RICHMOND, Va. (WTVR) - While high pressure brought a rare cloud-free Spring day to the Mid-Atlantic, NASA's Aqua satellite took full advantage of this opportunity to capture an image of Spring greening in our region. The picture was taken April 7, 2012 using NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, which is part of the Aqua satellite package. It depicts a beautiful green flush in Virginia's Piedmont especially. This is where trees, as we've known by the pollen counts since late March, have been in the High to Very High range as pine, oak, and other tree varieties really sprang into Spring bloom.
NASA explains the colors you see, "The Appalachians appear brown because cooler temperatures at higher elevations cause a lag in the greening. In this case, the trees at the higher elevations were likely still in bloom and hadn't started to produce leaves. The speckles of tan throughout the coastal plain are agricultural regions, where fields often stay bare or filled with dry crop stubble until late spring planting."
Satellites are measuring this Spring greening to better-understand changes in blooming dates over the years. University of Wisconsin-Milwaukee geographer Mark D. Schwartz studies these changes in Spring greening, and his research indicates that since 1960 in North America, Spring begins 1.1 days earlier with each decade. His research shows a faster Spring onset in the West, where it's beginning 1.5 days earlier per decade. Schwartz says this year's early Spring is "exceptionally early" when compared with other years. This certainly coincides with the warmest March on record in the Contiguous U.S. and specifically in Virginia. Changes in growing seasons fit with what the consensus of the scientific community understands about global warming.
BONUS: Click here to learn more from NASA about global warming.
However, NASA points out that not all trees will experience an earlier greening in Spring just because of a mild Winter and early onset of Spring. "Many woody species require a certain amount of exposure to cold in the winter to grow properly in the spring. A study of satellite observations from 1982 to 2005 found that about 30 percent of North America - particularly areas south of 35 degrees latitude - has actually been greening later due to the lack of cool winters."
Here is the full image from April 7, when Richmond reported a high temperature of 67 degrees (near-average temperature for that date):