We will address SASSIE science themes and questions through a multi-scale in situ, airborne, satellite, and modeling experiment. The primary aim of the field campaign is to capture the upper ocean structure during the transition from summer sea ice retreat to autumn sea ice advance. The types of measurements made by each instrument are shown as icons.

SalinityTemperature    Wind, Weather    Air-Sea Flux    Waves, Currents    Ice    Camera   

Ship-based

Vessel

Vessel »

The R/V Woldstad is a 121' steel-hulled ship that can survey to the edge of the marginal ice zone. It is equipped to continuously measure temperature, salinity and upper ocean currents. The vessel has cranes to deploy and recover SASSIE instruments. Its ship-shore communication system can receive satellite maps and imagery for cruise planning.

Underway CTD

Underway CTD

Peter Gaube, Lead

This instrument measures conductivity (i.e., salinity), temperature, and depth (CTD). It is coupled to a sensor that provides data on chlorophyll-a (i.e., indicator of ocean productivity). It will capture the variability in upper ocean layering from near the ice edge to the open ocean, including the depth and horizontal extent of the melt layer.

Salinity Snake

Salinity Snake »

Julian Schanze, Lead

This pumped system samples salinity and temperature in the uppermost 1-2 cm of the ocean, the depth observed by salinity satellites. It will be modified for use in polar environments and make continuous measurements throughout the cruise. The salinity snake will provide a novel way to assess horizontal and vertical salinity gradients.

Air-Sea Flux Sensors

Air-Sea Flux Sensors »

Viviane Menezes and Seth Zippel, Leads

A suite of shipboard atmospheric measurements will calculate air-sea heat and momentum fluxes throughout the cruise. The instruments will measure three-dimensional surface wind speed and direction; barometric pressure, air humidity and temperature; precipitation; and water vapor. Longwave and shortwave radiation will also be measured.

Piloted & Drifting

Wave Glider

Wave Glider »

Jim Thomson, Lead

These wave-powered, autonomous vehicles measure ocean currents and waves. One-meter tall masts measure atmospheric properties and a winch enables temperature and salinity profiles down to 150 m. SASSIE's Wave Gliders will sample from the ice edge to the open ocean, providing data to characterize melt pools and estimate heat and salt budgets.

SWIFT Drifter

SWIFT Drifter »

Jim Thomson, Lead

Drifting, wave-following surface buoys will measure near-surface temperature and salinity, upper ocean velocity and turbulence, wave spectra, and significant wave height. Above the water, they will measure wind, air temperature and pressure, and have onboard cameras. Some drifters will sample freeze-up conditions after the intensive sampling period.

Under Ice Float

Under Ice Float

Andrey Shcherbina, Lead

This autonomous profiling float has been used in numerous experiments and tested in the Arctic. A special version will be built for SASSIE, outfitted with temperature and salinity sensors, an upward-looking ocean current profiler, and high-resolution imaging system and altimeter for ice avoidance. It will remain in the water to sample the early stages of freeze-up.

Surface Velocity Program (with salinity) Drifters

Surface Velocity Program »

Mike Steele, Lead

For SASSIE, ice-strengthened drifters will track ocean surface currents, temperature, and salinity. They will sample every 5 min during the intensive sampling period, then every 30 min once frozen into ice. Data will be used for a mixed layer salinity budget during the summer-autumn transition and for comparison with satellite salinity data.

UpTempO Buoy

UpTempO Buoy »

Mike Steele, Lead

Upper Temperature of the Ocean (UpTempO) buoys are surface drifters specifically designed to measure the upper ocean of the Arctic. They will provide hourly upper ocean temperature and salinity evolution. UpTempO data will be used to understand relationships between surface anomalies and ocean layering throughout the summer-to-autumn transition period.

Ice Mass Balance Buoy

Ice Mass Balance Buoy »

Ted Maksym, Lead

Deployed by ships of opportunity during August 2022, these ice-deployed buoys will have sonars above / below the ice to monitor snow depth and ice thickness. Equipped with strings of temperature sensors, they will also provide surface and basal melt rates for the period before the field campaign and into the end of the melt season.

Jet Surface Salinity Profiler

Jet Surface Salinity Profiler »

Kyla Drushka, Lead

For SASSIE, an instrumented keel will be added to a jet-powered, remotely-operated kayak. It can operate independently of the ship and will be programmed to follow a set of waypoints in order to map out temperature and salinity profiles in the upper meter of the ocean. These data will help ascertain links between satellite data and near-surface layering.

Unmanned Aerial Systems

Unmanned Aerial Systems

Peter Gaube, Lead

Equipped with optical cameras, Unmanned Aerial Systems will be flown by licensed operators onboard ship. Images will be geo-rectified with pixel resolutions of ~1 cm over ~300 by 300 m frames. Images will be used to identify and measure the area of ice floes, provide surface ice drift estimates, and map sea ice edges for field campaign planning.

Airborne, Satellite & Modelling

Salinity Satellites

Salinity Satellites »

Sea surface salinity will be retrieved by the Soil Moisture Active Passive (SMAP) and Soil Moisture Ocean Salinity (SMOS) satellites. Data from the following sources will be employed: SMAP Remote Sensing Systems; SMAP Jet Propulsion Laboratory; SMOS LOCEAN; and SMOS Barcelona Expert Center. Satellite retrievals will be compared to data from several types of SASSIE sensors.

Airborne & Passive Active L- and S-band Sensor (PALS)

Airborne & PALS Sensor »

Ian Fenty and Sidharth Misra, Leads

Sea surface salinity measurements will be made with an airborne PALS microwave radiometer. A compact wideband radiometer will sense sea surface temperature and ocean wind speed. Aircraft data will give broad-scale context, enabling the quantification of sea surface salinity and temperature, their horizontal gradients, and sea ice signals.

Model Analysis

Model Analysis »

Ian Fenty, Lead

Three nested models will be derived from the Estimating the Circulation and Climate of the Ocean (ECCO) consortium's global ocean and sea ice state estimate. ECCO solutions are constrained by decades of satellite and in situ ocean and sea ice data. Modeling will be used for SASSIE's planning, hypothesis testing, and sensitivity experiments.