Summary of the Article on Atmospheric Nitrogen Deposition in CLM:

## Atmospheric Nitrogen Deposition in CLM

### Overview
- CLM uses a single variable to represent the total deposition of mineral nitrogen from wet and dry deposition of NOy and NHx onto the land surface.
- This flux represents reactive nitrogen from various natural and anthropogenic sources.

### Nitrogen Deposition Representation in CLM
- The nitrogen deposition flux is assumed to enter the soil NH4+ pool and is vertically distributed throughout the soil profile.
- CLM5 only represents a single mineral nitrogen pool, despite the complex pathways for wet and dry nitrogen deposition, including release from melting snowpack and direct foliar uptake.

### Input Data
- In offline (uncoupled) CLM5.0 simulations, monthly estimates of nitrogen deposition are provided.
- In coupled simulations, nitrogen deposition fluxes are passed to the land model at the frequency of the time step (every half hour) through the coupler.