The transfer of momentum, heat, and gas across the air-sea boundary is characterized and quantified by measuring the underlying physical mechanisms with remote sensing instruments.

The Ionian Sea Rainfall Experiment will attempt to link radar, rain gauge, and underwater ambient sound measurements of rain to show that such measurements will improve our ability to understand satellite measurements of rainfall over the oceans.

Chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF₆) are tracers that enter the ocean surface mixed layer through air–sea gas exchange and are then transported into the ocean interior. Because of their long time-scale evolution, these tracers are used to estimate ocean interior ventilation time scales (ages) as well as anthropogenic carbon uptake by the ocean.

A set of models to predict how changes in sources and environmental conditions will affect surface water concentrations of volatile organic compounds are being developed to aid regulatory decision makers.

AUVs will be deployed by a newly formed APL-UW AUV group as part of CMOP's experimental observation network which consists of multiple fixed and mobile platforms equipped with oceanographic sensors.

The experiment is a four-year collaborative project that couples state-of-the-art remote sensing and in situ measurements with advanced numerical modeling to characterize coherent structures in river and estuarine flows.

Remote sensing instruments can characterize the physical flow parameters of rivers and estuaries, ultimately determining the navigability of the waters.

APL-UW experts in autonomous undersea vehicle operation mapped the September 2012 outbreak of the non-toxic phytoplankton Mesodinium rubrum. This study of Columbia River ecology is conducted in collaboration with the Coastal Margin Observation and Prediction (CMOP) Science and Technology Center.

Investigators completed a series of experiments in April 2013 at the mouth of the Columbia River, where they collected data using drifting and airborne platforms. DARLA's remote sensing data will be used to drive representations of the wave, circulation, and bathymetry fields in complex near-shore environments.

Researchers at the University of Washington and Oregon State University are developing mobile instrumentation and methods for cost-effective environmental and performance monitoring of tidal in-stream energy conversion devices.

We have operated our coherent, X-band radar, RiverRad, at the Corps of Engineers Field Research Facility in Duck, NC in order to compare our measured return with that obtained by Merrick Haller of Oregon State University using a non-coherent, X-band, marine radar and with video images obtained by Rob Holman of the same institution. OSU graduate student Patricio Catalan is coordinating this comparison.

Doctoral student researcher Chris Bassett is analyzing a long time series of ambient noise data from Puget Sound. Vessel traffic is the most significant noise source, but breaking waves, precipitation, biology, and sediment moving on the seabed are other common underwater noise sources. The research is being pursued in conjunction with a program to assess the environmental impacts from a tidal energy conversion system placed on the seafloor.

Under an ONR-sponsored Department Research Initiative researchers are studying thermal signatures of inter-tidal sediments. The goal is to understand how sediment properties feedback on morphology and circulation, and the extent to which such properties can be sensed remotely.

Researchers are conducting an extensive survey of the oceanographic properties of a proposed tidal energy site in Puget Sound to inform the safety and effectiveness of power-generating turbines.

Estimates of the transport and divergence of carbon, oxygen, and nutrients in the Atlantic Ocean are based on two approaches: a multi-box inverse model based on WOCE/JGOFS data, and tracer data sets from the same period.

Part of the heat transported poleward from the tropics by the ocean is stored near the energetic western boundary currents. These storage reservoirs provide a source of interannual-to-decadal climate fluctuations through their impact on the ocean-to-atmosphere heat fluxes.

Interannual-to-decadal variations in the poleward transport of heat in the North Atlantic are a candidate mechanism for inducing climate variations. Heat from the tropical ocean is carried rapidly northward by western boundary currents to the mid-latitudes. Much of the upper ocean's heat is lost to the atmosphere here.

This research seeks to evaluate the accuracy of scatterometer winds, mapped wind fields, and wind products derived from the maps, and to evaluate ocean simulations forced by the winds and by flux fields derived from the winds.

A numerical model and observations of sea surface height from the TOPEX/Poseidon radar altimeter and sea surface temperature is used to examine ocean dynamics and thermodynamics along the boundaries of the subtropical gyre in the North Pacific.

