Zhaoyan Liu

Affiliation: NASA Ames Research Center (ARC)

Branch: Atmospheric Science Branch (SGG)

Email: Zhaoyan.liu@nasa.gov

Website: Zhaoyan Liu

Professional Biography

Dr. Liu is a Senior Research Scientist at NASA Ames with approximately 40 years of experience in lidar system development and optical remote sensing. During his Ph.D. studies in Univ of Fukui, he pioneered the use of the Mach-Zehnder interferometer (MZI) in Doppler wind lidar measurements. At NIES in Japan, he played a key role in Japan’s space lidar program, ELISE, where he led the development of data processing algorithms. Additionally, Dr. Liu developed a ground based HSRL system to measure Asian dust and to serve as a validation tool for ELISE.

At NASA Langley, Dr. Liu has been involved with the NASA-French joint CALIPSO satellite program since 2001. As a key member of the Lidar Science Working Group, he contributed to developing pre-launch and post-launch algorithms for CALIPSO lidar data processing. He also has extensive experience in studying dust occurrence and long-range transport. In recent years, Dr. Liu has participated in airborne lidar programs, including the CO₂ DIAL and Doppler wind lidar projects. He and his colleagues at NASA Langley proposed a novel idea to measure CO₂ and pressure on Mars using a DIAL and were awarded funding by the NASA PICASSO program to develop a compact fiber laser for the DIAL system.

At Ames, Dr. Liu leads a team using sunphotometer to do ground-based, shipborne, and airborne validation of various satellite measurements.

Education

Ph.D. in System Engineering Design, Fukui Univ., Fukui, Japan, 1996

M. in Optics: Harbin Institute of Technology (HIT), Harbin, China, 1987

B. in Laser Physics: HIT, Harbin, China, 1984

Research Interests

Laser, Lidar, Remote sensing, Cloud and aerosol, CO₂ and trace gases, Doppler wind, Databases, Software Development

Awards/Honors

NASA Langley Research Center Team Awards in 2006, 2007, 2009, 2020.

NASA Group Achievement Awards in 2007, 2008, 2009, 2010, 2011, 2024.

Special recognition of a citation for Excellence in Refereeing in the American Geophysical Union (AGU) of Journal of Geophysical Research-Atmospheres. September 27, 2011 in the AGU publication, Eos.

Guest Editor of Journal of Quantitative Spectroscopy & Radiative Transfer for a special issue published in 2011, 2013.

Select Publications

Z. Liu, et al., “Martian column CO2 and pressure measurement with differential absorption lidar at 1.96 mm” submitted to AMT, 2024.

Z. Liu, et al., “Discriminating between clouds and aerosols in the CALIOP version 4.1 data products” AMT, 12, 703-734, 2019.

Z. Liu, et al., “Evaluation of CALIOP 532 nm aerosol optical depth over opaque water clouds” ACP, 15, 1265-1288, 2015.

Z. Liu, et al., “Transpacific transport and evolution of the optical properties of Asian dust”, JQSRT, 116, 24-33, 2013.

Z. Liu, et al., “Effective lidar ratios of dense dust layers over North Africa derived from the CALIOP measurements,” JQSRT, 112, 204–213, 2011.

Z. Liu, et al., “The CALIPSO lidar cloud and aerosol discrimination: Version 2 algorithm and initial assessment of performance,” JTECH, 26, 1198–1213, 2009.

Z. Liu, D. Liu, J. Huang, et al., “Airborne dust distributions over the Tibetan Plateau and surrounding areas derived from the first year of CALIPSO lidar observations,” Atmos. Chem. Phys., 8, 5045-5060, 2008.

Z. Liu, A. Omar, M. Vaughan, et al., “CALIPSO Lidar Observations of the Optical Properties of Saharan Dust: A Case Study of Long Range Transport”, J. Geophys. Res., 113, D07207, doi:10.1029/2007JD008878, 2008.

Z. Liu, et al., “Estimating random errors due to shot noise in backscatter lidar observations”, Appl. Opt., 45, 4437-4447, 2006.

Z. Liu, M. McGill, Y. Hu, C. Hostetler, M. Vaughan, and D. Winker, “Validating Lidar Depolarization Calibration Using Solar Radiation Scattered By Ice Clouds,” IEEE Geosci. Remote Sens. Lett., 1, 157-161, 2004.

Z. Liu, M. Vaughan, D. Winker, C. Hostetler, L. Poole, D. Hlavka, B. Hart, and M. McGill, “Use of Probability Distribution Functions for Discriminating Between Cloud and Aerosol in Lidar Backscatter Data,” J. Geophys. Res., 109, D15202, doi:10.1029/2004JD004732, 2004.

Z. Liu, N. Sugimot, and T. Murayama, “Extinction-to-backscatter ratio of Asian dust observed by high-spectral-resolution lidar and Raman lidar,” Appl. Opt., 41, 2760-2767, 2002.

Z. Liu, and N. Sugimoto, “Simulation study for cloud detection with space lidars using analog detection photomultiplier tubes,” Appl. Opt., 41, 1750-1759, 2002.

Z. Liu, P. Voelger, and N. Sugimoto, “Simulations for the observation of clouds and aerosols with the Experimental Lidar in Space Equipment (ELISE)”, Appl. Opt., 39, 3120-3137, 2000.

Z. Liu, I. Matsui, and N. Sugimoto, “High spectral resolution lidar using an iodine absorption filter for atmospheric measurements,” Opt. Eng., 38, 1661-1670 (1999).

Z. Liu and T. Kobayashi, “Differential discrimination technique for incoherent Doppler lidar for measuring atmospheric wind and backscatter ratio,” Opt. Rev., 3, p.47, 1996.