A month and half ago (10th to 13th of May), Alena and I went to Zaragoza, Spain, to enjoy the warm and sunny late spring and some hiking in nearby mountain range – I recommend the astonishing canyon of Guara! Aside from the extra-curricular activities, we were there to attend a 5-day conference on paleo-climatology.
This is the 5th Open Science Meeting organised by an international consortium, PAGES (PAst climate chanGES), which aims to coordinate and promote past global change research and has been running since 1998. Every 4 years PAGES-OSM gathers numerous representatives of the research community studying paleo-climatology. With speciality spanning from proxy to model analyses, all scientists aim to reconstruct past climate variability, including precipitation and temperature trends, and also to understand the drivers of those changes, such as greenhouse gases concentration, volcanism, or solar variability. Proxy studies include chemical analysis of marine, lake sediments, speleothems, ice cores, corals, and foraminifera, as well as dendrochronology, palynology and geology. Model studies mainly focus on understanding the response of the climate system to change in orbital parameters, and the teleconnection between atmospheric circulation, ocean variability, ice sheets, and greenhouse gases. There is also a focus on the relationship between climate and human history. In total, near 1000 people attended the 2017 conference, coming from all over the world and with various backgrounds. It was split in a few plenary sessions, and numerous parallel sessions (30), accompanied by poster sessions (over 150 posters per day).
While Alena was presenting a poster about her first result on Karsandi lake to a community she already knows, I was keen to attend this conference as I only have a limited background on paleoclimatology. This was for me the opportunity to further my general understanding of the methods and the current research questions in paleo-climatology. I also wanted to be precisely informed of current knowledge about precipitation variability in my area of interest (South Asia) during the last 10,000 years (The Holocene) as well as about specific events that could have occurred around the world 4000 years ago, which is sometimes reported as the 4.2 ka event. Finally, I wanted to be introduced to people running models which simulate past climate conditions, as possible future advisers both for helping me to understand the limits and abilities of models, but also to make the first steps toward collaboration in the analysis of their simulations.
All three objectives were largely met at the meeting. Among the people I came across, the most important was Pascale Braconnot, a leading French specialist in paleo-simulations. I discussed my project with her, and as it is in keeping with her personal research interest, she offered me the use of some of her simulations and welcomed further contact to discuss my methods. She also gave me some contacts in Reading (Sandy Harrison) and Germany (Martin Claussen). I also met Nicholas Graham – who presented the result of his recent simulation of a Sahara dust outburst, which is regarded as a possible trigger of the 4.2 ka event – and Francesco Pausata, who is very active on climate simulation of the Holocene. There has been much consideration of the external forcing that could have driven the Holocene variability and the 4.2 ka event, and several posters presented on the occurrence of strong volcanic eruptions such as the Cerro Blanco in the Andes around 4.3 kyr BP and the Helka 3 in Iceland just prior to a cooling event assimilated to the 4.2 ka event. Solar variability was also investigated through various reconstructions. Numerous proxies studying climate conditions during the Holocene were also presented, several showing exciting change around 4000 years ago, and one occurring in South India was great interest.
This conference was an excellent opportunity to understand the variability of two major oceanic drivers of the Earth’s climate that impact the Indian monsoon and the winter precipitation that impact the area being studied by TwoRains: the El Niño-Southern Oscillation (ENSO) characterised by a gradient of sea surface temperature over the tropical Pacific Ocean, and the Atlantic Meridional Overturning Circulation (AMOC), also known as thermohaline circulation, the weakening of which being responsible of cold condition over Europe mainly. These two drivers exhibit peculiar variation during the Holocene, whose impacts in relation with the Indian monsoon are not fully understood.
Overall, this conference was a real push forwards for my PhD. In particular, it helped me prepare my first year PhD report and increase my confidence in the methodology I am going to use. I am particularly excited at the possibility of using the simulation offered by Pascale Braconnot, as it means that I won’t need to produce them myself and will also be a promising collaboration.