Seminar: Arturo Sanchez

View Calendar
January 11, 2021 11:30 am - 12:30 pm

Validating MODIS fPAR in a Tropical Dry Forest using Wireless Sensor Networks
Arturo Sanchez-Azofeifa, Ph.D., P.Eng. SM IEEE
Centre for Earth Observation Sciences, Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G2E3
Email: Arturo.sanchez@ualberta.ca

The fraction of Photosynthetic Active Radiation (fPAR) is a component of determining canopy photosynthesis and is a crucial component of determining carbon flux product. The MODIS fPAR product has been shown to work well in the Northern Hemisphere but has not been validated in the Tropical Dry Forest which encompasses 42% of all tropical forests. This study uses a Wireless Sensor Network (WSN) to produce a representative in-situ Green fPAR product in the Santa Rosa National Park Environmental Monitoring Super Site for validating the MODIS fPAR product between 2013-2017.  This study implements 2-flux fPAR estimation for the in-situ product before subsequently using the Savitsky-Golay derivate-based smoothing, univariate-wavelet transforms, and cross-wavelet analysis to compare the phenometric variables between in-situ and MODIS fPAR.  Results indicate that the MODIS fPAR products are incapable of accurately predicting the onset of green-up or senescence, with detection of these events 18-55 days; however despite these temporal offsets, the annual and inter-seasonal patterns are replicated in both the MODIS and in-situ products with significance (p<0.05).  These patterns break down under extreme water conditions, with the effects of droughts under-predicted by MODIS and hurricane effects not represented at all in the MODIS data.

Additionally, small scale fPAR changes and intra-seasonal differences are not significantly replicated by the MODIS fPAR products. This study, therefore, illustrates the inflexibility and insensitivity of the MODIS observations, and therefore these products should not be relied upon to give feedback to rapid changes in the phenological cycle of Tropical Dry Forests and more important provide important challenges to efforts to quantity essential climatic variables in tropical dry forest environments.

Related upcoming events

  • February 26, 2024 11:30 am - February 26, 2024 12:30 pm

    Out of Sight, Out of Mind

    Abstract: Join Bobby for a showcase of his detailed biological illustration, created under the pen name, NearsightGraphite. Highlighting his process, he’ll discuss the power of the observer and the illustrator’s role as a distiller of torrents of visual data. Bobby’s artwork amplifies intimate, obscure forms of life to give underrepresented organisms louder voices and to visualize their self-worlds. He aims to inspire curiosity in the intricacies of the natural world, and by extension, promote nature conservation.

    Bio: Robert J. Long ("Bobby") is a visual artist and educator from Silver Spring, Maryland. His zoologically-focused artwork has been exhibited throughout the United States and internationally. In 2013 he became Arizona’s first and only finalist in the internationally juried Adobe Design Achievement Awards. His illustrations have been published by Frontiers in Microbiology, Manifest Press, the Confluencenter for Creative Inquiry, and Edible Magazine, among others. Bobby is also an amateur reef aquarist and an avid photographer with experience in macro-photography and an interest in natural subjects.

  • March 4, 2024 11:30 am - March 4, 2024 12:30 pm

    Canopy Temperature

  • March 11, 2024 - March 15, 2024 All day
    No additional details for this event.
  • March 18, 2024 11:30 am - March 18, 2024 12:30 pm

    Carbon and Water Fluxes

  • March 25, 2024 11:30 am - March 25, 2024 12:30 pm

    Sustainability

  • April 1, 2024 11:30 am - April 1, 2024 12:30 pm

    Urban Ecology

  • April 8, 2024 11:30 am - April 8, 2024 12:30 pm

    Phenology

  • April 15, 2024 11:30 am - April 15, 2024 12:30 pm

    Kimberly Dibble, NPS

    KC Cushman, ORNL

    Soren Weber, ORNL

    Nicola Falco, Berkeley Lab

    Lucas Heintzman, USDA

    Cameron McIntire, USDA

     

  • April 22, 2024 11:30 am - April 22, 2024 12:30 pm

    Earth System Modeling

  • April 29, 2024 11:30 am - April 29, 2024 12:30 pm

    Microbes and Soil