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SEA LEVEL RISE WATCH AROUND PUERTO RICO:

(updated up to November 2016)

Figure 1 – Google Earth view showing the location of the NOAA tide gauge stations under study (white circles). San Juan and Magueyes Island.

Figure 2 – Sea level rise as observed at the San Juan tide gauge station. Monthly means.

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Figure 3 – Sea level rise as observed at the Isla Magueyes tide station. Monthly means.

Table 1:

LOCATION TREND FROM LINEAR LEAST-SQUARES FIT OF ALL MONTHLY DATA

(mm/year) San Juan 2.04

Isla Magueyes 1.80 Table 2:

LOCATION TREND FROM LINEAR LEAST-SQUARES FIT OF MONTHLY DATA STARTING IN 2010 (mm/year)

TREND FROM LINEAR LEAST-SQUARES FIT OF FILTERED DATA STARTING IN 2010 (mm/year)

San Juan 12.12 10.03 Isla Magueyes 10.31 8.27

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Figure 4 - San_Juan_Monthly_Sea_Level_Rise_Detrended. Monthly mean variability relative to long term linear trend.

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Figure 5 - Magueyes_Monthly_Sea_Level_Rise_Detrended. Monthly mean variability relative to long term linear trend.

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Figure 6 - San_Juan&Magueyes_Monthly_Sea_Level_Rise_Detrended. Smoothed monthly mean variability relative to long term trend.

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Figure 7 - San_Juan_Magueyes_Historical_SLR__Linear_Trend_up_to_September_2016. These plots show how the long term linear slopes have varied over time, starting in 1990.

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Figure 8 – Bar chart for San Juan showing the variablity of monthly means sea level as a function of time for each individual month. January to June.

Figure 9 – Bar chart for San Juan showing the variablity of monthly means sea level as a function of time for each individual month. July to December.

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Figure 10 – Bar chart for Isla Magueyes showing the variablity of monthly means sea level as a function of time for each individual month. January to June.

Figure 11 – Bar chart for Isla Magueyes showing the variablity of monthly means sea level as a function of time for each individual month. July to December.

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Figure 12 – Bar chart of monthly mean sea level elevations for the month of January. San Juan.

Figure 13 - Bar chart of monthly mean sea level elevations for the month of February. San Juan.

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Figure 14 – Bar chart of monthly mean sea level elevations for the month of March. San Juan.

Figure 15 - Bar chart of monthly mean sea level elevations for the month of April. San Juan.

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Figure 16 – Bar chart of monthly mean sea level elevations for the month of May. San Juan.

Figure 17 - Bar chart of monthly mean sea level elevations for the month of June. San Juan.

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Figure 18 – Bar chart of monthly mean sea level elevations for the month of July. San Juan.

Figure 19 - Bar chart of monthly mean sea level elevations for the month of August. San Juan.

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Figure 20 – Bar chart of monthly mean sea level elevations for the month of September. San Juan.

Figure 21 - Bar chart of monthly mean sea level elevations for the month of October. San Juan.

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Figure 22 – Bar chart of monthly mean sea level elevations for the month of November. San Juan.

Figure 23 - Bar chart of monthly mean sea level elevations for the month of December. San Juan.

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Figure 24 – Bar chart of monthly mean sea level elevations for the month of January. Magueyes Island.

Figure 25 - Bar chart of monthly mean sea level elevations for the month of February. Magueyes Island.

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Figure 26 – Bar chart of monthly mean sea level elevations for the month of March. Magueyes Island.

Figure 27 - Bar chart of monthly mean sea level elevations for the month of April. Magueyes Island.

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Figure 28 – Bar chart of monthly mean sea level elevations for the month of May. Magueyes Island.

Figure 29 – Bar chart of monthly mean sea level elevations for the month of June. Magueyes Island.

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Figure 30 – Bar chart of monthly mean sea level elevations for the month of July. Magueyes Island.

Figure 31 - Bar chart of monthly mean sea level elevations for the month of August. Magueyes Island.

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Figure 32 – Bar chart of monthly mean sea level elevations for the month of September. Magueyes Island.

Figure 33 - Bar chart of monthly mean sea level elevations for the month of October. Magueyes Island.

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Figure 34 – Bar chart of monthly mean sea level elevations for the month of November. Magueyes Island.

