TY - JOUR
T1 - Planetary-scale streak structure reproduced in high-resolution simulations of the Venus atmosphere with a low-stability layer
AU - Kashimura, Hiroki
AU - Sugimoto, Norihiko
AU - Takagi, Masahiro
AU - Matsuda, Yoshihisa
AU - Ohfuchi, Wataru
AU - Enomoto, Takeshi
AU - Nakajima, Kensuke
AU - Ishiwatari, Masaki
AU - Sato, Takao M.
AU - Hashimoto, George L.
AU - Satoh, Takehiko
AU - Takahashi, Yoshiyuki O.
AU - Hayashi, Yoshi Yuki
N1 - Funding Information:
We thank all of the members and contributors of the Akatsuki project. This study was partly conducted under the Earth Simulator Proposed Research Projects titled Simulations of Atmospheric General Circulations of Earth-like Planets by AFES and High Resolution General Circulation Simulation of Venus and Mars Atmosphere using AFES; and the simulations were performed on the Earth Simulator with the support of JAM-STEC. This study was also supported by MEXT as Exploratory Challenge on Post-K computer (Elucidation of the Birth of Exoplanets [Second Earth] and the Environmental Variations of Planets in the Solar System). This study was supported by JSPS KAKENHI 16H02225, 16K17809, and 17H02961. Data analyses and figures were produced with the libraries of GFD-DENNOU Club.
Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Cloud patterns are important clues for revealing the atmospheric circulation of Venus. Recently, a planetary-scale streak structure has been discovered in middle- and lower-cloud images of Venus’ night-side taken by IR2, the 2-μm camera, on board the Akatsuki orbiter. However, its formation mechanism has not been investigated. Here we succeed, for the first time, in reproducing the patterns of the observed streak structure, as regions of strong downward flows that develop in high-resolution global simulations of the Venus atmosphere. The streaks are formed in both hemispheres with equatorial symmetry, which is caused by equatorial Rossby-like and Kelvin-like waves with zonal wavenumber one. The low-stability layer that has been suggested by past observations is essential for reproducing the streak structure. The streaks of downward flow result from the interaction of the meridionally tilted phase lines of the Rossby-like waves and the characteristics of baroclinic instability produced around the low-stability layer.
AB - Cloud patterns are important clues for revealing the atmospheric circulation of Venus. Recently, a planetary-scale streak structure has been discovered in middle- and lower-cloud images of Venus’ night-side taken by IR2, the 2-μm camera, on board the Akatsuki orbiter. However, its formation mechanism has not been investigated. Here we succeed, for the first time, in reproducing the patterns of the observed streak structure, as regions of strong downward flows that develop in high-resolution global simulations of the Venus atmosphere. The streaks are formed in both hemispheres with equatorial symmetry, which is caused by equatorial Rossby-like and Kelvin-like waves with zonal wavenumber one. The low-stability layer that has been suggested by past observations is essential for reproducing the streak structure. The streaks of downward flow result from the interaction of the meridionally tilted phase lines of the Rossby-like waves and the characteristics of baroclinic instability produced around the low-stability layer.
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U2 - 10.1038/s41467-018-07919-y
DO - 10.1038/s41467-018-07919-y
M3 - Article
C2 - 30626864
AN - SCOPUS:85059795795
SN - 2041-1723
VL - 10
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 23
ER -