In July this year, a large ‘A’ was spotted in the sky over the Pacific Ocean near the Kamchatka Peninsula – a 780-mile-long (1,250 kilometres) peninsula located in the Russian Far East.
The image of the letter ‘A’ (which was taken from space) appears as though it was made by an airplane through skywriting, a process in which special smoke is expelled during flight to create writing that can be read by someone on the ground.
However, airplanes were not the ones responsible for the white letter in the sky. It was in fact ships crossing the ocean, scientists found.
On December 27, the National Aeronautics and Space Administration (NASA) posted the image of the A on its Earth Observatory website. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite snapped the photo on July 27. The image of the letter ‘A’ is now part of NASA’s Reading the ABCs from Space project.
The image shows how the steam of exhaust gasses coming from the ships can leave tracks across the sky; they are known as ship tracks.
Apart from creating intriguing images in the sky, ship tracks may also help scientists better understand how cloud formation over the oceans is affected by exhaust fumes. According to NASA’s Earth Observatory website, there are fewer environmental factor that influence clouds that form over the ocean, compared with cloud formation over land.
Scientists at the National Aeronautics and Space Administration who study climate found that burning fossil fuels generate aerosols – which are fine solid particles in air that can change the way in which clouds form, as well as their composition. According to NASA, aerosols can be either artificial (dust, haze, smoke, particulate air pollutants), or natural (geyser steam, forest exudates, fog).
Over time, aerosols that come from burned fossil fuels (like sulfate particles) have increased in Earth’s atmosphere, causing the clouds to reflect more solar radiation and become brighter than they used to be.
A report from the Intergovernmental Panel on Climate Change (IPCC) stated that the clouds may be impacted in a negative way, as aerosols can stop them from releasing water.
Further studies of ship tracks may provide more clues as to how pollution from burning fossil fuels, in the form of aerosols, influences cloud formations and the overall climate, researchers at the National Aeronautics and Space Administration said.
Image Source: yimg