Hallo Alois,

to actually download the global data files follow the instruction on page:

http://www.ecmwf.int/en/research/climate-reanalysis/era-interim

If you just download very few data files you may consider using the web interface (http://apps.ecmwf.int/datasets/data/interim-full-daily/), else it might be good to use the mars retrieving mechanism. However the later option requires the installation of additional software.

Please keep in mind, that you may have to create an account before you can download the data: https://apps.ecmwf.int/registration/?back=http://apps.ecmwf.int/datasets/data/interim-full-daily/licence/

After you downloaded the data you may use the Climate Data Operator (https://code.zmaw.de/projects/cdo/wiki/Cdo), for instance, to subtract the data for your region of interest, for example

cdo -f nc -sellonlatbox,LonEastValue,LonWestValue,LatSouthValue,LatNorthValue Input Output_OnlyRegionOfInterest.nc

If you would provide for the eastern/western as well as the north/southern boundaries identical values you shall get the values (time serie) for the closed point.

Good luck

Hi Alois,

The file your attached contents point locational data for a few projects in Namibia. You can use Google Earth to location a particular project. Thereafter, use your mouse to click and record four points (N, E, W, S) while the project is in the middle of your screen. The four points will depend on the size of the particular project (in your attached list).

You can use the procedures mentioned above by Christian making sure you resize the file (using the four reference points) to a spatial extent appropriate for your attached projects.

If you have ArcGIS (Multidimension tools) you can also read the files (*.nc) and convert to geotiff or an appropriate format for use in your research.

Another software program that you can also use is IDV 5.x. It will enable you to read the netcdf (nc) file and also convert it to tiff or even jpeg (picture for MS Word).

Good luck

Hi Christian·and Frans, 

Thanks a lot for the information really appreciate it. It is really useful information, I have already registered.

Kind Regards, 

Alois

Hi Alois

Another way is, if you only need point data from the ERA-Interim for your projects, to downloaded the ERA-interim data for for the whole of Namibia and then use ArcGIS or any other geo-spatial program to only extract the points (the Excel file you provided) from the netcdf (downloaded file). This will give you time series data for all the points. You can than compare these time series data sets with ground observation data recorded at the individual projects.

regards

Frans

Visit this page to have required help..Best..

https://software.ecmwf.int/wiki/display/CKB/How+to+extract+ERA-Interim+data+for+specific+locations

Hi

If you want to extract your NetCDF files (.nc), I would notify to you, please visit this site:

www.agrimetsoft.com

There are applicable software in it that you can extract your data through them easily.

Regards,

Nasrin

Simply use this simple python code..

#!/usr/bin/env python

from ecmwfapi import ECMWFDataServer

server = ECMWFDataServer()

server.retrieve({

# Specify the ERA-Interim data archive. Don't change.

"class": "ei",

"dataset": "interim",

"expver": "1",

"stream": "oper",

# Specify the ERA-Interim data for download

"type": "fc",

"levtype": "sfc",

"param": "228.128", # parameter 'total precipitation'

"date": "1979-01-01/to/2017-01-31",

"step": "12", # accumulation over 12 hours

# "time": "00:00:00", # from the first forecast initialized at 00:00

# "time": "12:00:00", # from the second forecast initialized at 12:00

"time": "00:00:00/12:00:00", # from the two forecasts initialized at 00:00 and 12:00

"grid": "0.125/0.125",

"area":"-0.9/29/-11.8/40.5", # restrict your area of interest (in N/W/S/E)

"format":"netcdf",

"target": "forecast_precip.nc" # change this to your output file name

})