Subtract temperature at different pressure levels
Added by Shreya Bhowmick over 2 years ago
I have a dataset having the temperature at 850hpa and 200hpa pressure levels. I want to subtract temp at 850 hPa from the temperature at 200 hPa. What CDO command should I use? I tried splitting the dataset into two levels and then subtracting them but it seems wrong when i plot it.
Replies (10)
RE: Subtract temperature at different pressure levels - Added by Karin Meier-Fleischer over 2 years ago
Hi Shreya,
you do not need to split the input data, you can use the operator chaining like (mybe you have to select the variable temp, too)
cdo -sub -sellevel,200 infile -sellevel,850 infile outfile
-Karin
RE: Subtract temperature at different pressure levels - Added by Shreya Bhowmick over 2 years ago
Karin Meier-Fleischer wrote in RE: Subtract temperature at different pressure levels:
Hi Shreya,
you do not need to split the input data, you can use the operator chaining like (mybe you have to select the variable temp, too)
[...]
-Karin
Thank you. This is working! The only problem is that I get the output for 1st timestep only. How can I do it for all the timesteps. I tried using seltimestep,1/4758 but it also gave the output for the first timestep only.
RE: Subtract temperature at different pressure levels - Added by Karin Meier-Fleischer over 2 years ago
It should work for all timesteps at once. Which CDO version are you using?
See following example (done with CDO 1.9.9):
infile="$HOME/data/CMIP5/atmos/ta_Amon_MPI-ESM-LR_historical_r1i1p1_198001-198912.nc"
cdo -sub -sellevel,20000 -selyear,1980 $infile -sellevel,85000 -selyear,1980 $infile tmp.nc
cdo infon tmp.nc
-1 : Date Time Level Gridsize Miss : Minimum Mean Maximum : Parameter name
1 : 1980-01-16 12:00:00 20000 18432 0 : -81.359 -58.373 -23.975 : ta
2 : 1980-02-15 12:00:00 20000 18432 0 : -82.093 -57.690 -17.707 : ta
3 : 1980-03-16 12:00:00 20000 18432 0 : -83.541 -58.449 -16.481 : ta
4 : 1980-04-16 00:00:00 20000 18432 0 : -84.239 -59.519 -18.832 : ta
5 : 1980-05-16 12:00:00 20000 18432 0 : -86.066 -60.755 -22.218 : ta
6 : 1980-06-16 00:00:00 20000 18432 0 : -88.062 -61.808 -19.838 : ta
7 : 1980-07-16 12:00:00 20000 18432 0 : -84.579 -61.778 -27.698 : ta
8 : 1980-08-16 12:00:00 20000 18432 0 : -85.964 -61.869 -29.521 : ta
9 : 1980-09-16 00:00:00 20000 18432 0 : -85.268 -61.288 -28.724 : ta
10 : 1980-10-16 12:00:00 20000 18432 0 : -82.551 -60.494 -25.970 : ta
11 : 1980-11-16 00:00:00 20000 18432 0 : -82.510 -58.850 -31.545 : ta
12 : 1980-12-16 12:00:00 20000 18432 0 : -82.590 -57.427 -26.239 : ta
RE: Subtract temperature at different pressure levels - Added by Shreya Bhowmick over 2 years ago
I am using CDO 1.9.3. I tried to install CDO 2.0.3 but due to some problem, it is not showing.
In the step 'make install' such output is shown.
make2: Entering directory '/home/shreya/Documents/cdo-2.0.3/src'
/bin/mkdir -p '/usr/local/bin'
/bin/bash ../libtool --mode=install /usr/bin/install -c cdo '/usr/local/bin'
libtool: install: /usr/bin/install -c cdo /usr/local/bin/cdo
/usr/bin/install: cannot create regular file '/usr/local/bin/cdo': Permission denied
Makefile:1037: recipe for target 'install-binPROGRAMS' failed
make2: * [install-binPROGRAMS] Error 1
make2: Leaving directory '/home/shreya/Documents/cdo-2.0.3/src'
Makefile:5703: recipe for target 'install-am' failed
make1: [install-am] Error 2
make1: Leaving directory '/home/shreya/Documents/cdo-2.0.3/src'
Makefile:492: recipe for target 'install-recursive' failed
make: ** [install-recursive] Error 1
The steps 'configure' and 'make' was executed properly.
