What is the difference between the GC_Current and WF2025 options?
Development of NESDIS vegetation health products (VHPs)
from the JPSS / VIIRS instruments requires a global land/water
mask and a VHP climatology database. This database gives long
term averages and maximum and minimum values of NDVI and thermal
channel brightness temperatures (TBs).
The current operational VHPs and climatology database are
based on a land/water mask that was in turn derived from an
old data set called “GlobalCover” compiled before 2010. A new
global land Water Surface Fraction (WF) dataset with 250m
spatial resolution was generated from the newer VIIRS, MODIS,
and other satellite observations in 2025 by the JPSS VIIRS
Surface Type team. To account for recent year changes of
ocean and lake coastlines and larger rivers, the VHP team
derived a new land/water mask from the WF data set (called
WF2025) and updated the VHP climatology database based on
the new WF2025 land/water mask.
The current operational VHPs
is temporarily called GC_Current while the experimental VHPs
are listed as WF2025. Both versions are provided for many
cases of the Province Weekly Mean plots although their
differences may be minimal per our assessment.
AdminVH Options - User considerations
Options
Land Water Mask
Spatial resolution
Climatology Data time span
Considerations
GC_Current (current operational version)
Uses the "GlobalCover" (GC) dataset.
Between 1km and 16km, depending on product.
1981–2017, generated in 2017.
Current official version with older climatology
WF2025 (experimental version)
Uses University of Maryland's VIIRS-AST Water Surface Fraction (WSF) data with a 50% threshold
250m spatial resolution
Spans 1981–2025 and includes newer VIIRS data (2017 -- mid-2025).
Longer and newer climatology timespan, more realistic water fraction values
