About nitrogen comparisons

[Javier Fernando Mendez Monroy]

Dear all.

I hope to find you safe an well during these times.

I am comparing nitrogen outputs with reported values from USGS stations. In APEX documentation there are two main outputs for Nitrogen; YN-Sediment transported N from subarea or reach and QN-Nitrogen in runoff. From USGS I am obtaining the following ones.

• Nitrate:  mg/l as N and mg/l as NO3
• Nitrite:  mg/l as N and mg/l asNO2
• Nitrogen, mixed forms (NH3), (NH4), organic, (NO2) and (NO3): mg/l
• Ammonia and ammonium:  mg/l as N and mg/l NH4
• Inorganic nitrogen (nitrate and nitrite):  mg/l as N
• Kjeldahl nitrogen: mg/l as N

I am comparing QN from APEX with Nitrate as NO3 from USGS.

I would like to ask you kindly if I am right or if you have any suggestion related to other comparisons I can do.

Thanks in advance for your help.

[Luca]

Dear Javier,

I would compare the model outputs against what is reported as N and not NO3.

I will try to find some time to look at the code to be sure of what I am suggesting you here.

Best,

Luca

[Javier Fernando Mendez Monroy]

Thank you so much.

I will be very attentive to your response.

On Monday, June 21, 2021 at 11:40:24 AM UTC-5 Javier Fernando Mendez Monroy wrote: