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A Numerical Study of Convection in a Condensing CO2 Atmosphere under Early Mars-Like Conditions
| Title: | A Numerical Study of Convection in a Condensing CO2 Atmosphere under Early Mars-Like Conditions |
| Authors: | Yamashita, Tatsuya Browse this author | | Odaka, Masatsugu Browse this author →KAKEN DB | | Sugiyama, Ko-Ichiro Browse this author | | Nakajima, Kensuke Browse this author →KAKEN DB | | Ishiwatari, Masaki Browse this author →KAKEN DB | | Nishizawa, Seiya Browse this author →KAKEN DB | | Takahashi, Yoshiyuki O. Browse this author →KAKEN DB | | Hayashi, Yoshi-Yuki Browse this author |
| Issue Date: | Oct-2016 |
| Publisher: | American Meteorological Society |
| Journal Title: | Journal of the atmospheric sciences |
| Volume: | 73 |
| Issue: | 10 |
| Start Page: | 4151 |
| End Page: | 4169 |
| Publisher DOI: | 10.1175/JAS-D-15-0132.1 |
| Abstract: | Cloud convection of a CO2 atmosphere where the major constituent condenses is numerically investigated under a setup idealizing a possible warm atmosphere of early Mars, utilizing a two-dimensional cloud-resolving model forced by a fixed cooling profile as a substitute for a radiative process. The authors compare two cases with different critical saturation ratios as condensation criteria and also examine sensitivity to number mixing ratio of condensed particles given externally. When supersaturation is not necessary for condensation, the entire horizontal domain above the condensation level is continuously covered by clouds irrespective of number mixing ratio of condensed particles. Horizontal-mean cloud mass density decreases exponentially with height. The circulations below and above the condensation level are dominated by dry cellular convection and buoyancy waves, respectively. When 1.35 is adopted as the critical saturation ratio, clouds appear exclusively as intense, short-lived, quasi-periodic events. Clouds start just above the condensation level and develop upward, but intense updrafts exist only around the cloud top; they do not extend to the bottom of the condensation layer. The cloud layer is rapidly warmed by latent heat during the cloud events, and then the layer is slowly cooled by the specified thermal forcing, and supersaturation gradually develops leading to the next cloud event. The periodic appearance of cloud events does not occur when number mixing ratio of condensed particles is large. |
| Rights: | © Copyright [2016.10] American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (https://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyrights@ametsoc.org. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/64937 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 小高 正嗣
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