Retrieval of Cirrus Cloud Properties from AIRS Data Using SARTA with Delta-Four Stream Approximation Steve S. C. Ou1, Brian Kahn2, K. N. Liou1, Y. Takano1, and Q. Yue2 1Joint Institute for Regional Earth System Science and Engineering University of California, Los Angeles, Los Angeles, California 2Jet Propulsion Laboratory, California Institute of Technology Pasadena, California