Sciences and Exploration Directorate

Xiaoguang (Richard) Xu


Org Code: 616

Mail Code: 616.2
Greenbelt, MD 20771


Brief Bio

Xiaoguang Xu’s research area has focused on development of aerosol retrieval algorithms, data assimilation, and OSSEs for aerosol remote sensing data, with emphasis on the integration of satellite remote sensing and chemistry transport model (e.g. GEOS-Chem) to characterize aerosol emitting sources, distributions, as well as their climate & environmental impacts. He has developed aerosol retrieval algorithms for both satellite (MODIS and EPIC) and ground-based (AERONET) remote sensing platforms. He implemented the capability to use GEOS-Chem adjoint for inverse modeling of dust emissions, with which he constrained speciated aerosol sources from satellite radiances. Xu is the primary developer of a numerical testbed for remote sensing of aerosol known as UNL-VRTM (https://unl- He currently leads the efforts in developing the HARP2 level 1 data processing algorithm for PACE satellite.



Gao, M., B. A. Franz, P.-W. Zhai, et al. K. Knobelspiesse, A. Sayer, X. Xu, V. Martins, B. Cairns, P. Castellanos, G. Fu, N. Hannadige, O. Hasekamp, Y. Hu, A. Ibrahim, F. Patt, A. Puthukkudy, and P. J. Werdell. 2023. Simultaneous retrieval of aerosol and ocean properties from PACE HARP2 with uncertainty assessment using cascading neural network radiative transfer models [10.5194/egusphere-2023-1843]

Gao, M., K. Knobelspiesse, B. A. Franz, et al. P.-W. Zhai, B. Cairns, X. Xu, and J. V. Martins. 2023. The impact and estimation of uncertainty correlation for multi-angle polarimetric remote sensing of aerosols and ocean color Atmospheric Measurement Techniques 16 (8): 2067–2087 []

Lu, Z., J. Wang, X. Chen, et al. J. Zeng, Y. Wang, X. Xu, K. E. Christian, J. E. Yorks, E. P. Nowottnick, J. S. Reid, and P. Xian. 2023. First Mapping of Monthly and Diurnal Climatology of Saharan Dust Layer Height Over the Atlantic Ocean From EPIC/DSCOVR in Deep Space Geophysical Research Letters 50 (5): [10.1029/2022gl102552]

Gao, M., K. Knobelspiesse, B. Franz, et al. P.-W. Zhai, A. Sayer, A. Ibrahim, B. Cairns, O. Hasekamp, Y. Hu, V. Martins, J. Werdell, and X. Xu. 2022. Effective uncertainty quantification for multi-angle polarimetric aerosol remote sensing over ocean Atmos. Meas. Tech. 15 (16): 4859–4879 [10.5194/amt-15-4859-2022]

Gao, M., K. Knobelspiesse, B. A. Franz, et al. P.-W. Zhai, V. Martins, S. P. Burton, B. Cairns, R. Ferrare, M. A. Fenn, O. Hasekamp, Y. Hu, A. Ibrahim, A. M. Sayer, P. J. Werdell, and X. Xu. 2021. Adaptive Data Screening for Multi-Angle Polarimetric Aerosol and Ocean Color Remote Sensing Accelerated by Deep Learning Frontiers in Remote Sensing 2 [10.3389/frsen.2021.757832]

Chen, X., J. Wang, X. Xu, et al. M. Zhou, H. Zhang, L. Castro Garcia, P. R. Colarco, S. J. Janz, J. Yorks, M. McGill, J. S. Reid, M. de Graaf, and S. Kondragunta. 2021. First retrieval of absorbing aerosol height over dark target using TROPOMI oxygen B band: Algorithm development and application for surface particulate matter estimates Remote Sensing of Environment 265 112674 [10.1016/j.rse.2021.112674]

Lu, Z., J. Wang, X. Xu, et al. X. Chen, S. Kondragunta, O. Torres, E. M. Wilcox, and J. Zeng. 2021. Hourly Mapping of the Layer Height of Thick Smoke Plumes Over the Western U.S. in 2020 Severe Fire Season Frontiers in Remote Sensing 2 [10.3389/frsen.2021.766628]

Zhou, M., J. Wang, X. Chen, et al. X. Xu, P. R. Colarco, S. D. Miller, J. S. Reid, S. Kondragunta, D. M. Giles, and B. Holben. 2021. Nighttime smoke aerosol optical depth over U.S. rural areas: First retrieval from VIIRS moonlight observations Remote Sensing of Environment 267 112717 [10.1016/j.rse.2021.112717]

Bian, Q., S. Kreidenweis, J. C. Chiu, et al. S. D. Miller, X. Xu, J. Wang, R. Kahn, J. A. Limbacher, L. A. Remer, and R. C. Levy. 2021. Constraining aerosol phase function using dual‐view geostationary satellites Journal of Geophysical Research: Atmospheres 126 [10.1029/2021jd035209]

Gao, M., B. A. Franz, K. Knobelspiesse, et al. P.-W. Zhai, V. Martins, S. Burton, B. Cairns, R. Ferrare, J. Gales, O. Hasekamp, Y. Hu, A. Ibrahim, B. McBride, A. Puthukkudy, P. J. Werdell, and X. Xu. 2021. Efficient multi-angle polarimetric inversion of aerosols and oceancolor powered by a deep neural network forward model Atmospheric Measurement Techniques 14 (6): 4083–4110 []

