How to assemble time series of observed air pressure


ssh sub@ecaccess.ecmwf.int
use code generator for password

This is the MARS request file ~/p/obs-rq:
 
retrieve,
                class   = od,
                stream  = oper,
                expver  = 1,

                date    = 19930801/TO/20000731,
                time    = 0000,
                range   = 1440,

                area    = 65.0/19.0/63.0/22.0,

                type    = ob,
                obstype = Land surface data,

                duplicates = remove,

                target  = "/scratch/ms/se/sub/obs.sd"

 

is called by shell script (batch job on Fujitsu VPP) my-retobs . Edit this script for date and area. There may be several stations in the area. We will write both their WMO ID-number and longitude/latitude.

The binary packed data  obs.sd is stored on the user disk area, which is important (the file is scratched immediately when the script is finished).

cd $SCRATCH
~/p/my-retobs
When the job is ready, file obs.sd must be unpacked.
cd $SCRATCH
ln -s obs.sd input_datafile
ln -s obs.dat time_series
~/bin/bfpress.x
Dialog:
     Retrieve ? (y/n) y
     Your choice : (enter the name of a variable that should be added to the standard set)
     Press Return
The standard set is Pressure  `PRESSURE´

The output can first be inspected on the terminal by piping it through more.

Remember: compile by

f77 bfpress.f $EMOSLIB


Finally, move the output  obs.dat  to your local computer, divide the different sites (and data columns if more than one)
and create bin ts files with tslist

Example:  froste:/home/hgs/ECMWF/time_series

A request issued at ECMWF on 2011-11-25:

retrieve,
                class   = od,4
                stream  = oper,
                expver  = 1,

                date    = 20100927/TO/20101231,
                time    = 0000,
                range   = 1440,

                area    = 58.0/10.0/56.0/13.0,

                type    = ob,
                obstype = Land surface data,

                duplicates = remove,

                target  = "/scratch/ms/se/sub/obs.sd"

One of the interesting stations is Göteborg, harbour site, IMO station code 2.513

awk '($3$4 == "2.513."){print substr($0,40)}' obs-wcse-100101.dat > obs-2.513-100101.dat
tslist obs-2.513-100101.dat -g'i4,4(1x,i5),t30,f10.0' -k2 -I -r1. -S0.01 -o ap-2.513-100101-1h.ts

note the -S0.01 to obtain hPa units

.bye