Guobao Xu has joined the lab as a post-doc in January 2018. Guobao has received a scholarship from the Chinese Academy of Sciences and will be in the Trouet Lab in Tucson for two years. His research interests focus on stable isotopes in tree rings and their application for climate reconstruction, ecology, and carbon cycle research. Geographically, Guobao's research focuses primarily on the Tibetan Plateau.
Our new paper in which we reconstruct the position of the summer North Atlantic Jet over the last 300 years is out now in Nature Communications (open access): https://www.nature.com/articles/s41467-017-02699-3
We used tree rings from the Balkans and from the British Isles -two locations with climates that are strongly influenced by the position of the North Atlantic Jet (NAJ) - for our reconstruction. We find an increase of NAJ variance since the 1960s that is unprecendented over the last 300 years and that corresponds to a variance increase in climate proxies in the North Pacific ocean. Such variance increases correspond to more frequent summer NAJ extremes, which result in more frequent summer extreme weather events (floods, droughts, heatwaves, wildfires) in northwestern and southeastern Europe.
A UA press release describes the relevance of our paper in layman's terms: https://uanews.arizona.edu/story/jet-stream-changes-1960s-linked-more-extreme-weather
Valerie received a Udall Center Fellowship, which gives her a course-release for Spring 2018. Yay!
more info on the Udall Center's webpage
Embroidery artist Bonnie Peterson made a beautiful piece based on our Belmecheri et al. (2016) Sierra Nevada SWE reconstruction that is currently part of an exposition at Yosemite National Park Museum.
Qichao Yao published the first paper from his PhD in GRL. In this paper, Qichao presents the first tree-ring based fire history for northeast China that goes back to 1774 and uses it to investigate climatic influences on past wildfire regimes. A photo of a fire-scarred sample from Qichao's study was also selected as the cover of this GRL issue. Cool stuff!
Ross Alexander successfully defended his PhD dissertation on Friday March 3. Ross’s dissertation is entitled “Determining the role of stand structure in shaping climate-growth relationships in eastern temperate forests of the US”. Congratulations, Ross!
The Trouet Lab will have a busy week at the AGU Fall meeting. Here's a chronological overview of our presentations and sessions:
8am-12.20pm poster: B11D-0489: B11D-0489 Latitudinal Gradients in Tree Ring Stable Carbon and Oxygen Isotopes Reveal Differential Climate Influences of the North American Monsoon System. (Paul Szejner et al.) Moscone South Poster Hall
8am-12.20pm poster: B11D-0497: B11D-0497 Validating the Spring Jet Stream Indices Using Extended Spring Index (SI-x) Models (Amy Hudson et al.) Moscone South Poster Hall
4.40pm: oral presentation: B14C-03 Stand structure and composition provide differential tree-ring growth signals in eastern U.S. forests (Ross Alexander et al.) Moscone West 2004
8am-12.20pm: session B21B Constraining Ecosystem Carbon Uptake and Long-Term Storage using Models and Data I Posters (David Moore and Valerie Trouet) Moscone South Poster Hall
4-6pm: session B24A Constraining Ecosystem Carbon Uptake and Long-Term Storage using Models and Data II oral session (David Moore and Valerie Trouet) Moscone West 2004
5.15pm: GC44B-06 Socio-ecological transitions trigger fire regime shifts and modulate fire-climate interactions in the Sierra Nevada, CA, 1600-2015 CE (Valerie Trouet et al.) Moscone West 3001
Our study about the impact of land-use changes - such as the mission establishment, the Gold Rush, and Smokey the Bear - on past wildfire regimes in the Sierra Nevada in California was published in PNAS today. This was the result of a collaboration with Alan Taylor (PSU), Carl Skinner, and Scott Stephens. The work was funded by the Joint Fire Science Program and the USGS Southwest Climate Science Center, amongst others. UANews wrote a press release about it.