SEASONS AND THE SUN PATH Altitude angle of

SEASONS AND THE SUN PATH

• Altitude – angle of elevation above the horizon • Zenith – directly overhead • Celestial Sphere - large sphere surrounding the earth, used to keep references to where celestial bodies lie in the sky.

• Tropic Of Cancer – 23 ½ o N • Tropic of Capricorn - 23 ½ o S • Solar Noon - the time of highest sun altitude

• Solar Noon – time when sun is highest in the sky • Insolation – Incoming Solar Radiation (energy we get from the sun) Sun’s Duration – length of time the sun is out = daylight hours • Sun’s intensity – higher the sun angle, more direct rays = more energy from sun and higher temperatures.

Reasons for the Seasons 1. Tilt of the Earth 23 ½ o

2. Earth’s Revolution around the Sun http: //www. mesoscale. iastate. edu/agron 206/animations/01_Earth. Sun. html

• Closer to sun in winter • Farther from sun in summer

Summer Solstice – June 21 Earth is tilted toward the sun Tropic of Cancer 23 ½ o N Equator Arctic Circle – 66 ½ o N Tropic of Capricorn – 23 ½ S o Sun is at zenith at the ? Antarctic Circle – 66 ½ o S Tropic of Cancer – 23 1/2 o N

Longest day of the year

Latitude of Norwich North of Arctic Circle will have ______ 24 hours of daylight? https: //lh 3. googleusercontent. com/-D 1 LC 3 Kkrc. Kw/Uvoyy 8 nd. GII/AAAAI 34/Nza 2 r 8_c. PGI/w 506 h 304/arctic%2 Bsummer. gif

Describe Sun at Norwich • High Sun Angle – shorter shadows • Long Days • High intensity of Sun’s rays, therefore its warmer

Sun Path at Norwich on Summer Solstice Zenith 71 o * Is the Sun at Zenith at Norwich? Describe where sun rises and sets. NO Rises north of east and sets north of west

Winter Solstice - December 21 Earth is tilted away from sun North Pole Arctic Circle – 66 ½ o N 23 1/2 o N Tropic Cancer equator South pole Sun is at zenith at 23 ½ o S Tropic of Capricorn Antarctic Circle – 66 ½ o S Tropic of Capricorn – 23 1/2 o S

Shortest day of the year

Winter Solstice Latitude of Norwich North of Arctic Circle will have ______ 24 hours of daylight?

Describe Sun at Norwich • Low Sun Angle – longer shadows • Short Days • Low intensity of Sun’s rays, therefore temperatures are not as warm

Sun’s Path at Norwich on Winter Solstice Zenith 25 o * Is the Sun at Zenith at Norwich? NO Describe where sun rises and sets. Rises south of east and sets south of west

Equinoxes –September 21, March 21 Earth is Perpendicular to the Sun (Autumnal) (Vernal) Arctic Circle – 66 1/2 o N Tropic of Cancer - 23 1/2 o N Equator Tropic of Capricorn - 23 1/2 o S Antarctic Circle - 66 1/2 o S Sun is at zenith at the Equator

12 hours of light and dark everywhere on the Earth

Latitude of Norwich Equal Days and Equal Nights everywhere on Earth Equinox means equal nights

Describe Sun at Norwich • Medium Sun Angle – medium shadows • 12 hour Days • medium intensity of Sun’s rays

Sun Path at Norwich on Equinoxes Zenith 48 o * Is the Sun at Zenith at Norwich? NO Describe where sun rises and sets. Sun rises directly east and sets directly west everywhere on the Earth

• Time of day of longest shadow: ____ Sunrise, sunset • Time of day of shortest shadow: _______ Noon • Season with shortest noon time shadow: Summer • Season with longest noon time shadow: Winter

• http: //janus. astro. umd. edu/astro/seasons/