Oceanographer, Pacific Coastal and Marine Science Center
I am a physical oceanographer who studies waves, hydrodynamics, and transport processes in coral reef environments. I also have expertise in internal waves and water-column dynamics. I use direct measurements to answer questions about how physical processes -across a range of temporal and spatial scales- affect coastal ecosystems, and to investigate how these patterns might alter with climate change.
Research Interests
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Waves, hydrodynamics, and transport processes in coral reef environments
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Effects of climate change on coastal physical and biological processes
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Coastal ocean physical processes and effects on nearshore ecosystems
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Internal tides and nonlinear internal waves over continental shelves
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Fine-scale gradients in biological and suspended particulate material
Professional Experience
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2012-present: Oceanographer, USGS Coastal and Marine Hazards and Resources Program
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2011-2012: Postdoctoral Researcher, Moss Landing Marine Laboratories
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2010-2011: Postdoctoral Researcher, University of California at Santa Cruz
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2008-2012: Postdoctoral Researcher, Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), University of California at Santa Cruz
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2008: Teaching Assistant & Lecturer, Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) Summer Course “Coastal Physical Oceanography and Marine Ecosystems,” University of California Santa Cruz
Education and Certifications
PhD: 2008, University of California Santa Cruz, Santa Cruz, CA
BA: 2002, Grinnell College, Grinnell, IA
Science and Products
Time-series data of water surface elevation, waves, currents, temperature, and turbidity collected between November 2017 and March 2018 off the west coast of Maui, Hawaii, USA
Time-series data of water surface elevation, waves, currents, temperature, and turbidity collected between November 2017 and March 2018 off the west coast of Maui, Hawaii, USA. The data are available in NetCDF format, grouped together in zip files by instrument site location. These data support a modeling study on the effects of potential watershed restoration on decreasing sediment loads to adjac
Cross-reef wave and water level data from coral reef environments
Coral reefs provide important protection for tropical coastlines against the impact of large waves and storm damage by energy dissipation through wave breaking and bottom friction. However, climate change and sea level rise have led to growing concern for how the hydrodynamics across these reefs will evolve and whether these changes will leave tropical coastlines more vulnerable to large wave even
Jurabi, Exmouth, Western Australia, 2016 Coral Reef Circulation and Sediment Dynamics Experiment
Carbonate reefs are a major source of sediment for coastlines in much of the tropical regions of the world, contributing to significant shoreline accretion and beach nourishment. A collaborative experiment between the U.S. Geological Survey and the University of Western Australia was conducted on Ningaloo Reef, northwest Australia, to investigate this problem and determine the primary oceanographi
Modeled effects of depth and semidiurnal temperature fluctuations on predictions of year that coral reef locations reach annual severe bleaching for various global climate model projections
Using global climate model projections of sea-surface temperature at coral reef sites, we modeled the effects of depth and exposure to semidiurnal temperature fluctuations to examine how these effects may alter the projected year of annual severe bleaching for coral reef sites globally. Here we present the first global maps of the effects these processes have on bleaching projections for three IPC
Waiakane, Molokai, HI, 2018 Coral Reef Circulation and Sediment Dynamics Experiment
Coral reefs generate significant volumes of carbonate sediment that becomes the primary source of beach material along many low-latitude shorelines that protect hundreds of millions of people globally. Despite this fact, there is little understanding of the specific processes that transport the carbonate sediment produced on the outer portions of coral reefs to the shoreline, let alone how those p
Observations of coral reef oceanographic and groundwater properties off Makua, Kauai, HI, USA, August 2016
Pervasive and sustained coral diseases contribute to the systemic degradation of reef ecosystems, however, an understanding of the physicochemical controls on a coral disease event is still largely lacking. Water circulation and residence times and submarine groundwater discharge all determine the degree to which reef organisms are exposed to the variable chemistry of overlying waters; understandi
Time series data of oceanographic conditions from La Parguera, Puerto Rico, 2017-2018 Coral Reef Circulation and Sediment Dynamics Experiment
