I am working on the relationship between climate extremes and conflict from 2010 to 2020 and I was wondering what is the correct way to standardize the following variables :
- The Warm Spell Duration Index where percentile (90) for the threshold is calculated over a reference period from 1960 to 2009 using daily maximum temperature.
- The Cold Spell Duration Index where percentile (10) for the threshold is calculated over a reference period from 1960 to 2009 using daily minimum temperature.
Their standardization should account for the variability specific to each of my observational units. I thought of using the same reference period (1960 -> 2009) to calculate the mean and standard deviation but I am not sure if this is correct since the reference period is already used in the calculation of percentiles. The question may seem strange but I can't decide on the methodology... I hope someone can help me and I thank you for reading !
