river forcing with seasonal variability?

[khantsoo]

Hi, I'm wondering how to write a river forcing netcdf file (or files) in such a way that a single point source can have discharge or other properties that vary over time. I wrote a simple river forcing netcdf file using Matlab commands and it worked for the upwelling test case, but now I am looking around and I haven't found any documentation for how to induce seasonal discharge. Sorry if I've missed something obvious here.

[kate]

You just need your netcdf file to have time dimensions, with properties depending on the time. Here's an example with not one but three time dimensions:

Code: Select all

netcdf NWGOA3_rivers {
dimensions:
	river_time = UNLIMITED ; // (10950 currently)
	river = 1968 ;
	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" ;
	int river(river) ;
		river:long_name = "river runoff identification number" ;
	double river_sign(river) ;
		river_sign:long_name = "river directional sign" ;
	int river_Xposition(river) ;
		river_Xposition:long_name = "river XI-position at RHO-points" ;
		river_Xposition:valid_min = 1 ;
		river_Xposition:valid_max = 689 ;
	int river_Eposition(river) ;
		river_Eposition:long_name = "river ETA-position at RHO-points" ;
		river_Eposition:valid_min = 1 ;
		river_Eposition:valid_max = 1089 ;
	int river_direction(river) ;
		river_direction:long_name = "river runoff direction" ;
	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_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" ;
	double river_Talk(river_bgc_time) ;
		river_Talk:long_name = "river runoff total alkalinity" ;
		river_Talk:units = "mmol/m3" ;
		river_Talk:time = "river_bgc_time" ;

I'm only showing a subset - hopefully it's clear enough. The river_bgc_time has 12 values for a monthly climatology - note the cycle_length attribute.