RE: Subtract temperature at different pressure levels - Added by Shreya Bhowmick over 2 years ago
Karin Meier-Fleischer wrote in RE: Subtract temperature at different pressure levels:
It should work for all timesteps at once. Which CDO version are you using?
See following example (done with CDO 1.9.9):
[...]
In my case this is the result
cdo -sub -sellevel,500 temp.nc -sellevel,850 temp.nc sub.nc
cdo infon sub.nc
-1 : Date Time Level Gridsize Miss : Minimum Mean Maximum : Parameter name
1 : 1982-05-01 06:00:00 500 7381 0 : 42224. 42710. 42977. : z
2 : 1982-05-01 06:00:00 500 7381 0 : 275.85 282.38 288.33 : t
cdo infon: Processed 14762 values from 2 variables over 1 timestep [0.00s 47MB]
RE: Subtract temperature at different pressure levels - Added by Karin Meier-Fleischer over 2 years ago
The installation error based on the fact that you do not have the permission to write to /usr/local/bin/. You can change the prefix or install CDO with miniconda (see https://code.mpimet.mpg.de/projects/cdo/wiki/Anaconda).
Can you upload the data file? If it is too large select a view timesteps in a sample file.
RE: Subtract temperature at different pressure levels - Added by Shreya Bhowmick over 2 years ago
Karin Meier-Fleischer wrote in RE: Subtract temperature at different pressure levels:
The installation error based on the fact that you do not have the permission to write to /usr/local/bin/. You can change the prefix or install CDO with miniconda (see https://code.mpimet.mpg.de/projects/cdo/wiki/Anaconda).
Can you upload the data file? If it is too large select a view timesteps in a sample file.
Thank you so much for your time. I changed the prefix and it installed properly. Still the cdo command could be found somehow. I have uploaded a sample file.
RE: Subtract temperature at different pressure levels - Added by Shreya Bhowmick over 2 years ago
I have updated my cdo version to 1.9.9 but still i am getting the subtracted value for 1 timestep only
RE: Subtract temperature at different pressure levels - Added by Karin Meier-Fleischer over 2 years ago
I used your uploaded file tmp.nc:
cdo -b F64 -sub -sellevel,500 -selname,t tmp.nc -sellevel,850 -selname,t tmp.nc outfile.nc cdo(1) sellevel: Process started cdo(2) selname: Process started cdo(3) sellevel: Process started cdo(4) selname: Process started cdo sub (Warning): Input parameters have different levels! cdo(4) selname: Processed 1800964 values from 2 variables over 122 timesteps. cdo(3) sellevel: Processed 900482 values from 1 variable over 122 timesteps. cdo(2) selname: Processed 1800964 values from 2 variables over 122 timesteps. cdo(1) sellevel: Processed 900482 values from 1 variable over 122 timesteps. cdo sub: Processed 1800964 values from 2 variables over 244 timesteps [0.03s 9076KB].
