Minor changes in solar activity strongly affect the climate

Very fragile connections between the 11-year solar cycle, the tropical stratosphere and the tropical synchronicity work in a coordinated way to create a global cycle of weather that has a global impact , according to a magazine study. Science magazine this week. This study could help scientists predict the strength of certain climatic phenomena, such as Indian color winds and tropical Pacific rainfall, many years ago.

A group of international scientists led by the National Center for Atmospheric Research (NCAR) has been using weather observations for more than a century and 3 very powerful computer models to understand one of the the most difficult question of meteorology: if the total energy from the Sun to Earth changes by about 0.1% in the solar cycle for 11 years, how such a small change can produce changes Big in the weather cycle on Earth?

The answer, according to new research, concerns the impact of the Sun on two seemingly unrelated areas. In the period when solar energy reaches Earth is maximum, chemicals in the stratosphere and ocean surface temperature in the Pacific respond in a way that amplifies the Sun's influence on some aspects of Air movement. This will increase the intensity of wind and precipitation, change the sea surface temperature and cloud cover in tropical and subtropical areas, and ultimately affect global weather.

NCAR scientist Gerald Meehl, author of the study, said: 'The Sun, the stratosphere and the ocean are interconnected in ways that can affect factors such as winter rainfall in the North. America. Understanding the role of the solar cycle can provide valuable knowledge to predict regional weather cycles over the next few decades. '

The research was funded by the National Science Foundation, NCAR and the Department of Energy. It builds on a number of recent articles by Meehl and colleagues to study the connection between the peak of the Sun cycle and events on Earth that show some of La Nina's points. Larger margins of La Nina and El Nino are always accompanied by changes in surface pressure, known as Southern oscillations. The connection between the maximum solar energy and colder seawater in the near-Pacific region was first discovered by Harry Van Loon of NCAR and the Colorado Research Association.

Up and down and up

The new contribution of Meehl and colleagues shows the joint activity of two mechanisms that link changes in solar energy and fluctuations in the Earth's climate to amplify reactions in tropical Thailand. Binh Duong.

The team first confirmed the theory that the rising portion of solar energy in the peak phase produces a sunspot that is absorbed by the stratospheric ozone . This energy warms the air in the stratosphere in tropical regions, where sunlight is the strongest, at the same time stimulating the formation of more ozone. Because the stratosphere is unevenly warm, with the most pronounced warming at lower latitudes, stratospheric winds are altered, and through a series of interconnected processes, increase tropical precipitation.

At the same time, the sunlight increased, causing the sea surface to warm up slightly along the subtropical Pacific region, where clouds blocking the Sun are often rare. This small amount of heat increases the evaporation process and creates a lot of steam. The steam is blown by trade winds to the rainy areas of the western tropical Pacific, making the rain more heavy and increasing the impact of the stratosphere mechanism.

Newly published research shows the impact of the interactions between the Sun and Earth on our climate. ( Photo: UCAR)

The top-down impact of the stratosphere and from the bottom of the sea together enhances this cycle and makes trade winds stronger. Because more sunlight comes to the drier areas, these changes support each other, leading to less cloudy subtropics, allowing more sunlight to reach the surface.

The reactions of the stratosphere and the sea during the peak of the Sun kept the eastern Pacific region cooler and drier than usual, creating the same conditions as La Nina.

However, the temperature drops from 1-2 degrees F to the farther east than a real La Nina, and is only half as strong and linked to different cycles in the stratosphere.

Earth's reaction to the solar cycle continues for a year or two. The same cycle as La Nina is stimulated by the maximum energy of the Sun tends to develop into a cycle similar to that of El Nino when slow currents replace the cool water of the eastern Pacific Ocean by warmer water. The reaction of the sea is only half as strong as that of El Nino and the slow warm water is not as consistent as the cycle that appears during the peak period of the Sun cycle.

Support the process of making 'cool' the sea

Maximum solar energy can support a real La Nina event or reduce a true El Nino event. La Nina in 1988-89 appeared near the peak of solar energy. La Nina that year became particularly strong and was accompanied by significant changes in the weather cycle, such as the dry winter in the southwestern United States.

The Indian monsoon, sea surface temperatures and precipitation, and other regional weather patterns are largely driven by the air rising and falling in the tropical and subtropical regions of the Earth. So this study helps scientists use solar cycle predictions to determine how this cycle will change in the next decade or two.

3 views, 1 answer

In order to understand the mechanisms that are difficult to capture linking the Sun and Earth, the team needed three computer models to provide overlapping views of the climate system.

A model, analyzing the interaction between sea surface temperatures and lower atmospheres, creates the cooling of the Pacific equatorial region during the years of the solar maximum. The second model, which simulates the reaction mechanism of stratospheric ozone, creates a number of increases in tropical precipitation but on a smaller scale than the observed cycles. The third model contains marine-atmospheric interactions as well as ozone. It shows that the sea and atmosphere combine to create a reaction in the Pacific tropical region during the peak solar years.

Meehl said: ' With the help of computer power, as well as observational findings, we are gradually learning about how these mechanisms combine to connect solar changes to gas. Our post and weather '.

The University studies atmospheric management of the National Center for Atmospheric Research under the sponsorship of the National Science Foundation.

Refer:

1. Gerald Meehl, Julie Arblaster, Katja Matthes, Fabrizio Sassi, and Harry van Loon.Amplifying the Pacific Climate System Response to a Small 11-Year Solar Cycle Forcing.Science, 2009;325 (5944): 1114 DOI: 10.1126 / science.1172872