multiple rivers with different time series

[adundunis]

Hi everyone,

I'm new to ROMS so please bear with me if my question seems too basic.

I am making a river discharge input file and my study site has multiple rivers.

So far I've created a river input file from the largest river in my site. Now, I want to include the small rivers.

I've also looked into an example of a river-discharge input file with multiple rivers. From what I inferred, that certain input file only has one set of river_time for all the river discharges so making an input file that includes all those separate rivers was possible.

However, the data that I have has a separate time series for each river. Some discharges are very time resolved while some are not.

Should I make a separate input file for each river discharge?

Thanks in advance!

[kate]

ROMS does not support multiple discharge files so you will have to combine them. Just do the best you can, maybe time interpolating between records on the small ones to match the times of the well-studied river. Or if it's a question of duration, come up with an annual cycle for all of them, setting an appropriate cycle_length attribute. One thing I did was have the river temperature use its own cyclic time while the discharge has interannual variability - two time variables in one file. I also added an option to ROMS so that it reads one temperature timeseries and applies it to all rivers at all depths.

[adundunis]

Thanks for the response Kate!

[adundunis]

I also added an option to ROMS so that it reads one temperature timeseries and applies it to all rivers at all depths.

Hi Kate, does this mean ROMS can read a separate time series (not river_time) for the temperature? If so, how can I do this option? Make a separate "time" variable in the river input file?

[kate]

Yes, make a separate time variable:

Code: Select all

netcdf NGOA_rivers_1980_2014 {
dimensions:
	river_time = UNLIMITED ; // (12784 currently)
	river = 1965 ;
	s_rho = 50 ;
	river_tracer_time = 365 ;
	river_bgc_time = 12 ;
variables:
	double river_time(river_time) ;
		river_time:units = "days" ;
		river_time:long_name = "river runoff time" ;
            :
            :
	double river_transport(river_time, river) ;
		river_transport:long_name = "river runoff vertically integrated mass transport" ;
		river_transport:units = "meter3 second-1" ;
		river_transport:time = "river_time" ;
	double river_tracer_time(river_tracer_time) ;
		river_tracer_time:units = "day" ;
		river_tracer_time:cycle_length = 365.25 ;
		river_tracer_time:long_name = "river tracer time" ;
	double river_temp(river_tracer_time) ;
		river_temp:long_name = "river runoff potential temperature" ;
		river_temp:units = "Celsius" ;
		river_temp:time = "river_tracer_time" ;
	double river_salt(river_tracer_time) ;
		river_salt:long_name = "river runoff salinity" ;
		river_salt:time = "river_tracer_time" ;
	double river_alk(river_bgc_time) ;
		river_alk:long_name = "river runoff alkalinity" ;
		river_alk:units = "mol/kg" ;
		river_alk:time = "river_bgc_time" ;
	double river_bgc_time(river_bgc_time) ;
		river_bgc_time:units = "day" ;
		river_bgc_time:cycle_length = 365.25 ;
		river_bgc_time:long_name = "river bgc time" ;

Note the "time" attribute on the various tracers - there are actually three times in this file, only one of which is unlimited (Netcdf4 supports multiple unlimited dimensions, but I didn't need more than one).

[adundunis]

Thank you so so much! This is really helpful!