Muddy Footprints: Satellite's View of Ship Pollution

NASA Earth Observatory
Wednesday, February 13, 2013
Global NOx Map: Image credit NASA

Long tracks of elevated nitrogen dioxide (NO2) levels show up along certain shipping routes when viewed from NASA's Aura satellite.

For more than a decade, scientists have observed “ship tracks” in natural-color satellite imagery of the ocean. These bright, linear trails amidst the cloud layers are created by particles and gases from ships. They are a visible manifestation of pollution from ship exhaust, and scientists can now see that ships have a more subtle, almost invisible, signature as well, according to 'NASA Earth Observatory'.

Data from the Dutch and Finnish-built Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite show long tracks of elevated nitrogen dioxide (NO2) levels along certain shipping routes. NO2, is among a group of highly-reactive oxides of nitrogen , known as NOx, that can lead to the production of fine particles and ozone that damage the human cardiovascular and respiratory systems. Combustion engines, such as those that propel ships and motor vehicles, are a major source of NO2 pollution.

The map shown is based on OMI measurements acquired between 2005 and 2012. The NO2 signal is most prominent in an Indian Ocean shipping lane between Sri Lanka and Singapore, appearing as a distinct orange line against (lighter) background levels of NO2. Other shipping lanes that run through the Gulf of Aden, the Red Sea, and the Mediterranean Sea also show elevated NO2 levels, as do routes from Singapore to points in China. These aren’t the only busy shipping lanes in the world, but they are the most apparent because ship traffic is concentrated along narrow, well-established lanes.

The Atlantic and Pacific Oceans also have heavy ship traffic, but OMI doesn’t pick up NO2 pollution tracks because the shipping routes are less consistent. The shapes of landmasses force ships into narrow paths in the Indian Ocean, while ships in the Atlantic and Pacific tend to spread out over a broad areas as they navigate around storms.

In addition, the air over the northeastern Indian Ocean is relatively pristine. Heavy NO2 pollution (dark red in the map) from cities and off-shore drilling activity along the coasts of China, Europe, and the United States obscures the ship tracks that might otherwise be visible to OMI.

In the map, the Arctic is gray because the lack of light during the winter and frequent cloudiness during the summer prevented OMI from collecting usable data in the area.

Urban areas and industrialization aren’t the only source of NO2 in the map. Agricultural burning in southern Africa and persistent westerly winds make an elevated band of NO2 that stretches from southern Africa to Australia. (In central Africa, easterly winds push pollutants from fires toward the Atlantic, keeping NO2 levels comparatively low over the northern Indian Ocean.) Lightning, which produces NOx, also contributes to background NO2 levels.

Just how much shipping contributes to overall NOx emissions remains an open question for scientists. Research suggests that shipping accounts for 15 to 30 percent of global NOx emissions; scientists are using satellite observations to reduce the uncertainty in such estimates.

Source: NASA Earth Observatory
 

Maritime Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter April 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

P&I Club warns on Enclosed Space Entry & Testing

The London P&I Club says it continues to see cases of injuries and fatalities associated with entry into enclosed onboard spaces, including cargo holds on bulk

OOCL Renews VOD Training Contract

Videotel, producer and distributor of training videos, 3D animation, and e-Learning courses to the maritime market and part of KVH Industries, Inc., (Nasdaq: KVHI),

Tech & Design Solutions for Modern Workboats

EPA Tier 4 regulations (for engines of 804 hp and higher) and propulsion advancements have many manufacturers and vessel designers changing course to adapt to new requirements and customer demands.

Environmental

GloMEEP Project Forges Ahead with Train-the-Trainer Workshop

A global Train-the-Trainer workshop on energy efficiency has been delivered in China (23-27 May), preparing the personnel needed to cascade knowledge on energy

Long Beach Port Maintains Strong Bond Rating

Fitch Ratings, one of the top three U.S. credit analysis agencies, has affirmed the Port of Long Beach’s “AA” rating on its outstanding debt. Fitch stated the AA rating — its highest for U.

Hansa Offenburg, Hansa Drakenburg Sail Scale-free

Leonhardt & Blumberg was founded in 1903 and has managed more than 180 vessels, the majority of which were general cargo vessels and bulk carriers. Today the company

Marine Science

P&I Club warns on Enclosed Space Entry & Testing

The London P&I Club says it continues to see cases of injuries and fatalities associated with entry into enclosed onboard spaces, including cargo holds on bulk

TAMRF Extends Research Vessel Charter

Overseas Drilling Ltd., a 100 percent owned subsidiary of Siem Offshore Inc., and Texas A&M Research Foundation (TAMRF) have agreed to extend the charter of the

Kongsberg Tech for Peruvian Arctic Research Vessel

Kongsberg Maritime has been chosen to deliver an integrated subsea technology systems package including two HUGIN Autonomous Underwater Vehicles (AUV) for a new

 
 
Maritime Careers / Shipboard Positions Maritime Security Navigation Pipelines Pod Propulsion Salvage Ship Electronics Ship Simulators Sonar Winch
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.0843 sec (12 req/sec)