Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars's dramatic climate variations are driven by the Sun

07.09.2012
On Mars's poles there are ice caps of ice and dust with layers that reflect to past climate variations on Mars. Researchers from the Niels Bohr Institute have related the layers in the ice cap on Mars's north pole to variations in solar insolation on Mars, thus established the first dated climate history for Mars, where ice and dust accumulation has been driven by variations in insolation. The results are published in the scientific journal, Icarus.

The ice caps on Mars's poles are kilometres thick and composed of ice and dust. There are layers in the ice caps, which can be seen in cliffs and valley slopes and we have known about these layers for decades, since the first satellite images came back from Mars. The layers are believed to reflect past climate on Mars, in the same way that the Earth's climate history can be read by analysing ice cores from the ice caps on Greenland and Antarctica.


The ice cap on Mars's north pole is primarily composed of water ice and containing a few percent of dust. It has a spiral structure formed by white, ice-covered areas and dark slopes where the layers in the ice cap can be seen

Credit: NASA/JPL/MSSS

Solar insolation on Mars has varied dramatically over time, mainly due to large variations in the tilt of Mars's rotational axis (obliquity) and this led to dramatic climate variations on Mars. For years people have tried to link the solar insolation and layer formation by looking for signs of periodic sequences in the visible layers, which can be seen in the upper 500 meters. Periodic signals might be traceable back to known variations in the solar insolation on Mars, but so far it has been unclear whether one could find a correlation between variations in insolation and the layers.

Correlation between ice, dust and sun

"Here we have gone in a completely different direction. We have developed a model for how the layers are built up based on fundamental physical processes and it demonstrates a correlation between ice and dust accumulation and solar insolation, explains Christine Hvidberg, a researcher in ice physics at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

She explains that in the model the layer formation is driven by insolation and the dust rich layers can be formed by two processes: 1: Increased evaporation of ice during the summer at high obliquity (when the rotational axis tilts down) and 2: Variations in dust accumulation as a result of variations in the axial tilt. The model is simple, but physically possible and it can be used to examine the relationship between climate variability and layer formation.

The researchers established a framework for the model that could explain the layer formation so that it was consistent with the observations. By comparing the layer distribution in the model with precise measurements of the layer structure from high resolution satellite images of the ice cap on Mars's north pole, they have discovered that the model is able to reproduce the complex sequences in the layers.

Climate history over 1 million years

"The model dates the upper 500 meters of the northern ice cap on Mars, equivalent to approximately 1 million years and an average accumulation rate of ice and dust of 0.55 mm per year. It links the individual layers to the maxima in solar insolation and thereby establishes a dated climate history of the north pole of Mars over 1 million years," says Christine Hvidberg.

Even though the model is only based on a comparison with the visible layers in the upper 500 meters, preliminary studies indicate that the entire thickness and internal structure of the ice cap can be explained by the model and can thus explain how ice and dust accumulation on Mars's north pole has been driven by variations in solar insolation for millions of years.

Article in Icarus
http://dx.doi.org/10.1016/j.icarus.2012.08.009
For more information contact:
Christine Schott Hvidberg, Associate Professor, Centre for Ice and Climate
Niels Bohr Institute, University of Copenhagen
Phone: +45-35 32 05 63, Email: ch@gfy.ku.dk

Gertie Skaarup | EurekAlert!
Further information:
http://www.nbi.dk

Further reports about: Climate change Copenhagen Icarus Mars crystalline ice caps satellite images

More articles from Physics and Astronomy:

nachricht Applicability of dynamic facilitation theory to binary hard disk systems
08.12.2016 | Nagoya Institute of Technology

nachricht Will Earth still exist 5 billion years from now?
08.12.2016 | KU Leuven

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>