Puthukkudy, A., J. V. Martins, L. A. Remer, et al. X. Xu, O. Dubovik, P. Litvinov, B. McBride, S. Burton, and H. M. Barbosa. 2020. Retrieval of aerosol properties from Airborne Hyper-Angular Rainbow Polarimeter (AirHARP) observations during ACEPOL 2017 Atmospheric Measurement Techniques 13 (10): 5207-5236 [10.5194/amt-13-5207-2020]

Knobelspiesse, K., H. M. Barbosa, C. Bradley, et al. C. Bruegge, B. Cairns, G. Chen, J. Chowdhary, A. Cook, A. Di Noia, B. van Diedenhoven, D. J. Diner, R. Ferrare, G. Fu, M. Gao, M. Garay, J. Hair, D. Harper, G. van Harten, O. Hasekamp, M. Helmlinger, C. Hostetler, O. Kalashnikova, A. Kupchock, K. Longo De Freitas, H. Maring, J. V. Martins, B. McBride, M. McGill, K. Norlin, A. Puthukkudy, B. Rheingans, J. Rietjens, F. C. Seidel, A. da Silva, M. Smit, S. Stamnes, Q. Tan, S. Val, A. Wasilewski, F. Xu, X. Xu, and J. Yorks. 2020. The Aerosol Characterization from Polarimeter and Lidar (ACEPOL) airborne field campaign Earth System Science Data 12 (3): 2183-2208 [10.5194/essd-12-2183-2020]

Remer, L. A., A. B. Davis, S. Mattoo, et al. R. C. Levy, O. V. Kalashnikova, O. Coddington, J. Chowdhary, K. Knobelspiesse, X. Xu, Z. Ahmad, E. Boss, B. Cairns, H. M. Dierssen, D. J. Diner, B. Franz, R. Frouin, B.-C. Gao, A. Ibrahim, J. V. Martins, A. H. Omar, O. Torres, F. Xu, and P.-W. Zhai. 2019. Retrieving Aerosol Characteristics From the PACE Mission, Part 1: Ocean Color Instrument Frontiers in Earth Science 7 [10.3389/feart.2019.00152]

Xu, X., J. Wang, Y. Wang, et al. J. Zeng, O. Torres, J. S. Reid, S. D. Miller, J. V. Martins, and L. A. Remer. 2019. Detecting layer height of smoke aerosols over vegetated land and water surfaces via oxygen absorption bands: hourly results from EPIC/DSCOVR in deep space Atmospheric Measurement Techniques 12 (6): 3269-3288 [10.5194/amt-12-3269-2019]

Xu, X., J. Wang, Y. Wang, et al. J. Zeng, O. Torres, Y. Yang, A. Marshak, J. Reid, and S. Miller. 2017. Passive remote sensing of altitude and optical depth of dust plumes using the oxygen A and B bands: First results from EPIC/DSCOVR at Lagrange-1 point Geophysical Research Letters 44 (14): 7544-7554 [10.1002/2017gl073939]

Wang, Y., J. Wang, R. C. Levy, X. Xu, and J. S. Reid. 2017. MODIS Retrieval of Aerosol Optical Depth over Turbid Coastal Water Remote Sensing 9 (6): 595 [10.3390/rs9060595]

Zhu, J., X. Xia, J. Wang, et al. H. Che, H. Chen, J. Zhang, X. Xu, R. Levy, M. Oo, R. Holz, and M. Ayoub. 2017. Evaluation of Aerosol Optical Depth and Aerosol Models from VIIRS Retrieval Algorithms over North China Plain Remote Sensing 9 (5): 432 [10.3390/rs9050432]

Wang, J., X. Xu, S. Ding, et al. J. Zeng, R. Spurr, X. Liu, K. Chance, and M. Mishchenko. 2014. A numerical testbed for remote sensing of aerosols, and its demonstration for evaluating retrieval synergy from a geostationary satellite constellation of GEO-CAPE and GOES-R J. Quant. Spectrosc. Radiat. Transfer 146 510-528 [10.1016/j.jqsrt.2014.03.020]

Wang, J., X. Xu, D. K. Henze, et al. J. Zeng, Q. Ji, S.-C. Tsay, and J. Huang. 2012. Top-down estimate of dust emissions through integration of MODIS and MISR aerosol retrievals with the GEOS-Chem adjoint model Geophysical Research Letters 39 (8): L08802 [10.1029/2012GL051136]

Wang, J., X. Xu, R. Spurr, Y. Wang, and E. Drury. 2010. Improved algorithm for MODIS satellite retrievals of aerosol optical thickness over land in dusty atmosphere: Implications for air quality monitoring in China Remote Sensing of Environment 114 (11): 2575-2583 [10.1016/j.rse.2010.05.034]


Mcbride, B., J. V. Martins, A. Puthukuddy, et al. X. Xu, R. A. Fernandez Borda, H. Barbosa, O. Hasekamp, and L. A. Remer. 2019. The Hyper-Angular Rainbow Polarimeter-2 (HARP-2): A wide FOV polarimetric imager for high resolution spatial and angular characterization of cloud and aerosol microphysics Proceedings of the 70th International Astronautical Congress IAC-19-B1.2.7 1-12