Using OPeNDAP to get ascii data is very difficult, not to mention that there is a 50 MB limit when returning ASCII via OPeNDAP - your request would take GBs of data. Thankfully, the server you are using to access data from supports the netCDF Subset Service, which allows you to make requests of data using the lat/lon/time bounds you are interested in obtaining data for withoutÂfiguringÂout the correct array indicies. The downside is that for gridded data (like model output), you will get a netCDF file back in return (only a downside if you need ascii data). However, there are several tutorials on how to convert a netCDF file into ascii, so that part should not be too bad. A good place to start would be the netCDF FAQ:
Now, back to getting the data! To use the Netcdf Subset Service, I would firstÂrecommendÂgoing to the main dataset THREDDS catalog page, found here:
Under the Access heading, look for the NetcdfSubset link. If you click that, you will be taken to this page:
Here you will be able to enter your lat/lon bounding box into some text boxes (make sure to uncheck the "disable horizontal subsetting"), as well as the date/time range you are interested in. As you enter information on the page, you should note that a URL is being built at the bottom of the page. This URL is what you can use directly to get the netCDF file.
Note that your full request is too big for the server to fulfill in one shot - you will need to request data in 5 year intervals. The URL for the first 5 years looks like this:
It does take some time for the server to fulfill the request, so patience will be needed. Once you get the file, I would rename to something meaningful and then request the next 5 years worth of data by simply editing the time range in the URL. Note that 5 years worth of data is roughly 125 MB, and this will expand substantially when you extract the data from the netCDF file to ascii...this is one of the many reasons that it is recommended to just use the netCDF file rather than going to ascii.
Best of luck!
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