A scientist at the Weizmann Institute investigates what is the connection between the width of rings on the trunks of pine trees in Israel and the warming of certain parts of the surface of the Pacific Ocean?
What is the connection between the width of rings in the trunks of pine trees in Israel and the warming of certain parts of the surface of the Pacific Ocean? Dr. Dan Yakir from the Department of Environmental Sciences and Energy Research at the Weizmann Institute of Science found that there is a connection between these phenomena. This discovery may help in more accurately predicting the amount of precipitation in our region, something that also has a decisive effect on the rates of agricultural crops.
Every three to seven years, around Christmas, extremely unusual weather phenomena occur in different parts of the world: floods, disappearance of fish, severe weather, storms, and more. All of these are related to the warming of parts of the surface of the Pacific Ocean in the equatorial region - a phenomenon known as "El Nino" ("El Nino" in Spanish means "the child", which is the Christian Jesus, whose birth is celebrated at Christmas).
These events cause great suffering to very large populations, and beyond that, they also cause very heavy damage to the economy of the countries where the events take place. Understanding the "El Nino" phenomenon and its changing cycle, and especially understanding the connection between this phenomenon and local climatic phenomena, may help in predicting the events and making appropriate economic preparations for them.
Now it turns out that "El Niño" is also related to the amount of precipitation falling in Israel. This surprising finding emerges from a study recently carried out by a research team led by Dr. Dan Yakir from the Weizmann Institute of Science. Prof. A. also participated in the team. Zangvil from the Negev Research Institute in Sde Boker and postdoctoral fellow Lev Yadon.
The researchers found that between the years 1975 - 1995 there is a great correspondence between years in which "El Nino" occurred and a decrease in larger than average amounts of precipitation in Israel. Another match was found between "El Nino" years and the formation of wide rings in the trunks of pine trees in Israel. On the one hand, these findings may make it possible to follow the "El Niño" years in the past. On the other hand, they may allow - through mathematical models predicting the occurrence of the "El Nino" - a prediction of the rates of decrease in precipitation and the various agricultural crops.
How does such a distant climatic phenomenon, occurring in the Pacific Ocean, affect the precipitation rates in Israel? The researchers who sought to answer this question used satellite imaging and performed various isotopic tests on the rainwater (such tests may indicate the origin of the precipitation water). The conclusion that emerges from these tests is that, in an "El Nino" year, there is coordination between changes in the atmospheric flow over equatorial Africa (which allow high clouds to move from the equatorial African region to the north), and changes in the atmospheric flow over the Mediterranean basin (which allows the "African" clouds to penetrate our region) .
