Roy A. Armstrong, PhD


Photo of Roy A. Armstrong, PhD, Professor: Bio-optical Oceanography, Remote Sensing.

Professor: Bio-optical Oceanography, Remote Sensing
Director, Bio-optical Oceanography Laboratory
PhD – University of Puerto Rico, Mayagüez Campus, 1990
Department of Marine Sciences
University of Puerto Rico, Mayagüez Campus
PO Box 9000
Mayagüez, PR 00681-9000

Tel. (787) 899-2048 ext. 249, 248
Fax: (787) 899-2630; 899-5500
Office: Magueyes Marine Laboratories

Download: Curriculum Vitae


• Remotely-based water quality assessments in coastal areas.
• Variability of apparent and inherent optical properties in southwestern Puerto Rico.
• Satellite and drone-based remote sensing of coastal marine communities.
• Relationships between water optics and coral reef parameters.
• Impacts of Sargassum accumulation on tropical marine ecosystems and water quality.
• Development of autonomous surface vehicles as platforms for acoustical and optical imaging.
• Development of UxS for validation of satellite ocean color products.
• Development of low-cost optical sensors for citizen science water quality monitoring.





Peer-reviewed Publications

Ortiz-Rosa, S., R.A. Armstrong, W.J. Hernández, and S.M. Williams. In review. Remote Sensing of “Black Water Events” in Puerto Rican Oligotrophic Waters. Remote Sensing.

Perez-Perez J., R.A. Armstrong, and W. Hernandez. In review. Using High-Resolution Sentinel 2 Multispectral Images to Monitor Sargassum Accumulations in Coastal Areas of Southwestern Puerto Rico. Remote Sensing Letters.

Mejias-Rivera, C., R.A. Armstrong, S. Balint, E. García-Troche, R.A. McKinney, J. M. Morell, A. Oczkowski, T.A. Courtney. 2023. Localized inshore warming, acidification, and elevated particulate organic matter across a coupled mangrove, seagrass, and coral reef ecosystem in La Parguera, Puerto Rico. Coral Reefs 42:1313–1327.

Lockwood, R., C.M. Bachmann, M. Chrisp, C. Smeaton, N. Pahlaven, E. Hochberg, M.J. Montes, Bo-Cai Gao, R. Frouin, A. Vodacek, C. Fichot, T.W. Bell, R.A. Armstrong, C. Li, L. Kennedy, S. Gillmer, L. Fuhrman, D. Brouhard, J. Wang, and K. Thome. 2023. Aquatic Ecosystems Science Using an Imaging Spectrometer. Proceedings, Society of Photo-Optical Instrumentation Engineers (SPIE).

Pawlik, J.R., Armstrong, R.A., Farrington, S., Reed, J. Rivero-Calle, S., Singh, H., Walker, B.K., White, J. 2022. Comparison of recent survey techniques for estimating benthic cover on Caribbean mesophotic reefs. Marine Ecology Progress Series, 686: 201-211.

Mera, D.E., R.A. Rodríguez-Solís, L. Reyes, R.A. Armstrong, W. Hernandez, A. Guzmán-Morales. 2022. A Power and Performance Study of Compact L Band Total Power Radiometers for UAV Remote Sensing Based in the Processing on ZYNQ and ARM Architectures. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, Vol. 15, 2022 

Torres-Perez, J.L., C.E. Ramos-Scharrón, W.J. Hernandez, R.A. Armstrong, M. Barreto-Orta, J. Ortiz-Zayas, L.S. Guild and R. Viqueira. 2021. River streamflow, remotely-sensed water quality, and benthic composition of two previously undescribed nearshore coral reefs in northern Puerto Rico. Front. Mar. Sci. 8:720712. doi: 10.3389/fmars.2021.720712 

Hernández, W., J.M. Morell & R.A. Armstrong 2021. Using high-resolution satellite imagery to assess the impact of Sargassum inundation on coastal areas, Remote Sensing Letters, 13:1, 24-34, DOI: 10.1080/2150704X.2021.1981558

Geiger, E.F., S.F. Heron, W.J. Hernández, J. Caldwell, K. Falinski, T. Callender, A. Greene, G. Liu, J.L. De La Cour, R.A. Armstrong, M.J. Donahue, C.M. Eakin. 2021. Optimal Spatiotemporal Scales to Aggregate Satellite Ocean Color Data for Nearshore Reefs and Tropical Coastal Waters: Two Case Studies. Frontiers in Marine Science, section Coral Reef Research.

