First Day of Spring

0:03 Calarogus Shark Media. Hi. I'm Mark Ellison. In Today's theme is First Day of Spring, Seasons, equinoxes, and the science of weather. Question one. Weather services often use a different calendar for the seasons than astronomers do in the Northern Hemisphere. On what date does meteorological spring begin and how does this differ from astronomical springs start at the March equinox? Question two. The word equinox suggests equal day and night, yet many places have slightly more than twelve hours of daylight on that date. What physical effects cause day length to exceed twelve hours at the equinox? Question three? On the March equinox, the first day of astronomical spring in the Northern Hemisphere, at which latitude is the Sun directly overhead at local noon? Question four. Many people assume seasons happen because Earth gets closer to or farther from the Sun.

1:10 What is the real reason Earth has seasons? Question five. As spring begins, a high altitude river of wind shifts poleward in the Northern Hemisphere, steering storms and bringing changeable weather. What is this feature called? We'll be right back with these answers after this break welcome back. Question one, what astronomical event defines the spring equinox? Answer? The sun crosses the celestial equator at the equinox. The subsolar point sits at Earth's equator, so both hemispheres receive nearly equal sunlight.

1:52 Day and night aren't exactly equal due to atmospheric refraction and the definition of sunrise slash sunset. The truly equal day is called the equiluc Question two, when does meteorological spring start in the Northern Hemisphere, answer March first. Meteorological seasons divide the year into three month blocks. Spring is March May based on temperature patterns and climate records. This makes data comparison and forecasting consistent, unlike the equinox, which can vary by date and time. Question three, what do we call the delay between longer days and warming temperatures? Answer seasonal lag. Oceans and land absorb in store heat, releasing it slowly, so temperatures respond after changes in solar input.

2:34 This thermal inertia means the warmest days typically arrive weeks after the equinox and the coldest days after the winter solstice. Question four. In the Southern hemisphere, which season starts at the March equinox. Answer autumn Earth's tilted axis means the March equinox marks the Sun crossing northward over the celestial equator, giving the southern hemisphere less direct sunlight. As a result. It's the star of autumn south of the equator, while its spring in the north. Question five, which pyramid shows the serpent's shadow at the equinox