Panama Canal ship size limit linked to El Niño

Posted: August 8, 2015 by oldbrew in Ocean dynamics

Sea surface height relative to normal ocean conditions on Dec. 1, 1997 [image credit: NASA/JPL]

Sea surface height relative to normal ocean conditions on Dec. 1, 1997 [image credit: NASA/JPL]

This type of restriction was also imposed due to the ‘super El Niño’ of 1998, inviting comparisons with what’s happening to El Niño this season. No doubt various claims will be made about the causes. BBC News reports:

The Panama Canal Authority says it will temporarily cut the size of ships allowed through because of drought caused by El Niño. From 8 September, the maximum draft of ships will be cut to 39ft (11.89m), which may affect up to 20% of traffic. A similar restriction was imposed for the same reason in 1998.

The authorities say a further cut in the draft could be imposed on 16 September if the situation does not improve.The authority has taken the action because water levels in the Gatun and Alhajuela lakes has reduced as a result of the El Niño weather phenomenon. The current draft limit is 39.5ft, which will be cut to 39ft on 8 September and then potentially to 38.5ft on 16 September. Shipping companies had been warned the cuts could be coming.

The Panama Canal celebrated its 100th anniversary last year, having seen more than a million ships pass through. Panama took control of the canal from the US in 2000, and has since been widely praised with the way it has handled the operation.Transit fees now bring in about $1bn (£645m) a year for the government.

Original report: Panama Canal to limit ship size due to drought – BBC News.

Definition: ‘El Niño is the warm phase of the El Niño Southern Oscillation (commonly called ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (between approximately the International Date Line and 120°W), including off the Pacific coast of South America.’ – Wikipedia

Full description of El Niño graphic (above): This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Dec. 1, 1997. In this image, the white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it’s about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. – NASA/JPL

  1. oldbrew says:

    ‘The battle of El Niño and the blob’

    ‘The El Niño weather pattern often brings deluges to California, quickly dropping inches of rain in what climatologists liken to turning on a fire hose.

    Except when it doesn’t. Except when it brings no extra rain.’

  2. Richard111 says:

    What is the tidal range relative to these temperature induced sea level changes?
    Never knew they used lake water for the locks. Not a good idea in an area subject to drought.

  3. oldbrew says:

    Richard: the lakes are man-made, created by damming rivers when the canal was built.

    Fodor’s says Gatun lake – the main one – encompasses 163 square miles.

    Big variation in tidal range: ‘A variation of about 70 centimetres (2.3 ft) between high and low water on the Caribbean coast contrasts sharply with over 700 cm (23 ft) on the Pacific coast’

  4. tchannon says:

    How does temperature alter water level?

  5. oldbrew says:

    ‘How does temperature alter water level?’

    tc: here’s an extract from the IPCC version.

    ‘As the ocean warms, the density decreases and thus even at constant mass the volume of the ocean increases. This thermal expansion (or steric sea level rise) occurs at all ocean temperatures and is one of the major contributors to sea level changes during the 20th and 21st centuries. Water at higher temperature or under greater pressure (i.e., at greater depth) expands more for a given heat input, so the global average expansion is affected by the distribution of heat within the ocean.’ [bold added]

    If you mean water level in the canal, drought = much less rainfall than usual to top up the lakes which are a large part of the crossing (see BBC graphic in the linked report).

  6. p.g.sharrow says:

    warm water is less dense and floats on top of cold water. Although I wasn’t aware of the magnitude before now.

    I think we must rethink our opinion on the effects of geothermal on long term ocean conditions and

  7. Richard111 says:

    Does this mean warm water is less inclined to flow downhill? (less inclined! yes!🙂 )

  8. tchannon says:

    I make that 1000 metres of water @ +1C, 300mm @ 0.3e-3 ~ 30C

    So 3000 feet of water or was it hotter, mysteriously heats up in how long?

    Or is there spin going on? Trust face value?

    Looks like an attempt to link sea temperature as causal of wave. Don’t trust French government stuff either, that’s the photoshop painters. (goes back some years, add tops and tails to the sea level plots, deviant from data, and of course in bright red)

    Read this

    ” The weakening of trades in the western equatorial Pacific causes warm water in the upper layer of the equatorial region to move eastward, leading to higher sea level and warmer water in the eastern equatorial Pacific. The wave of higher sea level (called a Kelvin wave) reflects off South America, and returns to the west at latitudes north and south of the equator. “

  9. Paul Vaughan says:

    The amount of precipitation falling on land globally is tied directly to ENSO. The correlation is tight. (Locally: lake & canal levels.)

    These restrictions will bias ship sea surface sampling spatiotemporally, but in this particular case it will probably amount to no big deal in the grander scheme of things:

    I know most people are just confused by this sort of thing and find it too frustrating trying to think about it …but it’s the interesting stuff because the symmetries of turbulent coupling are clear.

    For a lot of these variables it’s not about whether A causes B or B causes A but rather simply recognizing coupling of A & B and not being thrown off track by spatiotemporal aliasing …like for example surface sampling of temperatures doesn’t capture latent stuff and it doesn’t capture vertical action (atmosphere-ward & ocean-depth-ward) or even basic wind-driven eddy structure.

    We need to be heeding Hsieh’s wisdom about not fitting noise when probing exogenous backbone attractor structure. At wuwt they disregard his sage counsel and as a result they’ve been misled *way* off-track by activist dark agents. It’s funny watching how stubborn they are about not correcting their work.

    Big request: I hope KNMI Climate Explorer will update their “Make EOFs” feature to support varimax rotation. Heh. I bet some people don’t even realize why the LOD curve shifts before & after the opening of Panama Canal. KNMICE could quickly facilitate revelation by supporting varimax rotation. (Meanwhile there are viable workarounds for KNMICE users, but they’re cumbersome.)

    It’s all about recognizing simply symmetry & asymmetry.

  10. Best get some dredgers in there to deepen the cut!

  11. DD More says:

    Steve, they are already working on it or in scheduling phase.

    Program Description

    The program consists in the construction of two new sets of locks – one on the Pacific and one on the Atlantic side of the Canal. Each lock will have three chambers and each chamber will have three water reutilization basins.

    The program also entails the widening and deepening of existing navigational channels in Gatun Lake and the deepening of Culebra Cut.

    In order to open a new 6.1 km-long access channel to connect the Pacific locks and the Culebra Cut, four dry excavation projects will be executed.

    Upgrading the whole system for the super carriers (366 m length – 13,000 – 14,000 TEU) to get through vs 294 m length.