International satellite sees early signs of El Niño

Kelvin waves, a possible precursor to El Niño ocean conditions, roll across the equatorial Pacific to the coast of South America.– National Aeronautics and Space Administration reports (NASA)

The most recent sea level data from the US-European satellite Sentinel-6 Michael Freilich indicate early signs of an El Niño developing in the equatorial Pacific. The data show that Kelvin waves — about 5 to 10 centimeters high and hundreds of kilometers wide at the sea surface — move from west to east along the equator toward the west coast of South America.

As they form at the equator, Kelvin waves bring warm water, associated with higher sea levels, from the western Pacific to the eastern Pacific. A series of Kelvin waves that begin in spring is a well-known precursor to El Niño, a climate phenomenon that can affect weather patterns around the world. It is characterized by higher sea levels and warmer than average sea temperatures along the west coast of the United States.

Water expands as it warms, so sea levels are higher in places with warmer water. El Niño is associated with a weakening of the trade winds. This situation could bring cooler, wetter conditions in the southwestern United States and drought in the western Pacific, such as Indonesia and Australia.

The data shown here from the Sentinel-6 Michael Fröhlich satellite covers the period between early March and late April 2023. On April 24, Kelvin waves contained warmer water and higher sea levels (shown in red and white) concentrated off the coast of Peru. , Ecuador and Colombia. Satellites such as Sentinel-6 Michael Freilich can detect Kelvin waves with a radar altimeter, which uses microwave signals to measure the height of the ocean’s surface. When an altimeter passes over areas that are warmer than others, the data will show higher sea levels.

“We’ll be watching this El Niño like a hawk,” said Josh Willis, Sentinel-6 Michael Fröhlich project scientist at NASA’s Jet Propulsion Laboratory in Southern California. Face another wet winter.”

Both the U.S. National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization recently announced that the possibility of an El Niño by the end of summer has increased. Continuous monitoring of Pacific ocean conditions through instruments and satellites such as Sentinel-6 Michael Freilich The coming months will help clarify how strong it will be.

“When we measure sea level from space using satellite altimeters, we know not only the shape and height of the water, but also its motion, such as Kelvin and other waves,” said Natya Vinogradova Schiffer, NASA project scientist and manager of Sentinel-6. Michael Freilich in Washington. “Ocean waves sweep heat around the planet, bringing heat and moisture to our shores and changing our weather.”

El Niño (“The Boy”) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a group of warm ocean waters forming in the central and east-central equatorial Pacific (roughly between the International Date Line). and 120° W), including the Pacific coast of South America. ENSO is the warm and cool sea surface temperature (SST) cycle of the tropical central and eastern Pacific. El Niño is associated with high pressure in the western Pacific and low pressure in the eastern Pacific. El Niño phases are known to last almost four years; However, records indicate that cycles lasted from two to seven years. During the development of El Nino, rain falls from September to November. ENSO’s cold phase Spanish: La Niña, lit. “The Girl” will have below-average SSTs in the eastern Pacific, high pressure in the eastern Pacific and low pressure in the western Pacific. The ENSO cycle, which includes both El Niño and La Niña, causes global changes in temperature and precipitation.