How is Sunlight Changing? Mornings in North America (Back to Sunlight Observation) Shadows Change, Too! Are your students measuring the length of an object's shadow at the same time each week or month? They should begin to notice that the shadow gets shorter after the winter solstice as the sun appears higher in the sky. (The rays begin to the Earth more directly.) If your students are tracking sunrise and sunset times, they may have noticed these things this month: The sun appears to be making a comeback! Days are getting longer. Sunrise is earlier than it was in January (and sunset is later). *Look up your daylength by date and location here, or keep track each day using local paper. Remember, daylength shortens before the solstice and lengthens after the solstice. The daylength changes slowly before and after the winter solstice, but it will begin to change more rapidly as we approach the spring equinox. Why does all this matter? All seasonal changes – temperature, plant growth and life cycles, animal migrations, and so on – are driven by shifts in the amount of available sunlight (called daylength or photoperiod) and its intensity (related to the angle at which it strikes the Earth). For more information on changing sunlight, go here: Reasons for Seasons: Teacher Background Information Facebook Pinterest Twitter © 1997 – 2019 Journey North. All rights reserved.