| DOI: | 10.1038/ngeo2405
|
| 论文题名: | Moist convection in hydrogen atmospheres and the frequency of Saturn's giant storms |
| 作者: | Li C.; Ingersoll A.P.
|
| 刊名: | Nature Geoscience
|
| ISSN: | 17520894
|
| 出版年: | 2015
|
| 卷: | 8, 期:5 | | 起始页码: | 398
|
| 结束页码: | 403
|
| 语种: | 英语
|
| Scopus关键词: | atmospheric convection
; convection
; cooling
; frequency analysis
; global warming
; helium
; hydrogen
; Jupiter
; latitude
; lightning
; numerical model
; oscillation
; Saturn
; storm
; thermodynamics
; troposphere
; water vapor
|
| 英文摘要: | A giant storm erupted on Saturn in December 2010. It produced intense lightning and cloud disturbances and encircled the planet in six months. Six giant storms - also called Great White Spots - have been observed on Saturn since 1876, recurring every 20 to 30 years and alternating between mid-latitudes and the equator. Here we use thermodynamic arguments to demonstrate that the quasi-periodic occurrence of Saturn's giant storms can be explained by a water-loading mechanism, in which moist convection is suppressed for decades owing to the relatively large molecular weight of water in a hydrogen-helium atmosphere. We find that the interaction between moist convection and radiative cooling in the troposphere above the cloud base produces an oscillation that leads to giant storm generation with a period of approximately 60 years for either mid-latitudes or the equator, provided the mixing ratio of water vapour in the troposphere exceeds 1.0%. We use a two-dimensional axisymmetric dynamic model and a top-cooling convective adjustment scheme to apply our conceptual model to Saturn. For a water vapour mixing ratio of 1.1%, simulated storms show a recurrence interval, ammonia depletion and tropospheric warming that are consistent with 2010 observations. Jupiter's atmosphere is more depleted in water than Saturn, which may explain its lack of planet-encircling storms. © 2015 Macmillan Publishers Limited. All rights reserved. |
| Citation statistics: |
|
| 资源类型: | 期刊论文
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/106220
|
| Appears in Collections: | 气候减缓与适应
科学计划与规划
|
|
There are no files associated with this item.
|
|
作者单位: | Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
|
| Recommended Citation: | |
Li C.,Ingersoll A.P.. Moist convection in hydrogen atmospheres and the frequency of Saturn's giant storms[J]. Nature Geoscience,2015-01-01,8(5)
|
|
|