Why isn't the darkest time of the year also the coldest?

The darkest time of the year is winter solsticethe day with the least sunlight and the night the longest. However, the coldest time of year is usually about a month after the winter solstice. So why isn’t the darkest time of the year also the coldest?

The answer lies in the tilt of the Earth and the way our planet retains heat.

Earth’s axis – the imaginary line connecting the North and South Poles – is tilted about 23.4 degrees relative to the planet’s path around the sun. This means that one day per year on Earth, the North Pole points farthest from the sun. Another day, it’s the South Pole aiming as far away from the sun as possible. These days correspond to the northern and southern winter solstices respectively. explained Christopher Bairdassociate professor of physics at West Texas A&M University.

The more the Earth’s surface is tilted toward the sun, the less time it spends in daylight. The northern winter solstice, the shortest day in the northern hemisphere, occurs annually on December 21, 22, or 23, and the southern winter solstice occurs annually. June 20, 21 or 22.

Earth gets most of its heat from the sun, which might lead you to think that the winter solstices are the coldest days of the year in their respective hemispheres, Baird noted. However, the coldest temperatures in each hemisphere “tend to be about a month behind these solstices,” Nick Bassildirector of the State Weather Risk Communications Center at the University at Albany in New York, told Live Science. In the Northern Hemisphere, it is around mid-January.

The opposite is also true. The summer solstice, the longest day of the year – which occurs on June 20, 21 or 22 in the Northern Hemisphere and December 21, 22 or 23 in the Southern Hemisphere – is often not the hottest day of the year. Jason Steffenassistant professor of physics and astronomy at the University of Nevada, Las Vegas, told Live Science.

A diagram showing how the Earth rotates around the Sun on its axis

During the winter solstice in the northern hemisphere, the northern hemisphere is further from the sun. (Image credit: Grayjay via Shutterstock)

For example, “the Mojave is warmest in late July, well after the solstice,” Steffen said. “Florida’s Gulf Coast is warmest in August.”

This delay between the solstices and the coldest or hottest temperatures of the year, an effect called “seasonal lag,” “is because physical objects—lakes and oceans, soil, concrete, etc. — do not respond immediately to warmer temperatures. or colder temperatures,” Bassill explained. “In winter, this means that physical objects retain their heat from fall and summer longer than the air.”

The closer a place is to the ocean, the more attenuated these seasonal temperature variations are, because “it takes four times more energy to raise the temperature of water one degree than that of rock,” Steffen said . Moreover, “oceans circulate,” he added. This means that even when the nights are long, heat circulating in the ocean can help keep these places warm.

“For areas immediately downwind of a large body of water, such as places on the Pacific coast of the United States, their coldest temperatures in winter tend to be warmer than in other places at a similar latitude due to this effect,” Bassill said. “This may also mean that their seasonal shift may be greater than in other places, meaning that the time difference between their solstice and the coldest or hottest time of the year may be greater than in other places in the world further away from a large body of water.”

Apre-salomemanzo

Apre-salomemanzo

Why isn’t the darkest time of the year also the coldest?

Umito

Melbourne ranked among the world’s ten best cities for adrenaline seekers

Lawyer discusses possible immigration changes during Trump’s second term

Education Secretary ‘open-minded’ on England’s spanking ban

Gunfire led to Catawba lockdown – Salisbury Post