Planned Reanalysis Workshops Mike Bosilovich

Reanalysis Workshops Reanalysis systems are fairly complex interactions between the model, data assimilation and observations Recognizing this, NASA/GMAO held a one day workshop using MERRA data (Jan 2009), to convey to users lessons learned in devel. One tool in communications with users More could be done, for example, providing and using the analyzed observations, alongside weather case studies

Limitations Time consuming: Preparing examples, case studies and materials Some may not be ready at the time a workshop is held Self defined data formats make data easily accessible, and can be analyzed with most software (in other words, users figure it out) However, this can lead to a black box mentality (occasionally “reanalyses=obs”) Time and experience fill the void

US Climate Reanalyses and Integrated Earth System Analysis Sponsored by USCLIVAR – 2000 US Reanalysis workshop - Univ Maryland. – st CLIVAR Workshop on Ocean Reanalysis - Boulder – 2006, 2007, 2008: CLIVAR/GODAE ocean syntheses evaluation (ECMWF, MIT, JAMSTEC) Provide some guidance to program management Focus on new reanalysis systems (CFSR, 20C and MERRA), observations and the Earth system (Nov 1-3, 2010, Baltimore MD)

USCLIVAR Reanalysis Workshop Objectives Connect users and developers in discussions of strengths and weaknesses An opportunity for weather and climate users to demonstrate applications and accuracy requirements Develop quantitative metrics (diagnostics) for Integrated Earth System development Discuss the definitions and goals for Integrated Earth System Analysis

Technical Workshop on Reanalyses April 5-7, 2010 NASA/GSFC Invitation only hosted by the Global Modeling and Assimilation Office (GMAO) with representatives from ECMWF, JMA, NCEP, ESRL and NCAR Objectives – To review the current status of reanalyses and the lessons learned – Identify the primary technical issues (from assimilation system and observation perspectives) that need to be addressed or that will be addressed in the next reanalyses

Main Agenda Status and lessons learned from MERRA, ERA- Interim, JRA-25/55, CFSR, 20CR Technical issues – Observations – Cross-calibration of satellites – Homogenization of radiosondes – Data sources – keeping up to date with the latest versions of data – Quality Control Technical issues – Analysis Technical issues – Model

Planning for the next round of Reanalyses What will be new? Coupled analyses? Mechanisms for sharing information – Coordinated experimentation, comparison of innovation diagnostics, etc – Shared data, QC – What is the role of PCMDI in reanalyses comparisons, standard diagnostics? E.g. CMIP validation data and diagnostics Understanding model response to analyses – Sensitivity of reanalyses to the changing observing system – Uncertainty of analyses