Xiaoguang (Richard) Xu
Assistant Professor · Non-Tenure Track
Department of Physics Earth and Space Institute Goddard Earth Sci & Tech Center
About
My research integrates advanced satellite remote sensing, Earth system modeling, and machine learning, with a focus on atmospheric aerosol and cloud, to address critical challenges in climate change, air quality, and environmental health. I specialize in the fusion of hyper-spectral and polarimetric data (e.g., from NASA PACE, TEMPO satellites) to characterizeatmospheric aerosols and their impacts on urban and coastal environments. My work spans in the areas of: (1) developing next-generation radiative transfer models (UNL-VRTM) and physics-informed machine learning algorithms for efficient satellite data retrieval; (2) utilizing data assimilation to constrain aerosol sources and their climate forcing; and (3) applying these tools to interdisciplinary studies linking atmospheric composition to public health and climate resilience.
Research interests
Chemistry transport modeling; radiative transfer; satellite remote sensing of aerosols
Teaching interests
Climate modeling; Physical meteorology; atmospheric physics and chemistry; Remote Sensing
Education
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Ph D, Earth and Atmospheric Science
— University of Nebraska-Lincoln (2015) Retrieval of Aerosol Microphysical Properties from AERONET Photopolarimetric Measurements
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MS, Meteorology
— Lanzhou University (2008) Study on Predictability of the T63L16 Climate Model
- BS — Lanzhou University (2005)
Publications
- A new way to see the clouds: the hyper-angular rainbow polarimeter (HARP2) on the NASA PACE satellite mission 2025
- HARP2 Pre-Launch Calibration Overview: The Effects of a Wide Field of View 2025
- First results and on-orbit performance of the Hyper-Angular Rainbow Polarimeter on the PACE satellite 2024
- Pre-launch calibration and validation of the Airborne Hyper-Angular Rainbow Polarimeter (AirHARP) instrument 2024
- Polarimetric mapping of the lunar surface with the Hyper-Angular Rainbow Polarimeter 2 (HARP2) on the NASA PACE mission
- Science Products as Feedback for Calibration: Examples from the HARP2 polarimeter on NASA’s PACE mission
- Multi-angle and polarimetric characterization of various Earth surface types with the PACE HARP2 polarimeter
Presentations
- On-Orbit Performance Assessment of the HARP2 Multi-Angle Polarimeter on the NASA PACE Mission: Intercomparison with OCI and SPEXOne Instruments 2025
- The First Year of HARP2/PACE Performance Based on its Ground and On-Orbit Characterization 2025
- The First Year of the Hyper-Angular Rainbow Polarimeter (HARP2) on the NASA PACE mission: Performance, Science, and Synergy 2025
- Retrieving Aerosol and Surface Products Using Multi-Pixel approach from PACE Polarimeter HARP2 Observations with GRASP 2024
- Aerosol and Surface Products from PACE Polarimeter HARP2 Observations using GRASP 2024
- First Results and On-Orbit Performance of the Hyper-Angular Rainbow Polarimeter on the PACE Satellite 2024
- The measurement of aerosol and gases from space for climate and air pollution application 2024
- First results and on-orbit performance of the Hyper-Angular Rainbow Polarimeter (HARP2) on the PACE satellite 2024
- Advancements on the Hyper-Angular Rainbow Polarimeter (HARP) polarization characterization during NASA Plankton Aerosol and Ocean Ecosystem (PACE) pre-launch calibration 2023
Grants and Contracts
- PACE Activation 2026
- CAIG: Accelerating Radiative Transfer for Aerosol Satellite Remote Sensing Test Beds using Physics-Informed Neural Network 2026
- An AI-driven approach for retrieving aerosol and surface properties from HARP family of multi-angle polarimeter measurements 2025
- Travel support for students and early-career researchers to attend the 4th Advancement of POLarimetric Observations (APOLO-2024) Conference 2024
- Model Development for Polarimetric Remote Sensing of Clouds in the Thermal Infrared 2023
- EPIC Hourly Aerosol Optical Centroid Height (AOCH) product: mapping the diurnal variation of smoke and dust vertical distributions for air quality and climate studies 2022
- Determining Atmospheric Aerosol Properties from the UMBC HARP CubeSat in Space 2021
- Retrieval of Aerosol Vertical Distributions with Measurements from O2 A/B Bands and Polarimetric Data from Blue Bands: Algorithm Development and Synergistic Analysis 2020
- Multi-phase inversion of aerosol sources using MODIS, MISR, OMI, and AERONET data and the GEOS-Chem adjoint 2017
- Sensitivity analysis and recovery of dust emissions from spectral climate signals 2014
- Constraining Dust Refractive Index and Direct Radiative Effect in Long Wave Using Paired Sounder-Imager Sensors
- Establishing Altiplano Benchmark Sites for Vicarious Calibration of Satellite Polarimeters
- Snapshot spectral imaging CubeSat for dense multi-angle measurements
Courses Taught
- Physics and Chemistry of the Atmosphere