We are primarily a sea-going research laboratory with many active field programs in the coastal marine and open ocean environments. Our research interests are broad and multi-disciplinary:
- –bubble mediated gas flux at high to extreme wind speeds. Significant quantities of gases are exchanged between the atmosphere and ocean during storms, even through storms are relatively infrequent. We know this because measured air-sea gas transfer rates are often found to be non-linear (quadratic or cubic) functions of wind speed. However, there is also unexplained scatter between results of different experiments, even those conducted using the same techniques! Unexplained scatter between experiments results in significant uncertainty in global air-sea flux estimates for individual gases, like CO2 and O2. We measure gas fluxes in storms and were part of a team that measured for the first time gas fluxes in hurricanes. We are actively investigating the effects of wind and waves on gas fluxes and hope to develop improved parameterizations of bubble mediated air-sea gas exchange. Improved parameterizations will be used to better constrain global CO2 and O2 cycles.
- –dissolved gas cycling and the potential impacts of ocean warming on biogeochemistry. Rising atmospheric CO2 levels and ocean warming represent significant concerns for ocean health and biogeochemistry via altered pH and dissolved O2 concentrations. The Arctic Ocean is particularly susceptible to pH changes. We recently measured for the first time the annual cycle of pCO2 in the seasonally ice covered Beaufort Sea. Eastern basin Oxygen Minimum Zones (OMZs) are regions of the oceans that are potentially susceptible to altered global wind and warming patterns. OMZs are also important since they remove nutrients from the world oceans via denitrification processes. We are conducting cruises and deploying gas sensing floats in these regions to better understand how organic carbon export from productive near surface eddies can stimulate the microbial community that lives in the deeper anoxic waters to remove more nutrients from the water column.
- –river and estuarine processes and their effects on suspended sediment distributions. Suspended sediments in rivers and estuaries continuously transport eroded materials from the land to the ocean and in doing so locally impact water quality. We study the mechanisms and processes by which sediments (and bubbles) are suspended, concentrated, and redistributed within rivers and estuaries, and ultimately transported out the mouth of the estuary to the adjacent sea. Suspended sediments, bubbles, and actively mixing brackish waters composed of inhomogeneous mixtures of fresh and saltwater show significantly altered optical and acoustical backscatter relative to the surrounding waters. We use this this to our advantage to help find and locate estuarine features such as fronts, internal hydraulic jumps, breaking internal waves, and the salt-wedge intrusion, via their locally anomalous optical and acoustical backscatter then study the dynamics of these features in greater detail to better understand the sediment transport mechanisms. We make in situ measurements of optical and acoustical backscatter on REMUS 100 AUVs and are implementing onboard adaptive sampling strategies so the vehicles will target the features of interest to improve the quality and quantity of data collection in interesting features during the typically 8 hr missions.