Total Solar Eclipse to Help Study the Earth’s Energy
Buenos Aires, Argentina
It was during the daytime. One moment, the Sun was shining brightly in the sky, and another moment, the Moon’s shadow completely covered it, submerging the world in the twilight. The land below experienced a night-like environment for a little over two minutes, and during that time, very low levels of light reached the land.
The solar eclipse on August 21, 2017, was an incredible celestial event that left us waiting for the next total eclipse to come by. About every 18 months, a total solar eclipse occurs at any location on our planet, with the next one scheduled for July 2, 2019. Researchers are going to use this opportunity to study the Sun, the Moon, and the Earth’s energy system.
During the eclipse of 2017, a team of NASA scientists worked to gather data from both the land and satellites before, during, and after the total solar eclipse, to simulate the eclipse using a 3-D radiative transfer model.
This model is important for developing calculations to improve the research on solar energy reaching the land and the understanding of clouds, which play a key role in regulating the energy system of the Earth. Gathering valuable data from the total solar eclipse in Argentina on July 2, 2019, can further research into the complex workings of our planet’s energy systems.
The energy system of the Earth works to maintain a balance between the outgoing radiation into the space from Earth and the incoming radiation to the Earth from the Sun. This system is also referred to as the energy budget of the Earth, and clouds play an important role in its balance.
During the total solar eclipse in 2019, the Moon will cast a large shadow across the regions in South Pacific, Chile, and Argentina. The totality in Argentina will be visible from provinces Buenos Aires, Cordoba, La Rioja, San Luis, San Juan, and Santa Fe, and it will last for about 2 minutes and 30 seconds.
The scientists are looking forward to using this opportunity for gathering data with ground and space equipment and learning about the impact of the Moon’s shadow on the amount of sunlight reaching the surface of our planet. Moreover, calculating the energy that reaches the Earth thanks to the measurements used during previous eclipses, will help further understand the energy system.
The shadow of the Moon blocking the Sun during the total solar eclipse does not have the exact same properties as the clouds blocking the light of the Sun from reaching the surface. However, these phenomena are similar in the mathematical calculations used for understanding their impact. As a result, the knowledge gathered from the Moon’s shadow event could help learn about the clouds, especially thicker, observed at low altitude, clouds, that could cover about 30 percent of the sky at the time.
The total solar eclipse of 2017 simulated in a 3D radiative transfer marked the beginning of the research into the Sun’s energy reaching the Earth. The existing models depict one-dimensional images of clouds, which help make calculations for understanding the Earth’s atmosphere. However, three-dimensional calculations might provide more accurate results, as they reflect the energy from the Sun in several directions, including the top, bottom, and sides of clouds.
If scientists gather additional data from the 2019 total solar eclipse in Argentina, the technique developed in 2017 may be improved further. Right before and after the eclipse, the researchers could measure the amount of trace gases being absorbed into the atmosphere, including nitrogen dioxide, ozone, and aerosol particles for the use in the model.
Its successful implementation will result in the development of a tool for using in climate models and understanding the budget and climate of the Earth.
NASA’s research teams have been investigating the energy budget of the Earth for decades. Its EPIC, or Earth Polychromatic Imaging Camera, was used to observe the light leaving the planet, while MODIS satellite instruments provided data on conditions in the atmosphere and on the surface before and after the total eclipse.
The long-standing research on the solar energy reaching the Earth’s atmosphere has been made possible thanks to the ACRIMSAT, SOLSTICE (1991), and SORCE (2003) missions and the series of instruments called CERES (2011).