An integrated program of observations and numerical simulations will focus on understanding ice–ocean–atmosphere dynamics in and around the MIZ, with particular emphasis on quantifying changes associated with decreasing ice cover. The MIZ measurement program will employ a novel mix of autonomous technologies (ice-based instrumentation, floats, drifters, and gliders) to characterize the processes that govern Beaufort Sea MIZ evolution from initial breakup and MIZ formation though the course of the summertime sea ice retreat.

Mixed Layer Boundary Conditions of Chlorofluorocarbons in the North Pacific

A series of model experiments with the Hallberg Isopycnal Model (HIM) are used to investigate the mixed layer boundary conditions of CFCs in the North Pacific Ocean and the the implications of possible winter-time undersaturations on the interpretation of CFC-derived age distributions and anthropogenic carbon estimates in the ocean interior.

The objectives of the NPAL program are to understand the basic physics of low-frequency, long-range, broadband propagation, the effects of environmental variability on signal stability and coherence, and the fundamental limits to signal processing at long-range imposed by ocean processes.

In the North Atlantic and Arctic oceans observations by sensors on orbiting satellites are giving oceanographers insight to ocean processes on vast spatial and temporal scales.

Repeat Hydrography

The U.S. CLIVAR/CO2 Repeat Hydrography Program began in 2003 with the goal of repeating, on decadal time scales, several of the long line WOCE sections conducted in the 1990s. Data are used to investigate climate variability base don oxygen measurements and carbon distributions.

This ONR Departmental Research Initiative is in response to the observed decline in Arctic sea ice extent. The U.S. Navy has a renewed interest in understanding and predicting the environment in this region, including a desire to forecast the presence or absence of sea ice at a variety of lead times.

We are developing techniques for the long-term monitoring of surface velocity at the mouth of the Columbia River with microwave Doppler radars.

We will evaluate the use of the Gas Tension Device (GTD) to detect denitrification signatures in conjunction with high precision mass-spectrometry dissolved gas measurements.

A technical component of our hurricane project is the continued improvement of dissolved gas sensors for use on the APL mixed layer float (see Eric D%u2019Asaro%u2019s website at APL-UW).

The need for tighter airport security fuels demand for faster, more accurate detection of trace-level explosives. APL-UW is working for the first time with the Director of National Intelligence and the FBI on a promising advanced detection method employing laser beams.

The satellite Aquarius measures sea surface salinity across the global ocean. Using a towed surfboard instrument, APL-UW scientists are collecting salinity data at depth to calibrate the satellite measurements that may be corrupted by freshwater lenses formed on the sea surface during heavy rainfall.

There is a growing consensus that sea surface temperature (SST) products derived from satellite-based infrared (IR) sensors should include ocean skin temperature. To validate satellite-based measurements of skin temperature, widespread, in situ data are required.

The most promising method to monitor the generation of internal waves in the region of the Luzon Strait between the two ridges routinely is remote sensing. The limitations of visible sensors make microwave sensors a very attractive means of routinely monitoring internal wave generation.

Measuring phase-resolved waves around a ship is APL-UW's involvement in this four-part project by demonstrating wave height retrievals from both cross sections and Doppler shifts along a line.

A research cruise was conducted in October 2012 to find stormy conditions and heavy seas far out in the Pacific Ocean. The objectives were to measure, with remote sensing technologies, the intense winds, large waves, and the turbulence generated by wave breaking. Understanding the balance of energy going into and breaking out of waves will be used to improve open ocean wave forecasts.

Waves are generated by wind blowing across the ocean and dissipated by breaking, either as whitecaps or surf. This research aims to understand the breaking process and the resulting turbulence, especially in wave fields that are a mix of wind waves and swell. Measurements from APL-UW SWIFT instruments quantify the turbulence and the wave motions. Additional video measurements quantify the size distribution of the breakers. Applications include improved wave forecasting and parameterization of gas exchange.

The energy dissipation of breaking waves is quantified using simultaneous remote and in situ measurements.