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[笔记] 旋回：米兰科维奇 Milankovitch、丹斯果-奥什格尔 Dansgaard-Oeschger、厄尔尼诺

已有 3292 次阅读 2023-7-16 17:49 |个人分类:人类的宇宙环境|系统分类:科研笔记

[笔记] 旋回：米兰科维奇 Milankovitch、丹斯果-奥什格尔 Dansgaard-Oeschger、厄尔尼诺 El Niño

术语 terminology

地学： geoscience

旋回： cycle

米兰科维奇理论： Milankovitch theory

丹斯果-奥什格尔事件： Dansgaard-Oeschger events

亨里奇事件： Heinrich event

厄尔尼诺： El Niño

厄尔尼诺-南方涛动： ENSO, El Niño-Southern Oscillation

大西洋经向翻转环流： AMOC, Atlantic Meridional Overturning Circulation

一、旋回，地学术语简介

《中国大百科全书》词条“旋回/cycle/”的摘录：

https://www.zgbk.com/ecph/words?SiteID=1&ID=390653&Type=bkzyb&SubID=175631

沉积旋回是指在沉积记录中具有某种成因联系和重复性的地层序列，一般具有时间意义以及（准）周期性的变化。

根据时间尺度的不同，旋回可分为不同层次类型：日历旋回、亚米兰科维奇旋回、米兰科维奇旋回、长周期旋回（又称银河旋回）等。

①日历旋回包括由地月系统引力作用引起的潮汐旋回和地球的自转、公转旋回。其中潮汐旋回具有半日、1日、半月、1月等不同周期，

②亚米兰科维奇旋回是指周期为1年至1万年级的轨道旋回，主要与太阳活动及其与地球大气层和磁层的相互作用有关。

③米兰科维奇旋回是指由地球轨道的岁差、斜率和偏心率等参数的（准）周期性变化引起的天文旋回，是旋回地层学的主要研究对象。这些天文旋回的周期从近2万年至近40万年不等。

④长周期旋回主要体现在地质历史时期生物大灭绝以及生物成种与生物多样性的周期性变化，显示的周期从数百万年到数亿年不等。长周期旋回通常与星际事件引发的长时间尺度的地球、太阳系和太阳系外活动有关。

二、地球公转轨道的变化，可能会引起天气的变化

一些非线性动力系统研究表明：行星轨道似乎是“混沌 chaos”的。换言之，行星轨道的变化里有各种各样的周期性。

仔细分析地球公转、自转观测数据，应该能够发现有关的特征。

行星运动，在我们习惯的时间尺度下，表现为“弱混沌”：其中的周期性比较明显，周期性的变化较微弱（混沌）。

以我们的地球为例，月球的复杂运动（公转），会引起地球轨道的变化。地球公转轨道的变化，会引起地球在太阳引力场的势能变化。因此，地球轨道的各种变化，会在一定程度上引起地球大气运动的变化。

因此，太阳系行星运动，特别是地球运动的精确计算，可能对气候研究具有重大的基础性支撑作用。不过，这个问题实在太难了。仅用牛顿力学怕是不够的，要是加上广义相对论，怕是难上加难。

地球运动影响天气假设：

混沌运动的地球公转、自转，会引起地球在太阳引力场势能的变化。这些能量变化，通过“近似的能量守恒”会作用到地球的大气运动，即天气变化。

米兰科维奇旋回、哈因里奇事件、丹斯果-奥什格尔旋回、Bond旋回、新仙女木事件，以及厄尔尼诺 El Niño，或多或少都有地球轨道与自转变化的驱动。

由于地球的混沌运动，不同历史时期地球自转、公转的变化方式不同，造成了气候变化规律的不同。但不同时间尺度的天气变化，背后都有能量守恒与转化定律的作用。即，地球机械能的变化，会影响地球的大气运动（天气变化）。

