Sciences and Exploration Directorate

Amir Ibrahim

(Research AST, Oceanographic Studies)

 amir.ibrahim@nasa.gov

 301.286.7953

Org Code: 616

NASA/GSFC
Mail Code: 616.2
Greenbelt, MD 20771

Employer: NASA

Brief Bio


Dr. Amir Ibrahim is a scientist working at the Ocean Ecology Lab (OEL) within the NASA Goddard Space Flight Center (GSFC). He holds a key role in leading the development of atmospheric correction algorithms for NASA's Plankton, Aerosol, Clouds, ocean Ecosystem (PACE) mission. As a member of the PACE project science team, Dr. Ibrahim is actively involved in researching and assessing atmospheric correction methods for deriving ocean color data from the Ocean Color Instrument (OCI) in conjunction with multi-angle polarimeters (SPEXone and HARP2).

In addition to his contributions to the PACE mission, Dr. Ibrahim also serves as the instrument scientist for the ocean color instrument (OCX) of the NASA/NOAA GeoXO mission.

Dr. Ibrahim's academic journey includes the successful completion of his Ph.D. degree in February 2015 from the Electrical Engineering Department at the City College of the City University of New York (CCNY). During his doctoral research, he focused on ocean color remote sensing using polarimetric observations of light. Notably, he developed an innovative inversion algorithm known as the "c/a algorithm" based on Vector Radiative Transfer (VRT) models. This algorithm allows for the retrieval of macro- and micro-physical properties of oceanic hydrosols, which significantly enhances our understanding of ocean geochemical properties, carbon cycles, and the estimation of global chlorophyll and suspended mineral concentrations.

Dr. Amir Ibrahim's work in the field of ocean color remote sensing and atmospheric correction plays a vital role in advancing our knowledge of marine ecosystems and environmental monitoring from space-based platforms.

Current Projects


Ocean color instrument (OCX) on Geostationary Extended Observations (GeoXO)

Technology & Missions

Instrument scientist for the ocean color instrument (OCX) on the NASA/NOAA GeoXO mission.


Plankton, Aerosol, Cloud, and ocean Ecosystem (PACE)

Remote Sensing

Develop and evaluate atmospheric correction methods for derivation of ocean color from a hyperspectral space-borne and air-borne radiometer and combined multi-angle polarimeter.
 


The Hyperspectral Imager for the Coastal Ocean (HICO)

Remote Sensing

Develop and validate a hyperspectral atmospheric correction algorithm of molecular and aerosol scattering and compensate for gaseous absorption in the atmosphere (such as water vapor, oxygen, and ozone) for the HICO sensor in order to retrieve a hyperspectral remote sensing reflectance to derive ocean color products.

Positions/Employment


Research Oceanographer

Ocean Ecology Laboratory, NASA Goddard Space Flight Center - Greenbelt, MD

March 2021 - Present


Senior Research Scientist - Atmospheric Correction PACE Project Science Lead

SSAI - NASA GSFC, Greenbelt, MD

July 2018 - March 2021


Research Scientist

Universities Space Research Association (USRA) / NASA GSFC - Greenbelt, MD

March 2017 - July 2018

Atmospheric correction for Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission


Postdoctoral Researcher

Universities Space Research Association (USRA) / NASA GSFC - Greenbelt

June 2015 - March 2017

Support of the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission's Science Team activities to develop and evaluate atmospheric correction methods for derivation of ocean color from a hyperspectral radiometer and combined multi-angle polarimeter.


