From NASA JPL, signs that “the boy” isn’t leaving. Perhaps he’s receiving too warm a welcome.
El Niño 2009-2010 just keeps hanging in there. Recent sea-level height data from the NASA/European Ocean Surface Topography Mission/Jason-2 oceanography satellite show that a large-scale, sustained weakening of trade winds in the western and central equatorial Pacific during late-January through February has triggered yet another strong, eastward-moving wave of warm water, known as a Kelvin wave. Now in the central and eastern equatorial Pacific, this warm wave appears as the large area of higher-than-normal sea surface heights (warmer-than-normal sea surface temperatures) between 150 degrees west and 100 degrees west longitude. A series of similar, weaker events that began in June 2009 initially triggered and has sustained the present El Niño condition.
JPL oceanographer Bill Patzert says it’s too soon to know for sure, but he would not be surprised if this latest and largest Kelvin wave is the “last hurrah” for this long-lasting El Niño.
Patzert explained, “Since June 2009, this El Niño has waxed and waned, impacting many global weather events. I, and many other scientists, expect the current El Niño to leave the stage sometime soon. What comes next is not yet clear, but a return to El Niño’s dry sibling, La Niña, is certainly a possibility, though by no means a certainty. We’ll be monitoring conditions closely over the coming weeks and months.”
An El Niño also causes unusual changes in atmospheric circulation and convection around the globe. JPL’s Microwave Limb Sounder instrument on NASA’s Aura spacecraft captured a large eastward shift of deep convection from the current El Niño, indicated by large amounts of cloud ice in the upper troposphere.
An El Niño is characterized by an abnormal warming of sea surface temperatures in the equatorial central and eastern Pacific Ocean. This sea surface temperature change is accompanied by anomalous atmospheric circulation and convection changes around the globe. The 2010 El Niño reached maximum strength during January and February 2010. The Microwave Limb Sounder instrument on NASA’s Aura spacecraft observed a clear eastward shift of deep convection, indicated by large amounts of cloud ice in the upper troposphere. The enhancement of cloud ice from 13 kilometers (approximately 40,000 feet) and above is the greatest since Aura launched in July 2004.
On July 15, 2004, NASA’s Aura spacecraft launched from California’s Vandenberg Air Force Base on a mission to study Earth’s ozone layer, air quality and climate. Aura’s data are helping scientists address global climate change issues such as global warming; the global transport, distribution and chemistry of polluted air; and ozone depletion in the stratosphere, the layer of Earth’s atmosphere that extends from roughly 15 to 50 kilometers (10 to 30 miles) in altitude.
Aura is the third and final major Earth Observing System satellite. Aura carries four instruments: the Ozone Monitoring Instrument, built by the Netherlands and Finland in collaboration with NASA; the High Resolution Dynamics Limb Sounder, built by the United Kingdom and the United States; and the Microwave Limb Sounder and Tropospheric Emission Spectrometer, both built by JPL. Aura is managed by NASA’s Goddard Space Flight Center, Greenbelt, Md.
The Microwave Limb Sounder is a second-generation instrument that is helping scientists improve our understanding of ozone in Earth’s stratosphere, especially how it is depleted by processes of chlorine chemistry. The instrument measures naturally occurring microwave thermal emission from the edge of Earth’s atmosphere to remotely sense vertical profiles of atmospheric gases, temperature, pressure and cloud ice.
For more information on Aura on the Internet, visit http://aura.gsfc.nasa.gov/.
For more information on the Microwave Limb Sounder on the Internet, visit: http://mls.jpl.nasa.gov/.