The European Space Agency (ESA) recently deployed its Aeolus satellite into a polar orbit. Its name is taken from the Greek sovereign of the winds, Aeolus. This satellite marks the fifth Earth Explorer mission by the ESA and has been crafted to increase the accuracy of weather forecasts around the globe. Additionally, it utilizes an innovative laser technology referred to as the Atmospheric Laser Doppler Instrument (Aladin) to record wind patterns and aid in enhancing our understanding of atmospheric operations.
Aeolus Satellite and Its Unique Instrument- Aladin
The Aeolus satellite is equipped with one of the most high-tech instruments known as Aladin. This device unleashes a 10-megawatt ultraviolet laser blast onto the Earth’s surface at a rate of 50 times per second. By observing the minor changes in the reflected beam caused by air molecules and other atmospheric matter, scientists can measure wind velocity from space – a completely novel approach towards understanding our atmosphere.
Potential Benefits of Aeolus Data
Despite considerable advancements in weather forecasting in recent years, the Aeolus satellite could provide global wind profiles which will significantly enhance these predictions. The absence of direct global wind measurements was a key limitation in the Global Observing System, and with Aeolus stepping in to fill this gap, scientists will have the essential data to examine how wind, pressure, temperature, and humidity interact. In addition to this, the data collected by Aeolus can be incorporated into air quality models to better predict the presence of dust and other airborne particles that could affect public health.
Understanding Polar Orbits
A standard polar orbit travels north-south over the poles and takes about 90 minutes to complete a single rotation. With an inclination near 90 degrees, these satellites can get a comprehensive view of nearly every part of the Earth as it rotates. Satellites in this orbit typically operate at lower altitudes and can be utilized for a wide range of applications, like monitoring global security, crop conditions, ozone concentrations in the stratosphere, and atmospheric temperatures.
Sun-Synchronous Orbits
An orbit is categorized as sun-synchronous when the angle between the line connecting the Earth’s center to the satellite and the Sun remains constant throughout the orbit. These orbits are also referred to as “Low Earth Orbit (LEO)”, and enable the onboard cameras to capture images of the Earth under uniform sun-illumination conditions during each repeated visit. This unique feature enhances the utility of these satellites for Earth resources monitoring as it passes over any given point on Earth’s surface at the same local solar time.
Geosynchronous Orbits
Unlike polar orbits, geosynchronous satellites launch into an orbit in the same direction the Earth is spinning. These satellites can have any inclination, and when they are positioned in orbit at a specific altitude (roughly 36,000km above the Earth’s surface), their rotation matches that of the Earth. Geostationary orbits fall within the category of geosynchronous orbits with the key difference being that they remain parked over the equator. For these satellites, Earth’s gravity is just the right amount to provide the necessary acceleration for circular motion.