Postdoctoral Researcher

Research Foundation of The City University of New York - New York, NY

January 2015 - June 2015

Polarimetric remote sensing algorithm development and validation with in-situ optics

Education


PhD. in Electrical Engineering, CCNY

Bachelor of Electrical Engineering, CCNY

Professional Societies


American Geophysical Union

2015 - Present


Institute of Electrical and Electronics Engineers

2009 - Present

Awards


• Honorary Mention awarded for Best Student Paper titled “Retrievals of the Attenuation and Scattering Coefficients of Marine Particles Using the Polarization of Light” from the oceanography society at the Ocean Optics 2014 conference, Portland, Maine.
• Certificate of Distinguished Achievement in Academic Excellence, NOAA-CREST Institute, 2013, The City College of New York.
• Honorary Mention awarded for Best Student Paper titled “The Relationship between Upwelling Polarized Radiance and In-Water Attenuation to Absorption Ratio” from the oceanography society at the Ocean Optics 2012 conference, Glasgow, Scotland.
• Graduate Teaching Fellowship, 2011-2013.

Grants


Atmospheric correction for complex scenes using co-located polarimetric and ocean color observations.

Remote Sensing of Water Quality - UMBC (NNH16ZDA001N-RSWQ) - Awarded: 2017-07-14


Dates: 2017-10-12  - 2020-10-09

Coverage: 0.1


Advancing the Quality and Continuity of Marine Remote Sensing Reflectance and Derived Ocean Color Products from MODIS to VIIRS

The Science of TERRA, AQUA, and SUOMI NPP - NASA - Awarded: 2018-01-31


Dates:  - 


Joint MISR/MODIS ocean color atmospheric correction with a new algorithm that utilizes reflected sun glint

The Science of TERRA, AQUA, and SUOMI NPP - NASA - Awarded: 2018-01-31


Dates:  - 

Selected Publications


Refereed

Gao, M., B. A. Franz, P.-W. Zhai, et al. K. D. Knobelspiesse, A. M. Sayer, X. Xu, V. Martins, B. Cairns, P. Castellanos, G. Fu, N. Hannadige, O. Hasekamp, Y. Hu, A. Ibrahim, F. S. 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 Atmospheric Measurement Techniques 16 (23): [https://doi.org/10.5194/amt-16-5863-2023]

Agagliate, J., R. Foster, A. Ibrahim, and A. Gilerson. 2023. A neural network approach to the estimation of in-water attenuation to absorption ratios from PACE mission measurements Frontiers in Remote Sensing 4 [10.3389/frsen.2023.1060908]

Hannadige, N. K., P.-W. Zhai, P. J. Werdell, et al. M. Gao, B. A. Franz, K. Knobelspiesse, and A. Ibrahim. 2023. Optimizing retrieval spaces of bio-optical models for remote sensing of ocean color Applied Optics 62 (13): 3299 [10.1364/ao.484082]

Sayer, A. M., L. Lelli, B. Cairns, et al. B. van Diedenhoven, A. Ibrahim, K. D. Knobelspiesse, S. Korkin, and P. J. Werdell. 2023. The CHROMA cloud-top pressure retrieval algorithm for the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite mission Atmospheric Measurement Techniques 16 (4): 969-996 [10.5194/amt-16-969-2023]

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]

Zhang, M., A. Ibrahim, B. A. Franz, Z. Ahmad, and A. M. Sayer. 2022. Estimating pixel-level uncertainty in ocean color retrievals from MODIS Optics Express 30 (17): 31415 [10.1364/oe.460735]

Ibrahim, A., B. Franz, A. Sayer, et al. K. Knobelspiesse, M. Zhang, S. Bailey, L. McKinna, M. Gao, and P. J. Werdell. 2022. Optimal Estimation Framework for Ocean Color Atmospheric Correction and Pixel-level Uncertainty Quantification Applied Optics Vol. 61 No. 20 [10.1364/ao.461861]

Gilerson, A., E. Herrera-Estrella, R. Foster, et al. J. Agagliate, C. Hu, A. Ibrahim, and B. Franz. 2022. Determining the Primary Sources of Uncertainty in Retrieval of Marine Remote Sensing Reflectance From Satellite Ocean Color Sensors Frontiers in Remote Sensing 3 [10.3389/frsen.2022.857530]

