Even meteorologists who predict weather conditions on Earth acknowledge that they cannot always predict weather at any particular location. Forecasting the weather conditions on another planet can prove difficult.
A new study has shown that a widely-used method of forecasting on Earth can also be used on other worlds, like Mars and Titan, Saturn's largest moon.
J. Michael Battalio (a Yale University postdoctoral researcher), said that the first accurate predictions of Mars's days are only a decade away. It's just a matter combining better observational data with sufficient refined numerical models.
This technique employs an annular mode phenomenon, which is related to Earth's jet stream. Annular modes refer to variations in Earth's atmospheric flow that are not affected by seasonal changes. Annular nodes are able to impact the jet stream and cloud formation around the globe. These modes can also explain the inconsistent wind eddies and the air circulations that are responsible for severe Midwest storms and New England's blizzards.
Battalio wanted to know if similar weather patterns could be found on Titan and Mars. His colleagues and he analyzed 15 years worth of meteorological observations from Mars to discover that the Red Planet had annular modes. Juan Lora, a Battalios Professor at Yale, also created a global climate model that searches for annular modes in Titan.
This animation is based on images taken by NASA's Visual and Infrared Mapping Spectrometers (VIMS) during several Titan flybys in 2009 and 2010. It shows bright spots that can be interpreted as evidence for dust storms. Credits: NASA/JPL-Caltech/University of Arizona/University Paris Diderot/IPGP/S. Rodriguez et al. 2018
They found that annular modes were likely to be even more influential on these worlds than on Earth. Annular modes account at least half the wind variability on Mars, and at least two-thirds on Titan.
Each of the Earths modes, Titan and Mars, occur frequently. Researchers said that the annular modes have an impact on the dust storms that can cause them. Real-time analysis of these modes allows for simple predictions without the need to use a complicated model.
In a press release, Battalio stated that annular modes have been found on worlds other than Earth, such as Mars and Titan. This means they could be common in planetary atmospheres from Venus to the gas giants and exoplanets.
Lora added that methane clouds on Titan and surface changes due to methane rain have been previously observed. These events may be linked to the shifts in Titan's strong jet stream that is influenced by its annular mode.
Weather report from Gale Crater, Mars, based on the Curiosity Rover's weather instrument. Credit: NASA/JPL
Mars is a windy planet with dust storms that can blanket the entire planet. Many robotic missions that humans have sent to Mars have used weather instruments. These include the Phoenix Landers Telltale which provided wind data and the Perseverance Rovers Mars Environmental Dynamics Analyzer, (MEDA), which measures and reports daily and seasonal atmospheric pressure, humidity and ultraviolet radiation at Mars' surface and air temperature.
Astronomers have been able to use the plethora images taken by Mars Reconnaissance Orbiter satellite to get more information about Mars' weather systems.
Robotic missions and future human missions will benefit from being able to forecast storms on other planets.
Evidence of dust devils dancing upon Mars Credit: NASA/JPL/UArizona
Battalio stated that it is crucial to predict and understand these events for safety missions, especially those that rely on solar energy, as well as for all missions landing on the surface.
Yale University Press Release
Astronomy of Nature
Caption for the lead image: Illustration by Michael S. Helfenbein; Image credit to NASA/JPL–Caltech