Downscaled SIF dataset readme file
2016-06-20 
G. Duveiller


This dataset consists of downscaled values of the GOME-2 sun-induced chlorophyll fluorescence at 740m and 0.5° spatial resolution version 25 as provided by J. Joiner at http://avdc.gsfc.nasa.gov/pub/data/satellite/MetOp/GOME_F/ (see Joiner et al. 2013 for a description of that original product). To obtain this downscaled data, the methodology described in Duveiller & Cescatti (2016) is used. It consists in spatially disaggregating the information contained within each coarse SIF pixels by using a non-linear model based on the concept of light use efficiency (LUE). The strategy involves the aggregation of high-resolution (0.05°) remote sensing biophysical variables (MODIS NDVI, evapotranspiration and land surface temperature) to calibrate the downscaling model locally and independently at each time step, which can then be applied to non-aggregated data to create a new layer, denoted SIF*, with a spatial resolution of 0.05°


Data is organised as a netcdf file per year of global monthly values. The dataset currently runs from 2007 until end of 2013. The dataset is made available for further scientific studies, but must be cited accordingly by mentioning the corresponding paper (Duveiller & Cescatti 2016). It is encouraged to contact the authors and eventually invite them to collaborate, as they have the most detailed knowledge of the data issues and can provide guidance on their use. Questions, feedback and bug reports are welcome and can be addressed to the authors: Gregory Duveiller (gregory.duveiller@ec.europa.eu) and Alessandro Cescatti (alessandro.cescatti@ec.europa.eu).



References:

Duveiller, G. & Cescatti, A. (2016). Spatially downscaling sun-induced chlorophyll fluorescence leads to an improved temporal correlation with gross primary productivity. Remote Sensing of Environment, 182, 72–89. http://doi.org/10.1016/j.rse.2016.04.027

Joiner, J., Guanter, L., Lindstrot, R., Voigt, M., Vasilkov, a. P., Middleton, E. M., … Frankenberg, C. (2013). Global monitoring of terrestrial chlorophyll fluorescence from moderate-spectral-resolution near-infrared satellite measurements: methodology, simulations, and application to GOME-2. Atmospheric Measurement Techniques, 6(10), 2803–2823. http://doi.org/10.5194/amt-6-2803-2013