IrMaria

A couple of years ago a young friend mine, then a pre-med student at the University of Puerto Rico, told me of some of the projects going on there. I was intrigued by one. A professor was studying mitochondrial DNA composition across the Puerto Rican population. I was surprised to learn that a typical analysis showed a Puerto Rican had 50 % Spanish (or other southern European), 35% African, and 15% Taino heritage. I would have thought the fraction for the Taino, the peoples that populated the islands now known as the Greater Antilles prior to and during the Spanish arrival, would have been less. That it was as high as 15% indicates there must have been significant interactions among the Spanish and the Tainos after the Spanish got here, enough to overcome the effects of disease and war.

The Taino were in fact a generally peaceful people with a complex social structure. They were, at the time of the Spanish arrival, under stress from the more war-like Caribs to the east. Perhaps the Taino saw the Spaniards as allies against them. Their belief system included zemis, spirits or ancestors. One zemi, Artabey, had control over natural disasters, aided by his two assistants: Guatauba, in charge of hurricane winds, and Coatrisquie, creator of floodwaters. It is unclear whether Juracan was a zemi, or just the Taino word for hurricane. In any case, it is likely hurricane is derived from the Taino Juracan made known to the Spanish. It first entered English in Richard Eden’s Decades of the New World, published in 1555:

These tempestes of the ayer (which the Grecians caule Tiphones …) they caule furacanes.

Perhaps some mystic forces disturbed Guatauba, Coatrisquie and Juracan this year, an explanation perhaps better suited to climate change deniers than continually trying to downplay the effects of human-induced global warming. Puerto Rico suffered from two large hurricanes, but the devastation here was largely overshadowed by Hurricane Harvey in Texas, Irma in Florida, and wild fires in California. Even now, late November, 2017, two months after Maria, damages are apparent and recovery efforts are continuing.

Hurricanes Irma and Maria were both so-called Cape Verde hurricanes. These storms begin as a low pressure wave that exits the West African coast near the Cape Verde Islands. If storm development continues, the wave is tracked as an invest, then a tropical depression graduating to a tropical storm to a hurricane. Developing systems track westward across the tropical Atlantic, over large distances of warm water which favors storm development. Cape Verde hurricanes are usually the largest and longest-lived hurricanes of the season. This year the surface sea temperatures in the Atlantic were one to two degrees Celsius higher than long term average temperatures; this was a source of energy for the developing hurricanes.

Map of sea surface temperature anomalies , early September 2017. The colors represent departures from long term average temperatures. The Cape Verde islands are off the coast of Africa, at about 22 degrees west, 18 degrees north. See Notes and Sources for attribution.

Tropical low 93L which would develop into Hurricane Irma. Note the Cape Verde islands outlined below the clouds.

Hurricane Irma began as a tropical wave, invest 93L, first noticed on August 27 or 28. It was identified as a possible hurricane early on and various model runs showed it hitting or passing north of the Lesser Antilles. But that was still five or six days in the future, and model uncertainty is great over that time frame. Irma reached tropical storm status (and earned her name) on Wednesday, August 30. The next day, Irma’s eye became visible and she had intensified into a Category 2 hurricane. Model forecasts continued to show the Lesser Antilles at risk, and a strike on Florida not out of the question.

Irma intensified rapidly and by September 4 was a Category 5 hurricane. Irma, in fact, became the strongest hurricane ever recorded north of the Caribbean and east of the Gulf of Mexico, with sustained winds of 185 mph. She slammed into Antigua, Barbuda,  and St. Maarten, causing great damage. Irma was the most powerful hurricane ever recorded in these islands. A wind gauge on Barbuda recorded a gust of 155 mph before it failed.

A false color image of Hurricane Irma, September 6, 2017. The island of Barbuda (population about 1,500) is outlined in Irma’s eye.

Irma passed just north of Puerto Rico on September 2 and 3. The image at the top of this post shows Irma north of the Dominican Republic heading for the north shore of Cuba. The image also shows Katia (Category 1) to the left and Jose (Category 3) to the right. After pounding Cuba’s north coast, Irma would then veer more northerly and strike Key West and Florida. I’ll leave it to others to describe the consequences of that.

