Meteorological Forcing Overview

ADCIRC supports various meteorological forcing options through the NWS parameter. This overview helps you understand the different meteorological forcing options and their characteristics.

Input Files for Meteorological Forcing

Depending on the NWS value selected, ADCIRC uses different input files:

  • fort.22: Primary meteorological forcing file for most NWS options

  • fort.200: Used for NWS=10 (AVN model) and NWS=11 (ETA model)

  • fort.221-224: Used for NWS=12 (OWI format)

Meteorological Forcing Types

ADCIRC meteorological forcing can be categorized into several types:

  1. Direct Meteorological Input - NWS=1,2,-2: Wind stress and pressure specified directly - NWS=5,-5: Wind velocity and pressure at all nodes - NWS=4,-4: Wind velocity and pressure at selected nodes

  2. Gridded Meteorological Data - NWS=3: US Navy Fleet Numeric format - NWS=6: Rectangular grid of wind/pressure - NWS=7,-7: Regular grid of stress/pressure - NWS=10: NWS Aviation (AVN) model - NWS=11: NWS ETA 29km model - NWS=12: OWI format (nested grids)

  3. Parametric Hurricane Models - NWS=8: Dynamic Holland model - NWS=19: Asymmetric hurricane vortex - NWS=20: Generalized Asymmetric Holland Model (GAHM)

  4. Data-Assimilated Hurricane Models - NWS=15,-15: HWind files from NOAA HRD

  5. Coupled Model Systems - NWS=100-199: Wave radiation stress with meteorological forcing - NWS=300-399: SWAN+ADCIRC coupled model

Format Comparison

Format Comparison

Format Type

Input Unit

Interpolation

Coverage

Advantages

Limitations

Direct Input

Grid nodes

Temporal only

Full domain

Precise control

Large file sizes

Gridded Data

Regular grid

Spatial & temporal

Must cover domain

Standard formats

Interpolation errors

Parametric Models

Track data

Generated on-the-fly

Full domain

Small input files

Idealized storm structure

Data-Assimilated

Snapshots

Temporal between snapshots

Storm area only

Real observations

Limited spatial coverage

Coupled Models

Multiple sources

Model-dependent

Full domain

Physical consistency

Computational cost

Selecting the Appropriate Forcing

When choosing a meteorological forcing option:

  1. Consider data availability: - Historical simulations often use reanalysis or observation-based options - Forecasts typically use forecast model output or parametric models - Research applications may use idealized forcing

  2. Consider model domain: - Large domains benefit from gridded data or parametric models - Small, high-resolution domains may benefit from direct input - Hurricane simulations typically use parametric or data-assimilated models

  3. Consider computational resources: - Parametric models reduce I/O and storage requirements - Direct input may require large storage for forcing files - Coupled models incur additional computational cost

Common Challenges

  1. Ensuring proper coverage: Gridded meteorological data must completely cover the ADCIRC domain

  2. Time synchronization: Pay careful attention to start times and time intervals

  3. Format consistency: Follow exact format specifications for each NWS option

  4. Unit compatibility: Ensure units are consistent with ADCIRC expectations

  5. Hot start considerations: Some NWS options have specific requirements for hot starts

For detailed descriptions of each NWS option, see the NWS parameter documentation. For file format details, see Fort.22: Meteorological Forcing Data and Fort.200: Multiple File Meteorological Forcing Input documentation.