Ortiz-Rosa, Suhey, William J. Hernández, Stacey M. Williams, Roy A. Armstrong. 2020. Water Quality Anomalies following the 2017 Hurricanes in Southwestern Puerto Rico: Absorption of Colored Detrital and Dissolved Material. Remote Sens.,12, 3596; doi:10.3390/rs12213596.

León-Pérez, M., R.A. Armstrong, W.J. Hernández, and A. Aguilar-Perera. 2020. Seagrass Cover Expansion off Caja de Muertos Island, Puerto Rico, as determined by Long-term Analysis of Historical Aerial and Satellite Images (1950 – 2014). Ecological Indicators, 117:10656, DOI: 10.1016/j.ecolind.2020.106561

Gomez, Andrea M.; McDonald, Kyle C.; Shein, Karsten; DeVries, Stephanie; Armstrong, Roy A.; Hernandez, William J.; Carlo, Milton. 2020. "Comparison of Satellite-Based Sea Surface Temperature to In Situ Observations Surrounding Coral Reefs in La Parguera, Puerto Rico." J. Mar. Sci. Eng. 8, no. 6: 453.

Waters, S.M., Purdue, S.K., DeLeon, N., Armstrong, R.A., and Detres, Y. 2020. Metagenomic Investigation of African Dust Events in the Caribbean. FEMS Microbiology Letters. DOI: 10.1093/femsle/fnaa051

William J. Hernandez, Suhey Ortiz-Rosa, Roy A. Armstrong, Erick F. Geiger, C. Mark Eakin, Robert A. Warner. 2020. Quantifying the Effects of Hurricanes Irma and María on Coastal Water Quality in Puerto Rico using Moderate Resolution Satellite Sensors. Remote Sens. 12(6), 964;

León-Pérez, M.C., Hernández, W.J., and Armstrong, R.A., 2019. Characterization and distribution of seagrass habitats in a Caribbean nature reserve using high-resolution satellite imagery and field sampling. Journal of Coastal Research, 35(5), 937–947. Coconut Creek (Florida), ISSN 0749-0208.

Roman, M., Z. Wang, Q. Sun, V. Kalb, S.D. Miller, A.L. Molthan, L.A. Schultz, J.R. Bell, E. Stokes, K. Seto, B. Pandey, D.K. Hall, T. Oda, R.E. Wolfe, G. Lin, N. Golpayegani, S. Devadiga, C.C. Davidson, S. Sarkar, C. Praderas, J. Schmaltz, R.A. Boller, J. Stevens, O.M. Ramos, E. Padilla, J. Alonso, Y. Detres, R. Armstrong, I. Miranda, Y. Conte, N. Marrero, K. MacManus, T. Esch, E.J. Masuoka. 2018. NASA's Black Marble Standard Product Suite. Remote Sensing of Environment 210,113-143.

Wei, J., Z. Lee, R. Garcia, L. Zoffoli, R.A. Armstrong, Z. Shang, P. Sheldon, and R. Chen. 2018. An assessment of Landsat 8 atmospheric correction schemes and remote sensing reflectance products in coral reefs and coastal turbid waters. Remote Sensing of Environment 215, 18-32.

Hosannah, N., J. Gonzalez, R. Rodriguez, H. Parsiani, F. Moshary; L. Aponte, R. Armstrong, E. Harmsen, P. Ramamurthy, M. Angeles, L. Leon, N. Ramirez, D. Niyogi, and B. Bornstein. 2017. The Convection, Aerosol, and Synoptic-Effects in the Tropics (CAST) Experiment: Building an Understanding of Multi-Scale Impacts on Caribbean Weather via Field Campaigns. Bulletin of the American Meteorological Society 98(8), 
doi: 10.1175/BAMS-D-16-0192.1

Wei, J., Z. Lee, M. Ondrusek, A. Mannino, M. Tzortziou, and R. Armstrong. 2016. Spectral slopes of the absorption coefficient of colored dissolved and detrital material inverted from UV-visible remote sensing reflectance, J. Geophys. Res. Oceans, 121,

Perez-Hoyos, I.C., N.Y. Krakauer, R. Khanbilvardi, and R.A. Armstrong. 2016. A review of advances in the identification and characterization of groundwater dependent ecosystems using geospatial technologies. Geosciences 6, 17, doi:10.3390.

