Eric Kasischke, University of Maryland, and his team have done a good job of bringing people together from multiple disciplines to discuss key science questions for the ABoVE project. These questions reflect the strengths of the NASA Terrestrial Ecosystems program and are highly relevant to regional and global climate models, land managers, and society.
The scientists assembled for this workshop are actively engaged, with the emphasis and the majority of our time spent in one or more breakout groups. Each group is tasked with looking at a set of questions from one of several perspectives in hopes that we can develop an overall compelling vision for the ABoVE project. It is clear that the team leading ABoVE have already given this considerable thought and our input this week will supplement or fine-tune the vision already developed in previous scoping workshops. It is obvious that there are numerous points of potential interaction between ABoVE and NGEE Arctic. Our process studies and emphasis on scaling could complement and indeed benefit from a close association with ABoVE.
Although the majority of our time has been spent in breakout discussions, there were a series of plenary talks. One of those was presented by Dave McGuire (UAF) who spoke about critical knowledge gaps in our understanding of Arctic systems. Another presentation by Piers Seller (NASA) highlighted the strengths and weaknesses of current Earth System Models. He derived many of his comments from a NASA-sponsored workshop held in May to discuss the state of "Arctic Boreal Modeling". This was an outstanding presentation and, in summarizing the workshop, Piers emphasized that the needs of the climate model community could clearly be met by the ABoVE project. Much like the NGEE Arctic project, ABoVE would want to target key uncertainties in the models and identify strategies for scaling process-based studies to that of the scale of climate model grid cells. My discussions with Eric and his leadership team is that NGEE Arctic could uniquely contribute to ABoVE in two important ways. One would be to conduct process-level studies in support of gaining new knowledge needed to reduce model uncertainties. We view this as a strength of our project and our planned integration of surface and subsurface sciences. Another contribution would be in providing a multiscale modeling framework that ultimately would link to remote-sensing products generated through ABoVE. We could use these data products to evaluate model performance at scales relevant to climate models.
In addition to the plenary talks and group discussions, I had a couple good interactions with Michelle Walvoord, who is with the US Geological Survey. Michelle and her colleagues have used an airborne electromagnetic system to characterize permafrost to depths of several 100 meters. The approach provides information, for example, on active layer thickness and talik conditions beneath thaw lakes in the Alaska. Our NGEE Arctic geophyics team, led by Susan Hubbard at LBNL, has looked into this approach as a complement to our ground-based EM, GPR, and seismic measurements in Barrow.
I also spoke with Ted Hogg, who is with the Canadian Forest Service, Natural Resources Canada. Ted has made a series of observations of aspen mortality in boreal forests. It appears that this die-off of trees is initiated by drought, that then pre-disposes trees to insects and disease. The exact mechanism of mortality is unknown, although it is just this mechanism that represents a critical uncertainty in ecosystem and climate models that needs to be tackled in the coming years.
I leave Boulder for Alaska later this evening. My all night flight will allow me to join others from our team in Barrow tomorrow. We have a lot of work to do in the next week and it will be great to visit our plots now that snow melt has occurred. I will post pictures and updates once we get underway.
