当前位置: X-MOL 学术Glob. Planet. Change › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Hemisphere differences in response of sea surface temperature and sea ice to precession and obliquity
Global and Planetary Change ( IF 3.9 ) Pub Date : 2020-09-01 , DOI: 10.1016/j.gloplacha.2020.103223
Zhipeng Wu , Qiuzhen Yin , Zhengtang Guo , André Berger

Abstract The response of the climate system to astronomical parameters is an important scientific issue, but the internal processes and feedbacks need to be better understood. This study investigates the differences of the climate response to the astronomical forcing between the Northern (NH) and Southern (SH) hemispheres based on a more than 90,000-year long transient simulation using the model LOVECLIM. The astronomical parameters of the period 511–417 ka BP covering MIS-13, MIS-12 and MIS-11 are used, and greenhouse gases (GHG) concentrations and ice sheets are fixed, in order to investigate the role of insolation alone. Our results show that the response of sea ice and sea surface temperature (SST) to precession and obliquity is different between the two hemispheres. Precession plays a dominant role on the Arctic sea ice. This is mainly due to its response to the local summer insolation and also, to a less degree, the influence of the northward oceanic heat transport. However, obliquity plays a dominant role on the Southern Ocean sea ice through its influence on local solar radiation and also on the westerly winds. As far as the SST is concerned, it shows a strong precessional signal at low latitudes in both hemispheres. For the SST in the mid and high latitudes, obliquity plays a dominant role in the SH whereas precession is more important in the NH. This is largely due to the different response to insolation and feedbacks related to the different land-ocean distribution in the two hemispheres. Near the Equator, besides the precessional signal, the SST also shows strong half-precessional signal, which can be explained by the unique characteristics of the insolation variations at the Equator. Our results also show that during the period of low eccentricity, obliquity is more important than precession and the half-precessional signal vanishes due to reduced impact of precession, but precession is always more important in the NH than in the SH.

中文翻译:

海面温度和海冰对进动和倾角响应的半球差异

摘要 气候系统对天文参数的响应是一个重要的科学问题,但需要更好地理解其内部过程和反馈。本研究基于使用 LOVECLIM 模型进行了超过 90,000 年的长期瞬态模拟,研究了北半球 (NH) 和南半球 (SH) 对天文强迫的气候响应差异。使用涵盖 MIS-13、MIS-12 和 MIS-11 的 511-417 ka BP 时期的天文参数,并固定温室气体 (GHG) 浓度和冰盖,以研究单独的日晒作用。我们的结果表明,海冰和海面温度 (SST) 对进动和倾角的响应在两个半球之间是不同的。岁差在北极海冰上起着主导作用。这主要是由于它对当地夏季日照的反应,以及在较小程度上受到向北海洋热传输的影响。然而,倾角通过其对当地太阳辐射和西风的影响,在南大洋海冰中起着主导作用。就海温而言,它在两个半球的低纬度都显示出强烈的岁差信号。对于中高纬度的海温,赤纬占主导地位,而进动在北纬更为重要。这主要是由于两个半球对日照和反馈的不同反应与不同的陆海分布有关。在赤道附近,除了岁差信号外,海温还显示出强烈的半岁差信号,这可以通过赤道日照变化的独特特征来解释。我们的结果还表明,在低偏心率期间,倾角比进动更重要,由于进动的影响减弱,半进动信号消失,但进动在 NH 中始终比在 SH 中更重要。
更新日期:2020-09-01
down
wechat
bug