Hernandez, W.J. and R.A. Armstrong. 2016. Deriving Bathymetry from Multispectral Remote Sensing Data. Journal of Marine Sciences and Engineering 4(1)8.

Torres-Pérez JL, Guild LS, Armstrong RA, Corredor J, Zuluaga-Montero A, Polanco R (2015) Relative Pigment Composition (11): e0143709. doi: 10.1371/journal.pone.0143709

Uri ten Brink, Dwight Coleman, Jason Chaytor, Amanda Demopoulos, Roy Armstrong, Graciela Garcia-Molinero, Nicole Reineault, Brian Andrews, Roger Chastain, Katherine Rodriguez, and Mathieu Mercier-Gingras. 2014. Earthquake, landslide, and tsunami hazards and benthic biology in the Greater Antilles. Oceanography Vol 27 (1) Supplement, pp.34-35.

Anderson, D.A., R.A. Armstrong, and E. Weil. 2013. Hyperspectral sensing of disease stress in the Caribbean reef-building coral, Orbicella faveolata - perspectives for the field of coral disease monitoring. PLoS ONE 8(12): e81478. 

Torres-Pérez, J.L., L.S. Guild and R.A. Armstrong. 2012. Hyperspectral Distinction of Two Caribbean Shallow-Water Corals Based on Their Pigments and Corresponding Reflectance. Remote Sensing 4:3813-3832.

Torres J.L. and R.A. Armstrong. 2012. Effects of artificially-enhanced UV radiation on the growth, photosynthetic and photoprotective components, and reproduction of the Caribbean coral Porites furcata. Coral Reefs 31:1077-1091.

Locker S.D., R.A. Armstrong, T.A. Battista, J.J. Rooney, C. Sherman, and D.G. Zawada. 2010. Geomorphology of mesophotic coral ecosystems: current perspectives on morphology, distribution, and mapping strategies. Coral Reefs 29:329-345.

Jiménez-Vélez B., Y. Detrés, R.A. Armstrong, and A. Gioda. 2009. Characterization of African Dust (PM 2.5) across the Atlantic Ocean during AEROSE 2004. Atmospheric Environment 43:2659–2664.

Armstrong, R.A., H. Singh, S. Rivero-Calle, and F. Gilbes. 2009. Monitoring Coral Reefs in Optically-Deep Waters. Proceedings of the 11th International Coral Reef Symposium, Ft. Lauderdale, Florida, July 2008: 593-597.

Rivero-Calle S, R.A. Armstrong, F.J. Soto-Santiago. 2009. Biological and physical characteristics of a mesophotic coral reef: Black Jack reef, Vieques, Puerto Rico. Proceedings of the 11th International Coral Reef Symposium, Ft. Lauderdale, Florida, July 2008: 567-571.

Guild, L., B. Lobitz, R.A. Armstrong, F. Gilbes, A. Gleason, J. Goodman, E. Hochberg, M. Monaco, R. Berthold, and J. Kerr. 2009. NASA Airborne AVIRIS and DCS Remote Sensing of Coral Reefs. Proceedings of the 11th International Coral Reef Symposium, Ft. Lauderdale, Florida, July 2008: 616-620

Lobitz, B., L. Guild, M. Montes, R.A. Armstrong, and J. Goodman. 2009. Pre-Processing of 2005 AVIRIS Data for Coral Reef Analysis. Proceedings of the 11th International Coral Reef Symposium, Ft. Lauderdale, Florida, July 2008: 637-641

Torres J.L., R.A. Armstrong, and E. Weil. 2008. Enhanced ultraviolet radiation can terminate sexual reproduction in the broadcasting coral species Acropora cervicornis Lamarck. Journal of Experimental Marine Biology and Ecology 358:39-45.

