questions about green vegetation fraction dataset used in WPS

jessie_zhx

New member
Hi

I am trying to understand the green vegetation fraction (gvf) dataset used in WPS. I have searched through the forum and found a few posts related to it. I still have a few questions and mostly hope to get some clarification.
1) It seems that the older dataset in the folder /greenfrac is derived using the NDVI dataset from AVHRR, is my understanding correct? For the newer datasets in folders such as /freenfrac_fpar_modis, are MODIS FPAR data directly used as green vegetation fraction in WPS or some sort of conversion is done to related FPAR to gvf? Also, do you know the year of the MODIS fpar dataset?
2) What is the year for LAI dataset in folders /lai_modis_10m(30s). I have seen a post that describes the year the of the land cover type used, but I have seen anything related to LAI and gvf yet.

Thank you so much for the help!
Jessie
 

Ming Chen

Moderator
Staff member
Jessie,
The Noah LSM page identifies the sources of data that they use. For future reference, here is a link to the Noah page: Land Atmosphere Interactions | Research Applications Laboratory

To the best of our knowledge, greenfrac is probably derived from the USGS GLCC data for the period 1992-1993.
greenfrac_fpar is based on MODIS data for the period in early 2000s. Please see the following documents and hope you can find more details.

(1) Broxton, P. D., Zeng, X., Sulla-Menashe, D., & Troch, P. A. (2014). A global land cover climatology using MODIS data. Journal of Applied Meteorology and Climatology, 53(6), 1593-1605. DOI: 10.1175/JAMC-D-13-0270.1
and
(2) ftp://ftp.emc.ncep.noaa.gov/mmb/gcp/ldas/noahlsm/README
 
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