«Climate change is causing hurricanes to reach unpredictable places»

The image he saw on the screen was the one transmitted by the radar of the Puerto Rico meteorological service, a way to feel closer to home, supporting his loved ones, but suddenly the connection failed and everything went black. That radar had been in operation for decades and had withstood many hurricanes. That the image disappeared did not bode well.

The cut in communications prevented Mayra, for weeks, from knowing the status of her family. When she got it, the news was good: everyone was safe. “It was a very painful experience, especially living it from the outside, because I work studying these systems, I know their dynamics and technology, but I couldn’t do anything to help my family,” she says.

Almost five years have passed since then and, once again, the hurricane season has begun again, which officially extends from June to November. These systems need four key ingredients to form: heat or energy stored in the upper layer of the ocean; a high degree of humidity in the air, which is achieved through the evaporation of ocean waters above 26°C; favorable winds, weak enough to prevent the storm from breaking up; and rotation, to achieve its characteristic spiral shape, which comes from the Earth’s own movement as it rotates around its axis. However, climate change is altering its dynamics. Oyola-Merced resolves some doubts in this regard.

How does NASA contribute to hurricane science?

Although NASA is primarily known for its space program, its work also greatly influences climate science. For example, in the prediction, understanding and analysis of hurricanes, a task for which it has a fleet of more than 20 satellites and in which it collaborates with other partners, such as NOAA (National Office of Oceanic and Atmospheric Administration) or the FEMA (Federal Emergency Management Agency). The goal is to help communities prepare for these storms and respond to their impacts, to avoid, as much as possible, human and material losses.

What is the average number of hurricanes that occur in a season?

If we look at the last three seasons, 2020 was categorized as the second most active season for tropical cyclones in the Atlantic. 2021 was the third, and this year the initial forecast shows that the season is going to be much more active compared to the initial forecasts of 2020 and 2021. In 2022, 14 to 21 tropical storms are expected, of which between 6 and 10 can become hurricanes and, of that group, between 3 and 6 could be hurricanes of greater intensity, that is, categories 3, 4 or 5 – category 1 is the least intense, with winds of 119 to 153 km/h ; Category 5 is the most intense, with winds greater than 250 km/h.

Thanks to the technology we have today, are hurricanes easier to predict or is climate change complicating their forecast?

Certain aspects of hurricanes are now much easier to predict. For example, 40 years ago the accuracy of weather forecasts was 1-2 days. Now, however, we can make very accurate forecasts of 7 to 10 days, or more. All this thanks to the technological advances of computers and satellites, which provide us with much more information about the atmosphere.

At the same time, climate change is fostering certain patterns that were not previously seen. For example, what research tells us is that climate change is not necessarily increasing the number of systems in a season, but it is strengthening them. So we are seeing, especially since 2005, seasons with more intense category hurricanes, which were rare in the past and are now much more frequent.

In addition, this strengthening occurs in a shorter period of time, that is, hurricanes more easily go through a rapid intensification process, which implies that a system can transform from a tropical storm to a category 3, 4 or 5 hurricane in less than 24 hours. This poses a challenge to current prediction models.

Is hurricane season extending?

One of the primary factors for the formation and strengthening of hurricanes is ocean temperature. Right now, the oceans are absorbing 90% of the heat generated by greenhouse gases, that is, they are warming more than they should, which may influence the extension of the hurricane season. In fact, we’re already seeing storms forming out of season, sooner or later.

What other changes are being recorded in the characteristics of hurricanes?

As ocean temperatures increase due to climate change, we will see alterations in the track, thermodynamics, precipitation, rotation, and translational (linear) movement of hurricanes. For example, systems now reach places where they were previously unseen or rare, such as India. They also move more slowly, particularly after making landfall, which causes more damage; and they are more humid – for every degree of warming, the atmosphere can contain 7% more water vapor that could fall in the form of intense precipitation – which makes them more dangerous.

In addition, this year another factor is added. The cycle known as ‘El Niño’ and its opposite phase ‘La Niña’ are phenomena that naturally contribute to temperature changes in the atmosphere. During ‘el Niño’, high rainy seasons are common; while ‘La Niña’ (which we are in now) is characterized by more active hurricane seasons. Both are natural phenomena on Earth, but climate change aggravates them, because ‘La Niña’ generates higher temperatures in the Atlantic, which is already warmer due to climate change, so that hurricanes can intensify significantly. easier and faster.

The hurricane is a natural process with which the Earth regulates itself, why is it worrying that the number of hurricanes is increasing?

The most basic concern is the protection of life and the protection of property and the economy. The problem with the increase in the number of hurricanes is that the population is exposed to greater risk and, as a consequence, the number of climate refugees or environmental migrants could increase, that is, people displaced from their countries of origin by the disasters caused. by hurricanes in places that are not prepared to face these systems.

Why are hurricanes getting closer to Europe?

Hurricanes form in tropical areas, with warm waters, and when they approach areas where the waters are more temperate or cold (such as northern Europe), they weaken. It’s like it’s a car that’s leaking fuel. However, as the energy balance is altered by climate change, areas that were previously colder are now warmer, which causes the hurricane to weaken less.

But that’s not all, the fact that ocean temperatures are changing is also influencing the circulation patterns of the trade winds that generally direct hot surface waters from east to west, so their approach to places in the While it was rare to see tropical storms in the past, they will become more frequent.

Will a category 5 hurricane, like Katrina, reach Spain?

We don’t know for sure, but in recent years in the United States we have seen hurricanes reach areas where these phenomena practically did not reach before. One of the most recent and shocking examples was Hurricane Sandy, which reached New York and Washington, where a hurricane is rarely seen, leaving incredible damage in its wake, such as completely destroyed subway stations in New York. That is, we don’t know if something like this is going to happen, but everything indicates that it is possible. If this happens, the countries that will be affected first are those with a coast, such as Spain or Portugal, for example.

Is Europe prepared for a high intensity hurricane? What is the best way to protect yourself?

Europe’s infrastructure may need to be strengthened in case more hurricanes start to hit. On an individual level, the main thing is to stay informed with the right resources. There is a lot of misinformation circulating on the internet. It is advisable to go to the information sources of the local authorities. Also, get advice on the risks of the area in which you live. For example, what risk of flooding our street has, in order to know if we should leave the area and seek refuge elsewhere when the hurricane arrives. At home, it is advisable to have an emergency plan (canned food, bottled water, medications…). The most important thing is to take the time to think about what things we can do to avoid major problems.