Armstrong, R.A. 2007. Deep zooxanthellate coral reefs of the Puerto Rico - U.S. Virgin Islands insular platform. Coral Reefs, 26(4):945.

Suarez, E., J. Matta, M. Rolon, L. Maldonado, Y. Detrés, A. de la Motta, M. Gelado, J. Ramos, and R. Armstrong. 2008. Molecular identification of the bacterial burden in Sahara Dust Samples using a new method to improve the evidence for the effective management of public health measures during an SD event. Journal of Environmental Health Research 7(2):99-106.

Torres J.L., R.A. Armstrong, J.E. Corredor, and F. Gilbes. 2007. Physiological responses of Acropora cervicornis to increased solar irradiance. Photochemistry and Photobiology 83:839-850.

Morris, V., T.W. Yu, E. Joseph, R. Armstrong, R. Fitzgerald, R. Karim, X.Z. Liang, and Q. Min. 2007. The NOAA Center for Atmospheric Sciences (NCAS): Programs and Achievements. Bulletin of the American Meteorological Society, 88(2):141-145.

Morris, V., T.W. Yu, E. Joseph, R. A. Armstrong, Y. Detres, R. Fitzgerald, R. Karim, X. Liang, and Q. Min. 2007. The NOAA Center for Atmospheric Sciences (NCAS): Its Mission, Current Status, and Significant Achievements from 2002-2005. Bulletin of the American Meteorological Society (BAMS) 88(2):141-145.

Matta, J.L., J. M. Ramos, R.A. Armstrong, and H. D’Antoni. 2007. Response of Human Fibroblasts to Very Low Doses of Environmental UV Radiation. Caribbean Journal of Dermatology and Therapeutics 2:16-27.

Morris, V., P. Clemente-Colon, N. Nalli, E. Joseph, R. Armstrong, Y. Detres, M. Goldberg, P. J. Minnett, R. Lumpkin. 2006. Measuring Trans-Atlantic Aerosol Transport From Africa. EOS, 565-566.

Costa, C. S. B., R. Armstrong, Y. Detrés, E. W. Koch, M. Bertiller, A. Beeskow, L. S. Neves, G. M. Tourn, O. A. Bianciotto, L. B. Pinedo, A. Y. Blessio, and N. San Roman. 2006. Effect of Ultraviolet-B Radiation on Salt Marsh Vegetation: Trends of the Genus Salicornia along the Americas. Photochemistry and Photobiology 82: 878–886.

Díaz, S., C. Camilion, G. Deferrari, H. Fuenzalida, R. Armstrong, C. Booth, A. Paladini, S. Cabrera, C. Casiccia, C. Lovengreen, J. Pedroni, A. Rosales, H. Zagarese, and M. Vernet. 2006. Ozone and UV Radiation over Southern South America: Climatology and Anomalies. Photochemistry and Photobiology 82: 834-843

Armstrong, R.A., H. Singh, J. Torres, R. Nemeth, A. Can, C. Roman, R. Eustice, L. Riggs, and G. Garcia-Moliner. 2006. Characterizing the deep insular shelf coral reef habitat of the Hind Bank Marine Conservation District (US Virgin Islands) using the Seabed Autonomous Underwater Vehicle. Continental Shelf Research 26, 194-205.

Díaz, S., C.R. Booth, R. Armstrong, C. Brunat, S. Cabrera, C. Camilion, C. Cassiccia, G. Deferrari, H. Fuenzalida, C. Lovengreen, A. Paladini, J. Pedroni, A. Rosales, H. Zagarese, and M. Vernet. 2005. Multi-channel radiometers calibration: A new approach. Applied Optics 44 (26): 5374-5380.

Schweizer, D., R.A. Armstrong, and J. Posada. 2005. Remote sensing characterization of benthic habitats and submerged vegetation biomass in los Roques Archipelago National Park, Venezuela. Intl. J. of Remote Sensing 26(12): 2657-2667.

Matta, J., J. Ramos, R. Armstrong, and H. D’Antoni. 2005. Environmental UVA and UVB Threshold Doses for Apoptosis and Necrosis in Human Fibroblasts. Photochemistry and Photobiology 81, 563-568.

