Deutsch: Dunst / Español: Neblina / Português: Névoa seca / Français: Brume sèche / Italiano: Foschia
In the maritime context, haze refers to a reduction in visibility caused by fine particles or aerosols suspended in the atmosphere, such as dust, smoke, salt, or pollution. Unlike fog, haze does not form from condensed water vapor but instead results from dry particles scattering light, often producing a bluish, gray, or brown appearance over the sea.
Haze can affect navigation safety, visibility of coastal landmarks, and the performance of optical instruments used on ships, especially during daylight hours.
Definition
Haze is an atmospheric phenomenon characterized by limited visibility at sea due to the presence of dry, airborne particles. It typically occurs in hot, dry, or polluted conditions, and while it may not be as thick or dense as fog, it can still obscure the horizon, other vessels, and navigational markers.
In meteorological reporting and ship logs, haze is often noted with the code "HZ" and is assessed based on visibility range (typically reduced to between 2 and 5 nautical miles).
Typical Examples
– A cargo vessel approaching a port in Southeast Asia encounters haze caused by forest fires, reducing visibility to 3 nautical miles.
– A tanker navigating the Persian Gulf during summer experiences persistent haze due to dust and industrial emissions.
– Coastal haze in the Mediterranean limits the visual range of land-based navigation aids, requiring increased radar reliance.
– A cruise ship alters its sightseeing schedule due to thick haze from volcanic ash drift.
– Ships near desert coasts or in major shipping lanes often report haze due to sand and ship exhaust.
Recommendations
– Reduce speed: Lowering vessel speed improves reaction time in limited visibility situations.
– Sound fog signals: Though haze is dry, navigation rules still recommend using sound signals in visibility-restricted conditions.
– Use radar and AIS: These systems help detect other vessels when visual observation is impaired.
– Post additional lookouts: Extra personnel on watch improves situational awareness.
– Monitor environmental reports: Stay updated on haze advisories or pollution alerts from meteorological or port authorities.
– Switch to anti-glare filters: Use optical equipment with enhanced filters to improve visibility in hazy conditions.
– Keep windows and optics clean: Haze can leave residues that further impair visibility if not regularly cleaned.
Risks and Challenges
– Collision risk: Reduced visibility increases the likelihood of vessel collisions, particularly in busy sea lanes.
– Navigation errors: Difficulty seeing land, buoys, or lights can lead to misjudged positions.
– Delayed port operations: Pilots may be unable to board, or visibility may restrict berthing maneuvers.
– Crew health: Prolonged exposure to smoke-related haze can affect respiratory health.
– Instrument overreliance: In low visibility, excessive dependence on radar or AIS without cross-verification can lead to errors.
– Environmental impact: Haze from pollution or forest fires can signal larger ecological concerns affecting maritime regions.
Similar Terms
– Fog: Visibility impairment caused by water droplets; more dense and moist than haze.
– Mist: A thinner form of fog, with higher visibility than typical fog but lower than clear air.
– Smoke: Airborne particles from combustion; often a component of haze during wildfires or urban pollution.
– Smog: A type of haze specifically resulting from industrial and vehicular pollution, often urban-related.
– Dust storm: Can contribute to haze at sea, particularly in areas near arid landmasses.
Summary
Haze in the maritime context refers to reduced visibility caused by dry airborne particles such as dust, smoke, or pollution. It poses navigational challenges, requires enhanced lookout and instrument use, and can signal broader environmental issues. Mariners must exercise caution and adapt procedures when haze affects visibility at sea.
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