1. Research Scientist, Center for Environmental Sensing and Modeling, Singapore-MIT Alliance for Research and Technology Centre, 1 CREATE Way, Singapore 138602 (corresponding author).
2. Postdoctoral Fellow, Dept. of Civil and Environmental Engineering, Hong Kong Univ. of Science and Technology, Clear Water Bay, Hong Kong.
3. Associate Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., 50 Nanyang Ave., Singapore 639798.
4. Senior Research Engineer, Dept. of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139.