Annual Snowoff Date Maps for Alaska and Arctic Regions, 1988-2023

Passive Microwave-derived Annual Snowoff Date Maps, 1988-2023 provides a 36-year record of the last day of persistent snow across Alaska, Far East Russia, and northwest Canada at a 6.25 km resolution. The dataset was created by ORNL_CLOUD using calibrated passive microwave brightness temperature data and validated against SNOTEL station measurements and other satellite-derived snowoff products. Its spatial domain was designed to match and extend the temporal coverage of MODIS Alaska Snow Metrics.

Use Cases

• Analyzing long-term trends in snowmelt timing across Alaska using annual snowoff date maps.
• Validating regional climate models by comparing simulated snow duration with passive microwave-derived observations.
• Assessing hydrological impacts of changing snowmelt patterns on water resources in northwest Canada.
• Cross-comparing snowoff dates from passive microwave data with estimates from MODIS, Landsat, or IMS systems.

Strengths

• Covers a 36-year temporal range from 1988 to 2023, enabling analysis of long-term trends.
• Validation was performed against in-situ SNOTEL station snow depth data and three independent satellite-derived snowoff datasets.
• Data includes a coastal mask for 1988-2016 to mitigate potential water contamination in brightness temperature observations.

Limitations

• Specific column names, row counts, and dataset size are not provided by any source.
• There is a conflict in the reported last updated date: one source states 2026-03-12, while another states 2023-12 31.
• The coastal mask was only applied to data from 1988-2016, potentially creating an inconsistency in coastal pixel treatment post-2016.

Provenance

Source

ORNL_CLOUD

Collection Method

Derived from the MEaSUREs Calibrated Enhanced-Resolution Passive Microwave (PMW) EASE-Grid Brightness Temperature Earth System Data Record.

Time Range

1988-2023

Freshness

2026-03-12 22:53:34.621929

Geography

Alaska, parts of Far East Russia, and northwest Canada.