cdo infon outfile.nc
-1 : Date Time Level Gridsize Miss : Minimum Mean Maximum : Parameter name
1 : 1982-05-01 06:00:00 500 7381 0 : -34.396 -27.866 -21.915 : t
2 : 1982-05-02 06:00:00 500 7381 0 : -33.266 -27.294 -20.355 : t
3 : 1982-05-03 06:00:00 500 7381 0 : -33.491 -27.455 -20.683 : t
4 : 1982-05-04 06:00:00 500 7381 0 : -33.902 -27.012 -20.162 : t
5 : 1982-05-05 06:00:00 500 7381 0 : -34.238 -27.598 -22.664 : t
6 : 1982-05-06 06:00:00 500 7381 0 : -33.480 -27.871 -22.538 : t
7 : 1982-05-07 06:00:00 500 7381 0 : -34.255 -28.071 -20.691 : t
8 : 1982-05-08 06:00:00 500 7381 0 : -34.314 -27.937 -21.182 : t
9 : 1982-05-09 06:00:00 500 7381 0 : -34.433 -27.984 -22.230 : t
10 : 1982-05-10 06:00:00 500 7381 0 : -35.386 -28.125 -22.030 : t
11 : 1982-05-11 06:00:00 500 7381 0 : -34.845 -27.798 -22.234 : t
12 : 1982-05-12 06:00:00 500 7381 0 : -33.891 -27.584 -22.179 : t
13 : 1982-05-13 06:00:00 500 7381 0 : -34.224 -26.727 -21.701 : t
14 : 1982-05-14 06:00:00 500 7381 0 : -33.503 -26.027 -21.250 : t
15 : 1982-05-15 06:00:00 500 7381 0 : -32.337 -25.757 -20.457 : t
16 : 1982-05-16 06:00:00 500 7381 0 : -32.990 -25.912 -21.580 : t
17 : 1982-05-17 06:00:00 500 7381 0 : -32.076 -26.330 -22.568 : t
18 : 1982-05-18 06:00:00 500 7381 0 : -34.782 -26.905 -21.960 : t
19 : 1982-05-19 06:00:00 500 7381 0 : -35.132 -27.185 -21.825 : t
20 : 1982-05-20 06:00:00 500 7381 0 : -35.967 -27.580 -21.737 : t
21 : 1982-05-21 06:00:00 500 7381 0 : -35.735 -27.797 -22.191 : t
22 : 1982-05-22 06:00:00 500 7381 0 : -35.621 -28.473 -21.951 : t
23 : 1982-05-23 06:00:00 500 7381 0 : -34.368 -28.211 -21.335 : t
24 : 1982-05-24 06:00:00 500 7381 0 : -34.767 -27.987 -21.343 : t
25 : 1982-05-25 06:00:00 500 7381 0 : -35.536 -27.815 -21.060 : t
26 : 1982-05-26 06:00:00 500 7381 0 : -34.733 -27.346 -21.125 : t
27 : 1982-05-27 06:00:00 500 7381 0 : -33.304 -26.160 -20.626 : t
28 : 1982-05-28 06:00:00 500 7381 0 : -34.219 -26.063 -20.471 : t
29 : 1982-05-29 06:00:00 500 7381 0 : -36.877 -26.529 -20.596 : t
30 : 1982-05-30 06:00:00 500 7381 0 : -35.642 -26.918 -20.436 : t
31 : 1982-05-31 06:00:00 500 7381 0 : -33.373 -26.649 -20.483 : t
32 : 1982-06-01 06:00:00 500 7381 0 : -33.439 -26.815 -20.191 : t
33 : 1982-06-02 06:00:00 500 7381 0 : -34.059 -26.781 -19.086 : t
34 : 1982-06-03 06:00:00 500 7381 0 : -34.614 -26.155 -18.511 : t
35 : 1982-06-04 06:00:00 500 7381 0 : -34.725 -26.319 -17.117 : t
36 : 1982-06-05 06:00:00 500 7381 0 : -35.475 -26.129 -19.139 : t
37 : 1982-06-06 06:00:00 500 7381 0 : -35.633 -25.571 -19.428 : t
38 : 1982-06-07 06:00:00 500 7381 0 : -31.717 -25.401 -19.839 : t
39 : 1982-06-08 06:00:00 500 7381 0 : -31.404 -24.591 -20.535 : t
40 : 1982-06-09 06:00:00 500 7381 0 : -34.135 -24.792 -19.017 : t
41 : 1982-06-10 06:00:00 500 7381 0 : -34.357 -24.647 -18.278 : t
42 : 1982-06-11 06:00:00 500 7381 0 : -34.598 -24.883 -19.560 : t