Zhai, P.-W., M. Gao, B. A. Franz, et al. P. J. Werdell, A. Ibrahim, Y. Hu, and J. Chowdhary. 2022. A Radiative Transfer Simulator for PACE: Theory and Applications Frontiers in Remote Sensing 3 [10.3389/frsen.2022.840188]

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]

Korkin, S., A. Sayer, A. Ibrahim, and A. Lyapustin. 2021. A practical guide to writing a radiative transfer code Computer Physics Communications 271 108198 [10.1016/j.cpc.2021.108198]

Bisson, K. M., E. Boss, P. J. Werdell, et al. A. Ibrahim, R. Frouin, and M. J. Behrenfeld. 2021. Seasonal bias in global ocean color observations Applied Optics 60 (23): 6978 [10.1364/ao.426137]

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 [https://doi.org/10.5194/amt-14-4083-2021]

Knobelspiesse, K., A. Ibrahim, B. Franz, et al. S. Bailey, R. Levy, Z. Ahmad, J. Gales, M. Gao, M. Garay, S. Anderson, and O. Kalashnikova. 2021. Analysis of simultaneous aerosol and ocean glint retrieval using multi-angle observations Atmospheric Measurement Techniques 14 3233-3252 [10.5194/amt-14-3233-2021]

Hannadige, N. K., P.-W. Zhai, M. Gao, et al. B. A. Franz, Y. Hu, K. Knobelspiesse, J. Werdell, A. Ibrahim, B. Cairns, and O. P. Hasekamp. 2021. Atmospheric correction over the ocean for hyperspectral radiometers using multi-angle polarimetric retrievals Optics Express 29 (3): 4504 [10.1364/oe.408467]

Bisson, K. M., E. Boss, P. J. Werdell, A. Ibrahim, and M. J. Behrenfeld. 2020. Particulate backscattering in the global ocean: A comparison of independent assessments Geophysical Research Letters [10.1029/2020gl090909]

Gao, M., P.-W. Zhai, B. A. Franz, et al. K. Knobelspiesse, A. Ibrahim, B. Cairns, S. E. Craig, G. Fu, O. Hasekamp, Y. Hu, and P. J. Werdell. 2020. Inversion of multiangular polarimetric measurements from the ACEPOL campaign: an application of improving aerosol property and hyperspectral ocean color retrievals Atmospheric Measurement Techniques 13 3939–3956 [10.5194/amt-13-3939-2020]

Gilerson, A., C. Carrizo, A. Ibrahim, et al. R. Foster, T. Harmel, A. El-Habashi, Z. Lee, X. Yu, S. Ladner, and M. Ondrusek. 2020. Hyperspectral polarimetric imaging of the water surface and retrieval of water optical parameters from multi-angular polarimetric data Applied Optics 59 (10): C8 [10.1364/ao.59.0000c8]

Frouin, R. J., B. A. Franz, A. Ibrahim, et al. K. Knobelspiesse, Z. Ahmad, B. Cairns, J. Chowdhary, H. M. Dierssen, J. Tan, O. Dubovik, X. Huang, A. B. Davis, O. Kalashnikova, D. R. Thompson, L. A. Remer, E. Boss, O. Coddington, P.-Y. Deschamps, B.-C. Gao, L. Gross, O. Hasekamp, A. Omar, B. Pelletier, D. Ramon, F. Steinmetz, and P.-W. Zhai. 2019. Atmospheric Correction of Satellite Ocean-Color Imagery During the PACE Era Frontiers in Earth Science 7 [10.3389/feart.2019.00145]

