Good News If You’re Ready for Spring! Mar 18, 2017

Old Man Winter is on its last legs as the Vernal Equinox arrives on Monday, March 20th at 6:28 AM EST.  The first signs of spring have started showing up across much of the country as people, plants, and animals are beginning to emerge from their winter condition.

The vernal or spring equinox is one of two days of the year when the sun is directly overhead if you are at the equator.  The amount of sunlight on the equinox is the same for the northern and southern hemisphere.

While the word equinox means “equal night” in Latin, by time of the equinox in the northern hemisphere the day is already a bit longer than the night.  This unequal length of day and night on a day that should have them equal is due to atmospheric refraction and the way we define sunrise and sunset.  

Refraction of the sun’s light through the earth’s atmosphere causes the sun to appear slightly higher in the sky than it actually is. Refraction is the optical phenomenon that bends the sun’s light as it passes through Earth’s atmosphere.  That means that the first light of a sunrise gets to our eyes while the sun is still below the horizon.

The way we define sunrise and sunset is also responsible for the disproportionate day parts.  We define sunrise as the moment the sun’s upper edge appears on the horizon and sunset at the moment the the sun’s upper edge disappears below the horizon.  This way of defining a day and the optical phenomenon of refraction are responsible for a non-equal, equinox.  

Day and night hours are equal two times a year and we refer to that time as the “equilux”.  The equilux happens a few days before the spring equinox, and a few days after the autumn equinox.

Springtime does bring warmer temperatures to the northern hemisphere but you have to be patient.  Much of the warmth from longer days and higher sun angles during early spring is used to warm the earth and water in the northern hemisphere so it takes a while for those warmer temperatures to take hold.

Leave a comment

Your email address will not be published. Required fields are marked *

Tweets

Multiple tornado warnings were issued south of New Orleans, Louisiana Sunday morning. Kelly Moore captured this vid… https://t.co/TjHr81k4NZ

1 minute ago by WeatherNation

It's a stormy Sunday morning in southern Louisiana. Rain is falling in New Orleans, and tornado warnings have been… https://t.co/A9gPw9pY0Y

42 minutes ago by WeatherNation

TORNADO WARNING Lafourche and Jefferson Parishes until 10:30 AM CDT. Storm is moving northeast at 30 mph. https://t.co/PISDkmhcoe

54 minutes ago by WeatherNation

Goooood morning everybody! We'd love to see how the sun rose in your neighborhood! Tag us in your sunrise pictures… https://t.co/Qysi3jvj6f

3 hours ago by WeatherNation

Happy Earth Day! We're celebrating with an awesome 24 hour GOES-16 loop of Earth! Imagery: @CIRA_CSU &… https://t.co/y3CVT3NCYd

3 hours ago by WeatherNation

Temperatures are finally warming in places. That means ice and snow will be melting like it is in Caribou, ME. Watc… https://t.co/TF8sp44G1t

7 hours ago by WeatherNation

Looks like Portland, OR will get record heat this week, as well as some neighboring Pacific Northwest cities!… https://t.co/AspBLZJkR7

11 hours ago by WeatherNation

Here's a relaxing view of Pikes Peak out of Colorado Spring, CO as the cold and snow pushed out of the area Saturda… https://t.co/0CxT9txba5

11 hours ago by WeatherNation

DAMAGING WINDS AND HAIL - Severe weather pushes through North Texas on Saturday afternoon, with some spots seeing h… https://t.co/6xvMPm9SMS

12 hours ago by WeatherNation

**LISTEN TO THIS** And we're not just talking about hail in this Texas town today...@ngordon4 reacts to the "bucket… https://t.co/jLSE9308vR

13 hours ago by WeatherNation
Follow Us