43 : 1982-06-12 06:00:00 500 7381 0 : -32.687 -24.391 -19.684 : t
44 : 1982-06-13 06:00:00 500 7381 0 : -33.883 -24.162 -19.949 : t
45 : 1982-06-14 06:00:00 500 7381 0 : -33.388 -23.387 -19.960 : t
46 : 1982-06-15 06:00:00 500 7381 0 : -30.865 -23.522 -19.721 : t
47 : 1982-06-16 06:00:00 500 7381 0 : -31.478 -23.652 -20.124 : t
48 : 1982-06-17 06:00:00 500 7381 0 : -33.529 -23.736 -19.792 : t
49 : 1982-06-18 06:00:00 500 7381 0 : -37.852 -24.493 -19.678 : t
50 : 1982-06-19 06:00:00 500 7381 0 : -37.000 -25.502 -19.646 : t
51 : 1982-06-20 06:00:00 500 7381 0 : -36.053 -25.357 -19.779 : t
52 : 1982-06-21 06:00:00 500 7381 0 : -36.275 -24.426 -20.282 : t
53 : 1982-06-22 06:00:00 500 7381 0 : -37.036 -24.532 -20.483 : t
54 : 1982-06-23 06:00:00 500 7381 0 : -37.833 -24.483 -20.027 : t
55 : 1982-06-24 06:00:00 500 7381 0 : -36.802 -24.350 -20.014 : t
56 : 1982-06-25 06:00:00 500 7381 0 : -39.987 -25.031 -20.106 : t
57 : 1982-06-26 06:00:00 500 7381 0 : -37.614 -25.655 -20.030 : t
58 : 1982-06-27 06:00:00 500 7381 0 : -34.536 -26.037 -20.224 : t
59 : 1982-06-28 06:00:00 500 7381 0 : -32.752 -25.853 -20.299 : t
60 : 1982-06-29 06:00:00 500 7381 0 : -31.843 -25.181 -20.805 : t
61 : 1982-06-30 06:00:00 500 7381 0 : -31.057 -24.478 -20.033 : t
62 : 1982-09-01 06:00:00 500 7381 0 : -29.954 -22.653 -19.519 : t
63 : 1982-09-02 06:00:00 500 7381 0 : -27.576 -23.140 -18.771 : t
64 : 1982-09-03 06:00:00 500 7381 0 : -27.884 -23.032 -18.965 : t
65 : 1982-09-04 06:00:00 500 7381 0 : -28.374 -22.936 -19.712 : t
66 : 1982-09-05 06:00:00 500 7381 0 : -27.901 -22.681 -18.962 : t
67 : 1982-09-06 06:00:00 500 7381 0 : -29.677 -22.300 -17.577 : t
68 : 1982-09-07 06:00:00 500 7381 0 : -29.485 -22.383 -18.784 : t
69 : 1982-09-08 06:00:00 500 7381 0 : -28.148 -22.506 -18.785 : t
70 : 1982-09-09 06:00:00 500 7381 0 : -27.598 -22.149 -18.716 : t
71 : 1982-09-10 06:00:00 500 7381 0 : -28.103 -22.413 -20.006 : t
72 : 1982-09-11 06:00:00 500 7381 0 : -28.649 -22.867 -18.978 : t
73 : 1982-09-12 06:00:00 500 7381 0 : -28.648 -22.992 -20.030 : t
74 : 1982-09-13 06:00:00 500 7381 0 : -28.160 -22.567 -19.019 : t
75 : 1982-09-14 06:00:00 500 7381 0 : -29.009 -22.929 -19.269 : t
76 : 1982-09-15 06:00:00 500 7381 0 : -29.445 -23.497 -19.516 : t
77 : 1982-09-16 06:00:00 500 7381 0 : -31.101 -23.441 -18.514 : t
78 : 1982-09-17 06:00:00 500 7381 0 : -30.535 -22.954 -17.046 : t
79 : 1982-09-18 06:00:00 500 7381 0 : -28.060 -22.512 -17.329 : t
80 : 1982-09-19 06:00:00 500 7381 0 : -27.286 -22.745 -19.383 : t
81 : 1982-09-20 06:00:00 500 7381 0 : -28.706 -23.239 -20.748 : t
82 : 1982-09-21 06:00:00 500 7381 0 : -32.525 -23.563 -20.963 : t
83 : 1982-09-22 06:00:00 500 7381 0 : -30.522 -23.989 -20.278 : t
84 : 1982-09-23 06:00:00 500 7381 0 : -28.775 -23.683 -20.693 : t
85 : 1982-09-24 06:00:00 500 7381 0 : -27.582 -22.961 -19.365 : t
86 : 1982-09-25 06:00:00 500 7381 0 : -26.898 -22.728 -20.065 : t
