Traditional Culture Encyclopedia - Weather inquiry - Cycas blooms: "Typhoon Argentina" appears in front of us! Is the global climate chaotic?

Cycas blooms: "Typhoon Argentina" appears in front of us! Is the global climate chaotic?

On June 28th, local time, when many places in North America were immersed in the heat wave, a storm was dancing wildly in the South Atlantic Ocean east of Buenos Aires, Argentina, on the other side of the American continent. From the close-up of the high-definition cloud image of the Earth observation satellite, the storm along the coast of Argentina has a clear spiral structure, and there is even a circular cloud hole structure in the center, which looks very much like a developing tropical cyclone (typhoon).

Is this a typhoon/tropical cyclone? Although its tight spiral structure and "eye of the wind" structure look very much like tropical cyclones in other marine areas in the southern hemisphere, according to the existing analysis data, it still has many attributes of temperate system. Fortunately, it already has a warm core structure similar to a tropical cyclone. At present, many organizations have identified it as a subtropical storm, that is, a "hybrid" system between tropical cyclones and temperate cyclones, and it is not unreasonable to call it "Argentine typhoon".

However, unlike ordinary typhoons, both the cold single cloud outside the system and the cloud belt connected with high latitudes make it look like an extratropical cyclone. The appearance of this system is also induced by temperate system. According to the analysis data, the predecessor of this subtropical cyclone is the violent oscillation of the westerly belt over South America, with a deep trough extending all the way to Argentina. This vortex system has gradually separated from the westerly belt trough and moved to the offshore of Argentina, with a slow development. Up to now, it has developed to a relatively mature level. Brazil's meteorological department believes that its central air pressure is about 990 hectopascals, which is equivalent to the level of tropical storms.

However, compared with the general typhoon, the sea temperature of this "Argentine typhoon" is less than 20 degrees, while the development of the general typhoon needs a water temperature of more than 26 degrees, which also shows that its nature is somewhat unique. It is predicted that it will gradually move eastward after circling the coast of Argentina, and will gradually dissipate over the South Atlantic without affecting the land in South America.

Due to many reasons, such as large vertical wind shear, insufficient seawater heat, and uncoordinated atmospheric circulation situation, the South Atlantic has always been considered as an ocean area unsuitable for the development of tropical cyclone systems. Therefore, the appearance of this storm with "eye of the wind" structure is tantamount to the flowering of Cycas. The only recorded cyclone above typhoon level in this sea area was the "Catalina" storm in 2004. The appearance of this strange storm in the South Atlantic on June 28 still shows that there may be anomalies in the earth's atmospheric circulation at present, and other regions need to continue to be alert to the occurrence of extreme weather.

Katrina, the South Atlantic storm in 2004