NetCDF plotting assignments

So the assignment is here.

Problem 1. Time series of annual mean precipitation (pr) and temperature (tas) over your area compared with the global average for the historic period. (I am going to abbreviate this as historic: ts of annual mean pr and tas for area and globe).

download the nc files and then cut the south hemisphere (our region) out using cdo sellonlatbox or cdo elindexbox
```
cdo selindexbox,1,192,1,48 tas_Amon_MPI-ESM-LR_rcp85_r1i1p1_200601-210012.nc temp_rcp85_SH.nc
```

find the global and area annual mean using cdo fldmean and cdo yearmean, then convert the prec unit from kg/m^2s (mm/s) to mm/yr by multiply 31536000 and the temp unit from K to C

cdo fldmean prec_SH.nc prec_SH.mean.nc
cdo yearmean prec_SH.mean.nc prec_SH.annual.mean.nc
cdo mulc,31536000 prec_SH.annual.mean.nc prec_SH.annual.mean.mm_yr.nc
cdo addc,-273.15 temp_SH.annual.mean.nc temp_SH.annual.mean.C.nc

output the data to ascii using cdo output and then plot them in Excel or whatever
```
cdo output prec_SH.annual.mean.mm_yr.nc &gt; prec_SH.annual.mean.mm_yr.txt
```

Problem 2. historic: ts of annual anomaly of pr and tas for area and globe. The anomaly should be calculated relative to the period 1970-1999.

find the mean values for 1970-1999 using cdo seldate and cdo timmean

cdo seldate,1970-01-01,1999-12-31 prec_global.annual.mean.mm_yr.nc prec_global.annual.mean.7099.nc
cdo timmean prec_global.annual.mean.7099.nc out.nc

then I can find the mean prec and temp for 70-99:

 South Hemisphere mean prec 70-99: 1052.65 mm/yr
 South Hemisphere mean temp 70-99: 13.53 C
 Global mean prec 70-99: 1068.36 mm/yr
 Global mean temp 70-99: 14.08 C

subtract the mean value to get the anomaly time series cdo addc,-1052.65 prec_SH.annual.mean.mm_yr.nc prec_SH.anom.nc

Problem 3. climate change: ts of annual anomaly of pr and tas for area and globe for RCP4.5 and RCP8.5. The anomaly should be calculate relative to the period 1970-1999.

see problem 2

Problem 4. Historic: seasonal mean 2D map of pr and tas for your area for DJF, MAM, JJA, SON for the period 1970-1999. This should be 4 panels on one slide. cdo yseasmean $infile $outfile Problem 5. Climate change: seasonal mean 2D map of pr and tas for your area for DJF, MAM, JJA, SON for the periods 2020-2049 and 2070-2099 for RCP4.5 and RCP8.5. This should be 4 panels on one slide for each period and each RCP.

Problem 6. Climate change: repeat 5. as an anomaly to the period 1970-1999.

Problem 7. Climate change: 2D plots for RCP4.5 and RCP8.5 for your area with a mask that shows the areas in which mean annual temperature change and precipitation change are both in the upper 10% (basically show areas that are expected to experience both extreme temperature and precipitation change).

calculate the annual mean for periods 1970-1999 (historical) and 2070-2099 (RCP 4.5 and RCP8.5)
find the temp and prec relative differences between two time periods using cdo sub and cdo div
find the 90 percentile thresholds for both temp and prec using cdo fldpctl then find the grid cells larger than the thresholds using cdo gtc. Then find the intersection. ```bash cdo sub mean.seasonal.SH.prec_rcp85_global.7099.nc mean.seasonal.SH.prec_global.7099.nc out1.nc cdo div out1.nc mean.seasonal.SH.prec_global.7099.nc out2.nc cdo fldpctl,90 out2.nc out3.nc value=cdo output out3.nc | less vv=echo $value cdo gtc,$vv out2.nc outprec.nc

cdo sub mean.seasonal.SH.temp_rcp85_global.7099.nc mean.seasonal.SH.temp_global.7099.nc out1.nc cdo div out1.nc mean.seasonal.SH.prec_global.7099.nc out2.nc cdo fldpctl,90 out2.nc out3.nc value=cdo output out3.nc | less vv=echo $value cdo gtc,$vv out2.nc outtemp.nc

cdo add outprec.nc outtemp.nc out.nc cdo eqc,2 out.nc export.nc ```

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