下面是地球古气候变化的一些图片，直观地感受一些“旋回”现象：

SCIENCE 2001 Figure 4 Paleo-ENSO variability from fossil corals.jpeg

图1 引用自：Figure 4 Paleo-ENSO variability from fossil corals. 珊瑚化石中的古“厄尔尼诺-南方涛动”变化。 (A) (Left) Seasonal resolution (thin lines) and 2.25-year binomial-filtered (thick lines) skeletal δ18O records from all fossil corals used in this study, with the record from modern coral DT91-7 shown for comparison. (Right) 2.5- to 7-year (ENSO) bandpass-filtered coral δ18O time series. (B) Standard deviation of the 2.5- to 7-year (ENSO) bandpass-filtered time series of all modern and fossil corals discussed in this study. Asterisk indicates that the time series is <30 years long. The horizontal dashed lines indicate maximum and minimum values of standard deviation for sliding 30-year increments in the modern coral records. Black bars, modern corals; gray bars, fossil corals.

https://www.science.org/cms/10.1126/science.1057969/asset/e89343b6-a5bb-4345-afa3-0d4e11b697c0/assets/graphic/se0519182004.jpeg

https://www.science.org/doi/10.1126/science.1057969

Alexander W. Tudhope, Colin P. Chilcott, Malcolm T. Mcculloch, Edward R. Cook, John Chappell, Robert M. Ellam, David W. Lea, Janice M. Lough, Graham B. Shimmield. Variability in the El Niño-Southern Oscillation Through a Glacial-Interglacial Cycle [J]. SCIENCE, 25 Jan 2001, Vol 291, Issue 5508, pp. 1511-1517

DOI: 10.1126/science.1057969

NATURE 2017 Figure 1 Obliquity and short eccentricity band power for La2004,La20.jpg

图2 引用自：Figure 1: Obliquity and short eccentricity band power for La2004, La2010d and the Libsack FMI record. La2004、La2010d和Libsack FMI记录的倾斜和短偏心带功率。

a, Timescale and biostratigraphy (S.m. = Scaphites mariasensis, S.p. = Scaphites preventricosus, S.v. = Scaphites ventricosus, S.d. = Scaphites depressus, C.s. = Clioscaphites saxitonianus, C.v. = Clioscaphites vermiformis, C.c. = Clioscaphites choteauensis, D.e. = Desmoscaphites erdmanni, D.b. = Desmoscaphites bassleri, S.l. = Scaphites leei III, S.h. I = Scaphites hippocrepis I, S.h. II = Scaphites hippocrepis II) and the radioisotopically dated horizons for the Libsack core5,10. In total, five radioisotopic ages are used from the following biozones: D. bassleri, D. erdmanni, C. vermiformis, S. depressus, and S. preventricosus. S. preventricosus is selected as the nominal anchor in this study (see Methods). Each ash bed (except the anchor) is associated with two ages: the top number is the age calculated based on astrochronology (anchored to S. preventricosus), while the bottom number is the radioisotopic age for the bentonite layer, with its 2σ total uncertainty in parentheses (column X3 in Table 1). b, f, The astronomically tuned and anchored FMI data (in units of ohm metre) from the Libsack core. c–e, The obliquity band power extracted from the Libsack core, La2004 and La2010d. g–i, The short eccentricity band power extracted from the Libsack core, La2004 and La2010d. The approximately 1.2-Myr and 2.4-Myr cycles are labelled with dashed arcs. Tur., Turonian age.

https://www.nature.com/articles/nature21402/figures/1

https://www.nature.com/articles/nature21402

Chao Ma, Stephen R. Meyers, Bradley B. Sageman. Theory of chaotic orbital variations confirmed by Cretaceous geological evidence [J]. Nature volume 542, pages 468–470 (2017)

doi: 10.1038/nature21402

NATURE Reviews EE 2020 Fig. 1 Proxy records showing D–O variability across Mar.jpg