87 : 1982-09-26 06:00:00 500 7381 0 : -29.748 -22.909 -19.910 : t
88 : 1982-09-27 06:00:00 500 7381 0 : -31.353 -23.308 -19.807 : t
89 : 1982-09-28 06:00:00 500 7381 0 : -32.654 -23.581 -19.535 : t
90 : 1982-09-29 06:00:00 500 7381 0 : -34.112 -23.828 -19.100 : t
91 : 1982-09-30 06:00:00 500 7381 0 : -36.375 -25.017 -20.475 : t
92 : 1982-10-01 06:00:00 500 7381 0 : -34.535 -25.867 -21.641 : t
93 : 1982-10-02 06:00:00 500 7381 0 : -33.170 -25.537 -20.965 : t
94 : 1982-10-03 06:00:00 500 7381 0 : -31.495 -24.797 -21.199 : t
95 : 1982-10-04 06:00:00 500 7381 0 : -32.031 -25.248 -21.893 : t
96 : 1982-10-05 06:00:00 500 7381 0 : -32.472 -25.189 -22.318 : t
97 : 1982-10-06 06:00:00 500 7381 0 : -32.248 -25.361 -21.550 : t
98 : 1982-10-07 06:00:00 500 7381 0 : -32.597 -25.690 -21.750 : t
99 : 1982-10-08 06:00:00 500 7381 0 : -34.514 -26.292 -22.478 : t
100 : 1982-10-09 06:00:00 500 7381 0 : -34.411 -26.400 -22.776 : t
101 : 1982-10-10 06:00:00 500 7381 0 : -33.114 -26.276 -22.599 : t
102 : 1982-10-11 06:00:00 500 7381 0 : -33.432 -26.182 -22.419 : t
103 : 1982-10-12 06:00:00 500 7381 0 : -33.423 -25.429 -21.100 : t
104 : 1982-10-13 06:00:00 500 7381 0 : -33.948 -25.497 -21.776 : t
105 : 1982-10-14 06:00:00 500 7381 0 : -33.877 -25.509 -20.925 : t
106 : 1982-10-15 06:00:00 500 7381 0 : -32.718 -25.398 -21.417 : t
107 : 1982-10-16 06:00:00 500 7381 0 : -32.317 -25.176 -20.946 : t
108 : 1982-10-17 06:00:00 500 7381 0 : -31.803 -24.690 -21.058 : t
109 : 1982-10-18 06:00:00 500 7381 0 : -32.249 -24.147 -21.223 : t
110 : 1982-10-19 06:00:00 500 7381 0 : -32.375 -24.065 -20.522 : t
111 : 1982-10-20 06:00:00 500 7381 0 : -30.983 -24.291 -20.463 : t
112 : 1982-10-21 06:00:00 500 7381 0 : -30.066 -23.565 -20.490 : t
113 : 1982-10-22 06:00:00 500 7381 0 : -29.722 -23.487 -20.159 : t
114 : 1982-10-23 06:00:00 500 7381 0 : -28.924 -23.859 -20.701 : t
115 : 1982-10-24 06:00:00 500 7381 0 : -29.802 -24.118 -21.956 : t
116 : 1982-10-25 06:00:00 500 7381 0 : -29.144 -24.265 -21.744 : t
117 : 1982-10-26 06:00:00 500 7381 0 : -30.487 -24.533 -22.416 : t
118 : 1982-10-27 06:00:00 500 7381 0 : -29.530 -24.358 -21.962 : t
119 : 1982-10-28 06:00:00 500 7381 0 : -29.325 -24.463 -21.404 : t
120 : 1982-10-29 06:00:00 500 7381 0 : -28.391 -24.457 -21.790 : t
121 : 1982-10-30 06:00:00 500 7381 0 : -29.067 -24.451 -21.856 : t
122 : 1982-10-31 06:00:00 500 7381 0 : -29.972 -24.527 -21.658 : t
: Date Time Level Gridsize Miss : Minimum Mean Maximum : Parameter name
cdo infon: Processed 900482 values from 1 variable over 122 timesteps [0.01s 7584KB].
RE: Subtract temperature at different pressure levels - Added by Shreya Bhowmick over 2 years ago
Karin Meier-Fleischer wrote in RE: Subtract temperature at different pressure levels:
I used your uploaded file tmp.nc:
[...]
[...]
Thank you so much. This is working for me too after increasing the precision. It is giving values for all timesteps now.