In a new study, researchers have unveiled the reason behind nights warming up at a greater rate than days. Scientists knew about such variations between night and day, but they didn’t know the exact reason behind such trends seen all around the globe in recent decades.
Over the 50 years, nights have warmed up significantly and at a much faster rate when compared to the days. According to study, climate change and global warming have some role to play in such variation as night is more sensitive to weather changes than days.
Lead study author Richard Davy from Nansen Environmental and Remote Sensing Centre in Norway conducted the study and tried to identify reasons affecting the night. For the study, Davy constructed a global climate model of Earth in the 20th century and observed how climate change has led to rapid warming of nights.
In the study, it was found that a layer of air known as boundary layer is present just above the ground that separates ground air from rest of the atmosphere. This layer prevents temperature change.
Davy said that the boundary layer is thick (up to few kilometers) during daytime while it gets thinner (just few hundred meters) at night. It is due to this reason that nights are more sensitive to the climate change and temperature change.
He further added that carbon dioxide released in the atmosphere increases temperature in daytime as well as in night time. However, at night comparatively smaller volume is targetted and gets warmed than days. Thus, the effect of warming up of temperature is visible more in nights.
Study authors pointed out the fact that number of extremely cold nights has dropped by half during the last 50 years, in contrast to the extreme-cold days which have decreased by a quarter
The study appeared in the International Journal of Climatology.