Why chloride matters for corrosion
Chloride is one of the most important atmospheric modifiers for corrosion in marine environments. Sea-salt particles can deposit on metals, coatings, connectors and enclosure surfaces. When moisture is present, those salts can create conductive electrolyte films that support electrochemical corrosion.
This is why two locations with similar temperature and humidity may still behave very differently: a coastal site can carry a persistent chloride load that an inland site does not experience.
Marine corrosion screening should combine climate exposure with marine aerosol context. Distance to coast is useful, but it is not enough by itself.
Marine exposure is not a simple distance ring
A simple 0-1 km or 1-5 km coastline band is a helpful first approximation. Real exposure is more structured. Onshore winds, coastline orientation, terrain, precipitation, humidity and urban geometry can create strong spatial gradients.
Coastline distance
The marine signal is strongest near exposed coastlines and generally decreases inland.
Wind transport
Onshore flow can move sea-salt aerosol inland, while terrain and local flow patterns modify the footprint.
Humidity
Chloride becomes more relevant when surfaces remain wet or close to wet for long periods.
Deposition
The engineering concern is not only airborne salt, but the chloride-rich residue left on surfaces.
How Climetry screens chloride deposition
Climetry combines scientific climate data, coastline geometry, wind climatology and atmospheric transport screening to estimate where marine chloride exposure is likely to be elevated.
The method is intentionally engineering-oriented. It does not try to replace a regulatory air-quality model or a site-specific corrosion test. Instead, it translates environmental information into a practical exposure layer that helps engineers compare locations before deployment.
Coastline context, ERA5 wind and climate fields, terrain influence and regional calibration data.
Monthly transport screening converts marine influence into spatial chloride exposure patterns.
A chloride deposition proxy that can support corrosion screening and environmental classification.
Calibration concept
Public deposition networks such as NADP provide long-term chloride wet-deposition observations in the United States. These data are useful for regional plausibility checks and calibration of broad spatial patterns.
For corrosion engineering, airborne chloride and surface deposition are often the more direct concern. Climetry therefore treats chloride calibration as a layered problem: wet-deposition data can constrain the regional signal, while aerosol-speciation networks and future field measurements can improve the coastal exposure gradient.
A screening layer is not a site-specific ISO 9225 chloride candle measurement. It is an engineering exposure indicator designed to identify where marine influence deserves attention.
How engineers can use it
Chloride deposition screening is most useful early in the design process, before a product is installed or a portfolio is deployed. It helps identify whether marine exposure should be part of the qualification discussion.
Use as screening evidence alongside humidity, condensation, temperature and pollution context.
Use as screening evidence alongside humidity, condensation, temperature and pollution context.
Use as screening evidence alongside humidity, condensation, temperature and pollution context.
Use as screening evidence alongside humidity, condensation, temperature and pollution context.
Use as screening evidence alongside humidity, condensation, temperature and pollution context.
Limitations
Chloride exposure can vary strongly at small scales because of surf zone conditions, shielding, local wind flow, building geometry and maintenance state. A regional model cannot replace direct site measurements or product-specific corrosion qualification.
The value of Climetry is not to claim exact material loss. The value is to make marine exposure visible early enough that engineers can decide where more robust protection, more detailed testing or field measurements may be justified.
Screen marine influence before deployment.
Compare humidity, condensation, chloride context and environmental severity for coastal locations.