Re: [ferret_users] regridding of time axis

[saurabh rathore <rohitsrb2020@xxxxxxxxx>]

Hi Steffie,

here is the procedure to do annual values for the seasonal averages of that years. I have used monthly data for my study.

use file.nc

sh da

let temp1=variable

use climatological_axes
cancel data climatological_axes
let temp_cli=temp1[gt=month_`temp1,return=cal`@mod] !<<<<<<<<<<<forurisional file<<<<<<<<<<<<<<<<<<<<!
let temp_anm1=temp1-temp_cli[gt=temp1@asn]
let temp_anm=temp_anm1

let year_months=mod(l[gt=temp_anm],12)

define axis/units=years/edges/t0=15-dec-1978/t=15-jan-1979:15-jan-2016:1/calendar=gregorian t_yearly                 !!! please check your data starts from 15 of every month or 30  or 1 of every month !!!!!

                                                                                                                                                                      !!! because of /edges time axis starts from 1 month back as t0=15-dec-1978 and ends 1 month after as 15-jan-2016

!<<<<<<<<<<<<<<< Masking for fall(SON) <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<!
let mask1 = IF year_months le 11.0 then 1
let mask2 = IF year_months ge 9.0 then 1

!<<<<<<<<<<<<<<<<Masking for spring (MAM)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<!
let mask3 = if year_months ge 3.0 then 1
let mask4 = if year_months le 5.0 then 1

!<<<<<<<<<<<<<<<<Masking for summer(JJA)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<!
let mask5 = if year_months ge 6.0 then 1
let mask6 = if year_months le 8.0 then 1

!<<<<<<<<<<<<<<<<Masking for summer(DJF)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<!
let mask7 = if year_months eq 0.0 then 1
let mask8 = if year_months eq 1.0 then 1
let mask9 = if year_months eq 2.0 then 1

!<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<!
let mask_fall = mask1*mask2

let mask_spring = mask3*mask4

let mask_summer = mask5*mask6

let mask_D = mask7
let mask_j = mask8
let mask_f = mask9

let temp_anm_son = temp_anm*mask_fall
let temp_anm_mam = temp_anm*mask_spring
let temp_anm_jja = temp_anm*mask_summer
let temp_anm_d = temp_anm*mask_D
let temp_anm_j = temp_anm*mask_j
let temp_anm_f = temp_anm*mask_f

let temp_son=temp_anm_son[gt=t_yearly@ave]
let temp_mam=temp_anm_mam[gt=t_yearly@ave]
let temp_jja=temp_anm_jja[gt=t_yearly@ave]
let temp_anm_dec = temp_anm_d[gt=t_yearly@ave]
let temp_anm_jan = temp_anm_j[gt=t_yearly@ave]
let temp_anm_feb = temp_anm_f[gt=t_yearly@ave]
let temp_anm_jan1 = temp_anm_jan[l=@shf:1]
let temp_anm_feb1 = temp_anm_feb[l=@shf:1]
let temp_djf= (temp_anm_dec+temp_anm_jan1+temp_anm_feb1)/3.0

exit

let us know if you face any problem

regards, saurabh

On Mon, Nov 20, 2017 at 5:25 PM, Steffie Tom <tomsteffie@xxxxxxxxx> wrote:

hii

We have data from 1979-2015, which consists of various parameters like temperature etc. we need to create seasonal data i.e. say for summer jan-feb-march for all years i.e. separately for 1979, then jan-feb-march for 1980 etc. i.e in one file we want 111 months.

First of all how to achieve this ?

After that how to achieve the seasonal average of the same data above ?

thanks

--

REGARDS

Saurabh Rathore

Research Scholar (PhD.)

Centre For Oceans, Rivers, Atmosphere & Land Science Technology

Indian Institute Of Technology, Kharagpur

contact :- 91- 8345984434