Seasonal Climate Associated with Major Shipping Routes in the North Pacific and North Atlantic

Abstract

The major shipping routes in the North Pacific (NP) and North Atlantic (NA) are analyzed via ship-reported records compiled by the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). The shipping route seasonal characteristics and associated climatic features are also examined. In the NP, the dominant cross-basin route takes a great-circle path between East Asia and North America along 54°N north of the Aleutian Islands throughout the year. This route penetrates the Aleutian low center where ocean waves and winds are relatively weaker than those in the low's southern section south of 50°N. Moreover, the Earth's spherical shape makes a higher-latitude route shorter in navigational distance across the NP than a lower-latitude route. Two additional mid-latitude routes through the 40° -50°N region appear in summer when the Aleutian low vanishes. In the NA, the major shipping routes form an X-shaped pattern in the oceans south of 40°N to connect North America/the Panama Canal and the Mediterranean Sea/the British Isles and Europe. These major shipping routes are far from the influence of the Icelandic low and thus are used throughout the year due to the stability in marine conditions and their general efficiency. A third and more zonal route appears to the north of the X-shaped routes in the 40° -50°N region. Weak influence from the Icelandic low on marine conditions during summer and spring means that more ships take this route in summer and spring than in winter and fall.

Shipping routes in the South China Sea and northern Indian Ocean and associated monsoonal influences

“…Navigational safety is highly threatened by severe sea states caused by the Aleutian low in the NP (e.g., Terada and Hanzawa 1984;Fritz 1985;Zhang et al 2004;Ahrens 2005;Rodionov et al 2005) and by the Icelandic low in the NA (e.g., Sahsamanoglou 1990; Serreze et al 1997;Ahrens 2005). As such, major shipping routes have to find ways to avoid dangerous marine environments during both the developing and mature stages of these lows in fall and winter (e.g., Chen et al 2014). Different from previous studies on NP and NA shipping routes, paths across the NIO and SCS predominantly pass through tropical zones.…”

“…Accumulated ship-report numbers from ICOADS data are used to interpret the major shipping routes in the NP and NA (e.g., Chen et al 2012Chen et al , 2014. Adopting the above approach, climatological (1981 -2010) means of seasonally accumulated frequency patterns computed from ICOADS data were used to delineate major shipping routes in the SCS and NIO.…”

“…Economically, an across-basin route following a great circle over the high latitudes is shorter in navigational distance than the low-latitude route due to the spherical nature of the Earth, meaning savings in fuel and time. In the NA, Chen et al (2014) demonstrated that the major cross-basin routes were characterized by an X-shaped pattern, connecting North America/the Panama Canal on the western side of the Atlantic with the Mediterranean Sea/the British Isles and Europe on the eastern side. The X-shaped routes are located mainly in the oceans south of 40°N in winter to avoid strong winds and waves in the northern regions in company with the existence of the Icelandic low.…”

“…One key marine feature revealed by information on a ship's positions is major shipping routes. By interpreting seasonal frequency patterns based on accumulated ship-reported records from different ships, prevailing shipping routes over the North Pacific (NP) and North Atlantic (NA) are depicted by Chen et al (2014). Following their approach, winteraccumulation frequency patterns computed from different ship records averaged from 1981 -2010 ICOADS data in every 2° × 2° grid over the Northern Hemisphere (NH) are shown in Fig.…”

“…1. The path depicting the NP crossing between East Asia and North America is described as the great-circle route (e.g., Chen et al 2014). This route begins from Taiwan/China and moves northeastward passing Japan and Kuril Island toward a point southeast of the Russian Kamchatka Peninsula.…”