12.10 - 15.10.2015  
Fort Collins, USA

PAGES' NAmercia2k Working Group will meet again from the 12-15 October 2015 in Fort Collins, USA.

This meeting has 2 goals: an initial comparison of independent temperature reconstructions derived from tree rings, boreholes, pollen, and everything else; and an initial multiproxy comparison of droughts and pluvials in North America.

Brief summary of NAm2k Powell Center meeting and outcomes
by Nick McKay

Thanks to the USGS Powell Center, 15 NAm2k group members met from 12-15 October in Fort Collins, CO. The working meeting was focused on advancing the two major themes of phase two of NAm2k: 1) an update to the North American temperature reconstruction, and 2) multi-proxy investigations of hydroclimatic variability.

Most of the week was dedicated to wrapping up the tree-ring database, investigating initial tree ring and borehole based temperature reconstructions, and tracking down and formatting hydroclimate data. We finished the meeting by detailing plans for products over the next year or two.

The group strongly supported publishing data products separately from paleoclimatic investigations, in data journals such as Scientific Data. PAGES is planning a special issue in Climate of the Past with submission in the second half of 2016; this is an excellent opportunity to leverage NAm2k work with products from other regional groups, and provides a compelling timeline for submission for several papers.

Below I append a brief summation of the NAm2k intended products, along with 1-2 leaders and timelines for each:

1. Database of positive-responding, temperature-sensitive tree-ring records, including multiple detrending options (PI, NegEx, Signal Free, and RCS) for each chronology. Leaders: Greg Pedersen, Nick McKay Timeline: Completion/submission to Scientific Data in early 2016

2. Tree-ring point-to-point regression temperature field reconstruction. Leaders: Kevin Anchukaitis, Ed Cook Timeline: Completion/submission in early 2016

3. North American borehole temperature database and reconstruction. Leaders: Fernando Sauntero, Hugo Beltrami Timeline: Completion/submission in early 2016

4. Temperature synthesis – Synthesizing the results of the tree-ring, borehole, pollen and small number of “other” temperature reconstructions, quantitatively if possible. Leader: Nick McKay Timeline: Completion/submission in Summer/Fall 2016

5. Hydroclimate Database – uniformly formatted multiproxy (but not tree rings and not isotopes) database of North American records that provide quantitative or qualitative records of past hydrologic variability. Leader(s): Nick McKay, Bryan Shuman Timeline: Completion Spring 2016

6. Low-frequency hydroclimate synthesis – what are the major century- to millennial-scale patterns and trends in hydroclimate in North America over the past 2 kyr? Leader(s): Bryan Shuman Timeline: Submission late 2016

7. North American temperature – hydroclimate interactions over the past 2 kyr. Tree-ring reconstruction and model intercomparison to investigate the covariability of temperature and hydroclimate, especially during droughts, with respect to observations and projections. Leaders: Cody Routson, Samantha Stevenson Timeline: Mid 2016

NAm2k is open to all interested scientists. If you would like to get involved in the project and its intended products, please contact me. Or if you have ideas for new directions, or are working on a project that might complement the ongoing activities, please let me know.

Thanks to the Powell Center and especially Jill Baron and Leah Colasuonno for providing such an excellent opportunity to come together and make real progress on our group goals.

Nick McKay
Assistant Professor
School of Earth Sciences and Environmental Sustainability
Northern Arizona University
NAU Box 4099 Flagstaff, AZ 86011, USA
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