README file for the Daymet CONUS+ VPD Product and associated data production and visualization codes.

Updated 10 Jan 2025
Nick Corak

--DIRECTORY CONTENTS--
The resource contents are divided into three subdirectories: VPD_Data, Supplemental_Data, MATLAB
	1) /VPD_Data/ contains the main VPD_S netCDF files and is divided into /IGBP/ and /KG/ subdirectories. 
	2) /Supplemental_Data/ contains site information, correction factors, and netCDF files for climate and land cover, as well as the CONUS+ land mask
	3) /MATLAB/ contains all codes used in the creation of the data and codes for visualizing data (see below).


The HYDROSHARE resource currently contains 61 files
	1) forty-nine NetCDF files
	2) three .csv files
	3) nine MATLAB files


--NETCDF--
There are 49 NetCDF files in the current resource. 
	1 Land Mask File
	1 Koppen-Geiger (KG) climate file
	1 MODIS International Geophere-Biosphere Programme (IGBP) land cover for 2001-2023
	23 VPD_S by KG from 2001-2023
	23 VPD_S by IGBP from 2001-2023

All NetCDF files are on the trimmed Daymet CONUS+ grid [25 50] degrees latitude and [-125 -67] degree longitude.

VPD_S files are in units of Pa and are stored as 16-bit unsiged integers. They will need to be converted using 10^-3 scale factors to change units to kPa. Supplied data extraction codes have this built-in (see MATLAB section below).

*special note*
Daymet data is only 365 days so leap years do not include Dec 31. VPD_S follows the same convention.


--CSV--
There are two .csv files that contain the correction factors used to developed the scaled VPD product and correspond to tables found in the accompanying manuscript. 

VPD_CONUSPlus_siteinfo.csv contains a list of the AmeriFlux sites from the US, Mexico, and Canada used in this study along with the corresponding:
	1) latitutde
	2) longitude
	3) IGBP land cover
	4) Climate
	5) Years of data
	6) Citations of data


--MATLAB--
Accompanying MATLAB scripts for data development include
	1) Daymet_Timeseries_Extraction.m  - Code to export Tmax, Tmin, and VP from Daymet for all AmeriFlux sites
	2) create_VPD_Timeseries_from_Daymet.m  - Code to compute VPD from Tmax, Tmin, and VP for all AmeriFlux sites
	3,4) correction_factors_IGBP.m, correction_factors_KG.m - Codes to develop correction factors by IGBP and KG classifications
	5) Making_Maps_of_Correction_Factors.m  - Code to make maps of correction factors 
	6,7) Make_NETCDF_VPD_S_IGBP.m and Make_NETCDF_VPD_S_KG.m - Codes to make netCDF files for VPD_S by IGBP and KG classifications 

Accompanying MATLAB scripts are include to visualize the data as
	8) Make_Map_Daily_VPD_Scaled_CONUS_plus.m creates a map of VPD for any day of year.
	9) VPD_Scaled_Timeseries.m creates a time series for any given lat/lon pair.