2024-12-19 ヒューストン大学（UH）
＜関連情報＞
- https://uh.edu/news-events/stories/2024/december/12192024-mars-wx-breakthrough.php
- https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024AV001389
火星と地球の異なるエネルギー収支 Distinct Energy Budgets of Mars and Earth
Larry Guan, Liming Li, Ellen C. Creecy, Xun Jiang, Xinyue Wang, Germán Martínez, Anthony D. Toigo, Mark I. Richardson, Agustín Sánchez-Lavega, Yeon Joo Lee
AGU Advances Published: 19 December 2024
DOI:https://doi.org/10.1029/2024AV001389
Abstract
The radiant energy budget (REB) is a fundamental physical parameter for planetary bodies, though studies constraining the REB for bodies beyond Earth are relatively limited. We generate the first meridional profiles of Mars’ REB at seasonal and annual timescales through measurements based on long term multi-instrument observations from spacecraft orbiting Mars. Then, we compare our findings to Earth’s REB using contemporary satellite data sets. Each planet exhibits remarkably distinct seasonal REB distributions due to differences in their orbital, atmospheric, and surface properties. Annually, Earth’s REB exhibits a tropical energy surplus and a deficit at the poles. In contrast, Mars’ annual REB displays an inverted meridional distribution with significant hemispheric asymmetry. Additionally, global dust storms significantly modify the Martian REB. Our observations are employable in future studies to improve models on Mars’ general circulation, meteorology, and polar ice cap evolution.
Key Points
- We generate the first meridional profiles of Mars’ radiant energy budget at seasonal and annual scales, then compare them to those of Earth
- Mars’ annual radiant energy budget shows deficits in the tropics and surpluses at other latitudes, while Earth’s configuration is opposite
- Global dust storms significantly modify the radiant energy budget of Mars
Plain Language Summary
The climate and weather patterns of a planet or moon are significantly influenced by its radiant energy budget (its solar energy absorbed vs. heat energy emitted). Here, we determine Mars’ radiant energy budget averaged at each latitude per season. While Mars’ global energy budget remains roughly balanced over the course of a Martian year, as expected for rocky planets, there is a significant imbalance within each season. Mars’ southern hemisphere during its spring season is the most striking example. Not only is the strongest energy excess amongst all Martian seasons found here – this excess is also the largest in terms of areal coverage, spanning almost all southern latitudes. Such an energy surplus contributes to the development of Mars’ atmospheric circulation and dust storms. The influence of global dust storms on the radiant energy budget is also examined. Finally, we compare Mars’ radiant energy budget to that of Earth, which reveals dramatic differences in the meridional distribution of radiant energy at both seasonal and annual timescales between the planets. These differences are attributed to the unique properties of each planet and have profound impacts on their respective climate systems.
