A fruitful collaboration at summer school
Published: 7/5 - 2012 Last updated: 31/5 - 2012
A group of early career scientists discussed climate model results and proxy data at the ACDC 2011 summer school, and decided to condense the discussion to a short article. The article was published in the beginning of April.
The young Bjerknes-scientist Petra Langebroek is the lead author of the article ”Improved Proxy Record of Past Warm Climates Needed”, published in AGUs member Newspaper EOS.
The group of writers are early career scientists from different corners of the world: Catherine Bradshaw (Bristol University, Bristol), Anastasia Yanchilina (Lamont-Doherty Earth Observatory, NY), Rocio Caballero-Gill (Brown University, Rhode Island), Caroline Pew and Kyle Armour (University of Washington, Seattle), Shih-Yu Lee (Research Center for Environmental Changes, Taipei) and Ida-Maria Jansson (Earth Science Centre, Toronto). All of them participants at the ACDC summer school at Friday Harbor, Washington, last summer.
New research questions
”The summer school was on the topic of past warm climates, and all of us participating are working with climate modelling and proxy data. We had a discussion on how much we can trust the data available from past warm climate periods. The article started from this discussion. We were evaluating sea-surface temperature proxies in different regions and in different time periods” Petra Langebroek says.
The basis for all paleo-scientists working on past warm climates, is to better understand future climate change. The writers were looking at different time periods, but had to limit their research to the Eocene and Pliocene for the article. During the Eocene some 50 million years ago, the climate was in general warmer than today. In particular, the high latitudes were 10-20 degrees warmer than today, giving a very weak equator to pole temperature gradient. The dynamical reason for this low latitudinal temperature gradient is not fully understood, and a topic for much discussion at the summer school.
”We were looking at all paleo sea-surface temperature reconstructions available for the Eocene (around 15 datapoints) and investigated if this is enough data to reconstruct a reliable latitudinal temperature gradient. We tested this by reconstructing the modern gradient using only observational data at the Eocene core locations, and compared this with the full present-day sea-surface temperature dataset (see figure 2 in the EOS article). We identified large differences in the Northern Hemisphere that are only caused by the limited number of data available. To make it worse, we know that these Eocene reconstructions have large uncertainties. If we exclude problematic data from this comparison, it is hard to reconstruct any Eocene latitudinal temperature gradient at all!”
The mission is therefore to focus research on past warm climates, it is a cry for more research, Langebroek says with a smile.
Langebroek, P., C. Bradshaw, A. Yanchilina, R. Caballero-Gill, C. Pew, K. Armour, S.-Y. Lee, and I.-M. Jansson (2012), Improved proxy record of past warm climates needed, Eos Trans. AGU, 93(14), 144, doi:10.1029/2012EO140007.