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.
Fig. 2.Reconstructed present-day latitudinal sea surface temperature (SST) gradient using Eocene paleolocations (red [cf. Bijl et al., 2009]) or all annual mean Hadley SST data (black).
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!”, Langebroek says.
The mission is therefore to focus research on past warm climates, it is a cry for more research, Langebroek adds with a smile.
Networking and internationalisation
“Together with colleagues from University of Washington and Massachusetts Institute of Technology, we have established the ACDC summer school series as a meeting place for young scientists working with fundamental climate problems such as the role of the ocean circulation in the poleward heat transport, the interaction between ocean and ice sheets, or the dynamics of past warm climates” Professor Tore Furevik, leader of the Centre for Climate Dynamics at the BCCR says.
Furevik and Kerim Nisancioglu from UNI Research are now planning this year's summer school, which will be held at Dovre, Norway in August this year. This fourth school in the ACDC series will be on "Landscapes and Climate".
The goal of the summer schools is to bring together the very best lecturers and the brightest young students from various disciplines to focus on particular hot topics within the climate science, stimulating new ways of thinking and new scientific collaborations.
“Both the EOS article from the summer school at Friday Harbor last year, and a similar article from the summer school in Lyngen, Troms in 2010, shows that we have succeeded with our goals” Furevik says, adding:
“Main sponsor for the summer schools has been the Norwegian Centre for International Cooperation in Education (SIU) through a partnership program between Norway and North America. The project ends this year, and we are therefore in the process of seeking alternative funding for the continuation of the series of summer school.”
Reference:
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.