This award will enable researchers to pursue a coordinated and multidisciplinary approach to improving the understanding of the interactions between climate variability and climatic mean state over the past 50,000 years. Specifically, the researchers will compile a global array of existing data, acquire high-resolution records that focus on climate variability across the western Americas and eastern Pacific Ocean, place these data on a common timescale to quantify age uncertainties, use traditional and newly developed time series analysis tools to quantify the nature of climate change and variability in the region, and integrate numerical models and data.
Specifically, the research team will pursue the following science questions: 1) How does the mean state of the climate system influence climate variability? 2) What is the feedback of climate variability on the long-term mean climate state? 3) Does variability change as a threshold in the climate system is approached? and 4) What is the sensitivity and response of terrestrial and marine systems to changes in mean climate and climate variability?
The research strategy allows for assessing the ability of climate models to simulate changes in climatic variability and providing guidance for future experimental designs in terms of direct implications on predictions of future climate variability. Process modeling will help address a myriad of questions relevant to climate science, terrestrial and marine ecosystems, and water resources management.
The project will directly support the next generation of paleoclimate scientists by supporting several graduate students and post-doctoral scholars, emphasizing cross-training in data acquisition, data analysis, and modeling, and ensuring that science results are disseminated to the broader public through an interactive website and active public outreach.
This study includes a strong element of interagency cooperation between the National Science Foundation (NSF) and the U.S. Geological Survey (USGS) thorough the active involvement of USGS researchers with academic colleagues. The USGS commitment of personnel and computing resources will be leveraged with the NSF commitment to the academic researchers and their institutions in a cost-effective partnership to help the project achieve its science goals.
@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } PALEOVAR was a multi-institution (Oregon State University, University of Oregon, University of Minnesota), multi-investigator project to improve of our understanding of patterns and causes of climate variations that take place on time frames of less than 1000 years to more than 50,000 years. The project assembled and synthesized available data from around the world, developed new ways of measuring and dating climate change in great detail in geologic records, and used the data to constrain newly developed quantitative models of climate systems. New data include information from marine sediment cores with very high sedimentation rates, layered cave deposits, marine corals, lake sediments and ice cores. Data synthesis products include compilations of global and regional variability during a time of variability prior to the peak of the last ice age, the major transition from the last ice age to the present interglacial interval, and variations within the present interglacial interval, and into the modern time that has been perturbed by human activities. Part of this effort included development of statistical methods to assess uncertainties in paleoclimate simulations. Climate model developments contributed to refinement of a hierarchy of numerical models, included addition of a simplified dynamical atmosphere (known as PUMA) to the University of Victoria/OSU "intermediate complexity" model. Research using modeling tools used paleoclimate data gathered in the project to constrain the sensitivity of climate to greenhouse gas forcing, and revealed the importance of past ice sheet height and extent in controlling the ocean’s large scale circulation, which in turn influences variability of all other elements of the climate system. Another model development include the application of a much more detailed coupled atmosphere-ocean model (GENMOM) to assess interannual-to-decadal climate variations such as the well-known El Nino-Southern Oscillation, and climate of the monsoon regions, in the transition between ice age and modern climate. PALEOVAR participants contributed to many major climate synthesis efforts in the US and worldwide, including a US Climate Change Science Program Synthesis and Assessement Report, the Third Paleoclimate Modeling Intercomparison Project, the Multiproxy Approach to Reconstructruction of the Glacial Ocean, and the IPCC Fifth Assessment Report. PALEOVAR produced (to date) over 80 peer reviewed publications, directly funded 4 PhD dissertations and 1 MS thesis, contributed to the education of a total of 11 graduate students, and to the creation of two new graduate courses.
