Chicago (IL) - The changing appearance of Earth's green surface strata on a regional scale recently got a serious examination courtesy of NASA and some high resolution aerial photos from the private sector. These tools of choice allow time-lapse sequences from compiled satellite images and close-up photos, which reveal trends seen in the disappearing green.
The single-frame image may not reveal much to the untrained eye. However, a series of time-lapse photographs taken over the same regional location reveal subtle variations visible from space. When large areas are identified, close-up high resolution commercially available aerial photos are then sequenced to reveal what's changed and by how much.
Scientists from the NASA Ames Research Center in Moffett Field, CA, and California State University-Monterey Bay in Seaside, CA, are looking at whether or not changes on our planet are due to human activity or extreme climate.
Looking for patterns, they poured over several years of image data collected via NASA satellites. They took the results and "fused" them together with high-resolution commercial images to identify changes in locally vegetative "green" areas. They found that regional land cover disturbances can be identified, such as the recent wildfire-burned areas and extensive forest harvests.
NASA reported findings that between 1970 and 2005, California experienced what they say is a 75 percent increase in its population. This resulted in a rapid and extensive urbanization and loss of natural vegetative ground coverage. Imagery taken between 2001 and 2005, examined in a time series analysis, found the forests and shrublands showed most of the continual reduction in surface area.
High resolution commercial images of the affected areas were then consulted, allowing NASA the ability to "examine in greater detail the Earth's diminishing vegetation coverage." They found the analysis showed a recent wildfire-burned area and extensive forest harvests near Lower Bear River Reservoir in Amador County, CA. Similar areas showed extensive forest cutting in the state's Mendocino, Butte, and Pulmas counties.
NASA plans to expand its monitoring program and will soon include a craft dedicated to the continuous measurement of worldwide greenhouse gas levels. With the upcoming February 23 launch of its Orbiting Carbon Observatory craft from Vandenberg Air Force Base in California, the craft will begin its ongoing mission to "study atmospheric carbon dioxide levels."