Mean Chloride Deposition (2020–2024)

Overview

This dataset represents modeled global atmospheric chloride deposition developed to support ISO 9223 atmospheric corrosivity modeling for the period 2020–2024.

Atmospheric chloride deposition is one of the most important environmental variables influencing:

• Atmospheric corrosion
• Marine aerosol transport
• Electrochemical corrosion processes
• Coating degradation
• Corrosion initiation and propagation

The raster represents estimated long-term ambient atmospheric chloride deposition behavior at approximately 1 km spatial resolution.

Units:

• Milligrams per square meter per day (mg/m²/day)

Background

Atmospheric chloride deposition is a primary environmental driver of atmospheric corrosion and is a core variable within the ISO 9223 atmospheric corrosivity framework.

Chloride deposition is primarily associated with:

• Marine aerosol transport
• Coastal salt spray
• Ocean-derived particulate matter
• Wind-driven sea salt movement

Higher chloride deposition environments generally result in increased atmospheric conductivity, electrolyte persistence, corrosion initiation, and corrosion propagation.

This dataset was developed to provide global chloride deposition estimates suitable for corrosion engineering, environmental modeling, and GIS-based exposure assessment.

Modeling Methodology

The chloride deposition framework integrates atmospheric reanalysis data, coastal transport analytics, terrain effects, and marine aerosol transport behavior.

Primary chloride inputs include:

• MERRA-2 Sea Salt Dry Deposition (SSDP)
• MERRA-2 Sea Salt Wet Deposition (SSWT)

The modeling framework incorporates:

Wind Transport

• Mean wind speed
• Resultant wind direction
• Marine aerosol transport dynamics

Coastal Exposure

• Distance-to-coast relationships
• Coastal amplification effects
• Inland chloride decay behavior

Terrain Effects

• Bathymetry and elevation
• Terrain shielding
• Terrain ruggedness (WindRIX)

Environmental Modifiers

• Temperature
• Humidity
• Marine persistence factors
• Peninsula amplification effects

The resulting framework was designed to improve representation of ambient atmospheric chloride deposition behavior within coastal, inland, and complex terrain environments.

Interpretation Guidelines

Higher chloride deposition values generally indicate increased atmospheric corrosion potential and greater marine aerosol influence.

Spatial Resolution

Data Sources

Primary environmental inputs include:

• NASA MERRA-2 Atmospheric Reanalysis
• NASA Giovanni System
• NOAA Integrated Surface Database (ISD)
• National Data Buoy Center (NDBC)
• Coastal and terrain analytics datasets

Derived environmental layers include:

• Wind Speed
• Wind Direction
• Distance to Coast
• Bathymetry / Elevation
• WindRIX Terrain–Wind Exposure Index

Intended Applications

This dataset may be used for:

• Atmospheric corrosion assessment
• ISO 9223 modeling
• Marine exposure analysis
• Coastal environmental assessment
• Corrosion engineering
• GIS visualization
• Environmental modeling
• Enterprise API workflows

Related Datasets

Corrosion Layers

• ISO 9223 Steel Corrosion Rate
• ISO 9223 Zinc Corrosion Rate
• ISO 9223 Aluminum Corrosion Rate
• ISO 9223 Copper Corrosion Rate

Supporting Atmospheric Layers

• Mean Sulfate Deposition
• Mean Annual Temperature
• Mean Relative Humidity
• Time of Wetness (TOW)

Supporting Coastal & Terrain Layers

• Distance to Coast
• Bathymetry 2024 – Terrain Elevation
• WindRIX Terrain–Wind Exposure Index
• Wind Resultant Direction (0–360°)
• Wind Speed

Attribution

Joseph Mazzella
AtmosphericIQ LLC
Engineering Director, Inc.

Dataset Citation

Mazzella, J. (2026). Mean Chloride Deposition Raster (2020–2024). AtmosphericIQ LLC / Engineering Director, Inc.

Supporting Dataset Citations

NASA MERRA-2

NASA Global Modeling and Assimilation Office (GMAO). MERRA-2 Atmospheric Reanalysis Dataset.
https://gmao.gsfc.nasa.gov/reanalysis/MERRA-2/

NASA Giovanni

NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). NASA Giovanni System.
https://giovanni.gsfc.nasa.gov/giovanni/

NOAA ISD

NOAA National Centers for Environmental Information (NCEI). Integrated Surface Database (ISD).
https://www.ncei.noaa.gov/products/land-based-station/integrated-surface-database

ISO 9223 Standard

ISO 9223:2012. Corrosion of metals and alloys — Corrosivity of atmospheres — Classification, determination and estimation.
https://www.iso.org/standard/53499.html

Version Information