I am investigating the change in NDVI in Iceland from 1990-2020.

I have downloaded MODIS MYD13Q1 V6 data from the earth explorer website for the 1st May - 31st September (the growing season) and inserted each NDVI band into ArcMap. I have used the cell statistics tool to calculate the maximum NDVI of these to get the maximum NDVI of the growing season. I then removed negative values using the raster calculator set null tool and reclassified them into breakpoints of 0.1 from 0-1. My aim is to now make a time series figure to show annual change over my study time period. I would also like to map a single map showing the change in NDVI from 2010-2020 - please could someone advise me on how to do this in ArcMap?

I have also collected mean annual temperature and total annual precipitation data from the Icelandic Meteorological Office as well as annual atmospheric CO2, CH4 and N2O (greenhouse gases) data from the Mauna Loa observatory from the NOAA website.

My aim here is to do some statistical analysis between these climatic factors and NDVI but I do not know how to execute this. For example, I want to see if there is a relationship between temperature and NDVI over time, the same for precipitation and NDVI and the greenhouse gases mentioned and NDVI. Does anyone know of a statistical analysis test that would be appropriate for this and where I would get the values from my NDVI layer in ArcMap to be able to do this.

I am familiar with Rstudio so any recommendations on how to do the statistical analysis in R would be greatly appreciated! (e.g. packages/codes/scripts to use)