Sunday, June 25, 2023

"The Secret Messages in Ancient Storms"

Like many other blogs and websites we've looked at paleotempestology a couple times, so here's hoping we don't bore you. If interested the problems we run into are after the jump.

From, June 23:

Paleotempestology promises to uncover patterns of historical hurricanes—to better predict destructive weather of the future.

“Blow, till thou burst thy wind, if room enough!”
—William Shakespeare, The Tempest, 1610-1611

One Sunday in August 1635, the Mather family from England was finally about to reach the New World when a furious storm caught the ship and its crew by surprise. The cables anchoring the boat near a group of islands, 6 miles off the New England coast, reportedly snapped, and the vessel with its dozens of passengers hurtled toward a rocky shore. Fortunately, the winds turned at the last minute and steered the ship in another direction, their son Increase Mather would later write.

But others weren’t so lucky. According to colony governors in what are now Boston and Plymouth, Massachusetts, the storm drove other ships aground, toppled sundry houses, blew down hundreds of thousands of trees, and caused the sea to swell by up to 20 feet. “[It] was such a mighty storm of wind and rain,” the governor of Plymouth Plantation wrote, “as none living in these parts … ever saw.”

Indeed, contemporary simulations suggest the Great Colonial Hurricane was a Category 3.5 storm, probably the strongest in recorded eastern New England history. (For reference, Sandy, which killed nearly 150 people and caused some $65 billion in damage in the United States, was technically no longer even a hurricane when it made landfall in the New York metro area in 2012.)

Scientists know about the Great Colonial Hurricane’s impact not only from written reports but curiously, also from hidden, physical impressions the long-ago storm left on the landscape.

Hurricanes are not solely random events, but can come in waves across the ages.

At the bottom of a pond, Jeffrey Donnelly, a hurricane scientist at the Woods Hole Oceanographic Institution, and his colleagues found subtle, buried evidence of the storm that almost felled the Mather line. The researchers were collecting sediment cores from a lakebed on Cape Cod. The spot, known as Salt Pond, lies about a third of a mile from the ocean and has long been a place of mud. But in their core samples, they found a pinky finger-thick layer of pure ocean sand in layers that dated back to roughly 1635. The only thing that could have pulled that much beach material over the sand barrier and that far inland was a truly massive storm.

The cores revealed other clues, too. Although written accounts suggest the 1635 tempest was the strongest of its time, the exhumed samples showed it wasn’t the only intense storm in the area. Donnelly found evidence for 10 major storms1 in the area between 1400 and 1675—a surprising toll, given that major hurricanes are virtually unheard of this far north today. The fact that hurricanes were much more frequent in the past begs the question of why, and whether these levels of storm activity could someday return.

Which is why researchers like Donnelly are traipsing along coastlines and digging in the muck. They hope their relatively new branch of science, paleotempestology (the study of old storms), can use these buried traces of long-gone winds to augur ancient patterns. Patterns that might also help us predict the weather that lies ahead.

Paleotempestology seems like it could be a flighty field, an esoteric subniche of imprecise weather science, borne as it is from shifty grains of sand and mud. But since its birth in the 1990s, it has generated important insights into hurricane activity over centuries and even millennia. And like so many important developments in science, it took off with a seemingly simple question.

During a 1989 lecture, Kam-biu Liu, a scientist at Louisiana State University, was explaining how ash layers marked the activity of ancient volcanoes, when one of his students, Miriam Fearn, asked if hurricanes also left behind detectable traces. This was a possibility he hadn’t considered before....


From a 2022 post, "Blue Holes Show Hurricane Activity in the Bahamas Is at a Centuries-Long Low":

This research is all well and good and in fact is pretty darn creative but what I would like to know is what the action was like during previous warm periods. Unfortunately we run into what is almost an event-horizon, beyond which, like the black hole's event-horizon, we can't observe

As noted in the outro from "How Wall Street Is Gaming ESG Scores":

When a business/finance researcher uses language like "With supercharged hurricanes, massive floods and unprecedented wildfires sweeping the globe" you can tell he's a newbie to the science.

Just yesterday I was looking for hurricane data from the Roman Climatic Optimum and the Minoan Warm Period and the so-called paleotempestology gets pretty sparse at even 1200 years ago, much less 2000 and 3500.

And that's just a moment ago in time. If we are looking back to previous interglacial periods what were the hurricanes like in the Eemian interglacial, 125,000 years ago? Or the one a quarter-million years ago? Or the interglacial a million years ago. And 50 million years ago? 500 million?

Just what are we comparing the present to when we make these sweeping statements?

We just went through an 11-year period 2006 - 2016 with zero cat. 3 and above landfalling hurricanes hitting the U.S. Is that our baseline?

None of the coupled climate models had that happening. (Sandy wasn't much more than a giant tropical storm when it made its New Jersey landfall but throw in a landing at daily high tide and the full moon monthly high tide and Chris Christie walks President Obama to re-election)

The thing is, we just don't know what is "normal" and all we can do is hope that our recency bias doesn't lead us into some very dark (literally and politically) places as we feel our way forward.