Thursday, November 26, 2015

The King of King Tides Approaches

Fig. 1 King Tides on Steroids SLR
Happy Thanksgiving.

Some areas are talking about "king tides" this week ("King Tides Take Over Coastal Towns Just in Time for Thanksgiving", Weather Channel).

Any subject that deals with activities on coastlines around the world is not complete in the Anthropocene Epoch without some discussion of sea level rise (SLR), as one way of envisioning the near future in real time:
To avoid confusion, it’s important to know that king tides aren’t part of climate change; they are a natural part of tidal cycles but they do give us a sneak preview of what higher sea levels could look like. The actual height reached by a king tide will depend on the local weather and ocean conditions on the day.

It is possible that by 2060 to 2070 [an underestimate IMO - Dredd] we could experience tides of the magnitude of king tide events every month due to sea level rise induced by climate change.

This project aims to promote awareness of the impacts of sea level rise, and help to visualize coastal areas that are vulnerable to tidal inundation which can be monitored over time.
(King Tides Project). The subject matter today concerns why SLR is turning regular king tides into more serious flooding events (Fig. 1).

Note especially, though, that the addition of SLR causes flooding at different rates in different areas.

But before we launch into that aspect of the subject, let's refresh our memory about the natural aspect of king tides:
When a new moon or full moon align with Earth and the sun, the gravitational pull on Earth's oceans causes strange things [to] happen. Water creeps up
Fig. 2 Newton's Law of Gravity
along the shore and even into coastal towns – some of the highest tides of the year.

"The king tides arise from a combination of two factors. First, this is the time of year, known as perigee, when the moon is closest to Earth, exhibiting the strongest gravitational pull," meteorologist Jonathan Erdman says. "Secondly, around the full and new moon each month, the Earth, moon and sun are roughly aligned, and that increases the gravitational tug on the tides. Then, if either a storm is approaching or simply onshore winds are persisting, water will pile up along the shore, leading to further water rise."
(Weather Channel). That is one "type" of gravity which impacts upon sea level and tides, but there are other types of gravity that do so even more (The Gravity of Sea Level Change).

Fig. 3 This king tide never happened to Grandpa
There is only one factor that causes glacial ice and ice sheets to have a more dramatic gravitational impact on sea level than the Sun and Moon have.

That factor is distance (Fig. 2).

When communities are close to large glacier fields, or close to ice sheets, then as those icy areas melt, the gravity decreases in Newton proportion to the loss of ice mass (Proof of Concept - 3).

Fig. 4 San Francisco history
Media operatives continue to "soften" the reality of the SLR danger that civilization is facing, and will continue to face, whether it wants to face it or not.

Focusing on a "flood" event, using "king tide" to describe that event, is dishonest when we know that the area did not flood at king tides of the past (Bay Area may see flooding this week thanks to strong king tides, This week’s king tides bring danger of flooding, glimpse of future).

Fig. 5 Future Projection
The honest reporter will say "king tides did not flood this area in times past, but this area is experiencing SLR now, which is causing the flooding in our time that did not happen in earlier times."

I have discussed the constitutional right to lie (It Takes A Culture To Raise A Compulsive Liar).

But, that right vanishes when it causes harm, and when it causes fraud (Agnotology: The Surge - 18).

The "Hundred Years War" now under way (Watch The Ice Shelves) is not composed of king tide armies, rather, it is composed of the impact that our fossil fuel use has caused.

I am talking about global warming induced SLR (Greenland & Antarctica Invade The United States, 2, 3, 4; The Extinction of Chesapeake Bay Islands, The Extinction of Houston, The Extinction of Providence).

The king tide is hitting the "bay area" of San Francisco this week, so I added two graphs which show actual tide gauge station historical sea level change (SLC) data, as well as the actual historical pattern of global mean sea level (GMSL) and global mean surface temperature (GMST) data (Fig. 4).

There is little doubt that local sea level there is on the rise, with GMSL and GMST generally on the rise elsewhere.

Thus, the king tides of today are higher than those of our grandfathers.

What about the king tides of the future?

Check out Fig. 5 for some ideas.

The next post is this series is here.

We can all contribute data or start a chapter:

1 comment:

  1. Your precise and compelling work just keeps advancing Dredd! Like the 'tides'!

    20 years ago the movie 'Waterworld" and its apocalyptic, melted polar cap scenario was ridiculed; likely by the FUD crowd.

    Doesn't seem such a big leap now!

    [speaking of dry land]

    Mariner:( Kevin Costner) Because I haven't seen it. And I've sailed further than most men have dreamed.