Role of determining the sea temperature of dust

Recent warming trends in the Atlantic are mainly due to air dust reductions and volcanic eruptions in the past 30 years, according to new research.

Since 1980, the tropical Atlantic has warmed about ¼ degrees Celsius (half an Fahrenheit) a decade. Although this number seems small, it may have a major impact on storms, which appear more often when warm water, Amato Evan said. He is a researcher at the Institute of Meteorological Research at the University of Wisconsin-Madison and the lead author of the study. For example, the difference in sea temperature between 1994, a year of less typhoon, and 2005, the year of record breaking storms, is only 1 degree F.

More than two thirds of this upward trend in recent decades is due to changes in African dust storms and tropical volcanic activity, Evan and colleagues report. Their findings were published in the March 26 issue of Science.

Evan and his colleagues have previously shown that dust and other gas particles from Africa can limit storm activity by reducing the amount of sunlight reaching the sea surface and keeping the water surface cooler. In the dusty years there are fewer storms, while less dusty years, including 2004 and 2005 - storms occur more frequently and stronger.

In the new study, scientists combined satellite data on dust and other gas elements in the climate model to assess the effect of sea temperature. They also calculated an increase in temperature observed during the past 26 years that could be attributed to changes in dust storms and tropical volcanic activity, mainly eruptions in El Chichón, Mexico in 1982, and Mount. Pinatubo in the Philippines in 1991.

The dust storm in Morocco was taken by NASA's MODIS Aqua aerosol satellite on March 12, 2009. The new study by Amato Evan of UW-Madison shows a sea-going change of African dust storms and eruptions. Tropical volcanoes can affect up to 70% of Atlantic warming temperatures observed in the past 3 decades. Because warmer water is an important component in the formation of storms, dust and other air particles will play an important role in improving our understanding of these storms in climate conditions. change. (Photo: Amato Evan).

In fact, that's a huge amount, Evan said: 'Much of this warming trend in the long-term cycle can be explained by dust storms and volcanoes. About 70% is due to a combination of dust and volcanoes, and about a quarter is due to dust storms'.

The results show that only about 30% of the temperature rise in the Atlantic is due to other factors such as warming. Evan said this adjustment makes the assessment of global warming's impact on Atlantic more plausible when compared to lower sea temperatures elsewhere, eg the Pacific.

He continued: 'This is perfectly reasonable, because we do not think that global warming can make the sea temperature rise so quickly.'

Volcanoes are unpredictable so it is difficult to include climate models. However, new climate models will need to add dust storms as a key factor to accurately predict the change in sea temperature.

He commented: 'We do not really understand the change in dust in the current climate, and the change in the dust cloud can have a good or bad effect'.

Satellite research on dust storm activity is a relatively new research activity, and no one clearly understands what determines the change of dust year after year. However, the fundamental role of the North Atlantic temperature for storm formation and intensity means that this factor is essential in understanding climate change and storms.

Evans concluded: 'Volcanoes and dust storms are important if you want to understand changes in the long term. If they have a big impact on sea temperatures, they will have the same impact on the sea's change. '

The authors of the paper include Ralf Bennartz and Daniel Vimont of UW-Madison and Andrew Heidinger and of the National Marine and Atmospheric Administration and UW-Madison.

Refer:
1. Amato T. Evan, Daniel J. Vimont, Andrew K. Heidinger, James P. Kossin, and Ralf Bennartz.The Role of Aerosols in the Evolution of Tropical North Atlantic Ocean Temperature Anomalies.Science, 2009;DOI: 10.1126 / science.1167404