Circling Cyclones

Since we’re currently in hurricane season, it seems a good time to talk about hurricanes and cyclones. These types of weather systems don’t often find themselves in a traffic jam in Earth’s vast oceans, but when they do, there are consequences.

When two storms move too close together, they start to influence one another’s strength and track. This tropical tango is known as the Fujiwhara effect. That scenario played out this week when Hurricanes Imelda and Humberto danced together off the southeastern US coast.

After devastating the coast of North Carolina, Humberto moved out to sea, but as it did so, it tugged Imelda to go with it.

On Tuesday (9/30), they were both Category 1 hurricanes and they were within 467 miles of each other, which is the closest that two Atlantic hurricanes have come to each other in at least the past 60 years. Two hurricanes churning side-by-side is more common in the Pacific Ocean but rarely happens in the Atlantic.

The interactions during these events can vary greatly, which can make forecasting the tracks and intensity a challenge. Imelda’s track forecast changed dramatically after she was pulled away from the US and toward Bermuda.

Both hurricanes struggled in the face of the other’s wind shear, with Humberto weakening and finally dissipating Wednesday morning. After that, forecasters expect Imelda to hit Bermuda on Thursday as a Category 2.

In 1921, Japanese meteorologist Sakuhei Fujiwhara published a paper that said two storms spinning near each other could start rotating together around a common center point. He was right.

How close the storms need to be to trigger the Fujiwhara effect is dependent on the size of each storm. If two large storms—those that span hundreds of miles—get within about 850 miles of each other, they start to dance. The distance shrinks to 350 miles for smaller storms.

Closely matched storms will orbit around a common point but then go their separate ways. The circling tugs each storm off the path they would have taken. In 2017, Hilary and Irwin had this experience in the east Pacific. They were well matched. Both systems interacted for so long, they eventually dissipated around the same time.

But if one storm is much stronger than the other, the stronger one could consume the weaker one. In the west Pacific in 2022, the powerful typhoon Hinnamnor was headed for Taiwan before it met a tropical depression that was trying to grow. Hinnamnor and the depression rotated until the typhoon devoured the depression. Hinnamnor slowed and weakened for a bit, but when it restrengthened, it took a nearly 90-degree turn from its original track.

In a rare Fujiwhara scenario, two weak storms spinning together could merge and create a larger storm,

All of these potential interactions and outcomes pose an incredible forecasting challenge, even for computers. Any small changes in the strength or size of each storm, or slight deviation from the anticipated track throws a model’s complex calculations into chaos.

 

https://www.nola.com/news/hurricane/hurricanes-humberto-imelda-fujiwhara/article_14cec9cf-1c86-422c-983d-71b320682d2b.html

https://www.msn.com/en-us/weather/topstories/here-s-what-can-happen-when-two-hurricanes-get-too-close-together/ar-AA1NiXg4?ocid=hpmsn&cvid=68d5abc4f3d04d0b915ca4e4134e1350&ei=63

Ancient Note Pad

These days, most people do a lot of their shopping by clicking a few buttons. That might be convenient, but it can make it difficult to keep track of when your new armoire or bookshelf will actually show up. In ancient Turkey, somebody kept such details written down on a palm-sized piece of clay.

The Accana Mound is the site of the ancient Anatolian city of Alalah, which served as the capital of the Mukis Kingdom. The ruins found there date as far back as 4,000 years ago. At an excavation at the Accana Mound, researchers recently unearthed a small clay tablet inscribed with cuneiform writing. A study of the tablet has narrowed its origin to some time in the 15^th century BC, during the Late Bronze Age.

Initial readings of the tablet’s Akkadian cuneiform revealed details of a major furniture purchase, including an ample number of wooden tables, chairs, and stools. The experts are still working through the writing and are slowly gathering information about the buyers and sellers involved. Therefore, this small tablet offers a window into the city’s economic processes. Alalah was located along a trade route at the time, so it would have been a center of commerce in addition to being a capital.

The small piece of clay measures only 4.2 centimeters by 3.5 centimeters and is just 1.6 centimeters thick. It weighs 28 grams. But despite its small size, the tablet will help paint a much larger picture of Bronze Age Turkey.

There have been other similar discoveries in the region, including in 2023 when another cuneiform tablet was discovered that details the purchase of an entire city and, one presumes, the furniture in it.

The area was first excavated in the late 1930s. But, after finding this clay list of furniture, it seems there’s still plenty of things to discover.

And who knows? Perhaps the tablet’s details will provide some home-décor inspiration.

 

https://www.msn.com/en-us/news/technology/archaeologists-uncovered-a-mysterious-ancient-tablet-with-major-historical-implications/ar-AA1M0JK3?ocid=hpmsn&cvid=fdce9a9bb7794d6189ca2cd589838f5c&ei=14