2 PhD positions in Climate Science on Global Dimming and Brightening in Zürich

100%, Zurich, temporary

The Institute for Atmospheric and Climate science has an opening for 2 PhD positions in the area of Global Dimming and Brightening.

Solar radiation reaching the Earth's surface is a critical factor in the discussion of climate change, as it provides the energy for a wide range of environmental processes, and ultimately enables life on our planet. There is growing evidence that the amount of solar radiation at the Earth’s surface is not stable over time but undergoes substantial multidecadal variations. Particularly, a decrease in surface solar radiation has been noted from the 1950s to the 1980s at widespread observation sites, a phenomenon popularly known as “global dimming”, followed by a partial recovery known as “brightening”. Although air pollution has been suggested of being responsible for these variations, the causes of this phenomenon are still not fully understood, and global climate models do not adequately reproduce these variations. A better understanding of the underlying causes, which appear to have a profound impact on various aspects of climate and environmental change, is therefore necessary and is the aim of the project “Towards an improved understanding of the Global Energy Balance: Causes of decadal variations of solar radiation” funded by the Swiss National Science Foundation. Two complementary PhDs are supported by this project, one focusing on the observational aspects of the project, and the other on the modeling aspects.

The two PhD candidates in this project will perform research to obtain a better understanding of the strong decadal variations of solar radiation at the Earth’s surface, from an observational (PhD1) and from a modelling (PhD2) perspective. PhD1 will work with comprehensive observational datasets, obtained from both worldwide surface networks as well as satellite space missions, to better quantify and understand the variations in surface solar radiation. The analyses will be done under both cloudy (“all-sky”) and cloud-free (“clear-sky”) conditions, to clarify the relative importance of clouds and aerosol, with the aim to identify if the variations in surface solar radiation are caused by human interference with the climate system or if they are rather a result of  natural climate variations. PhD2 will investigate to what extent the latest generation of climate models (CMIP6) is able to reproduce the observed variations and will perform simulations with the inhouse Earth system model to investigate the factors responsible for the variations. Both PhDs will strongly interact to elucidate the origins of the phenomenon of global dimming and brightening both in the modelling and real world.

We offer a friendly and stimulating work environment at a leading climate research institute with excellent infrastructures. The positions are funded for three years. PhD salaries are in accordance with .

The successful candidates should hold a master degree in Atmospheric/Earth/Environmental Sciences, Physics, Computational Sciences or equivalent. Applicants are expected to have a strong background in atmospheric sciences and (applied) mathematics and/or (geo-)statistics. Both PhDs require the willingness and ability to cope with large amounts of data. Excellent skills in programming (UNIX environment) and data processing are therefore necessary, as well as advanced communication skills in oral and written English. The ability to work in a team as well as in a self-dependent manner with a high degree of dedication is a further asset.

ETH Zurich is one of the world’s leading universities specialising in science and technology. We are renowned for our excellent education, cutting-edge fundamental research and direct transfer of new knowledge into society. Over 30,000 people from more than 120 countries find our university to be a place that promotes independent thinking and an environment that inspires excellence. Located in the heart of Europe, yet forging connections all over the world, we work together to develop solutions for the global challenges of today and tomorrow.