Winter 2021

Winter 2021 Seminars

All Winter 2021 seminars will be done remotely via Zoom.

Seminar Coordinator: Marilou Sison-Mangus

For disability-related accommodations: call (831) 459-4730 or email Rondi Robison

 


    January 15

  • Steve Palumbi, Stanford University

    Resilience in the face of climate change: examples from the genetics, ecology and future of coral reefs
    Shifts in the physical and biological components of marine ecosystems have accelerated over the past decades, exerting unprecedented pressure on ocean species and reducing the value of ocean life for coastal human communities. The ability of populations to respond to change is termed adaptive capacity, and includes aspects of individual physiology such as plasticity, aspects of evolutionary change such as genome-based selection, and shifts in species abundance such as for symbionts. I’ll present some work we have been doing with corals in the Pacific in order to try to answer questions about the mechanisms and limits of adaptive capacity and what this might mean for the future of coral reefs around the world.

  • January 22

  • Jacqueline McSweeney, Oregon State University

    Overlapping Processes that drive Temperature and Stratification Variability on the Inner Shelf

    The inner shelf, the area separating the surf zone and mid-continental shelf, is a dynamically complex region that is influenced by a multitude of physical processes that overlap in space and time.  Both jointly and individually, these processes have important implications for coastal water quality, ecological connectivity, and the cross-shelf transport of sediment, biota, energy, and heat.  In this talk I’ll discuss how different processes, including internal waves, propagating plumes, and submesoscale fronts, drive temperature and stratification variability throughout the inner shelf.  I’ll present observational data from 42 moorings deployed on the central California inner shelf, ranging from 10-100 m water depth and spanning 40 km of coastline, as well as complementary remote sensing measurements.        

     


  • January 29

  • Lihini Aluwihare, Scripps Institute of Oceanography

     Diverse roles of dissolved organic molecules in seawater

    Dissolved organic molecules in seawater can store nutrients, participate in the biological carbon pump, be involved in microbial cross-feeding, act as chemical cues, serve as toxins etc. In this talk I will discuss how my lab gathers chemical information on the complex pool of organic molecules in the ocean to better characterize their role in biogeochemical cycling and ecosystem function.


  • February 5

  • Maike Sonnewald, Princeton University, NOAA

    Revealing mechanisms of change in the Atlantic Meridional Overturning Circulation under global heating
    The North Atlantic ocean is key to climate through its role in heat transport and storage, but the response of the circulation’s drivers to a changing climate is poorly constrained. Climate models show that the circulation is weakening, and here the cause is revealed addressing the fundamental question regarding the existence of dynamical coherent regions and the associated mechanisms. Using the transparent machine learning method Tracking global Heating with Ocean Regimes (THOR), dynamical regimes are identified and tied to distinct currents and mechanisms such as the formation of deep water masses, and the location of the Gulf Stream and the Trans Atlantic Current. Drivers of the circulation are identified using the two dimensional fields depth, dynamic sea level and wind stress. Moving beyond a black box approach, THOR is engineered to reveal its source of predictive skill. A labeled dataset is engineered by an explicitly interpretable equation transform and k-means application to ocean model data, allowing theoretical inference. A multilayer perceptron is then trained, explaining its skill using relevance maps and theory. With abrupt CO2 quadrupling, the circulation weakens due to a shift in deep water formation areas and a northward shift of the Gulf stream and an eastwards shift in the Trans Atlantic Current. If CO2 is increased 1% yearly, similar but weaker patterns emerge. THOR is scalable and applicable to a range of models, needing only commonly available fields, and could accelerate model analysis and facilitate process oriented intercomparisons.
    Significance: The North Atlantic circulation is key to climate through heat transport and storage, and is projected to weaken under global heating. The mechanisms of change remain obscure, but are addressed here using a machine learning method with interpretable and explainable skill. Tackling the fundamental question of identifying dynamically coherent regimes governing the circulation, the Tracking global Heating with Ocean Regimes (THOR) method reveals a weakened circulation under abrupt CO2 quadrupling, seeing a shift in deep water formation, the Gulf Stream and Trans Atlantic Current. If CO2 is increased 1% yearly, similar but weaker patterns emerge. THOR is readily applicable to other models needing only depth, wind stress and sea surface height fields as input, and could accelerate discovery and analysis.

  • February 12

  • Heidi Dierssen, University of Connecticut

    Better quantification of the “lungs” of the ocean:  Hyperspectral remote sensing from the great wet barnyard of Long Island Sound

    Satellites provide unprecedented views of the swirling, dynamic patterns of ocean life. Even though we cannot directly see the microscopic phytoplankton that fuel the ocean food web from space, we can see how they absorb light as they photosynthesize. The evolution of chlorophyll-a derived from satellites over the last twenty years has outlined fronts where fish congregate, intense algal blooms that can be toxic, and changes in productivity of the vast deserts in the center of ocean gyres. 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 “hyperspectral” with 60 channels across the same visible spectrum of light.  New missions like NASA’s upcoming Plankton Aerosol Cloud and ocean Ecosystem (PACE) mission will better quantify how the ocean and atmosphere breathe through exchange of carbon dioxide and oxygen – the “lungs” of the planet. 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. Here, I will provide an overview of how hyperspectral measurements will help to better constrain productivity measurements in the ocean by assessing phytoplankton composition and dynamics.  I will draw from research conducted in my lab over the last decade in Long Island Sound (LIS), the largest urban estuary in the U.S. with 9 million people living within the watershed.  Highly impacted by human activities, F. Scott Fitzgerald (1925) referred to LIS as “the most domesticated body of salt water in the Western hemisphere, the great wet barnyard of Long Island Sound.” Field data from this dynamic and optically complex estuary illustrate how multi-spectral imagery is not sufficient to characterize phytoplankton dynamics and how hyperspectral measurements will allow us to better quantify phytoplankton changes through time.


  • February 19

  • Yibin Huang, MBARI, UCSC

    New Insights of the Biological Pump in the Northeast Pacific From the Biogeochemical Argo Observations

     

    Biological-mediated carbon transfer from the surface to the depth, aka biological pump, plays a vital role in regulating the oceanic sequestration of carbon and the Earth’s climate. The recent advent of the biogeochemical-Argo (BGC-Argo), a network of profiling floats carrying biogeochemical and bio-optical sensors,  provide a powerful means to characterize biological pump at spatiotemporal resolutions that were previously out of reach.  In this talk, I will present two lines of our work forged to better understand the biological pump by leveraging the multiple BGC-Argo deployed in Northeast Pacific,  including the development of a novel approach for remote partitioning of distinct biogenic carbon export and a synthesis of mesopelagic remineralization and upper carbon carbon supply that helps solve an enduring mystery of carbon budget in the mesopelagic zone.  


  • February 26

  • Craig Nelson, University of Hawaii at Manoa

    Of Microbes and Mucus: Coral Reef Organic Geochemistry in the Anthropocene

    Coral reefs are productive ecosystems that thrive in tropical oceans that are nearly devoid of nutrients to support photosynthesis. This makes coral reefs sensitive to human activities that change nutrient and organic matter inputs and recycling, such as fishing and wastewater discharge. In this talk I will discuss our current work on the ecosystem microbiology of coral reefs: the microbial denizens of reefs and the roles they play in reef processes. I will also discuss our efforts to untangle the role of benthic coral and algae in reef nutrient cycling and how they influence reef microbial dynamics through the release of dissolved organic matter. 


  • March 5

  • Andy Moore, UC Santa Cruz


  • March 12

  • Kyle Kavanaugh, UCLA