New Examine Hyperlinks Photo voltaic Variability to the Outbreak of Decadal La Nina Occasions – Watts Up With That?
The authors apply a 22-year solar clock to find an elusive correlation
NATIONAL CENTER FOR ATMOSPHERIC RESEARCH / UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH
Research news
A new study shows a correlation between the end of solar cycles and a move from El Nino to La Nina in the Pacific, suggesting that the variability of the sun may affect seasonal weather variability on Earth.
If the link described in the journal Earth and Space Science holds, it could greatly improve the predictability of the largest events in El Nino and La Nina, which have a range of seasonal climate effects over land. For example, the southern United States is warmer and drier during a La Nina, while the northern United States is colder and wetter.
“Energy from the sun is the main driver of our entire earth system and enables life on earth,” said Scott McIntosh, scientist at the National Center for Atmospheric Research (NCAR) and co-author of the paper. “Nevertheless, it was unclear to the scientific community what role solar variability plays in influencing weather and climate events here on earth. This study shows that there is reason to believe that it absolutely is and why the connection may have been overlooked in the past. “
The study was led by Robert Leamon at the University of Maryland-Baltimore County and co-authored by Daniel Marsh at NCAR. The research was funded by the National Science Foundation, the sponsor of NCAR, and the NASA Living With a Star program.
Application of a new solar clock
The appearance (and disappearance) of spots on the sun – the outwardly visible signs of the sun’s variability – has been observed by humans for hundreds of years. The growth and decrease in sunspot numbers occurs over approximately 11 year cycles, but these cycles do not have different beginnings and ends. This fuzziness in the length of a particular cycle has made it difficult for scientists to reconcile the 11-year cycle with changes on Earth.
In the new study, researchers rely on a more accurate 22-year solar activity clock, derived from the Sun’s magnetic polarity cycle, which they have described as a more regular alternative to the 11-year solar cycle in several recently published companion studies in scientific journals .
The 22-year cycle begins when oppositely charged magnetic tapes encasing the sun appear near the star’s polar latitudes, according to recent studies. During the cycle, these bands migrate towards the equator, causing sunspots as they move through the mid-latitudes. The cycle ends when the bands meet in the middle and annihilate each other in what the research team calls the Terminator event. These terminators provide precise signposts for the end of one cycle and the beginning of the next.
The researchers imposed these terminator events on sea surface temperatures in the tropical Pacific, which date back to 1960. They found that the five Terminator events that occurred between that time and 2010-11 all coincided with a flip from an El Nino (when sea surface temperatures are warmer than average) to a La Nina (when sea surface temperatures are cooler than average are). The end of the most recent solar cycle that is now playing out also coincides with the start of a La Nina event.
“We are not the first scientists to study how the variability of the sun can affect changes in the earth system,” said Leamon. “But we are the first to use the 22-year-old solar watch. The result – five consecutive terminators pending with a switch in the El Nino oscillation – is probably no coincidence. “
In fact, the researchers performed a series of statistical analyzes to determine the likelihood that the correlation was just a coincidence. They found that there was only a 1 in 5,000 or less chance (depending on the statistical test) that all five terminator events included in the study happened to coincide with increases in sea temperatures. Now that a sixth Terminator event – and the corresponding start of a new solar cycle in 2020 – also coincided with a La Nina event, the chance of a random occurrence is even less, the authors said.
The paper does not investigate which physical connection between the sun and earth might be responsible for the correlation, but the authors note that there are several possibilities that need further investigation, including the influence of the sun’s magnetic field on the amount of cosmic rays , escape into the solar system and eventually bomb the earth. However, a robust physical relationship between variations in cosmic rays and the climate has yet to be determined.
“If further research can show that there is a physical connection and that changes in the sun do indeed create variability in the oceans, we may be able to improve our ability to predict events in El Nino and La Nina,” said McIntosh.
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About the article:
Title: Termination of the Solar Cycle and Correlated Tropospheric Variability
Authors: Robert J. Leamon, Scott W. McIntosh, and Daniel R. Marsh
Journal: Earth and Space Science DOI: 10.1029 / 2020EA001223
This material is based on work supported by the National Center for Atmospheric Research, a major facility sponsored by the National Science Foundation and administered by the University Corporation for Atmospheric Research. All opinions, results, conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.
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