There are some seemingly simple questions that only science can answer. One such question concerns why some clouds “reflect more” than others. A team of researchers from the Institute of Atmospheric and Climate Sciences of the National Research Council (Isac-Cnr) in Bologna recently confirmed experimentally a hypothesis formulated two decades ago that is of important climatological significance. And The results were published in the influential journal Nature.
The explanation
“That clouds form from small particles of atmospheric particulate matter has already been known for several years, but for the first time we have discovered that organic surfactant compounds of marine origin form cloud droplets much more effectively thus increasing the cooling effect of sea clouds”-says Maria Cristina Facchini, research executive at Isac-Cnr and coordinator of the Italian team that collaborated on the study together with other European, U.S. and Canadian universities and research centers. These are nanometer particles rich in organic compounds, resulting in clouds that contain a much higher number of droplets, even up to ten times, and are therefore more reflective and less likely to form precipitation. “The combination of these two factors exerts a cooling effect on the climate that, in light of these new results, can be better quantified.”
The discovery then invests the reflectivity (“albedo”) and precipitation-producing ability of clouds. Theoretical and laboratory studies had suggested the potentially important role in the cloud forma tion process of organic surfactants contained in atmospheric particulate matter. “Such an effect had in particular been hypothesized more than a decade ago in work I conducted (Facchini et al., Nature 1999), but it had never been observed in a real environment, much less simulated by models”-Maria Cristina Facchini points out-“That’s why we are talking about a study that constitutes a real breakthrough in the understanding of cloud formation processes from both experimental and theoretical perspectives. Now the challenge lies in determining the significance of the observed process at the large scale through further refinement of global climate models.
To put it in simpler words
Clouds are fundamental elements of our planet’s radiative balance-that is, the ratio of solar radiation that reaches Earth and that which is reflected back to space; the limited ability of the models currently developed and used by scholars to reproduce the processes of cloud formation and evolution, therefore, was a key uncertainty factor in the analysis and prediction of climate change, but now this study found how organic surfactants increase the ability of marine clouds to reflect solar radiation, affecting precipitation and climate. And we all know how, especially in recent years, temperature, rain and drought are increasingly on the agenda, debated by the media but also by the so-called man in the street.
