Scholarlink

<p>Venus and Earth are similar in bulk properties yet followed dramatically different climatic trajectories. Reconstructing the climate evolution of Venus requires understanding how variations in rotation rate, obliquity, orbital eccentricity, and solar luminosity shaped the spatial and temporal distribution of incident energy and the atmospheric response. Here we present latitude-orbital phase maps of incident solar flux for Venus at the present epoch and at an age of 0.5&#xa0;Gyr, when the Sun was fainter and Venus may have occupied a different dynamical state. We explore endmember rotation regimes (slow-rotator and fast-rotator), moderate obliquity (10°), and elevated eccentricity (<InlineEquation ID="IEq1"> <EquationSource Format="MATHML"><math> <mi>e</mi> <mo>=</mo> <mn>0.15</mn> </math></EquationSource> <EquationSource Format="TEX">$e = 0.15$</EquationSource> </InlineEquation>–0.30), motivated by dynamical studies that quantify plausible limits. To translate the flux maps into climate-relevant quantities, we apply an idealized atmospheric energy-balance framework, including both global (0-D) and latitude-dependent (1-D) formulations calibrated to modern Venus. This framework is used to define a radiative relaxation timescale that links forcing variability to expected thermal response. This approach provides a link between orbital forcing and surface energy balance, allowing an assessment of seasonal and orbital variability relative to Venus’s extreme greenhouse state. Our results show that, while early Venus could experience substantial redistribution of insolation across latitude and orbital phase, the orbit-averaged incident flux varies only modestly across the explored parameter space and the dominant control on surface temperature remains atmospheric opacity. Insolation variations therefore act primarily as modulators rather than primary drivers of climate state, with their climatic expression governed by the competition between the forcing timescale and the radiative adjustment time. The provided insolation maps and response diagnostics may serve as boundary conditions for future 3-D climate simulations that investigate the early history of Venus, including regimes in which temperate surface conditions may have been sustained.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Seasonal insolation variability on early Venus: implications for energy budget

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月12日

查看全文
  • Stephen R. Kane

摘要

Venus and Earth are similar in bulk properties yet followed dramatically different climatic trajectories. Reconstructing the climate evolution of Venus requires understanding how variations in rotation rate, obliquity, orbital eccentricity, and solar luminosity shaped the spatial and temporal distribution of incident energy and the atmospheric response. Here we present latitude-orbital phase maps of incident solar flux for Venus at the present epoch and at an age of 0.5 Gyr, when the Sun was fainter and Venus may have occupied a different dynamical state. We explore endmember rotation regimes (slow-rotator and fast-rotator), moderate obliquity (10°), and elevated eccentricity ( e = 0.15 $e = 0.15$ –0.30), motivated by dynamical studies that quantify plausible limits. To translate the flux maps into climate-relevant quantities, we apply an idealized atmospheric energy-balance framework, including both global (0-D) and latitude-dependent (1-D) formulations calibrated to modern Venus. This framework is used to define a radiative relaxation timescale that links forcing variability to expected thermal response. This approach provides a link between orbital forcing and surface energy balance, allowing an assessment of seasonal and orbital variability relative to Venus’s extreme greenhouse state. Our results show that, while early Venus could experience substantial redistribution of insolation across latitude and orbital phase, the orbit-averaged incident flux varies only modestly across the explored parameter space and the dominant control on surface temperature remains atmospheric opacity. Insolation variations therefore act primarily as modulators rather than primary drivers of climate state, with their climatic expression governed by the competition between the forcing timescale and the radiative adjustment time. The provided insolation maps and response diagnostics may serve as boundary conditions for future 3-D climate simulations that investigate the early history of Venus, including regimes in which temperate surface conditions may have been sustained.