The Mexican military conducts security operations over Sinaloa, and some Mexican Air Force planes have been flying over the past three years with other types of “weapons.”.
On board, they transport containers with valves that must be opened at the correct place and time to hit the target.
His goal becomes very necessary: Make it rain in water-stressed areas.
The strategy is colloquially called “bombing” or “cloud seeding,” but technically it’s “rainfall stimulation.”
According to official data, 35% to 60% increase in rainfall in applied areas.
The work was carried out in the north-central states of the country, such as Sinaloa, where rainfall is no longer as high as it used to be, or comes later in the agricultural season.
In addition, there are places where livestock pastures cannot grow due to lack of water, and basins that supply water to large cities such as Monterey that have water problems.
Engineer Santiago Argüelles Campos, one of the strategic coordinators at the Ministry of Agriculture and Rural Development (Sader), explained to BBC Mundo: “Worldwide we have been facing a process of desertification, and neither has Mexico. exception.”
“For us, this strategic project is an innovation given the ongoing drought conditions since 2019,” he said.
While the effectiveness numbers reported by Sadr are very encouraging, researchers in the field of atmospheric science believe that, so far, no strong evidence The level of operation of such projects can have an impact.
But what does Yunfeiyue do and how to measure its results?
Since the mid-20th century, scientists around the world have been testing ways to modify the weather, primarily the precipitation of rain or snow.American scientist Vince Schaefer (Vince Schaefer) for inventing “Artificial rainfall”.
In Mexico, similar experiments have been carried out for decades Results “never reached conclusions”According to researchers Fernando García García and Guillermo Montero Martínez from the Cloud Physics Group of the Institute of Atmospheric Sciences and Climate Change.
But Argüelles explained that, since 2019, Sader has been promoting a new rainfall-stimulation strategy using an innovative approach from Mexico.
“We’re not looking for or intending to create cloudiness, we’re just looking at cloudy paths that occur under normal weather conditions,” he said.
Clouds form when rising air cools to a certain temperature and the water vapor it contains condenses.
“It’s very similar to how steam condenses on a mirror in the shower and forms water droplets. It’s the same mechanism as condensation in the atmosphere,” Katja Friedrich, a researcher at the Department of Atmospheric and Oceanic Sciences at the University of Colorado, USA, explained to BBC Mundo. “
To “bomb” the clouds, Mexico used aircraft from FAM (and other public and private entities that joined the project), in which Install sprinklers and pressurized tanks.
“In the polygon we defined, under cloudy conditions, a solution of silver iodide in acetone diffuses, stimulating the formation of condensation nuclei,” Arguilles explained.
The presence This chemical agent stimulates rainfall It is already present in clouds in the selected area, and due to natural factors, it may dissipate rather than settle.That’s why this Mexican method Does not seek to create clouds, but to affect clouds already present in the atmosphere.
In 2023, the plan has been applied to 10 polygons Provides care to areas suffering from water shortages in the central, northern and western states of the country such as Aguascalientes, Chihuahua, Coahuila, Durango, Sinaloa, Sonora, Tamaulipas and Zacatecas, among others.
How do you measure its effectiveness?
Polygons that stimulate rainfall can be as large as 2 million hectares. In these areas, the National Weather Service (SMN) has historical rainfall records and calculates projected rainfall based on statistical models.
After the plane sprayed water, there are rain gauges on the ground that the authorities can use Measures precipitation in addition to regular averages What are SMN’s expectations for a given period?
and 250 flights According to the research team, rainfall increased by one-third to two-thirds. “This means that in addition to the expected average precipitation, Between 35% and 60%.What matters is that they have defined three parameters’, Arguilles pointed out.
These are: A 35% to 60% increase in rainfall compared to the SMN forecast; A 100% efficiencybecause every time water is sprinkled, rain is produced; and a 93% effectivewhich represents the number of polygons that were rained compared to predicted.
“Generally, we choose areas of high water stress, crop-growing areas where primarily basic grains are grown or grasslands where food self-sufficiency goals are prioritized, and canyons or basins with significant runoff to dams that manage water consumed by humans. OR agricultural irrigation,” the official explained.
The latter has implications for large cities such as monterey or mexico cityas some overflights stimulate rainfall in the basins that feed the dams and other water management systems that meet the needs of these cities.
“Now that there’s an El Niño, SMN explained to us that we’re going to find more clouds in the Pacific in the middle of the country, but that doesn’t necessarily mean there’s going to be more precipitation. So it’s a matter of implementing this innovation , take advantage of this cloud opportunity”, Argüelles points out.
Is this a good solution to drought?
Al-Sadr emphasized that the project benefits areas with severe water scarcity, which no longer have the amount of water needed for agricultural irrigation, or areas where rains come later and the planting cycle has passed without the opportunity to sow any more.
They also observed an increase in grassland vegetation, which would benefit the cattle industry. They’ve even used the rainfall stimulus to mitigate forest fires, such as this year’s fires in the Altega Mountains in Coahuila state.
However, experts suggest that The outcome of such projects must be treated with caution.. There are so many variables in the climate that making the study of rainfall stimuli impossible to be sure or just do arithmetic.
It is difficult to measure whether rainfall increases are due to strategies such as cloud seeding or bombardment because Rainfall tends to vary from year to year in the same area. Furthermore, rainfall patterns differ between different regions of the same country and are not comparable.
“Precipitation varies a lot, and you can see how much the impact varies from one year to the next”Friedrich said he has seen results between 5% and 30%. Significant changes could exceed 20%, he noted.
After long-term research, years or even decadescan yield accurate results on whether strategies such as Mexico’s cloud stimulus are effective.
Arguilles acknowledged that there are doubts about the country’s strategy, but noted that there is “a lot of confusion” among some analysts because of the various approaches that exist in the world. “They mentioned other types of technologies, some of which were about creating clouds, and we didn’t focus on that,” he argued.
“What we’re saying is that with this technology, for us, We have quantified the resultsincreased precipitation and a positive cost-benefit,” he added.
The official also explained that the government does not see stimulating rainfall as a solution to the drought, but as part of measures to ease pressure on the country’s water resources.
“You can’t do (rainfall stimulation) as a single job, it’s an overall strategy that complements different projects,” he said.
He went on to say that the country must prepare for more severe water shortages in the near future: “We believe that in the future, irrigation with clear water will become a luxury.”
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