Additional Sites: Tumblr | Flickr | Vine | Weather Research | SF Giants Blog


Christina Loren is a Certified Meteorologist with an enthusiastic passion for atmospheric science.

The Beauty of Science: Why Autumn Leaves Burst With Color

By: Christina Loren

Fall color is gradually becoming more conspicuous in California as summer swiftly comes to a close. Vivid reds, oranges, yellows, and purple hues of changing leaves will paint beautiful natural scenery from September through November, although peak color only lasts for around one to three brisk weeks.

Hours of Daylight Over Cooler Weather 

Contrary to what some may think, the reason why leaves change color in autumn is predominantly the product of available daylight hours as opposed to changing weather patterns. Picture worthy foliage is caused by changes in the process of photosynthesis which means, “putting together with light.” Chlorophyll is a chemical that makes photosynthesis happen and responsible for the green color of leaves. As days get shorter in the fall there is less available sunlight for the production of chlorophyll, which slows and eventually stops. Resultantly stunning fall colors are gradually uncovered before leaves wither and fall off of trees. Variables like temperature, wind, cloud cover, and soil conditions widely influence color intensity and duration of the foliage exhibit although they are not the main cause for the metamorphosis. 

Not All Trees Have Changing Leaves 

There are two primary types of trees: evergreens and deciduous trees. Evergreens stay true to their designation and hold on to their green color all year long. Meanwhile deciduous trees shed their leaves annually in the fall and then in the spring they grow back as days get longer. Deciduous trees are often called ‘broadleaf’ trees because instead of thin needles, they have larger and wider leaves making for a substantial surface for the photosynthesis process. 

Peak Fall Color 

Lake Tahoe: Late September through October 
Napa Valley: Mid-October through early November 
Big Sur: Late October 
Yosemite: Mid-Late October 
Big Bear Lake: Mid-October through early November

Labels: , , , , ,

posted by Christina Loren @ 1:14 PM,


Post a Comment

<< Home