Mars’ imbalanced energy budget can be fuelling dust storms: Study

According to a new study, a seasonal imbalance of the ratio of solar energy absorbed by Mars and heat released by the planet into space may be fuelling dust storms in the red planet.

Key findings:

• The ratio, known as energy budget, goes out of balance in the spring and summer seasons of red planet’s southern hemisphere.
• The resultant dust storms cover areas as large as continents on Earth and last for weeks.
• According to NASA, the storms are so intense that they’ve been captured by Earth’s telescopes.
• Energy excess (when the planet absorbs more energy than it emits) can be one of the drivers of Mars’ dust storms.

How is it important for us?

• Earth has an energy budget, too. Therefore, Mars’ energy budget might provide clues about the role Earth’s energy budget plays in developing severe storms, including hurricanes.
• The researchers calculated that the global average emitted power is around 111.7 watts per square metre on Mars.
• But this varied during seasons.
• The energy excess in ‘northern autumn’, a southern hemisphere season, is roughly 15.3 per cent of the emitted energy.
• This imbalance could affect the seasonal change of surface temperature on Mars.
• The researchers found a correlation between dust storms and emitted energy by comparing emitted energy in dust storm years and non-dust storm years on Mars.
• Dust storms lift clouds of dust from the surface to the atmosphere, thereby changing the incoming solar energy and outgoing thermal energy.
• For the energy imbalance at longer time scales (more than one Earth year), Earth has a small energy imbalance (lesser than 0.1 per cent of the emitted thermal energy).
• Such an energy imbalance plays a critical role in global warming and climate change on Earth.

Energy Budget:

• The radiant energy budget of a planet is essential to understanding its surface and atmospheric processes.
• Mars has strong seasonal and diurnal variations of emitted power.
• The strong seasonal variations further suggest an energy imbalance at the time scale of Mars’ seasons (e.g., ∼3% of the emitted power in the Northern autumn for the Southern Hemisphere), which could play an important role in generating dust storms on Mars.