Time-series data of water surface elevation, waves, currents, temperature, and salinity collected between 17 May 2017 and 17 Jan 2018 off the southwest coast of Puerto Rico in support of a study on circulation and sediment transport dynamics over coral reefs. The data are available in NetCDF format, grouped together in zip files by instrument site location. A README.txt file details the files cont
Filter Total Items: 28
Observations of coastal circulation, waves, and sediment transport along West Maui, Hawaiʻi (November 2017– March 2018), and modeling effects of potential watershed restoration on decreasing sediment loads to adjacent coral reefs
Terrestrial sediment discharging from watersheds off West Maui, Hawaiʻi, has been documented as a primary stressor to local coral reefs, causing coral reef health to decline. The U.S. Geological Survey acquired and analyzed physical oceanographic and sedimentologic field data off the coast of West Maui to calibrate and validate physics-based, numerical hydrodynamic and sediment transport models of
Physicochemical coastal groundwater dynamics between Kauhakō Crater lake and Kalaupapa settlement, Moloka‘i, Hawai‘i
Land-based sources of groundwater pollution can be a critical threat to coral reefs, and a better understanding of “ridge-to-reef” water movement is required to advance management and coral survival in the Anthropocene. In this study a more complete understanding of the geological, atmospheric, and oceanic drivers behind coastal groundwater exchange on the Kalaupapa peninsula, on Moloka‘i, Hawai‘i
The role of pH up-regulation in response to nutrient-enriched, low-pH groundwater discharge
Coral reefs and their ecosystems are threatened by both global stressors, including increasing sea-surface temperatures and ocean acidification (OA), and local stressors such as land-based sources of pollution that can magnify the effects of OA. Corals can physiologically control the chemistry of their internal calcifying fluids (CF) and can thereby regulate their calcification process. Specifical
Characterization of the biological, physical, and chemical properties of a toxic thin layer in a temperate marine system
The distribution of plankton in the ocean is patchy across a wide range of spatial and temporal scales. One type of oceanographic feature that exemplifies this patchiness is a ‘thin layer’. Thin layers are subsurface aggregations of plankton that range in vertical thickness from centimeters to a few meters, which may extend horizontally for kilometers and persist for days. We undertook a field cam
Bomb-produced radiocarbon across the South Pacific Gyre — A new record from American Samoa with utility for fisheries science
Coral skeletal structures can provide a robust record of nuclear bomb produced 14C with valuable insight into air-sea exchange processes and water movement with applications to fisheries science. To expand these records in the South Pacific, a coral core from Tutuila Island, American Samoa was dated with density band counting covering a 59-yr period (1953–2012). Seasonal signals in elemental ratio
Land-based sediment sources and transport to southwest Puerto Rico coral reefs after Hurricane Maria, May 2017 to June 2018
The effects of runoff from land on nearshore ecosystems, including coral reef communities, are influenced by both sediment supply and removal by coastal processes. Integrated studies across the land-sea interface describing sources and transport of terrestrial sediment and its nearshore fate allow reef protection initiatives to target key onshore and offshore areas. Geochemical signatures in the f
Rapid observations of ocean dynamics and stratification along a steep island coast during Hurricane María
Hurricanes are extreme storms that affect coastal communities, but the linkages between hurricane forcing and ocean dynamics remain poorly understood. Here, we present full water column observations at unprecedented resolution from the southwest Puerto Rico insular shelf and slope during Hurricane María, representing a rare set of high-frequency, subsurface, oceanographic observations collected al
Spectral wave-driven bedload transport across a coral reef flat/lagoon complex
Coral reefs are an important source of sediment for reef-lined coasts by helping to maintain beaches while also providing protection in the form of wave energy dissipation. Understanding the mechanisms by which sediment is delivered to the coast as well as better constraining the total volumes generated are critical for projecting future coastal change. A month-long hydrodynamics and sediment tran
Sea‐level rise will drive divergent sediment transport patterns on fore reefs and reef flats, potentially causing erosion on atoll islands
Atoll reef islands primarily consist of unconsolidated sediment, and their ocean‐facing shorelines are maintained by sediment produced and transported across their reefs. Changes in incident waves can alter cross‐shore sediment exchange and, thus, affect the sediment budget and morphology of atoll reef islands. Here we investigate the influence of sea level rise and projected wave climate change o
Internal tides can provide thermal refugia that will buffer some coral reefs from future global warming
Observations show ocean temperatures are rising due to climate change, resulting in a fivefold increase in the incidence of regional-scale coral bleaching events since the 1980s; analyses based on global climate models forecast bleaching will become an annual event for most of the world’s coral reefs within 30–50 yr. Internal waves at tidal frequencies can regularly flush reefs with cooler waters,
