Abstract In paleoclimatology, the concept of latitudinal insolation gradients (LIGs), reckoned in various ways, has received increasing attention regarding glacial/inter-glacial climatic transitions and oscillations. In particular, the Holocene, which permits the reconstruction of past climatic proxies with an increasingly finer spatial and temporal resolutions, has provided evidence that suggests that LIGs are a key forcing on climate at different timescales. Nevertheless, LIGs’ own dynamics (chiefly their variations in relation to astronomical parameters and geographical zones) and even basic definitions, have not been properly investigated, especially during the last part of the present geological epoch. The main reason is the lack of broadly accessible, theoretical insolation data that account for short-term orbital variations (i.e., for describing sub-Milankovic-orbital forcing during the Holocene). Based on our latest astronomical-orbital solutions, we present an in-depth discussion on the calculation of LIGs and their variations all through the Holocene and 1 kyr into the future. Our results show a much more complex variety and behaviour of LIGs than those that were shown previously. We report that during the studied period, daily LIGs in summer, around the solstitial days (both hemispheres), are strongly modulated by obliquity only at mid-latitude band, whereas at tropical and polar bands LIGs are modulated by “precession”. Summer half-year LIGs for the Northern Hemisphere show a marked modulation in out-of-phase sense with obliquity, just for the mid-latitude and polar bands. Surprisingly, this competing effect between “precession” and obliquity also produces the fact that the southern counterpart of these LIGs are more modulated by “precession” than obliquity. In cases involving inter-band latitudes or different intra-annual lapses, they need to be examined separately and carefully and the results could be very different from traditional presumptions. Our novel results and study are based on the precise estimation of the duration of the orbital interval considered in the definition of LIGs. Our new study also avoids the difficulties of insolation calculations regarding the relationship between orbital longitudes and time.

中文翻译：

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关于整个全新世纬度日照梯度的计算

摘要 在古气候学中，纬度日照梯度（LIGs）的概念以各种方式计算，在冰期/间冰期气候转变和振荡方面受到越来越多的关注。特别是全新世，它允许以越来越精细的空间和时间分辨率重建过去的气候代理，提供的证据表明 LIG 是不同时间尺度上气候的关键推动力。尽管如此，LIG 自身的动力学（主要是它们与天文参数和地理区域相关的变化）甚至基本定义都没有得到适当的研究，尤其是在当前地质时代的最后阶段。主要原因是缺乏解释短期轨道变化的广泛可用的理论日照数据（即，用于描述全新世期间的亚米兰科维奇轨道强迫）。基于我们最新的天文轨道解决方案，我们深入讨论了 LIG 的计算及其在整个全新世和未来 1 kyr 的变化。我们的结果显示 LIG 的种类和行为比以前显示的要复杂得多。我们报告说，在研究期间，夏至日（两个半球）附近的每日 LIG 仅在中纬度波段受到倾斜度的强烈调制，而在热带和极地波段，LIG 受“岁差”调制。北半球的夏季半年 LIG 显示出与倾斜的异相意义上的显着调制，仅适用于中纬度和极地波段。出奇，“岁差”和倾角之间的这种竞争效应也产生了这样一个事实，即这些 LIG 的南部对应物更受“岁差”而不是倾角的调节。在涉及跨带纬度或不同的年度内失误的情况下，需要分别仔细审查，结果可能与传统推定大不相同。我们的新结果和研究基于对 LIG 定义中考虑的轨道间隔持续时间的精确估计。我们的新研究还避免了关于轨道经度和时间之间关系的日照计算的困难。它们需要分别仔细地审查，结果可能与传统的假设大不相同。我们的新结果和研究基于对 LIG 定义中考虑的轨道间隔持续时间的精确估计。我们的新研究还避免了关于轨道经度和时间之间关系的日照计算的困难。它们需要分别仔细地审查，结果可能与传统的假设大不相同。我们的新结果和研究基于对 LIG 定义中考虑的轨道间隔持续时间的精确估计。我们的新研究还避免了关于轨道经度和时间之间关系的日照计算的困难。