Findings published in Nature Geoscience also indicate a way to make more accurate predictions about future climate trends
An international team of scientists, including Minghua Zhang, Dean and Director of Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS), has found that man-made aerosol emissions from industrial processes have changed the relationship between temperature and precipitation in the northing tropics. The findings, published early online in Nature Geoscience, may help to indicate the shifts in seasonal rainfall in Central America, which is critical for agriculture in the region.
Professor Minghua Zhang, right, and graduate student Tingyin Xiao, discovered that industrial emissions of aerosols over the last 100 years dramatically changed the atmospheric asymmetry between the North Atlantic and South Atlantic and thus the relationship between temperature and precipitation in the northern tropics.
The team reconstructed rainfall patterns and temperature over 450 years by analyzing the chemical composition of a stalagmite recovered from a cave in Belize in Central America. Stalagmite in the cave was formed through deposition of calcium carbonate and other minerals, which precipitated from mineralized water solutions. These water solutions contain oxygen and carbon.
The team used the oxygen and carbon isotopic ratios from each layer of stalagmite deposits to recover the cumulative signals of climatic and hydrogeological variations over the past 450 years that include rainfall and temperature. Because of the unique seasonal variation of precipitation in Belize, the researchers were able to accurately date the layers of deposits.
Professor Zhang and Tingyin Xiao, a Stony Brook SoMAS graduate student, conducted research that found out-of-phase relationships between temperature and rainfall within the last 100 years in the northern tropics that is contrary to how the atmospheric dynamical system is expected to work.
The stalagmite analysis indicated a shift in the relationship between temperature and rainfall after the industrial revolution. The team then explained that aerosols from industrial emissions have changed the hemispheric contrast of radiative energy between the northern tropics and southern tropics that shifted the relationship between temperature and rainfall.
“We found an unexpected relationship between temperature and rainfall in the northern tropics with a systemic trend of decreasing rainfall,” said Professor Zhang. “This corroborated with what the entire research team found over a much longer period of time based on the cave data.”
Lead author, Dr. Harriet Ridley, from the Department of Earth Sciences at Durham University in the United Kingdom, which led the study, added “The research presents strong evidence that industrial sulphate emissions have shifted this important rainfall belt, particularly over the last 100 years.”
In the paper, titled “Aerosol forcing of the position of the intertropical convergence zone since AD 1550,” the researchers also identified a substantial drying trend from 1850 onwards, coinciding with a steady rise in sulphate aerosols building in the atmosphere as a result of burning fossil fuels during the European and American Industrial Revolution.
Professor Zhang explained that sulphate aerosols from emissions moderated temperatures in the Northern Hemisphere by reflecting the Sun’s radiation. This resulted in the Intertropical Convergence Zone – a tropical rainfall belt near the equator – to be shifted toward the warmer Southern Hemisphere, which leads to drier conditions in the northern tropics.
The international research team included scientists from Durham University, Stony Brook University, the University of New Mexico, Pennsylvania State University, Northern Arizona University, ETH Zurich, and the Potsdam Institute for Climate Impact Research.
The work was funded in part by the National Science Foundation.
Manager of Media Relations, School of Medicine
Gregory Filiano | newswise
Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft
How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology