Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

ABoVE: Passive Microwave-derived Annual Snowpack Main Melt Onset Date Maps, 1988-2023

Metadata Updated: September 19, 2025

This dataset provides the annual date of snowpack seasonal beginning melt (i.e., main melt onset date, MMOD) across northwest Canada, Alaska, US, and parts of far eastern Russia at 6.25-km resolution for the period 1988-2023. MMOD was derived from the daily 19V (K-band) and 37V (Ka-band) GHz bands from the Making Earth Science Data Records for Use in Research Environments (MEaSUREs) Calibrated Enhanced-Resolution Passive Microwave (PMW) EASE-Grid Brightness Temperature (Tb) Earth System Data Record (ESDR). The PMW MMOD dataset was validated using the transition date from Freeze Degree Days (FDD) to Thaw Degree Days (TDD) from in situ air temperature observations from 31 SNOw TELemetry network (SNOTEL) stations, and compared to an established Freeze-Thaw ESDR (FT-ESDR) spring onset date record. The resulting MMOD data record is suitable for documenting the spatial-temporal impacts of MMOD variability in ecosystem services, wildlife movements, and hydrologic processes within the ABoVE (Arctic Boreal Vulnerability Experiment) domain. The data from 1988-2016 included a coastal mask removing coastal pixels due to potential water contamination from coarse brightness temperature observations (Dersken et al., 2012). No coastal mask is used for the 2017-2023 data. The full data are included, and data users should be aware that values adjacent to large water bodies can be adversely affected.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025
Publisher ORNL_DAAC
Maintainer
Identifier 10.3334/ORNLDAAC/1841
Data Last Modified 2025-09-10
Category Earth Science
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 8f34b99b-d423-4cf9-8497-4f2947dbe505
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://search.earthdata.nasa.gov/search?q=Main_Melt_Onset_Dates_1841&ac=true
Old Spatial {"WestBoundingCoordinate":-180.0,"NorthBoundingCoordinate":72.4085,"EastBoundingCoordinate":-107.83,"SouthBoundingCoordinate":51.6089},"CARTESIAN"
Program Code 026:000
Source Datajson Identifier True
Source Hash 92e848744787ada73aada85aa06fb90bd21d4083f25f45945af92648a3f7088c
Source Schema Version 1.1
Spatial
Temporal 1988-02-09/1988-02-09

Didn't find what you're looking for? Suggest a dataset here.