ROMA (ITALPRESS) – An international study, coordinated by the Institute of Polar Science of the National Research Council of Bologna (Cnr-Isp), and published in Nature Communications, has shown that solar cycles, phases in which the activity of the Sun oscillates by touching minimum and maximum values, influence the break of the antarctic coastal ice.
The research, supported by the National Research Programme in Antarctica (PNRA), carried out in collaboration with the Universities of Trieste, Pisa, Naples “Parthenope”, Bonn (Germany), Cambridge and Plymouth (England) and with the National Institute of Oceanography and Experimental Geophysics – Ogs of Trieste, introduced a new method of high-resolution analysis for the study of sea ice anchored at the coast, called “fast ice”.
“We picked up sedimentary carrots in the bottom of the Ross Sea, in the inlet of Edisto, located in the northern part of the Victory Land. Through the analysis of submillimetric scale images, integrating the data of chemical biomarkers obtained from the layers of sediment with associations of diatoms, microalgae present in marine environment, we managed to reconstruct the variability of coastal marine ice in the last 3.700 years”, says Tommaso Tesi, researcher of the Cnr-Isp and coordinator of the study.
“This approach has proven to be effective in extending the viewing capacity back in time, far beyond the limits imposed by satellite images currently available. In this way we were able to see that the rupture of ice does not follow an annual cycle, but shows a very complex pattern that manifests itself on longer time scales, around 90 and 240 years, synchronized with specific solar cycles.”.
The new method of investigation – which goes beyond the time limits of satellite images acquired since the 80s of the last century – and the wide availability of sediments opens to the possibility to more effectively understand the factors affecting the antarctic chlosphere, allowing to distinguish natural variability on long time scales from the effects of climate change caused by man.
-Photo IPA Agency-
(ITALPRESS).
