latitudes than at mid- and high latitudes.
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U2 - 10.1038/s41598-020-59278-8
DO - 10.1038/s41598-020-59278-8
M3 - Article
C2 - 32103048
AN - SCOPUS:85080091255
SN - 2045-2322
VL - 10
JO - Scientific reports
JF - Scientific reports
IS - 1
M1 - 3448
ER -