Coastal Perspectives Lecture – Mar 8, 2022

Heidi Dierssen Profile PictureSensing New Connections between Earth’s Greatest Fluids – the Ocean and Atmosphere

Heidi Dierssen, Ph.D., Professor, Department of Marine Sciences, University of Connecticut

 

We are beginning to fully comprehend how changes in the coupled ocean and atmosphere together produce extreme weather events like the recent tornados in Kansas, droughts and wildfires in California and hurricanes along the Eastern seaboard.  The ocean and the atmosphere are thousands of times wider than they are thick — like thin pages in a book. Their behaviors are intimately connected, but the two fluids are often monitored and studied as different chapters rather than woven together in a single story. NASA’s upcoming Plankton Aerosol Cloud and ocean Ecosystem (PACE) satellite scheduled to launch in 2024 is the first mission designed by a team of atmospheric and oceanic scientists led by Dr. Heidi Dierssen here at the University of Connecticut. Sensor technology has improved considerably over the last few decades and space-borne sensors that provided only 3 to 8 channels of information in visible wavelengths are now able to be “hyperspectral” with 60 channels across the same visible spectrum of light.  PACE contains a hyperspectral scanning Ocean Color Imager (OCI) with 1-2 day coverage at 1 km2 pixel size and two polarimeters measuring the hyperspectral and hyperangular polarized light reaching the satellite.  What makes the hyperspectral sensor unique is that it can provide a spectral “fingerprint” for monitoring the biodiversity of photosynthesizing flora and fauna in the water column, on the seafloor, and floating on the sea surface. Merged with polarimetric data, PACE will allow us to delve deeper into the changing world including dust storms, ice clouds, and ocean whitecaps.  A host of PACE Early Adopters are already on board to use the data to assess coastal processes across the globe including detecting harmful algal blooms, pathogens, and oil slicks. Together, these sensors will provide insights into the functioning of atmospheric aerosols, clouds, water quality, and ocean biology and are poised to change the way we literally “see” the ocean and atmosphere.

Biography:

Dr. Dierssen leads the Coastal Ocean Laboratory for Optics and Remote Sensing at the University of Connecticut (www.colors.uconn.edu) and has a joint appointment in Marine Sciences and Geography. Her CV can be found here. Our current projects involve optics and remote sensing of the coastal zone ranging from Long Island Sound to the Southern Ocean using hyperspectral techniques. We are developing algorithms to use remotely sensing imagery to quantify phytoplankton community composition, benthic habitats in optically shallow waters, and to assess biogeographical distributions of organisms. We are also involved in research assessing microplastics on the sea surface, backscattering, particle size distributions and bubbles. Our laboratory has a variety of equipment for measuring optical and physical properties of the water column that can be loaned out to interested students or investigators. My current research projects, provided in more detail on my laboratory webpage (www.colors.uconn.edu), include:

  • Plankton Aerosol Cloud and Ocean Ecosystem (PACE) Mission
  • Interdisciplinary Sea Ice and Phytoplankton Interactions West of the Antarctic Peninsula
  • Advancing Remote Sensing of Microplastics on the Ocean Surface  
  • Hyperspectral Remote Sensing of Coastal Habitats:  Seagrass, floating vegetation, sediments, macroalgae and carbon export

COLORS strives to develop quantitative linkages from remote sensing products to biogeochemical properties that contribute to a global understanding of elemental cycling.  Our research bridges the gap between ship-based sampling at discrete points and spatially comprehensive assessments from satellites and aircraft.

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