SASSIE: Arctic Ocean Salinity and Temperature Profiles from ALTO/ALAMO Floats

NASA's SASSIE field campaign deployed two types of profiling floats with different ice-avoidance behaviors to capture the transition from summer melt to autumn ice advance in the Beaufort Sea. ALTO floats halted transmissions at near-freezing surface temperatures to survive winter, while ALAMO floats continued reporting during freeze-up at the likely cost of their survival. This dataset provides in situ temperature and salinity measurements from August-October 2022 within approximately 200 kilometers of the sea ice edge.

Use Cases

• Modeling sea-ice growth dynamics based on observed salinity anomalies and stratification.
• Analyzing the seasonal transition from open water to ice-covered ocean using time-series profiles.
• Comparing the performance and data recovery of ice-avoidance (ALTO) versus non-avoidance (ALAMO) float firmware.
• Validating remote sensing observations of sea surface temperature and salinity near the ice edge.

Strengths

• Data captures a specific, critical seasonal transition period (August-October 2022).
• Deployment of two float types with contrasting strategies provides a controlled observational experiment.
• Observations are spatially focused within ~200 km of the Beaufort Sea ice edge.

Limitations

• Key metadata (row count, file size, specific columns) is unavailable across all sources.
• Conflicting 'last updated' dates (2022-10 15 vs. 2026-04-09) create uncertainty about dataset versioning.
• Data coverage for the ice-covered winter season is speculative, dependent on float survival and future transmissions.

Provenance

Source

NASA SASSIE project field campaign.

Collection Method

In situ measurements from ALTO and ALAMO profiling floats deployed in the Beaufort Sea.

Time Range

August-October 2022.

Freshness

Last updated dates conflict: 2022-10-15 and 2026-04-09.

Geography

Beaufort Sea, within ~200 km of the sea ice edge.