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4th Talk

4th Talk. Developing the Sparse Input Reanalysis for Climate Applications (SIRCA) 1850-2014. Gilbert P. Compo, Jeffrey S. Whitaker, Prashant D. Sardeshmukh, and Benjamin Giese compo@colorado.edu Univ. of Colorado/CIRES Climate Diagnostics Center and

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4th Talk

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  1. 4th Talk

  2. Developing the Sparse Input Reanalysis for Climate Applications (SIRCA) 1850-2014 Gilbert P. Compo, Jeffrey S. Whitaker, Prashant D. Sardeshmukh, and Benjamin Giese compo@colorado.edu Univ. of Colorado/CIRES Climate Diagnostics Center and NOAA Earth System Research Laboratory/PSD Compo et al. 2011, doi:10.1002/qj.776 Special thanks to NCEP/EMC, NCDC, Hadley Centre, Chesley McColl, ACRE partners

  3. Uses of historical reanalyses The Twentieth Century Reanalysis Project: An international collaborative project led by NOAA and CIRES to produce high-quality tropospheric reanalyses for the last 130+ years using only surface pressure observations (this is not a minus!). Status and Plans 20th Century Reanalysis Project 1871-2010 http://www.esrl.noaa.gov/psd/data/20thC_Rean Advances and Improvements towards Sparse Input Reanalysis for Climate Applications (SIRCA) spanning 19th-21st centuries over the next 2-10 years Available 2014 – SIRCA (1850-2014) Available 2017 – include coupling, OARCA (1800-2016) Requires international cooperation

  4. Uses of historical reanalyses • Effectively doubling or tripling the reanalysis record length for climate change detection and attribution studies  • Climate model validation dataset for large-scale synoptic anomalies during extreme periods, such as droughts (30’s, 50’s). Need to extend to 1850 for full overlap with CMIP5 integrations. • Better understand events such as the 1920-1940’s Arctic warming. • Determining storminess and storm track variations over last 100-150 years. • Developing and improving forecasts of subseasonal (e.g., Pacific-North America pattern, North Atlantic Oscillation) atmospheric variations. • Understanding changing atmospheric background state associated with interdecadal hurricane activity. • Estimating risks of extreme events.

  5. The Twentieth Century Reanalysis Project Summary: An international collaborative project led by NOAA and CIRES to produce high-quality tropospheric reanalyses for the last 130+ years using only surface pressure observations (this is not a minus!). The reanalyses provide: -First-ever estimates of near-surface and tropospheric 6-hourly fields extending back to end of the 19th century; -Estimates of uncertainties in the basic reanalyses; -Estimates of uncertainties in derived quantities (storm tracks, etc.) Higher quality in the Northern Hemisphere than in the Southern Hemisphere. US Department of Energy INCITE, Office of Science computing awards and NOAA Climate Program Office partnership to produce 1871-2008 and extend to 2010 in fall of 2011. Compo et al. 2011, doi:10.1002/qj.776

  6. Historical Reanalysis Status and Plans 20th Century Reanalysis Projecthttp://www.esrl.noaa.gov/psd/data/20thC_Rean • Data Access: Analyses and ISPD (with feedback) freely available from NCAR, analyses from NOAA/ESRL and DOE NERSC. Coming Soon: NOAA/NCDC. • Fall 2011: 1871-2-1-(includes time-varying CO2, volcanic aerosols, GFS from NCEP). Ensemble mean and spread and some individual member variables online now. • http://www.esrl.noaa.gov/psd/data/gridded/data.20thC_ReanV2.html (NOAA ESRL) • http://dss.ucar.edu/datasets/ds131.1 (NCAR) • http://portal.nersc.gov/20C_ReanalysisEvery member (US Dept of Energy, NERSC) • http://nomads.ncdc.noaa.gov (NOAA NCDC, coming soon) • Coordinate with PCMDI CMIP5 distribution and validation for IPCC AR5 ECMWF Reanalysis -Climate (ERA-CLIM)(upcoming talk from Dee) • Series of reanalyses, including Surface-observation based back to 1900 (ERA-20C). • ERA-20C: T159 spectral (~125km grid spacing)

  7. An overview of the proposed NOAA climate reanalysis effort • NCEP and ESRL will plan to conduct a set of hierarchical climate reanalysis streams. • AMIP: SST and boundary forcing • Surface data based reanalysis (SIRCA 1850-2014) • Conventional data based reanalysis • Satellite era reanalysis • The hierarchical aspect involves staggered parallel execution of reanalysis streams in increasing order of complexity • Results from basic streams may be used to bias correct, detrend, or otherwise adjust inputs into runs at the next higher complexity level

  8. Advances and Improvements towards Sparse Input Reanalysis for Climate Applications (SIRCA)spanning 19th-21st centuries over the next 2-10 years • More land and marine observations back to early 19th century, especially Southern Hemisphere and Arctic. • User requirements for, and applications of, reanalyses • Higher resolution, improved methods (e.g., Hybrid EnKF), possibly other surface variables (e.g., wind) • Uncertainty in forcings (e.g, CO2, solar, SST) • Possibly Multi-model (e.g., NASA, NCAR, NCEP, GFDL, ESRL) Available 2014– SIRCA (1850-2014) Available 2017 – include coupling, OARCA (1800-2016) Requires international cooperation, e.g., Atmospheric Circulation Reconstruction over the Earth initiative http://www.met-acre.org

  9. Summary • Demonstrated that surface-based reanalyses have skill throughout the troposphere using advanced data assimilation and surface pressure observations. • Effectively doubling the reanalysis record length from ~70 year to 140 years, allowing current atmospheric circulation patterns to be placed in a broader historical context. • Southern Hemisphere fields may be an improvement over first-generation upper-air based reanalyses before the satellite era. • Challenges: Validating the dataset in regions of sparse observations and rapid change, e.g., the Arctic. • Need to extend back to at least 1850 for full overlap with CMIP5 and other uses. Longest possible reanalysis record is needed for increasing sample size for extremes. • Additional observations currently in paper archives will further improve these reanalyses for SIRCA. • For additional information, email or go to • jeffrey.s.whitaker@noaa.gov, • compo@colorado.edu

  10. 5th Talk

  11. Improvements from JRA-25 Significantly reduced cold bias in the lower stratosphere owing to the improved radiation process Much smoother atmospheric flow Improved quality of precipitation over land Reduced dry bias over the Amazon basin Much better forecast performance Deficiencies that still exist in JRA-55 Overestimation of precipitation in the tropics Necessity to improve the convection scheme

  12. Spring 2013 JRA-55 calculation will be completed. Autumn 2013 JRA-55 products will be released for research use. Basic products of JRA-55C and JRA-55AMIP will be released as well but it may be delayed. Spring 2014 JRA-55 based JCDAS will be released. Note that current JRA-25 based JCDAS will be replaced. JCDAS: JMA Climate Data Assimilation System

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