Ramos, J., Villa, J., Ruiz, A., Armstrong, R., and J. L. Matta. 2004. UV dose determines key characteristics of non-melanoma skin cancer. Cancer Epidemiology, Biomarkers & Prevention 13(12): 2006-2011.

Armstrong, R.A., F. Gilbes, R. Guerrero, C. Lasta, and H. Miazán. 2004. Validation of SeaWiFS chlorophyll algorithm for the Rio de la Plata Estuary and adjacent waters. Intl. J. of Remote Sensing 25(7-8):1501-1505.

Gilbes, F. and R.A. Armstrong. 2004. Phytoplankton dynamics in the eastern Caribbean Sea as detected by space remote sensing. Intl. J. of Remote Sensing 25(7-8):1449-1452.

Corredor, J., J. Morell, J. López, J. Capella and R.A. Armstrong. 2004. Cyclonic Eddy Entrains Orinoco River Plume in Eastern Caribbean. EOS Transactions, American Geophysical Union 85(20):197, 201-202.

Singh, H., R.A. Armstrong, R. Eustice, C. Roman, O. Pizarro, and J.Torres. 2004. Imaging Coral I: Imaging Coral Habitats with the SeaBED AUV. Subsurface Sensing Technologies and Applications 5(1):25-42.

Corredor, J., J. Morell, J. López, R. Armstrong, A. Dieppa, C. Cabanillas, A. Cabrera and V. Hensley. 2003. Remote continental forcing of phytoplankton biogeochemistry: Observations across the “Caribbean-Atlantic front”. Geophysical Research Letters 30(20):1-4.

Armstrong, R.A., H. Singh, and F. Gilbes. 2002. Benthic Survey of Insular Slope Coral Reefs Using the SeaBED AUV. Backscatter 13(3): 22-25.

Gilbes, F., R.A. Armstrong, R. Webb, and F. Muller-Karger. 2001. SeaWiFS Helps Assess Hurricane Impact in the Caribbean Sea. EOS, Transactions, American Geophysical Union, Vol. 82, No. 45, pages 529 and 533.

Detrés, Y., R.A. Armstrong, and X. Connelly. 2001. Ultraviolet-induced responses in two species of climax tropical marine macrophytes. Photochemistry and Photobiology 62(1-2):55-66.

Armstrong, R.A., J. Lopez, and F. Gilbes. 2000. Apparent optical properties at the Caribbean Time Series Station. Ocean Optics XV – CDROM Publication.

Gilbes, F., and R.A. Armstrong. 2000. Inherent optical properties at the Caribbean Time Series Station (CaTS). Ocean Optics XV – CDROM Publication.

Corredor, J., A.W. Bruckner, F. Muszynski, R.A. Armstrong, and J.M. Morell. 2000. UV-absorbing compounds in three species of Caribbean zooxanthellate corals: depth distribution and spectral response. Bulletin of Marine Science 67:821-830.

Navarro, A., J. Corredor, J. Morell, and R.A. Armstrong. 2000. Distribution of the cyanophyte Trichodesmium in the Eastern Caribbean Sea: Influence of the Orinoco River. Intl. J. of Tropical Biology 48(1).

Muszynski, F., A. Bruckner, R.A. Armstrong, J.M. Morell, and J.E. Corredor. 1998. Within-colony variations of UV absorption in a reef building coral. Bull. Mar. Sci., 63(3): 589-594.

Matta, J.L., C.M. Nazario, R.A. Armstrong, and J. Navas. 1998. Epidemiological trends of melanoma in Puerto Rico from 1975 – 1991. Boletín de la Asociación Médica de Puerto Rico 90(1-3): 221-224.

Stoner, A.W., P.A. Pitts, and R.A. Armstrong. 1996. The interaction of physical and biological 	factors in the large-scale distribution of queen conch populations in seagrass meadows. Bull. Mar. Sci., 58(1): 217-233.

Johnson, L., B. Lobitz, R. Armstrong, R. Baldy, E. Weber, J. DeBenedictis, and D. Bosch. 1996. Remotely sensed observations of phylloxera-infested vineyard in the Napa Valley. California Agriculture (50) 4:14-18.

