The second of the two big articles I alluded to is out at GSA Special Publications. We brought together 11 experts in their fields to take another look at this keystone site in the Canadian High Arctic. Amongst its unique features is a marine/estuarine muddy layer with molluscs from both the Pacific and Atlantic-derived Arctic, demonstrating the Bering Strait was open at or by this time. But we didn't stop at the molluscs. Magnetostratigraphy, Amino Acid racemerisation, oribatid mites, ostracods, beetles, macroflora, moss, pollen, dendrology, stratigraphy and so much more. It was a privilege to bring it together with this team. Thank you to the staff at GSA who found insightful reviewers during the height of the pandemic. ABSTRACT Meighen Island, in the Canadian Arctic Archipelago, is one of the most important localities for study of the late Neogene Beaufort Formation because of the presence of marine sediments interbedded with terrestrial fossiliferous sands. The stratigraphic succession, fossils from the marine beds, correlation with reconstructions of sea level, and paleomagnetic data from the Bjaere Bay region of the island suggest that the Beaufort Formation on Meighen Island was likely deposited either at 3.2–2.9 Ma or during two intervals at ca. 4.5 Ma and 3.4 Ma. The exposed Beaufort Formation on Meighen Island probably encompasses at least one warm interval and eustatic sea- level highstand of the Pliocene. Fossils of plants and arthropods are abundant in the alluvial sands exposed in the Bjaere Bay region. The lower part of the sequence (Unit A), beneath the mud- dy marine sequence (Unit B), contains plant taxa that have not been seen above the marine beds. Sediments below the marine beds are dominated more by fossils of trees, whereas the organic debris from above marine beds contains many fossils of plants, insects, and mites characteristic of open treeless sites. Regional tree line probably occurred on Meighen Island during deposition of the upper sediments, which implies a mean July climate at least 9 °C warmer than at present. When the marine sedi- ments were deposited, nearshore water temperatures probably did not fall below 0 °C; hence, the Arctic Ocean probably lacked perennial ice cover. This confirms recent modeling experiments exploring the causes of Arctic amplification of temperature that have found the removal of sea ice to be a key factor in resolving previous proxy- model mismatches. Barendregt, R.W., Matthews, J.V., Jr., Behan-Pelletier, V., Brigham-Grette, J., Fyles, J.G., Ovenden, L.E., McNeil, D.H, Brouwers, E., Marincovich, L., Rybczynski, N., and Fletcher, T.L., 2021, Biostratigraphy, Age, and Paleoenvironment of the Pliocene Beaufort Formation on Meighen Island, Canadian Arctic Archipelago: Geological Society of America Special Paper 551, p. 1–39, https://doi.org/10.1130/2021.2551(01).
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One of the special features of the Marie Sklodowska-Curie Fellowship is the focus on training, and making sure you have the skills to move your career in your desired direction. For me, that focus has largely been on skills that directly relate to my research, but there are many other skills researchers need to progress in their careers. Today I have been attending a course by Susan Chritton, hosted by the OD&PL (Organisational Development and Professional Learning) on personal branding. The importance of really thinking about who you are, what are your values and strengths to build an authentic brand, was reflected in almost half the session focusing on those aspects. Other take-aways include considering your emotional attributes and which ones you want to highlight and bring to your personal brand and thinking about the content by asking whether your readers will say 'this is someone I want to work with'.
Although I took lead of bringing it into the world, the knowledge and experience behind the paper belongs to the career of my mentor and friend, John Matthews Jr. who passed in late January this year. He is sorely missed in our community. So too, our colleague Alice Telka, who leant her expertise to the project, and was also taken from us early.
