Research Article| January 01, 2013 Hot summers in the Bighorn Basin during the early Paleogene Kathryn E. Snell; Kathryn E. Snell * 1Earth and Planetary Sciences Department, University of California, 1156 High Street, Santa Cruz, California 95064, USA2Department of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California 91125, USA *E-mail: ksnell@caltech.edu. Search for other works by this author on: GSW Google Scholar Bridget L. Thrasher; Bridget L. Thrasher 1Earth and Planetary Sciences Department, University of California, 1156 High Street, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar John M. Eiler; John M. Eiler 2Department of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar Paul L. Koch; Paul L. Koch 1Earth and Planetary Sciences Department, University of California, 1156 High Street, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Lisa C. Sloan; Lisa C. Sloan 1Earth and Planetary Sciences Department, University of California, 1156 High Street, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Neil J. Tabor Neil J. Tabor 3Huffington Department of Earth Sciences, Southern Methodist University, P.O. Box 750395, Dallas, Texas 75275, USA Search for other works by this author on: GSW Google Scholar Geology (2013) 41 (1): 55–58. https://doi.org/10.1130/G33567.1 Article history received: 26 Apr 2012 rev-recd: 06 Jul 2012 accepted: 10 Jul 2012 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Kathryn E. Snell, Bridget L. Thrasher, John M. Eiler, Paul L. Koch, Lisa C. Sloan, Neil J. Tabor; Hot summers in the Bighorn Basin during the early Paleogene. Geology 2013;; 41 (1): 55–58. doi: https://doi.org/10.1130/G33567.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract During the early Paleogene, climate in continental interiors is thought to have been warmer and more equable than today, but estimates of seasonal temperature variations during this period are limited. Global and regional climate models of the Paleogene predict cooler temperatures for continental interiors than are implied by proxy data and predict a seasonal range of temperature that is similar to today. Here, we present a record of summer temperatures derived from carbonate clumped isotope thermometry of paleosol carbonates from Paleogene deposits in the Bighorn Basin, Wyoming (United States). Our summer temperature estimates are ∼18 °C greater than mean annual temperature estimated from analysis of fossil leaves. When coupled, these two records yield a seasonal range of temperature similar to that in the region today, with winter temperatures that are near freezing. These data are consistent with our high-resolution climate model output for the Early Eocene in the Bighorn Basin. We suggest that temperatures in continental interiors during the early Paleogene greenhouse were warmer in all seasons, but not more equable than today. If generally true, this removes one of the long-standing paradoxes in our understanding of terrestrial climate dynamics under greenhouse conditions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
We describe the latest version of the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6). The archive contains downscaled historical and future projections for 1950-2100 based on output from Phase 6 of the Climate Model Intercomparison Project (CMIP6). The downscaled products were produced using a daily variant of the monthly bias correction/spatial disaggregation (BCSD) method and are at 1/4-degree horizontal resolution. Currently, eight variables from five CMIP6 experiments (historical, SSP126, SSP245, SSP370, and SSP585) are provided as procurable from thirty-five global climate models.
We describe the expansion of a publicly available archive of downscaled climate and hydrology projections for the United States. Those studying or planning to adapt to future climate impacts demand downscaled climate model output for local or regional use. The archive we describe attempts to fulfill this need by providing data in several formats, selectable to meet user needs. Our archive has served as a resource for climate impacts modelers, water managers, educators, and others. Over 1,400 individuals have transferred more than 50 TB of data from the archive. In response to user demands, the archive has expanded from monthly downscaled data to include daily data to facilitate investigations of phenomena sensitive to daily to monthly temperature and precipitation, including extremes in these quantities. New developments include downscaled output from the new Coupled Model Intercomparison Project phase 5 (CMIP5) climate model simulations at both the monthly and daily time scales, as well as simulations of surface hydrologi- cal variables. The web interface allows the extraction of individual projections or ensemble statistics for user-defined regions, promoting the rapid assessment of model consensus and uncertainty for future projections of precipitation, temperature, and hydrology. The archive is accessible online (http://gdo-dcp.ucllnl.org/downscaled_ cmip_projections).
Atmospheric simulation chambers continue to be indispensable tools for research in the atmospheric sciences. Insights from chamber studies are integrated into atmospheric chemical transport models, which are used for science-informed policy decisions. However, a centralized data management and access infrastructure for their scientific products had not been available in the United States and many parts of the world. ICARUS (Integrated Chamber Atmospheric data Repository for Unified Science) is an open access, searchable, web-based infrastructure for storing, sharing, discovering, and utilizing atmospheric chamber data [https://icarus.ucdavis.edu]. ICARUS has two parts: a data intake portal and a search and discovery portal. Data in ICARUS are curated, uniform, interactive, indexed on popular search engines, mirrored by other repositories, version-tracked, vocabulary-controlled, and citable. ICARUS hosts both legacy data and new data in compliance with open access data mandates. Targeted data discovery is available based on key experimental parameters, including organic reactants and mixtures that are managed using the PubChem chemical database, oxidant information, nitrogen oxide (NOx) content, alkylperoxy radical (RO2) fate, seed particle information, environmental conditions, and reaction categories. A discipline-specific repository such as ICARUS with high amounts of metadata works to support the evaluation and revision of atmospheric model mechanisms, intercomparison of data and models, and the development of new model frameworks that can have more predictive power in the current and future atmosphere. The open accessibility and interactive nature of ICARUS data may also be useful for teaching, data mining, and training machine learning models.
Abstract A new technique for statistically downscaling climate model simulations of daily temperature and precipitation is introduced and demonstrated over the western United States. The localized constructed analogs (LOCA) method produces downscaled estimates suitable for hydrological simulations using a multiscale spatial matching scheme to pick appropriate analog days from observations. First, a pool of candidate observed analog days is chosen by matching the model field to be downscaled to observed days over the region that is positively correlated with the point being downscaled, which leads to a natural independence of the downscaling results to the extent of the domain being downscaled. Then, the one candidate analog day that best matches in the local area around the grid cell being downscaled is the single analog day used there. Most grid cells are downscaled using only the single locally selected analog day, but locations whose neighboring cells identify a different analog day use a weighted combination of the center and adjacent analog days to reduce edge discontinuities. By contrast, existing constructed analog methods typically use a weighted average of the same 30 analog days for the entire domain. By greatly reducing this averaging, LOCA produces better estimates of extreme days, constructs a more realistic depiction of the spatial coherence of the downscaled field, and reduces the problem of producing too many light-precipitation days. The LOCA method is more computationally expensive than existing constructed analog techniques, but it is still practical for downscaling numerous climate model simulations with limited computational resources.
We describe the latest version of the NASA Earth eXchange Downscaled Climate Projections 30 arcseconds (NEX-DCP30-CMIP6). The archive contains downscaled historical and future projections for 1950–2100 based on output from Phase 6 of the Climate Model Intercomparison Project (CMIP6). The downscaled products were produced using a daily variant of the monthly bias correction/spatial disaggregation (BCSD) method and are at 30-arcsecond horizontal resolution. Four variables (maximum temperature, minimum temperature, precipitation, and vapour pressure) from five CMIP6 experiments (historical, and the four Tier 1 scenarios: SSP1.2-6, SSP2.4-5, SSP3.7-0, and SSP5.8-5) are provided as available from thirty global climate models. The downscaled data cover the coterminous United States (CONUS), extending from approximately 24-50 degrees North and 235–294 degrees East.
