MODIS/Terra CGF Snow Cover Daily L3 Global 500m SIN Grid, Version 61
Data set id:
MOD10A1F
DOI: 10.5067/MODIS/MOD10A1F.061
This is the most recent version of these data.
Version Summary
Version Summary
Initial release
Overview
This global Level-3 data set (MOD10A1F) provides daily cloud-free snow cover derived from the MODIS/Terra Snow Cover Daily L3 Global 500m SIN Grid data set (MOD10A1). Grid cells in MOD10A1 which are obscured by cloud cover are filled by retaining clear-sky views of the surface from previous days. A separate parameter is provided which tracks the number of days in each cell since the last clear-sky observation. Each data granule contains a 10° x 10° tile projected to the 500 m sinusoidal grid.
The terms "Version 61" and "Collection 6.1" are used interchangeably in reference to this release of MODIS data.
Parameter(s):
SNOW COVER
Platform(s):
Terra
Sensor(s):
MODIS
Data Format(s):
HDF-EOS2
Temporal Coverage:
- 24 February 2000 to present
Temporal Resolution:
- 1 day
Spatial Resolution:
- 500 m
- 500 m
Spatial Reference System(s):
Not Specified
Spatial Coverage:
- Northern latitude90Southern latitude-90Eastern longitude180Western longitude-180
Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.
Strengths and Limitations
Strengths
- Daily cloud-gap-filled (CGF) snow-cover maps provide excellent cloud-free representations of extent of snow cover at 500-m resolution for a given day (Hall et al., 2019; Riggs and Hall, 2020).
- MODIS daily snow-cover record begins on February 24, 2000, representing more than two decades of moderate-resolution (500 m) snow-cover maps (Hall et al., 2019).
- The daily MODIS snow-cover record is useful to assess regional snow cover and trends (Riggs and Hall, 2020).
- MODIS snow-cover products provide Normalized Difference Snow Index (NDSI) values from 0 – 100. The NDSI value can be converted to binary snow cover or it can be descaled and converted to fractional snow cover (Salomonson and Appel, 2004; Riggs et al., 2019).
- Daily CGF snow-cover maps include polar darkness and other features (Riggs et al., 2019).
- This product is superior to MOD10A2 because a user can select a unique compositing period and is not restricted to 8-day composites; each day is a cloud-free representation of the snow conditions on that day, subject to the limitations, below.
Limitations
- The biggest limitation to the use of the CGF MODIS snow-cover products is cloud cover, which can prevent mapping of some snow (Hall and Riggs, 2007).
- If a pixel is “cloudy,” according to the cloud mask, then the CGF algorithm uses the snow-mapping result from the last clear day, thus snow cover may not be mapped if a snowfall occurred and the resulting snow on the ground melted before the clouds cleared (Riggs et al., 2019).
- Polar darkness prevents snow-cover mapping in polar regions during the winter (Riggs et al., 2019).
- Areas of ephemeral snow cover and very thin snow cover may not be mapped by MODIS (Hall et al., 2010).
Data Access & Tools
A free NASA Earthdata Login account is required to access these data. Learn More
Documentation
User Guide
General Resources
Quality Assessment Reports
Help Articles
General Questions & FAQs
This article covers frequently asked questions about the NASA NSIDC DAAC's Earthdata cloud migration project and what it means to data users.