In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
The character and energetics of infragravity (IG, 25 s < period < 250 s) and very-low frequency (VLF, period > 250 s) waves over coral reef flats can enhance shoreline erosion or accretion, and also govern extreme shoreline events such as runup, overwash, and flooding on coral reef-lined coasts. Here we use in situ wave measurements collected along cross-reef transects at 7 sites on Pacific island
Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi
Pervasive and sustained coral diseases contribute to the systemic degradation of reef ecosystems, however, to date an understanding of the physicochemical controls on a coral disease event is still largely lacking. Water circulation and residence times and submarine groundwater discharge all determine the degree to which reef organisms are exposed to the variable chemistry of overlying waters; und
Science and Products
- Data
Time-series data of water surface elevation, waves, currents, temperature, and turbidity collected between November 2017 and March 2018 off the west coast of Maui, Hawaii, USA
Time-series data of water surface elevation, waves, currents, temperature, and turbidity collected between November 2017 and March 2018 off the west coast of Maui, Hawaii, USA. The data are available in NetCDF format, grouped together in zip files by instrument site location. These data support a modeling study on the effects of potential watershed restoration on decreasing sediment loads to adjacCross-reef wave and water level data from coral reef environments
Coral reefs provide important protection for tropical coastlines against the impact of large waves and storm damage by energy dissipation through wave breaking and bottom friction. However, climate change and sea level rise have led to growing concern for how the hydrodynamics across these reefs will evolve and whether these changes will leave tropical coastlines more vulnerable to large wave evenJurabi, Exmouth, Western Australia, 2016 Coral Reef Circulation and Sediment Dynamics Experiment
Carbonate reefs are a major source of sediment for coastlines in much of the tropical regions of the world, contributing to significant shoreline accretion and beach nourishment. A collaborative experiment between the U.S. Geological Survey and the University of Western Australia was conducted on Ningaloo Reef, northwest Australia, to investigate this problem and determine the primary oceanographiModeled effects of depth and semidiurnal temperature fluctuations on predictions of year that coral reef locations reach annual severe bleaching for various global climate model projections
Using global climate model projections of sea-surface temperature at coral reef sites, we modeled the effects of depth and exposure to semidiurnal temperature fluctuations to examine how these effects may alter the projected year of annual severe bleaching for coral reef sites globally. Here we present the first global maps of the effects these processes have on bleaching projections for three IPCWaiakane, Molokai, HI, 2018 Coral Reef Circulation and Sediment Dynamics Experiment
Coral reefs generate significant volumes of carbonate sediment that becomes the primary source of beach material along many low-latitude shorelines that protect hundreds of millions of people globally. Despite this fact, there is little understanding of the specific processes that transport the carbonate sediment produced on the outer portions of coral reefs to the shoreline, let alone how those pObservations of coral reef oceanographic and groundwater properties off Makua, Kauai, HI, USA, August 2016
Pervasive and sustained coral diseases contribute to the systemic degradation of reef ecosystems, however, an understanding of the physicochemical controls on a coral disease event is still largely lacking. Water circulation and residence times and submarine groundwater discharge all determine the degree to which reef organisms are exposed to the variable chemistry of overlying waters; understandiTime series data of oceanographic conditions from La Parguera, Puerto Rico, 2017-2018 Coral Reef Circulation and Sediment Dynamics Experiment
Time-series data of water surface elevation, waves, currents, temperature, and salinity collected between 17 May 2017 and 17 Jan 2018 off the southwest coast of Puerto Rico in support of a study on circulation and sediment transport dynamics over coral reefs. The data are available in NetCDF format, grouped together in zip files by instrument site location. A README.txt file details the files cont - Publications
Filter Total Items: 28
Observations of coastal circulation, waves, and sediment transport along West Maui, Hawaiʻi (November 2017– March 2018), and modeling effects of potential watershed restoration on decreasing sediment loads to adjacent coral reefs
Terrestrial sediment discharging from watersheds off West Maui, Hawaiʻi, has been documented as a primary stressor to local coral reefs, causing coral reef health to decline. The U.S. Geological Survey acquired and analyzed physical oceanographic and sedimentologic field data off the coast of West Maui to calibrate and validate physics-based, numerical hydrodynamic and sediment transport models ofPhysicochemical coastal groundwater dynamics between Kauhakō Crater lake and Kalaupapa settlement, Moloka‘i, Hawai‘i