图3 引用自：Fig. 1: Proxy records showing D–O variability across Marine Isotope Stage 3. 显示海洋同位素第3阶段“丹斯果-奥什格尔事件”变化的代理记录。

a | 231Pa/230Th from the Bermuda Rise10. b | North Greenland Ice Core Project (NGRIP) oxygen isotope ratio (δ18O) on the Greenland Ice Core Chronology 2005 (GICC05)229, with the interstadials numbered. c | Atmospheric methane (CH4) concentration from the West Antarctic Ice Sheet (WAIS) Divide ice core159. d | Sea-surface temperature (SST) estimate based on the alkenone unsaturation index (Uk′37) from sediment core MD01-2443 retrieved from the Iberian margin26. e | Total reflectance (L*) of sediment from the Cariaco Basin45. f | δ18O record from Hulu Cave, China43. g | WAIS δ18O record97. h | Atmospheric CO2 concentration from Siple46 and Talos230 Domes. Blue shading indicates Dansgaard–Oeschger (D–O) stadials and purple shading indicates Heinrich (H) stadials 5 through to 3. These proxy records show that each stadial is associated with weakening of the Atlantic meridional overturning circulation (AMOC) (panel a), cooling over Greenland (panel b) and the North Atlantic (panel d), low atmospheric CH4 content (panel c), dry conditions in the northern tropics (panel e) and a weaker East Asian monsoon (panel f), indicating a southward shift of the Intertropical Convergence Zone. D–O stadials are associated with a small δ18O increase over Antarctica (panel g). Heinrich stadials are associated with an increase in CO2 (panel h) and a more pronounced δ18O increase over Antarctica, indicating much warmer conditions. Data for panel a from ref.10. Data for panel b from ref.229. Data for panel c from ref.159. Data for panel d from ref.26. Data for panel e from ref.45. Data for panel f from ref.43. Data for panel g from ref.97. Data for panel h from refs46,230.

https://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs43017-020-00106-y/MediaObjects/43017_2020_106_Fig1_HTML.png?as=webp

https://www.nature.com/articles/s43017-020-00106-y/figures/1

Laurie C. Menviel, Luke C. Skinner, Lev Tarasov, Polychronis C. Tzedakis. An ice–climate oscillatory framework for Dansgaard–Oeschger cycles [J]. Nature Reviews Earth & Environment volume 1, pages 677–693 (2020)

doi: 10.1038/s43017-020-00106-y

https://www.nature.com/articles/s43017-020-00106-y

《Zhang, X., Barker, S., Knorr, G. et al. Direct astronomical influence on abrupt climate variability. Nat. Geosci. 14, 819–826 (2021).》 对气候突变的直接天文影响

doi: 10.1038/s41561-021-00846-6

https://www.nature.com/articles/s41561-021-00846-6

是一个好的开始。

Fig. 3 Triggering dynamics of orbitally induced AMOC changes..jpg

图4 引用自：Fig. 3: Triggering dynamics of orbitally induced AMOC changes. 轨道诱导的“大西洋经向翻转环流”变化的触发动力学。

a,b, Imposed precession changes (a) and simulated AMOC index (b) in experiment E40ka_34kaEP (only changing the eccentricity-modulated precession in E40ka_CTL). d,e, Applied obliquity changes (d) and simulated AMOC index (e) in experiment E40ka_34kaObl (only changing the obliquity in E40ka_CTL). c,f, Anomalies between the mean climatology before the onset of abrupt AMOC reduction in E40ka_34kaEP (c) and E40ka_34kaObl (d) and the mean climatology of control run E40ka_CTL, representing the climate tendency after changes in precession and obliquity, respectively. The climatology in E40ka_34kaEP and E40ka_34kaObl is represented by 40- and 100-year averages of the period indicated by the red and blue bold line in b and e, respectively. Grey/black lines in b and e represent original/30-year running mean AMOC indices. Shading in c shows total net freshwater flux (units, mm per day), vectors (arrows) show the vertical integrated moisture transport (units, kg m−1 s−1) and contours (and attached values) show sea-level pressure (units, Pa). The shading in f shows sea-ice concentration (units, %) and contours (and attached values) show the vertical mixed layer depth (units, m).