Related Experiment Video
Updated: Apr 8, 2026
06:10
Using Generative Art to Convey Past and Future Climate Transitions
Published on: March 31, 2023
1.6K
Obliquity Control On Southern Hemisphere Climate During The Last Glacial
C J Fogwill1, C S M Turney1, D K Hutchinson2
1Climate Change Research Centre School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052. Australia.
Scientific Reports
|June 27, 2015
Summary
Southern Hemisphere glacial climate was driven by Antarctic sea-ice expansion, not Northern Hemisphere insolation. This altered storm tracks, causing Patagonian cooling and influencing ice sheet growth during the early Last Glacial Maximum.
Area of Science:
- Paleoclimatology
- Glacial dynamics
- Climate modeling
Background:
- Traditional views link Northern Hemisphere insolation to synchronous global climate and ice-sheet volume during glacial cycles.
- Recent paleoclimate data challenge this synchronous model, suggesting regional variations in glacial timing.
- The response of the Patagonian Ice Sheet to past climate forcings remains incompletely understood.
Purpose of the Study:
- To investigate the drivers of an early Last Glacial Maximum (eLGM) in Patagonia.
- To test the hypothesis that Southern Hemisphere climate dynamics, particularly Antarctic sea-ice extent, influenced Patagonian Ice Sheet expansion.
- To assess the role of orbital changes and sea-ice anomalies in Southern Hemisphere glacial climate.
Main Methods:
- Analysis of paleoclimate reconstructions to determine the timing of Patagonian Ice Sheet maximum expansion.
- Numerical simulations using a suite of climate models.
- Incorporation of prescribed and evolving sea-ice anomalies and orbital forcing in climate model experiments.
Main Results:
- Patagonian Ice Sheet maximum expansion occurred at 28.4 ± 0.5 ka, predating the Northern Hemisphere insolation minimum and formal Last Glacial Maximum (LGM).
- Antarctic sea-ice expansion at 28.5 ka altered Southern Hemisphere storm tracks, causing a 5 °C cooling in Patagonia and mid-southern latitudes.
- During the LGM, continued Antarctic sea-ice expansion led to reduced regional temperature and precipitation, limiting Patagonian Ice Sheet growth.
Conclusions:
- Orbital forcing significantly influences Southern Hemisphere glacial climate through its impact on Antarctic sea-ice extent.
- Mid-latitude regions are highly sensitive to changes in Antarctic sea-ice, affecting regional climate and ice-sheet dynamics.
- The findings challenge the paradigm of synchronous global climate forcing during the last glacial cycle, emphasizing Southern Hemisphere drivers.
More Related Videos
10:46A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
11.2K
10:28Investigating the Relationship between Sea Surface Chlorophyll and Major Features of the South China Sea with Satellite Information
Published on: June 13, 2020
6.4K
Related Concept Videos
01:50Global Climate Change
29.8K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
29.8K
01:16What is Climate?
21.5K
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
21.5K
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
1.2K
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
1.2K
01:19Magnetic Declination
659
Magnetic declination is the angle between true north, which aligns with the Earth's rotational axis, and magnetic north, which follows the direction of the Earth's magnetic field. This discrepancy exists because the magnetic poles do not coincide with the geographic poles. The value of magnetic declination depends on the observer's location on Earth and is subject to changes over time due to the dynamic nature of the Earth's magnetic field.The declination is called eastern when magnetic north...
659
01:27Microbes and Climate Change
56
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
56
01:24Gyroscope: Precession
6.0K
Precession can be demonstrated effectively through a spinning top. If a spinning top is placed on a flat surface near the surface of the Earth at a vertical angle and is not spinning, it will fall over due to the force of gravity producing a torque acting on its center of mass. However, if the top is spinning on its axis, it precesses about the vertical direction, rather than topple over due to this torque. Precessional motion is a combination of a steady circular motion of the axis and the...
6.0K