On average, 1400 containers are lost at sea per year but since December 2020 that number has risen to 3500. According to Gcaptain the shipping industry is seeing the biggest spike in lost containers in seven years with more than 3000 containers lost at sea last year and over 1000 so far this year.
This blog helps explain how the changing weather pattern has contributed to the overall situation.
Surprisingly, the common theme among the recently impacted vessels that have lost containers is that they were all mostly in the North Pacific on sea routes connecting Asia’s economies to consumers in North America during the Northern Hemisphere Winter. So why is this?
Fig.1: Historical AIS Density between Dec 2020 to Feb 2021 from Otis
The majority of routes across the Pacific indicate (westbound) a Great Circle (GC) to about 30N then rhumb line (RL) direct to China via Osumi Kaikyo. A more conservative route is highlighted by either GC or RL to roughly 15.30N/156W then either GC or RL direct to their destination based on the current pattern. There are very few tracks between 35N to 50N due to the consistent Gale/Storm track residing in these latitudes, and any vessels transiting out of the Pacific Northwest USA/Canada generally route via the Bering Sea north of the Aleutian Islands, which help shelter ships from the adverse sea and weather conditions further south. In more normal years the dominant cross-basin route takes a GC path along 54N north of the Aleutian Islands throughout the year.
Weather pattern change
This shift to more conservative routing in the winter can be linked to recent climate variations that have been affecting the basin during that time.
Fig.2: Plot of 20-year average of extreme wave height altimetry scan (Dec-Jan Feb, top/Jun-July-Aug, bottom, courtesy of IH Cantabria – Universidad de Cantabria)
Fig 2 shows the average highest waves within the North Pacific reached a formidable 17m across much of the basin during the winter months with a sharp decrease to 7-8m in the summer months. This seasonal contrast is reflected in Figure 3 where the correlation between the phases of the Arctic Oscillation(AO) and El Nino are compared to wave heights. The green shading represents a negative correlation between the index and wave heights and orange-red shows a positive correlation. This correlation suggests that a stronger negative AO and El-Nino phases provide the ingredients for some extreme wave heights in the North Pacific.
Fig.3 Influence of the Arctic Oscillation (Left) and ENSO NINO3 index (Right) on wave heights. (courtesy of IH Cantabria – Universidad de Cantabria)
According to NOAA this last winter of 20/21 (see Fig 4.) had some of the strongest negative AO indices with the index falling as far as -1.8 in January 2021; the lowest it has been in 10 years. The AO’s positive phase is characterised by lower-than-average air pressure over the Arctic and higher-than-average pressure over the northern Pacific/Atlantic Oceans. So when positive the jet stream is farther north than average, so storms can be shifted northward of their usual paths. Conversely, it’s negative phase has higher-than-average air pressure over the Arctic region and lower-than-average pressure over the northern Pacific/Atlantic Oceans. This shifts the jet stream toward the equator, so it is south of its average position allowing the gale/storm track to extend into the Trans-Pacific shipping lanes.
Fig 4: Arctic Oscillation Index from 2010-2021, courtesy of LuAnn Dahlman on NOAA Climate.gov
Fig 5 shows the NOAA Wavewatch III Significant Wave Height (SWH) analysis for 30 Nov 20 (one day before meteorological winter), when a large storm off Japan created SWHs up to 16m within the core of the system at around 44N, with very rough seas up to 6m extending as far south at 35N between 170E and the prime meridian. This vastness in size makes such seas almost unavoidable and inherently more dangerous if under pressure to arrive on time.
Fig 5. NOAA Significant wave heights 0000UTC November 30, 2020
Another example is shown for 9th January 2021 when a very strong storm in the Eastern Pacific (Fig 6) produced SWHs up to 17.5m (Fig 7) at the centre with very rough seas up to 6m extending south to near 30N.
Fig 6. NOAA GFS Surface analysis for 0000Z 9 Jan 21
Fig. 7 NOAA Significant Wave Heights 0000Z 9 Jan 21
There are numerous other possible reasons behind these peak losses. These range from ever larger vessels being stacked higher than before, to ships being fully laden (or close to this) with improperly secured container stacks, inadequate maintenance of the securing systems, and incorrect stack weights impacting ship stability. Furthermore, bigger ships, at or near full capacity, can lead to stronger (more violent) ship motions within strong and persistent storms which put additional strain on lashings. According to Gcaptain, experts believe the situation has been exacerbated by a surge in e-commerce following the explosion in consumer demand arising from the covid pandemic, dramatically increasing pressure on shipping lines to deliver products as quickly as possible.
While the International Maritime Organisation is currently awaiting results of investigations into the latest incidents, it is already clear the changed weather pattern over the last winter contributed to these losses. Fleetweather closely monitors such large-scale climate variations and how these will changes impact on current and future seasonal routing. Regarding El Niño-Southern Oscillation (ENSO), we are currently in the neutral phase for the summer but with the recent La Nina Watch put in effect by the Climate Prediction Center for winter, this could mean good news for Trans-Pac vessels this coming winter.
Stay connected and safe.