1. a Environmental Science and Technology Center, College of Science, George Mason University , Fairfax, VA, 22030, USA
2. b Biospheric Sciences Branch , NASA/GSFC/614.4, Greenbelt, MD, 20771, USA
3. c Sigma Space Corporation , 4801 Forbes Boulevard, Lanham, MD, 20706, USA
4. d Physics and Astronomy, College of Science, George Mason University , Fairfax, VA, 22030, USA