1. Chemical Kinetics and Photochemical Data for use in Atmospheric Studies: NASA (JPL) Panel for Data Evaluation C.E. Kolb Aerodyne Research, Inc. 45 Manning Road Billerica, MA 01821-3976 Prepared for Constructing a Kinetics Data Base Workshop National Institute for Standards and Technology Gaithersburg, MD 20899 April 19, 2004 AERODYNE RESEARCH, INC. ARI File No. VGR/123

2. NASA Kinetics Panel History 14 Published Evaluations from 1977 to 2002 15 th Evaluation Underway – Due in Late 2004 Evaluations #1 - #12 (1977-1997) Published in Hard Copy Evaluations #13 (2000) and #14 (2002) Web Published: http//jpldataeval.jpl.nasa.gov/

4. Key Characteristics A Critical Data Evaluation Not a Review - All known published or submitted for publication data considered - Statistical and probable systematic errors are examined/estimated - Multi-source data plots are prepared - Best estimate and estimated errors for parameters are evaluated and published Since 1997 not all process are re-evaluated in each edition – 2004 Evaluation will complete a full update cycle of 1997 evaluation. Panel members take lead responsibility for specific parameter types – but full panel is responsible for final evaluation decisions Strong continuity of panel members ensures corporate memory Since 2000 Evaluation data evaluation plots are retained on private web site to facilitate re-evaluations

5. Description of Effort Scope: Evaluated gas phase and heterogeneous chemical kinetic rate parameters, photochemical absorption cross sections and quantum yields, Henry’s Law constants, and gas phase species thermochemical parameters needed for studies of stratospheric and free troposphere chemistry Target Audiences: Atmospheric modelers, atmospheric data analysts, designers of atmospheric instrumentation, laboratory scientists studying atmospheric chemistry processes Temperature Range: Focused on evaluations for 200–300K, data at higher and lower temperatures considered as required to increase confidence in evaluations Pressure Range: 1.0 to 0.01 atmospheres, data at higher and lower pressures considered as required. Wavelength Range: 170 to 700 nm as required (UV and Visible – Not Infrared)

16. Issues With Authors, Editors and Reviewers Data Presentation Full data tables with illustrative data plots as required. Full and clear error analysis presentation – statistical and estimated systematic. Error estimates for all published data points and error bars on plotted data figures. If journal space restraints make it difficult to publish full data tables, they should be included as supplementary material on journal’s web site. Data Certification Authors/laboratories with multiple publications on the same process should clearly certify which data are preferred and which data are superseded by subsequent studies. Publications should cite and sort all previous work by that author/laboratory on subject processes. Publication Standards Authors should not submit and reviewers/editors should reject any papers not meeting the data presentation and certification standards detailed above.

17. Summary Points NASA Data Evaluation Panel Represents a Sustained, High Quality Effort to Provide Evaluated Kinetic and Thermochemical Data to the Atmospheric Chemistry Community Evaluated Data has Greatly Facilitated and Aided Intercomparability of Atmospheric Chemistry Modeling Results and Model Based Data Analysis Efforts Data Evaluation Efforts are Only Credible if the Evaluators have Direct Experience with the Experimental Techniques Used to Acquire the Data Theoretical Methods to Determine Kinetic, Photochemical, and Thermochemical Parameters are Increasingly Reliable – But are Still Best Used to Guide Evaluation and Extrapolation of Experimental Data