slp1 = slp_seas(time|:,{lat|latS1:latN1},{lon|lonL1:lonR1})
; select southern station
latS2 = 37
latN2 = 38
lonL2 = 24
lonR2 = 26
slp2 = slp_seas(time|:,{lat|latS2:latN2},{lon|lonL2:lonR2})
;***************************************************************
; calculate the standardize anomlaies for the season DJF
;***************************************************************
slp1_std = dim_standardize_n_Wrap(slp1,1,0)
slp2_std = dim_standardize_n_Wrap(slp2,1,0)
;****************************************************************
; calculate the difference
;****************************************************************
Delta = slp2_std - slp1_std
copy_VarCoords(slp1_std, Delta)
if(any(ismissing(Delta))) then
print("Your data contains some missing values. Beware.")
end if
if (any(isnan_ieee(Delta))) then
value = -1.e34
replace_ieeenan (Delta, value, 0)
Delta@_FillValue = value
end if
printVarSummary(Delta)
printMinMax(Delta,0)
;*****************************************************************
; Plot
;*****************************************************************
yrStart = 1978
yrLast = 2007
yyyymm = yyyymm_time(yrStart, yrLast, "integer")
yyyyfrac = yyyymm_to_yyyyfrac(yyyymm,0.0)
wks = gsn_open_wks("pdf","time")
res = True
res@trXMinF = yrStart ; starting point along X axis
res@trXMaxF = yrLast+1 ; ending point along X-axis
res@vpWidthF = .7 ; stretch the plot to be wider (in NDC units)
res@vpHeightF = .25 ; and not as tall
res@vpXF = .15 ; set the start point along the X-axis in NDC units
plot = gsn_csm_xy(wks,yyyyfrac,Delta,res)