Armstrong, R.A. 1994. Oceanic fronts in the northeastern Caribbean revealed by satellite ocean color imaging. International Journal of Remote Sensing 15(6): 1169-1171.

D'Antoni, H., R. Armstrong, J. Coughlan, J. Skiles, and G. Daleo. 1994. Effects of stratospheric ozone depletions and increased levels of ultraviolet radiation on subantartic forests and western patagonian steppe: A research project. In: Stratospheric Ozone Depletion/UV Radiation in the Biosphere, R.H. Biggs and M. Joyner (eds.), NATO ASI Series, Vol I 18, Springer-Verlag, Berlin.

Stoner, A.W., M.D. Hanisak, N.P. Smith, and R.A. Armstrong. 1994. Large-scale distribution of queen conch nursery habitats: Implications for stock enhancement. pp. 169-189 In: R.S. Appeldoorn and Q. Rodriguez (eds.) Queen Conch Biology, Fisheries and Mariculture. Fundación Científica Los Roques, Caracas, Venezuela.

Armstrong, R.A. 1993. Remote sensing of submerged vegetation canopies for biomass estimation. International Journal of Remote Sensing 14(3): 621-627.

Goenaga, C., V.P. Vicente, and R.A. Armstrong. 1989. Bleaching induced mortalities in reef corals from La Parguera, Puerto Rico: A precursor of change in the community structure of coral reefs? Carib. J. Sci., 25(1-2): 59-65. 


Armstrong, R.A., O. Pizarro, C. Roman. 2019. Underwater Robotic Technology for Imaging Mesophotic Coral Ecosystems. In: Loya, Y., Puglise, K. and Bridge T. (Eds.). Mesophotic Coral Ecosystems of the World. Springer.

Garcia-Moliner, G., R.A. Armstrong and M.J. Cerame Vivas. 2019. Essential Fish Habitats of the Deep – Puerto Rico and the U.S. Virgin Islands. Published by the Caribbean Fishery Management Council, NOAA. 195 pages.

Hooker, S.B., C. del Castillo, R.N. Lind, J.H. Morrow, C.R. Booth, J.W. Brown, R.M. Kudela, H.F. Houskeeper, K. Suzuki, and R.A. Armstrong, 2018: “The HARPOONS Vicarious Calibration Project.” In: Hooker, S.B., R.N. Lind, J.H. Morrow, J.W. Brown, R.M. Kudela, H.F. Houskeeper, K. Suzuki, 2018: Advances in Above- and In-Water Radiometry, Vol. 2: Autonomous Atmospheric and Oceanic Observing Systems. TP–2018–219033/Vol. 2, NASA Goddard Space Flight Center, Greenbelt, Maryland, 8–64.

Armstrong, R.A. 2016. “Landscape-level imaging of benthic environments in Optically-Deep Waters”. Chapter 10 In: C.W. Finkl, C. Makowski (eds.), Seafloor Mapping along Continental Shelves, Coastal Research Library 13, Springer International Publishing Switzerland.

Torres-Pérez, J.L., R.A. Armstrong, and Y. Detrés. 2014. Impacts of UV radiation on tropical marine organisms. In: Radosevich, J. (Ed.) UV radiation: Application, Processes and Mechanisms. NOVA Publishers. 

Armstrong, R.A. and H. Singh. 2012. Mesophotic Coral Reefs of the Puerto Rico Shelf. Chapter 24 In “Seafloor Geomorphology as Benthic Habitat: GeoHab Atlas of seafloor geomorphic features and benthic habitats”, P.T. Harris and E.K. Baker (eds.), Elsevier Insights.

Ballantine, D.L.; Appeldoorn, R.S.; Yoshioka, P.; Weil, E.; Armstrong, R.; Garcia, J.R.; Otero, E.; Pagan, F.; Sherman, C.; Hernandez-Delgado, E.A.; et al. Biology and Ecology of Puerto Rican Coral Reefs. In Coral Reefs of the USA; Springer Science and Business Media LLC: Berlin/Heidelberg, Germany, 2008; Volume 1, pp. 375–406.

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