近日，加拿大维多利亚大学Deitrick, Russell最近的研究发现短日照下潮汐共振引起的云层组织使过去地球变暖。该研究于2024年7月1日发表于国际一流学术期刊《自然—地球科学》杂志上。

研究人员运行不同自转速率下的一般环流模式来模拟共振及其对气候的影响。共振对热带云量、对流和降雨起主要控制作用：日出和日落多云多雨，而中午和午夜晴朗干燥。通常正午晴朗的天空会降低反照率，使全球平均气温上升2-4 K，这将有助于抵消太阳减弱10%的影响。水文循环变得更加活跃，大气变得更加湿润。研究结果强调了潮汐诱导的绝热膨胀在控制热带降水中的作用，有助于解释现代观测到的半日降水模式。

据介绍，太阳的加热引起了地球大气层的周期性的膨胀和收缩，即所谓的大气潮汐。这是在地表观测到的半日压力振荡，似乎影响对流和降雨。大约5亿到10亿年前，一天大约是21-22个小时，潮汐应该是共振的或者频率接近，大气兰姆波的周期为10.5-11.0个小时。这种“兰姆共振”会放大压力振荡，也许足以影响全球或热带气候。

附：英文原文

Title: Past Earth warmed by tidal resonance-induced organization of clouds under a shorter day

Author: Deitrick, Russell, Goldblatt, Colin

Issue&Volume: 2024-07-01

Abstract: Solar heating causes the periodic expansion and contraction of Earth’s atmosphere known as the atmospheric tide. This is observed at the surface as a semidiurnal pressure oscillation that appears to influence convection and rainfall. Roughly 0.5 to 1.0 billion years ago, when day length was roughly 21–22hours, the tide would have been resonant, or close in frequency, with atmospheric Lamb waves of 10.5–11.0hour periods. This ‘Lamb resonance’ would have amplified the pressure oscillation, perhaps strongly enough to affect the global or tropical climate. Here we run a general circulation model at different rotation rates to model the resonance and its impact on climate. The resonance exerts a dominant control on tropical cloud cover, convection and rainfall: sunrise and sunset are cloudy and rainy, whereas midday and midnight are clear and dry. Generally clear skies at noon lower the albedo, contributing 2–4 K warming in the global average, which would have helped counter the 10% fainter Sun. The hydrological cycle becomes more active, and the atmosphere moister. Our work highlights the role of tidally induced adiabatic expansion in controlling tropical precipitation, helping explain modern-day observations of a semidiurnal rainfall pattern.

DOI: 10.1038/s41561-024-01469-3

Source: https://www.nature.com/articles/s41561-024-01469-3