Puerto Rico was lucky. Not only did Irma not make a direct hit on the island, but the storm track was such that the weaker, left (with front as the direction of travel) quadrant affected the northeastern coast. But is was enough to cause damage. San Juan lost power for several days, as did other communities on the northeastern coast. The local power utility was able to get things back together in fairly short order. But by this time, Maria was lurking.

Tropical Invest 96L was noted on September 13 or 14. By the 15th, it showed more organization; the National Hurricane Center gave it a high probability of developing into a hurricane. Computer models forecast potential tracks and growth in intensity even as early as September 15th. The figure below shows potential storm tracks for the developing storm. Note that most of the solutions put Puerto Rico right in the cross hairs for a direct hit.

Forecast tracks for tropical invest 96L which would develop into hurricane Maria. These model runs were done of September 15th, 5 days before actual landfall. Note that most predicted storm tracks, but certainly not all, showed Puerto Rico at of a direct hit from the developing storm. The numbers along each track show hours into the future; 240 would be 10 days.

Like Irma, Maria intensified rapidly. She grew from a low end Category 1 storm to a Category 5 in less than one day. Her track took her a bit further south than Irma; Maria made a direct hit on Dominica as a full-fledged Category 5  on the evening of September 18. Maria was only the fifth hurricane to make landfall in Dominica since the 1830s. Cool ocean temperatures to the east typically prevent storms for strengthening to hurricane status before reaching Dominica. But, as noted above, ocean temperatures were warmer than usual along Maria’s track, abetting rapid storm intensification.

By this time, it was clear Maria was headed to Saint Croix (of the US Virgin Islands) and then Puerto Rico, with a track taking across the island from the southeast to the northwest. This in fact happened, with well-documented catastrophic results. Maria was a devil. Other hurricanes have struck here, but never has one so devastated the whole island. In the past, the population could shift to the undamaged parts as the damaged portions were rebuilt, That was not an option with Maria.

I will leave it to another post to describe the government response, both federal and local. I note in anticipation of that, if I remember correctly,  the federal government did not mention Puerto Rico in any briefing until four days after the storm. The President was golfing, as I recall. When President Trump did come, he tossed paper towels into a crowd gathered within a gated community. Paul Krugman, New York Times columnist, wrote a column with the title ‘Let Them Eat Paper” a few days after that performance.

I arrived here November 15, almost two months after Maria. Fortunately, the power in my building had been restored three days before my arrival. Power is slowly being restored through San Juan – a friend of ours in Old San Juan got her power back 60 days after the storm.

I’ll end this post with some images I’ve collected over the past few days.

A convoy of utility trucks from Con Ed, located in downstate New York. They were swarming over Old San Juan. They had arrived a few days before. Residents were delighted to see them.

Utilities from New York State have recently sent crews and equipment here. I don’t yet know why or how, or why they are here now and not sooner, but I’ll find out. I saw seven or eight ConEd trucks in Old San Juan the Monday and Tuesday before Thanksgiving. I’ve also seen convoys of the same utility heading into other parts of San Juan. Needless to say, the residents are most grateful.

An uprooted banyan tree in Old San Juan. This is near the cathedral, looking towards the San Juan Gate.

Banyan trees, both in Old San Juan but especially in Parc Luis Munoz Rivera, were especially hard hit.

The wind was strong enough to twist streets lights out of alignment.

Many if not most of the street lights are not working. This seems to have made no difference in traffic flow. But is does make a bus ride through an intersection interesting.

You may be happy to know that some things are as normal as ever.

Notes and Sources: See Wikipedia entries for Taino culture, Decades of the New World, and Cape Verde hurricanes.

The meteorology information came mostly from the excellent blog posts on Weather Undergound, www.wunderground.com. The blogs, by Dr, Jeff Masters and Bob Henson, are clear and informative. See the blog archives for more information about the satellite images I used.

The sea temperature graphic came from a NOAA website: http://www.ospo.noaa.gov/Products/ocean/sst/anomaly/.

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