Jakarta, CNN Indonesia —
The researchers stated Earth has dimmed over the years allegedly as a result of climate change.
Scientists from the Big Bear Solar Observatory in California, United States say they have studied it and made measurements of the solar cycle and cloud cover for the last 20 years.
They observed a phenomenon known as earthshine. A phenomenon that according to the United States Aeronautics and Space Administration (NASA) occurs when the dark face of the Moon catches the reflection of Earth’s light and returns the light.
The strength of the earthshine varies because the light reflected from the Earth is also different.
A new study, published in the AGU journal Geophysical Research Letters, found a significant decrease in Earth’s reflectance, or albedo, over the past two decades.
Albedo is a quantity that describes the ratio between sunlight arriving at the earth’s surface and being reflected back into space with a change in wavelength.
As reported Stuff, the researchers say Earth now reflects about half a watt less light per square meter than it did 20 years ago. Most of the decline occurred in the last three years.
“The drop in albedo really surprised us when we analyzed the data for the last three years after 17 years of nearly flat albedo,” said New Jersey Institute of Technology researcher Philip Goode, who was the lead author on the study.
Scientists use satellite data to measure the factors driving Earth’s light to dim. Land, ice, clouds and open oceans all have different levels of reflectivity that contribute to Earth’s glow Gizmodo.
The observed change in Earth’s albedo does not correlate with periodic changes in the Sun’s brightness, meaning it is caused by something else. The scientists then noticed a decrease in the cover of bright, reflective clouds over the eastern Pacific Ocean in recent years particularly on the west coasts of North and South America.
Climate change has increased heat everywhere, including in the oceans. That could reduce cloud cover in the region.
When there is a lot of cloud cover, sunlight is reflected back into space, conversely, when there are fewer clouds, more sunlight enters.
“Recent decreases in albedo are associated with warming of the eastern Pacific, which is measured to reduce lowland cloud cover,” the scientists wrote in their study.
(whine / ayp)
– .