After a couple of week of on boarding admin and finishing off a big manuscript that has been in the pipeline some 30 years (I'll post a bit on that project soon!), this week is all about getting to know my new team, both at Leeds and in PlioMIP (Pliocene Modelling Intercomparison Project). This afternoon is the first of two I will have the pleasure of spending getting to know about the other work of ERCs in the PlioMIP. There are some familiar names, with Ran Feng presenting on past terrestrial hydroclimate driven by Earth System Feedbacks and Dan Lunt talking about GMST and polar amplification in the PlioMIP ensemble - results from IPCC, and some new colleagues such as Julia Tindall, presenting on comparing the PlioMIP2 ensemble to Pliocene proxy data: how good are the models? One of the interesting questions we need to address in proxy-model mismatch for Arctic amplification of temperature is how to tell if our proxies are bias or if our models are missing or mischaracterising processes in the climate. In palaeoclimate, best practice is to apply multiple proxies, each with different underlying basis for the relationship to the climate variable of interest, e.g. delta18O of tooth enamel and leaf physiognomy at the same locality to estimate mean annual temperatures. In general, if these agree, and don't contravene the Whitlock Principal of Least Astonishment, we have good confidence in our estimates. And yet all the training data for all our models is based on the modern world - what if our bias comes from the current climate space for which the Pliocene (and future) is not analogous, could this lead to all proxy-schemes being bias in the same way? If a climate variable currently covaries with the 'important' climate variable that is driving the relationship, but is not itself tightly bound to our proxy, this may be true. A big of all Marie Sklodowska-Curie fellowships is training. For me, that training will be in brushing off and extending my skills in statistical modelling. This will be key to thinking about the mechanics of how our currently proxies work and their potential pitfalls - as well as generating a new proxy for cloud. I am looking forward to getting deep into it in the coming weeks.
This evening I am starting day 2 of the Explorer's Festival with Explorers Symposium: Reflecting on a Year and a Legacy. "For 133 years, National Geographic has illuminated our world and what it means to be human. To reflect on the past year is to listen intently to voices new and old and to learn from immense change. To reflect on our legacy is to tell stories with an even more expansive audience and to engage in an even deeper exploration of the world. It's an hour and a half of inspiring discovery from across the world." One example - Justine Ammendolia, who is an amazing example of an adaptable young scientist making a difference in difficult circumstances, from a failed project in Greenland, to making the most of being stuck without a project in a city, during COVID. "When you're in the field and things fail, you have to adapt." Later on I will be joining my colleagues in polar research as we discuss a new Polar Hub to facilitate working together and sharing resources in this incredible part of the world. Coming up next week, the first virtual National Geographic Explorers Festival has over 6000 explorers invited and I am excited to attend. In 2016, a National Geographic Research and Exploration grant, in combination with the Polar Continental Shelf Program and the NSF division of Polar Programs, funded my field season at three sites in the Canadian Arctic Archipelago – Beaver Pond, Fyles Leaf Beds, and Ekblaw. Five years, three international moves, and three fellowships later, the samples we took keep allowing me to answer questions about what the Arctic was like in the nearest analogue we have for our near future climate. Although 5 years ago, National Geographic is still supporting my career with training in Effective Mapmaking, Advanced Storymaps with ESRI, and Making an Impact. I look forward to applying these new skills to my new research on palaeoclouds, as well as the related work we keep trickling out on fire in the Pliocene Arctic.
Organising an international move between two countries that aren't your 'home nation', during a pandemic has been pretty rough, I won't lie, but here we are in isolation with our fabulous friends, finally in London waiting and hoping for our three negative COVID-19 tests as our last step on our way to T' North. I am looking forward to getting to know my new colleagues and getting into the search for palaeocloud proper after quite a few years thinking about how clouds effect the world below them. Time in isolation is passing quickly as we pay our dues with help on the Victorian Renovation. Only the best of friends would take you in while they renovate their home! |
ProjectClouds cause the greatest uncertainty in climate models, but we currently have no way of testing cloud model performance in a climate with higher CO2 than the historical records. Palaeontology gives us access to such a past, but currently, we don't have a method to reconstruct cloud in deep time. Archives
June 2023
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