Remer, L. A., K. Knobelspiesse, P.-W. Zhai, et al. F. Xu, O. V. Kalashnikova, J. Chowdhary, O. Hasekamp, O. Dubovik, L. Wu, Z. Ahmad, E. Boss, B. Cairns, O. Coddington, A. B. Davis, H. M. Dierssen, D. J. Diner, B. Franz, R. Frouin, B.-C. Gao, A. Ibrahim, R. C. Levy, J. V. Martins, A. H. Omar, and O. Torres. 2019. Retrieving Aerosol Characteristics From the PACE Mission, Part 2: Multi-Angle and Polarimetry Frontiers in Environmental Science 7 [10.3389/fenvs.2019.00094]

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]

Gao, M., P.-W. Zhai, B. A. Franz, et al. Y. Hu, K. Knobelspiesse, P. J. Werdell, A. Ibrahim, B. Cairns, and A. Chase. 2019. Inversion of multi-angular polarimetric measurements over open and coastal ocean waters: a joint retrieval algorithm for aerosol and water leaving radiance properties Atmospheric Measurement Techniques 12 (7): 3921–3941 [10.5194/amt-12-3921-2019]

Chowdhary, J., P. Zhai, E. Boss, et al. H. M. Dierssen, R. J. Frouin, A. Ibrahim, Z. Lee, L. A. Remer, M. Twardowski, F. Xu, X. Zhang, M. Ottaviani, W. R. Espinosa, and D. Ramon. 2019. Modeling Atmosphere-Ocean Radiative Transfer: A PACE Mission Perspective Frontiers in Earth Science 7 100 pp. [10.3389/feart.2019.00100]

Ibrahim, A., B. A. Franz, Z. Ahmad, and S. W. Bailey. 2019. Multiband Atmospheric Correction Algorithm for Ocean Color Retrievals Frontiers in Earth Science 7 [10.3389/feart.2019.00116]

Jamet, C., A. Ibrahim, Z. Ahmad, et al. F. Angelini, M. Babin, M. J. Behrenfeld, E. Boss, B. Cairns, J. Churnside, J. Chowdhary, A. B. Davis, D. Dionisi, L. Duforêt-Gaurier, B. Franz, R. Frouin, M. Gao, D. Gray, O. Hasekamp, X. He, C. Hostetler, O. V. Kalashnikova, K. Knobelspiesse, L. Lacour, H. Loisel, V. Martins, E. Rehm, L. Remer, I. Sanhaj, K. Stamnes, S. Stamnes, S. Victori, J. Werdell, and P.-W. Zhai. 2019. Going Beyond Standard Ocean Color Observations: Lidar and Polarimetry Frontiers in Marine Science 6 [10.3389/fmars.2019.00251]

Gao, M., P.-W. Zhai, B. Franz, et al. Y. Hu, K. Knobelspiesse, P. J. Werdell, A. Ibrahim, F. Xu, and B. Cairns. 2018. Retrieval of aerosol properties and water-leaving reflectance from multi-angular polarimetric measurements over coastal waters Optics Express 26 (7): 8968 [10.1364/oe.26.008968]

Ottaviani, M., R. Foster, A. Gilerson, et al. A. Ibrahim, C. Carrizo, A. El-Habashi, B. Cairns, J. Chowdhary, C. Hostetler, J. Hair, S. Burton, Y. Hu, M. Twardowski, N. Stockley, D. Gray, W. Slade, and I. Cetinic. 2018. Airborne and shipborne polarimetric measurements over open ocean and coastal waters: Intercomparisons and implications for spaceborne observations Remote Sensing of Environment 206 375-390 [10.1016/j.rse.2017.12.015]

Ibrahim, A., B. Franz, Z. Ahmad, et al. R. Healy, K. Knobelspiesse, B.-C. Gao, C. Proctor, and P.-W. Zhai. 2018. Atmospheric correction for hyperspectral ocean color retrieval with application to the Hyperspectral Imager for the Coastal Ocean (HICO) Remote Sensing of Environment 204 60-75 [10.1016/j.rse.2017.10.041]

Zhai, P.-W., K. Knobelspiesse, A. Ibrahim, et al. B. A. Franz, Y. Hu, M. Gao, and R. Frouin. 2017. Water-leaving contribution to polarized radiation field over ocean Optics Express 25 (16): A689 [10.1364/oe.25.00a689]

