**6. Acknowledgments**

This work was supported by the following NASA grants to H.H. Shugart: NNG-05-GN69G, NNX-07-A063G, NNX-07-AF10G, NAG-11084. We greatly appreciate the support and encouragement of Dr. Pavel Groisman and the Northern Eurasian Earth Science Partnership Initiative (NEESPI) in regard to this ongoing research. We extend our thanks to Dr. Paolo D'Odorico and Dr. Virginia Seamster for suggestions and feedback on earlier versions of this manuscript.
