CALPUFF: Status and UpdateTyler Fox9thConference on Air Quality ModelingOctober 9, 2008CALPUFF History• CALPUFF modeling system:– CALPUFF, a non-steady-state Lagrangian puff model– CALMET, a diagnostic 3-D wind field model• CALPUFF was promulgated April 2003 as EPA’s preferredmodel for long-range transport (LRT) applications, beyond50 km, primarily for Class I increments• CALPUFF developer (Earth Tech) arranged to maintaincontrol of code development and distribution andcopyrighted code• CALPUFF also identified in Appendix W for near-fieldapplications involving “complex winds” on a case-by-casebasis (more on this later)• CALPUFF also used for Class I AQRV analyses, not underAppendix W purviewScorecard of CALPUFFVersions- 5.7 April 2003 (promulgated version)- 5.711a July 2004 (previous regulatory)- 5.711b December 2005- 5.754 February 2006 (original VISTAS)- 5.756 August 2006 (latest VISTAS)-5.8 June 2007 (current regulatory)- 6.112 April 2006 (MMS)April, 2003July, 2004Dec., 2005Feb., 2006April, 2006August, 20065.7 5.711a 5.711b5.7545.7566.112FEDs Discussions on CALPUFF:Spring 2006• Reason: Earth Tech sells CALPUFF rights to TRC (April2006) and EPA experiences difficulties in assessing/updating to VISTAS version 5.754• Representatives from Federal Agencies discussedcurrent situation with CALPUFF (status and regulatoryupdates)– EPA– FLM– MMS• Discussed the following issues:– lack of adequate documentation– responsiveness to issues by developer– need for funding to address anyissues from Federal community,despite regulatory classification of the modelEPA contacts TRC:June 30, 2006• CALPUFF must meet Appendix Wrequirements for regulatory models,Section 3.1.1(b)-(d):– *.exe to run on a common platform– current model documentation– input/output test data w/model– users can operate model from availabledocumentation– documentation must include comparisonw/tracer data– model/code cannot be proprietaryTRC to EPA response:July 11, 2006• TRC provides copy of Use Agreement• States that ... “Permission to modify theFortran computer codes is granted tousers with the provision that modifiedversions of the model codes must beprovided promptly to TRC, along withappropriate written documentation andinstructions for use”TRC to EPA response:July 11, 2006• Use Agreement also states...“It is the user's responsibility to determineif the CALPUFF modeling system isappropriate for any particular application,and the user assumes all responsibilityand liability for its use.”AnalysisToolSourcesMeteorologyTerrainDifferences?Resolve DocumentBETABASECALPUFF Update ToolCALPUFF Regulatory Update:Version 5.7 to 5.711a• Model Change Bulletin-A provideddescription of changes– Only minor changes in coding• Application of Update Tool showedminimal differences/impacts onconcentrations– Clearly attributed differences to bug fixes• Approved 5.711a - June 15, 2006CALPUFF Regulatory Update• Began update process with v5.754 in June,2006• Engaged with TRC in discussions to understand5.711a vs. 5.754 differences• August 15, 2006—Received e-mail from TRCindicating a new VISTAS v5.756 would bereleased• OAQPS decided to focus on update for newVISTAS v5.756– newest features, latest corrections, etc. for usercommunity (including MMS updates for over water)CALPUFF Regulatory Update:5.711a -> 5.756• Found large ‘unresolved’ differencesbetween 5.711a/5.756– CALMET versions (5.53a vs. 5.726)—up to83% for scenarios 2, 3, (Pacific NW), 5 (deepvalley)– CALPUFF versions (5.711a vs. 5.756)— up to7% for scenario 5 (deep valley)• PROBLEM = incomplete documentation– Missing Model Change Bulletins (MCBs)– No in-code comparisons– Inadequate model documentationWhile we wait for response . . .• BART usage– “Good faith” effort to use “best” availablemodel version– Attempt to be “consistent” with App W and‘wall off’ any potential bad precedents• OAQPS becomes increasingly concernedabout NSR/PSD permit modeling– Appendix W provides “rules of the game”Clearing the Air on CALPUFF• OAQPS makes clear position statement atmonthly call with RO modelers (January 2007)• Region 4 communicates with VISTAS so PatBrewer contacts OAQPS and facilitatesdiscussion with TRC (Feb 2007)• Request for documentation from TRC viaVISTAS (Feb. 2007)• Received documentation from TRC on March15, 2007CALPUFF Modeling System:Update on Recent Activities• OAQPS updated regulatory version to 5.8 in June 2007– CALMET, CALPUFF, CALPOST• OAQPS has multiple concerns on science and codeimplementation and has undertaken evaluations– Currently completing performanceevaluations, both near-field andLRT, and preparing documentation for release prior to 9thModelingConference• Pending assessment of v5.8’n’ and v6 updates– Currently “on hold” due to broader issues• Goal = Get firm handle on science and its implementationso use of model with confidence in regulatory applications;engage with community at 9thModeling ConferenceGame Plan & Next Steps• Post v5.8 update documentation on SCRAM• Issue near-field “Clarification Memo”• Post additional documentation of technicalissues/concerns with near-field applications• Complete CALPUFF performance evaluations anddocument• Compile list of issues and recommendations– June workshop in Denver w/ R/S/L modelers– Communicate issues & recommendations to TRC/Scire– Discuss with FED users group (short-term and long-termimplications)• Engage community at 9thModeling Conference, Oct 2008– Update on status, issues, and applications– Performance evaluation & findings– Science and implementation issues• OAQPS expects to fund thorough and fully informed peerreview of CALPUFF modeling system