Figure 35 - Bar chart of monthly mean sea level elevations for the month of December. Magueyes Island.

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IMPLICATIONS

There are many consequences of this observed rise in sea level. I will mention just a few.

• Nuisance flooding

What is called “nuisance flooding” is already happening in the island. This has been documented in the news, and also by several scientists. Figure 35 shows a scenario that has been happening in some streets in El Condado in some streets facing the Condado Lagoon for several years now. Figure 36 was taken in 2012 at a coastal community in Mayaguez. Figure 37 shows the El Nuevo Dia report about how the residents of the low-lying areas on the western shore of the San Jose Lagoon Photos are copying with the almost annual flooding that happens in their community. Figures 38-40 were obtained by Dr. Katia Aviles and were obtained with the approval of Dr. Jorge Bauza. They show how water from the Laguna San Jose floods the surrounding low lying areas. This flooding peaks during the high-water stance during the months of August-September-October. There are many areas where living depends on the presence, and work, of water pumps. The San Juan International Airport is already feeling the problem, according to an engineer who spoke with me. In places where still there is no sea water penetration, flooding still occurs each time more frequently due to the poor drainage to the sea, as Figure 41 shows, also in the low-lying area bordering the San Jose Lagoon.

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Figure 36 – San Juan Star.

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Figure 37

Figure 38 – Taken from El Nuevo Dia.

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Figure 39 – How locals are trying to cope with what has become an almost annual event in the low-lying areas on the western shore of Laguna San Jose.

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Figure 40 – How locals are trying to cope with what has become an almost annual event in the low-lying areas on the western shore of Laguna San Jose.

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Figure 41 – How locals are trying to cope with what has become an almost annual event in the low-lying areas on the western shore of Laguna San Jose.

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Figure 42

• Increased Coastal erosion It is a fact that the higher the sea level, the easier for the waves to penetrate inland, and the consequent erosion. This has been documented all over the planet, and it is a logical consequence of a high water stance. It happens in scales from a few hours to months, to hundreds, or thousands, of years. On the scale of a few hours a storm surge can erode large sand dunes, as shown in Figure 42.

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Figure 43 – Coastal (dune) erosion during a storm surge.

The same can happen on scales of weeks to a few months. The best example of this is what happens in the Hawaiian Islands when they are bathed by warm core eddies moving east to west. Being warm core, sea level is raised in their core, and it doesn’t has to be much. Figure 43 shows a newspaper clip describing what happened in 2003, in the island of Maui. This scenario is the one that most resembles what happens in Puerto Rico during the high-water months of August to October.

The same process is observed at scales of several years in the Great Lakes (see Figure 44). Finally, sea level rise at the scale of several decades is obviously tied in to long-term coastal erosion, as has been documented elsewhere, being Hawaii a good example (Romine et al., 2013; Anderson et al., 2015).

In Puerto Rico we also have a plethora of examples of examples of the coastal damage that is exacerbated during the peak months of August to October. Figure 45 shows the sad situation of Palominito Island, with a photo taken back in 2012. Figure 46 shows how during the 2012 high water stance the Ocean Park beach started to get attention due to its accelerated erosion. The same happens all around the island. The Loiza municipality road erosion event in late 2015 is another example of the consequences of what is becoming more, and more, frequent, which is the record sea level peaks observed during September-October. When these unusual events happen our beaches are caught with “with their pants down”, and a disequilibrium follows. These events might be unusual for now, but will become the norm as time progresses.

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Figure 44 – Coastal erosion in Hawaii due to warm core eddies.

• Coastal flooding due to storm surges and waves. It should also be obvious that when a storm surge, or just a wave attack, happens during these high sea level stances then conditions are more favorable to exacerbate inland flooding. For example, in 2015 the monthly mean sea levels for September-October were above 0.2 m above MSL. In islands like Puerto Rico, where the hurricane wind setup is weak, an initial elevation to start with of 0.2 m could be the equivalent of a category 1, or 2, hurricane stillwater elevation at some coastal locations, especially at those with extremely narrow shelves (to be determined). Or it could also be the equivalent of the amplitude of a coastally-trapped infragravity wave.

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Figure 45 – Coastal erosion in the Great Lakes due to lake level fluctuations.

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Figure 46 – Isla Palominito in the past and what remains in 2012.

Figure 47 – Ocean Park beach during September-October 2012.

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