The research study that explains their findings was led by Haifeng Xiao, a research assistant with the Institute of Geodesy and Geoinformation Science at the Berlin Technical University. He was joined by scientists from Stanford University, the Université Paris-Saclay, the Institut Universitaire de France, and the German Aerospace Centers (DLR) Institute of Planetary Research and Institute of Atmospheric Physics.
Time-lapse video showing seasonal changes around Mars South Pole. Credit: W.M. Calvin, et al. (2015 ).
What we understand about the Martian polar ice caps indicates that they are made up of 3 parts. There is the Residual (or Permanent) Ice Cap, which consists of sheets of water ice several meters thick at the North Pole, and an 8-meter (~ 10 feet) thick sheet of frozen carbon dioxide at the South Pole. Underneath that are the Polar Layered Deposits (PLDs), which are 2 to 3 km (mi) thick and made up of water ice and dust.
Last is the Seasonal Ice Cap, a layer of frozen CO2 deposited on top of the long-term ice caps every winter. For the sake of their research study, Haifeng and his associates concentrated on the Seasonal Ice Caps to expose how they are impacted by variations in seasonal temperature levels and solar radiation– and how this is connected with yearly variations in Mars climate. As Haifeng informed Universe Today via email:
“In addition, the seasonal accumulation of the CO2 ice to form these seasonal polar caps can be affected by dust storms, cold spots, katabatic and orographic winds, and regional watching. Thus, long-lasting and short irregularities of the seasonal polar caps could also suggest the irregularities of the Mars environment.”
During a Martian year, which lasts over 687 Earth days (or 668.5 Sols), seasonal changes result in climatic co2 migrating from the North Pole to the South Pole (and vise versa). These seasonal actions are responsible for carrying large quantities of dust and water vapor, which leads to frosts and the development of big cirrus clouds visible from area.
This image from the Mars Reconnaissance Orbiter (MRO) shows the “spiders” emerging from the co2 ice cap at the South Pole of Mars. Credit: NASA/JPL-Caltech
This process of sublimation and exchange between the poles is likewise responsible for noteworthy geological functions on Mars, such as the araneiform surface (aka. “spiders”) near the South Pole and the method the dune fields in the northern airplanes end up being furrowed with the arrival of seasonals. As Haifeng discussed, comprehending the relationship in between the seasonal polar caps and the development of geological features on Mars might result in a much better understanding of the Martian environment.
Over the past two years, measurements of the polar ice caps have actually been performed utilizing various approaches– gravity gamma-ray, variation, and neutron flux– and designed based on General Circulation and Energy Balance models. For their study, Haifeng and his coworkers depend on information obtained by the Mars Orbiter Laser Altimeter (MOLA) instrument aboard the MGS to obtain accurate measurements of the height and volume of Marss polar ice caps gradually.
This included reprocessing the MOLA Precision Experiment Data Records (PEDR)– or MOLAs private altimetry readings– utilizing the latest available MGS orbit information and Mars rotational design. They then self-registered these profiles into a self-consistent Digital Terrain Model (DTM), which acted as a static mean surface area measurement for Mars. As Haifeng explained:
” We have actually proposed and verified the co-registration of local dynamic Mars Orbiter Laser Altimeter (MOLA) profile segments to static Digital Terrain Models (DTMs) as a method for obtaining seasonal CO2 ice cover depth variations on Mars. In addition, we have also proposed a post-correction treatment based upon the pseudo cross-overs of MOLA profiles to additional enhance the precision of the depth variation time series.”
” Furrowed” dunes in the cratered area near the Martian North Pole. Credit: NASA/JPL-Caltech/University of Arizona
The outcome of this was a series of height-change measurements with a precision of ~ 4.9 cm (1.93 inches) and peak-to-peak height variations of ~ 2.2 m (7.2 ft). The team likewise extended these results to the entire South Pole, which they wish to cover in higher information in another soon-to-be-published study. Haifeng and his coworkers also plan to compare their results with radar altimetry data gotten by the SHAllow RADar sounder (SHARAD) aboard NASAs Mars Reconnaissance Orbiters (MRO).
” As the next action, We will attempt the SHARAD radar altimetry to cross-validate the MOLA measurements and to derive the long-lasting seasonal depth advancement of the seasonal polar caps of Mars, which will also be very important for assessing the long-term stability of the underlying Martian Residual Polar Caps, especial the Residual South Polar Cap that is thought about to be in a quasi-stable state,” said Haifeng.
These measurements will enable planetary scientists to learn a lot more about the Martian environment and the yearly changes it goes through. They will also help prepare future robotic and human exploration objectives to the Red Planet, which are still expected for a long time in the next decade.
More Reading: arXiv
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On Earth, seasonal variations in temperature level and rainfall cause the polar ice cap in one hemisphere to grow while the ice cap in the other hemisphere shrinks.
In addition to snow drizzling down on the polar ice caps throughout winter season, the Martian polar ice caps also receive a fantastic deal of frozen carbon dioxide (” dry ice”) in addition to snow. There is the Residual (or Permanent) Ice Cap, which consists of sheets of water ice numerous meters thick at the North Pole, and an 8-meter (~ 10 feet) thick sheet of frozen carbon dioxide at the South Pole. Last is the Seasonal Ice Cap, a layer of frozen CO2 transferred on top of the permanent ice caps every winter season. “In addition, the seasonal accumulation of the CO2 ice to form these seasonal polar caps can be affected by dust storms, cold spots, orographic and katabatic winds, and local watching.
Like Earth, Mars experiences climatic variations throughout the course of a year due to the fact that of the tilted nature of its orbit (aka. seasonal change) These variations in temperature outcome in interaction in between the environment and the polar ice caps. In the world, seasonal variations in temperature level and rainfall trigger the polar ice cap in one hemisphere to grow while the ice cap in the other hemisphere shrinks.
In addition to snow drizzling down on the polar ice caps throughout winter season, the Martian polar ice caps likewise receive a fantastic deal of frozen carbon dioxide (” dry ice”) in addition to snow. Just recently, a global group of researchers utilized information from NASAs Mars Global Surveyor (MGS) mission to determine how the worlds polar ice caps grow and decline.
