October 15, 2014 - Fall colors in the northeastern United States

Fall colors in the northeastern United States

As daylight shortens and temperatures begin to fall, the leaves of deciduous trees change from green to brilliant hues. In the northern hemisphere, this change of season begins in mid-September and ends by mid-November, when the leaves have browned and fallen on the forest floors. Until that final ending, the colorful show is spectacular – from the ground or from space.

The Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard NASA’s Aqua satellite captured this true-color image of fall colors brightening the landscape of the northeastern United States on October 12, 2014.

According to The Foliage Network on October 13, tree color had reached its peak in much of the southern half of Maine, central and western New Hampshire, much of Vermont, portions of upstate New York and isolated locations in southwest Pennsylvania – the same areas that are visibly orange-shaded in this image.

Leaves are colored green due to the pigment chlorophyll, which is also the molecule that plants use to synthesize food. The synthesis requires ample sunlight and warm temperatures, and chlorophyll must be continuously synthesized. When temperatures drop and daylight shortens, the level of chlorophyll in deciduous leaves do as well. As concentrations of chlorophyll drop, the green fades, offering a chance for other leaf pigments—carotenoids and anthocyanins—to show off their colors. Carotenoids appear yellow and anthocyanins appear red.

According to the U.S. Forest Service, different species of tress produce different fall colors. Oaks generally turn red, brown, or russet; hickories become golden bronze; aspen and yellow-poplar turn golden. Maples differ by species. Red maple turns brilliant scarlet; sugar maple, orange-red; and black maple, yellow. Leaves of some trees, such as elms, simply become brown.

Image Facts
Satellite: Aqua
Date Acquired: 10/12/2014
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC