Relationship between solar radiation and dimethylsulfide concentrations using in situ data for the pristine region of the southern hemisphere

Abstract

The biological processes have been proposed as climate variability contributors. Dimethylsulfide (DMS) is the main biogenic sulfur compound in the atmosphere; it is mainly produced by the marine biosphere and plays an important role in the atmospheric sulfur cycle. Currently it is accepted that terrestrial biota not only adapts to environmental conditions but also influences them through regulations of the chemical composition of the atmosphere. In the present study we used a wavelet method to investigate the relationship between DMS, Low cloud cover (LCC), Ultraviolet Radiation A (UVA), Total Solar Irradiance (TSI) and Sea Surface Temperature (SST) in the so called pristine zone of the Southern Hemisphere. We found that the series analyzed have different periodicities which can be associated with large scale climatic phenomena such as El Niño (ENSO) or the Quasi-Biennial Oscillation (QBO), and/or to solar activity. Our results show an intermittent but sustained DMS-SST correlation and a DMS-UVA anti correlation; but DMS-TSI and DMS-LCC show nonlinear relationships. The time-span of the series allow us to study only periodicities shorter than 11 years, then we limit our analysis to the possibility that solar radiation influences the Earth climate in periods shorter than the 11-year solar cycle. Our results also suggest a positive feedback interaction between DMS and solar radiation.