相关论文: Atmospheric nitrogen evolution on Earth and Venus
Agriculture is one of the oldest forms of technology on Earth. The cultivation of plants requires a terrestrial planet with active hydrological and carbon cycles and depends on the availability of nitrogen in soil. The technological…
Venus and Earth are similar in bulk properties yet followed dramatically different climatic trajectories. Reconstructing Venus's climate evolution requires understanding how rotation, obliquity, eccentricity, and solar luminosity shaped…
Small, close-in exoplanets are divided into two sub-populations: super-Earths and sub-Neptunes. Most super-Earths are thought to have lost their primordially accreted hydrogen-dominated atmospheres via thermally driven winds. We consider…
The migration of U and Th inside a planet is controlled by its oxidation state imposed by the volatile composition. In the deep interior of a planet, an absence of oxidative volatiles will cause U and Th to stay in a state of metal or low…
Venus' atmosphere -- specifically its clouds buoyed up 40 to 60 km above the surface -- has long been suspected to encompass a biosphere where Earth-like living organisms could grow and flourish. This idea has been recently rekindled by the…
Atmospheric electrification is not a purely terrestrial phenomenon: all Solar System planetary atmospheres become slightly electrified by cosmic ray ionisation. There is evidence for lightning on Jupiter, Saturn, Uranus and Neptune, and it…
Carbon dioxide is one of the major contributors to the radiative forcing, increasing both the temperature and the humidity of Earth's atmosphere. If the stellar irradiance increases and water becomes abundant in the stratosphere of an…
In the past decade, observations from space and ground have found H$_2$O to be the most abundant molecular species, after hydrogen, in the atmospheres of hot, gaseous, extrasolar planets. Being the main molecular carrier of oxygen, H$_2$O…
Photochemical hazes are expected to form and significantly contribute to the chemical and radiative balance of exoplanets with relatively moderate temperatures, possibly in the habitable zone of their host star. In the presence of humidity,…
As oxygen is essential for respiration and metabolism for multicellular organisms on Earth, its presence may be crucial for the development of a complex biosphere on other planets. And because life itself, through photosynthesis,…
Chemistry in Titan's N2-CH4 atmosphere produces complex organic aerosols. The chemical processes and the resulting organic compounds are still far from understood, although extensive observations, laboratory, and theoretical simulations…
The upper atmospheres of the planets and their satellites are more directly exposed to sunlight and solar wind particles than the surface or the deeper atmospheric layers. At the altitudes where the associated energy is deposited, the…
Sulfur-bearing species play crucial roles in atmospheric physical-chemical processes, atmosphere-surface interactions, and the geological evolution of Venus. This chapter provides a comprehensive overview of (1) instrumental data on the…
Observations made during the New Horizons flyby provide a detailed snapshot of the current state of Pluto's atmosphere. While the lower atmosphere (at altitudes <200 km) is consistent with ground-based stellar occultations, the upper…
The long-term evolution of hydrogen-dominated atmospheres of sub-Neptune-like planets is mostly controlled by two factors: a slow dissipation of the gravitational energy acquired at the formation (known as thermal evolution) and atmospheric…
Condensible substances are nearly ubiquitous in planetary atmospheres. For the most familiar case-water vapor in Earth's present climate-the condensible gas is dilute, in the sense that its concentration is everywhere small relative to the…
Oxygen is the most common element after hydrogen and helium in Jupiter's atmosphere, and may have been the primary condensable (as water ice) in the protoplanetary disk. Prior to the Juno mission, in situ measurements of Jupiter's water…
It is now understood that the accretion of terrestrial planets naturally involves giant collisions, the moon-forming impact being a well known example. In the aftermath of such collisions the surface of the surviving planet is very hot and…
Measurements of trace-gases in planetary atmospheres help us explore chemical conditions different to those on Earth. Our nearest neighbor, Venus, has cloud decks that are temperate but hyper-acidic. We report the apparent presence of…
A plausible explanation for the absence of primordial argon, krypton, and xenon in Titan's current atmosphere is that these gases were sequestered in clathrate hydrates during Titan's "open-ocean" phase. We examine how clathrate hydrate…