Signs of Spring: Celebrating the Equinox
Yesterday (March 20, 2022) was the vernal equinox, the official beginning of spring in the Northern Hemisphere. Or as I should say, "astronomical spring." I recently learned that there is also a "meteorological spring," which follows the calendar and is based on the annual temperature cycle. For the Northern Hemisphere, meteorological spring runs from March 1 to May 31. I assume that climate change will affect the dates of the meteorological seasons at some point, while the astronomical seasons will remain the same.
The "reason for the seasons" is an area of many misconceptions, including the pervasive, though incorrect, idea that the Earth is closer to the Sun in the summer than the winter. An unintended contribution to this misconception may be the many diagrams that depict Earth's orbital path as an exaggerated ellipse (it's actually closer to circular). In actuality, Earth's axial tilt as it revolves around the Sun and the resulting differences in intensity of sunlight are what cause the changes we use to define seasons.
In the science classroom, understanding, modeling, and explaining the seasons falls into the middle school years with Performance Expectation MS-ESS-1: Develop and use a model of the Earth-sun-moon system to describe the cyclic patterns of lunar phases, eclipses of the sun and moon, and seasons. There's good reason to place this concept in middle school: it requires abstract thinking that elementary students (on the whole) aren't ready for yet. But that doesn't mean there isn't work to be done during the elementary years to pave the way.
In my experience, students who have greater background knowledge of observable characteristics in seasons (including temperature, length of daylight, growth and activity of plants and animals) are better able to make sense of the underpinning astronomical reason. Yet we know that children are not outside as frequently and that we can't assume all students have had the same experiences. What can we do to build this schema of seasonal variation?
In short: get outside! Invite children to notice and document their observations over the course of many months and seasons. Here are a few of my favorite strategies:
Select a sit spot, or an outdoor spot to return to again and again. This can be in a yard, a local park, or even a schoolyard. As the article notes: children may need practice building up the patience and stamina to remain in a sit spot for enough time to truly observe and record their observations. Don't skip this crucial step!
Pay attention to sunrise and sunset times throughout the year, and discuss them with your children. Weather apps often include these times right along with the temperature and forecast, making them easily accessible. Ask children if they notice any patterns in the time the sun rises or sets. This also provides a great opportunity to practice calculating elapsed time--a tricky mathematical skill in the elementary grades!
Participate in the many seasonal citizen science projects offered through Journey North, including tracking leaf out, ice out, tulip emergence and blooming, the amount of sunlight. These projects are not just intended for classroom use - they are perfect for science and nature-loving families as well!
Keep a phenology journal. Phenology is the study of cyclic and season natural phenomena, especially in relation to climate and plant and animal life (in other words, everything I've been describing throughout much of this post!). A phenology journal can take many forms, from a blank notebook to a one with more structured entries to a phenology wheel.
Finally, I can't post without sharing a beautiful book published this past year. Night Becomes Day: Changes in Nature by Cynthia Argentine describes changes that happen on all scales and time frames, from an acorn sprouting to a volcano erupting. While not all changes are seasonal, the breathtaking photographs will engage children and set the stage for their own observations.
Happy Spring! Get outside: explore, notice, and celebrate!