Land-based sources of groundwater pollution can be a critical threat to coral reefs, and a better understanding of “ridge-to-reef” water movement is required to advance management and coral survival in the Anthropocene. In this study a more complete understanding of the geological, atmospheric, and oceanic drivers behind coastal groundwater exchange on the Kalaupapa peninsula, on Moloka‘i, Hawai‘iThe role of pH up-regulation in response to nutrient-enriched, low-pH groundwater discharge
Coral reefs and their ecosystems are threatened by both global stressors, including increasing sea-surface temperatures and ocean acidification (OA), and local stressors such as land-based sources of pollution that can magnify the effects of OA. Corals can physiologically control the chemistry of their internal calcifying fluids (CF) and can thereby regulate their calcification process. SpecificalCharacterization of the biological, physical, and chemical properties of a toxic thin layer in a temperate marine system
The distribution of plankton in the ocean is patchy across a wide range of spatial and temporal scales. One type of oceanographic feature that exemplifies this patchiness is a ‘thin layer’. Thin layers are subsurface aggregations of plankton that range in vertical thickness from centimeters to a few meters, which may extend horizontally for kilometers and persist for days. We undertook a field camBomb-produced radiocarbon across the South Pacific Gyre — A new record from American Samoa with utility for fisheries science
Coral skeletal structures can provide a robust record of nuclear bomb produced 14C with valuable insight into air-sea exchange processes and water movement with applications to fisheries science. To expand these records in the South Pacific, a coral core from Tutuila Island, American Samoa was dated with density band counting covering a 59-yr period (1953–2012). Seasonal signals in elemental ratioLand-based sediment sources and transport to southwest Puerto Rico coral reefs after Hurricane Maria, May 2017 to June 2018
The effects of runoff from land on nearshore ecosystems, including coral reef communities, are influenced by both sediment supply and removal by coastal processes. Integrated studies across the land-sea interface describing sources and transport of terrestrial sediment and its nearshore fate allow reef protection initiatives to target key onshore and offshore areas. Geochemical signatures in the fRapid observations of ocean dynamics and stratification along a steep island coast during Hurricane María
Hurricanes are extreme storms that affect coastal communities, but the linkages between hurricane forcing and ocean dynamics remain poorly understood. Here, we present full water column observations at unprecedented resolution from the southwest Puerto Rico insular shelf and slope during Hurricane María, representing a rare set of high-frequency, subsurface, oceanographic observations collected al
Spectral wave-driven bedload transport across a coral reef flat/lagoon complex
Coral reefs are an important source of sediment for reef-lined coasts by helping to maintain beaches while also providing protection in the form of wave energy dissipation. Understanding the mechanisms by which sediment is delivered to the coast as well as better constraining the total volumes generated are critical for projecting future coastal change. A month-long hydrodynamics and sediment tranSea‐level rise will drive divergent sediment transport patterns on fore reefs and reef flats, potentially causing erosion on atoll islands
Atoll reef islands primarily consist of unconsolidated sediment, and their ocean‐facing shorelines are maintained by sediment produced and transported across their reefs. Changes in incident waves can alter cross‐shore sediment exchange and, thus, affect the sediment budget and morphology of atoll reef islands. Here we investigate the influence of sea level rise and projected wave climate change oInternal tides can provide thermal refugia that will buffer some coral reefs from future global warming
Observations show ocean temperatures are rising due to climate change, resulting in a fivefold increase in the incidence of regional-scale coral bleaching events since the 1980s; analyses based on global climate models forecast bleaching will become an annual event for most of the world’s coral reefs within 30–50 yr. Internal waves at tidal frequencies can regularly flush reefs with cooler waters,In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
The character and energetics of infragravity (IG, 25 s < period < 250 s) and very-low frequency (VLF, period > 250 s) waves over coral reef flats can enhance shoreline erosion or accretion, and also govern extreme shoreline events such as runup, overwash, and flooding on coral reef-lined coasts. Here we use in situ wave measurements collected along cross-reef transects at 7 sites on Pacific islandPhysicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi
Pervasive and sustained coral diseases contribute to the systemic degradation of reef ecosystems, however, to date an understanding of the physicochemical controls on a coral disease event is still largely lacking. Water circulation and residence times and submarine groundwater discharge all determine the degree to which reef organisms are exposed to the variable chemistry of overlying waters; und - News