This is a set of images produced by Temporal Fourier Analysis (TFA) of Modis minimum Relative humidity data:

Modis: Minimum Relative Humidity

The imagery summarises some key environmental indicators, incorporating seasonal dynamics, for The European and North African extent.
This series of Modis  data, processed according to Scharlemann et al (2008), has been updated to include imagery for 2015.

Process:

Image values were extracted from MODIS( Min Relative Humidity) 5 km imagery for 2015.  Each parameter extract dataset was then processed by a temporal Fourier processing algorithm. A stepwise system of thresholds and interpolations screened erroneous values and bridged gaps in the time series. The smoothed series was sampled at 5-day intervals and transformed into a set of sine curves describing annual, bi-annual, and tri-annual fluctuations. For each of these curves, the Fourier algorithm generated images expressing the amplitude, phase, and variance. Other output recorded the mean, minimum, and maximum of the time series, and error measured during the Fourier transform. For a detailed description of the Fourier algorithm and its output, please see the article by Scharlemann et al., 2008 (https://doi.org/10.1371/journal.pone.0001408)  
Sea pixels were masked with a VIIRS land/sea layer and the images were projected from sinusoidal to geographic (WGS84). The E4Warning study region was a subset of global images. Idrisi rasters were converted to GeoTIFF format in order to give data users more flexibility.

This new RH Modis Dataset is used as an update and continuation of our MODIS TFA product and can be utilised in the same way. 

Projection + EPSG code:
Latitude-Longitude/WGS84 (EPSG: 4326)

File names:

The last two characters of each file name denote the output from Fourier processing:
a0 - mean
mn - minimum
mx - maximum
a1 - amplitude of annual cycle
a2 - amplitude of bi-annual cycle
a3 - amplitude of tri-annual cycle
p1 - phase of annual cycle
p2 - phase of bi-annual cycle
p3 - phase of tri-annual cycle
d1 - variance in annual cycle
d2 - variance in bi-annual cycle
d3 - variance in tri-annual cycle
da - combined variance in annual, bi-annual, and tri-annual cycles
vr - variance in raw data

Parameter Fourier Variable Image values are
ERA5  A0, A1, A2, A3, Min, Max, Vr Reflectance values  monthly total precipitation in mm
ALL D1,D2,D3,Da Percentages
ALL E1,E2,E3 Percentages
ALL P1,P2.P3 Months*100. (Jan=100)