Ibrahim, A., A. Gilerson, J. Chowdhary, and S. Ahmed. 2016. Retrieval of macro- and micro-physical properties of oceanic hydrosols from polarimetric observations Remote Sensing of Environment 186 548-566 [10.1016/j.rse.2016.09.004]

Gu, Y., C. Carrizo, A. A. Gilerson, et al. P. C. Brady, M. E. Cummings, M. S. Twardowski, J. M. Sullivan, A. I. Ibrahim, and G. W. Kattawar. 2016. Polarimetric imaging and retrieval of target polarization characteristics in underwater environment Applied Optics 55 (3): 626--637 [10.1364/AO.55.000626]

Brady, P. C., A. A. Gilerson, G. W. Kattawar, et al. J. M. Sullivan, M. S. Twardowski, H. M. Dierssen, M. Gao, K. Travis, R. I. Etheredge, A. Tonizzo, A. Ibrahim, C. Carrizo, Y. Gu, B. J. Russell, K. Mislinski, S. Zhao, and M. E. Cummings. 2015. Open-ocean fish reveal an omnidirectional solution to camouflage in polarized environments Science 350 (6263): 965-969 [10.1126/science.aad5284]

Ibrahim, A., A. Gilerson, T. Harmel, et al. A. Tonizzo, J. Chowdhary, and S. Ahmed. 2012. The relationship between upwelling underwater polarization and attenuation/absorption ratio Opt. Express 20 (23): 25,662-25,680 [10.1364/OE.20.025662]

Tonizzo, A., A. Gilerson, T. Harmel, et al. A. Ibrahim, J. Chowdhary, B. Gross, F. Moshary, and S. Ahmed. 2011. Estimating particle composition and size distribution from polarized water-leaving radiance Applied Optics 50 (25): 5047-5058 [10.1364/AO.50.005047]

Non-Refereed

Foster, R., A. Ibrahim, A. Gilerson, et al. C. Carrizo, A. El-Habashi, and S. Ahmed. 2015. Polarized above sea surface hyperspectral observations and their relationship with measured water properties Hyperspectral Imaging and Sounding of the Environment HT3B--4

Gilerson, A., C. Carrizo, A. Tonizzo, et al. A. Ibrahim, A. El-Habashi, R. Foster, and S. Ahmed. 2013. Polarimetric imaging of underwater targets SPIE Defense, Security, and Sensing 872403--872403

Ahmed, S., A. Tonizzo, A. Ibrahim, et al. A. Gilerson, B. Gross, and F. Moshary. 2012. Algal fluorescence: impact and potential for retrieval from measurements of the underwater degree of polarization SPIE Remote Sensing 85320I--85320I

Gilerson, A., A. Ibrahim, T. Harmel, A. Tonizzo, and S. Ahmed. 2012. Polarization techniques for the retrieval of water parameters from above and below water polarimetric observations Proc. of SPIE Vol 8372 83720T--1

Harmel, T., A. Tonizzo, A. Ibrahim, et al. A. Gilerson, J. Chowdhary, and S. Ahmed. 2011. Measuring underwater polarization field from above-water hyperspectral instrumentation for water composition retrieval SPIE Remote Sensing 817509--817509

Ibrahim, A., T. Harmel, A. Tonizzo, et al. I. Ioannou, A. Gilerson, and S. Ahmed. 2011. Exploring the relation between polarized light fields and physical-optical characteristics of the ocean for Remote Sensing applications SPIE Optical Engineering+ Applications 81600H--81600H

Hlaing, S., T. Harmel, A. Ibrahim, et al. I. Ioannou, A. Tonizzo, A. Gilerson, and S. Ahmed. 2010. Validation of ocean color satellite sensors using coastal observational platform in Long Island Sound Remote Sensing 782504--782504