Sensitivity Modeling UpdateUniversity of North Carolina (UNC-IE)

ENVIRON International Corporation (ENVIRON)

April 29, 2015

Western States Air Quality Study

Intermountain West Data Warehouse

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Summary• Winter O3 Modeling• Boundary Conditions Study• MOVES2014 Sensitivity

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Winter O3 Modeling• Objectives

– To develop and test an operational WRF-SMOKE-CAMx winter O3 model

– Produce a winter O3 modeling configuration to use in simulation Base11b and 2014 modeling

• Design– WRF and CAMx configuration; no emissions adjustments– WRF configuration with SNODAS snow fields and landcover

albedo adjustments– CAMx prototype that adjusts albedo based on snow cover and

snow age– January – March 2011 simulation

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Winter O3 ModelingUGWOS Hourly O3

• February Results– Winter

configuration leads to systematically lower O3

– WRF and CAMx configuration alone doesn’t reproduce winter O3 peaks

– Performance actually declines for winter O3 in UGWOS

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Winter O3 ModelingAQS Hourly O3

• February Results– Myton, UT

corroborates the WY O&G basin results

– Welby, CO is a non O&G site; shows that the winter configuration helps some of the over prediction biases

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Winter O3 Modeling• Preliminary Results– Meteorology and CAMx configurations alone

won’t reproduce the winter O3 peaks– Need to explore the incremental addition of

emissions changes; TOG increases and NOx decreases

Boundary Condition Sensitivity Tests

• Objectives– Investigate regional model performance issues related to boundary

conditions (BCs) downscaled from global chemistry models (GCMs)– Identify systematic problems in the available GCM BCs– Produce recommendations for how to use GCM BCs for regional

modeling in the West– Find a best-performing BC dataset for simulation 2011b

• Design– Downscale MOZART, GEOS-Chem, and AM3 to CONUS36-km BCs

with CB6r2 chemistry– Winter/summer simulations with CAMx to evaluate the influence

of the different BCs on model performance

Initial BC Sensitivity Tests

• CAMx V6.1– 2011 36/12/4 km two-way grid

nesting– GCM to define lateral BCs

around 36 km CONUS domain

• 2011a MOZART BCs (MZBC)• 2011b GEOS-Chem BCs (GCBC)• Dust performance issues,

especially for MZBC, documented in wiki:

• http://vibe.cira.colostate.edu/wiki/wiki/1043/bc-sensitivity-modeling-results

• PM2.5 Monthly Bias (%) MPE

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Additional BC Sensitivity Tests

• CAMx V6.2 (can use TOPCON BC)– Initial BC Sens runs use zero-gradient TOPCON BC as

used in CAMx V6.1 and CMAQ– Jan/Jul 2011 36/12 km initial BC tests

• MOZART BCs (MZBC)– Fine crustal (FCRS) greatly overestimated in Jul

• GEOS-Chem BCs (GCBC)– Some periods with very high FCRS and CCRS in Jul

• AM3 BCs (AMBC)– Some high CCRS in Jul

Jan Jul Jan Jul

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Additional BC Sensitivity Tests

• Still setting up AMET for 2011 will use to evaluate MZBC, GCBC and AMBC– Need AMBC MPE results for next steps; select best performing BCs

for additional analysis

• May need to cap BC dust concentrations at 10 µg/m3 (FCRS and CCRS)– Perform Jan/Jul 2011 36/12 km BC sensitivity tests

• If MPE seems reasonable, run with TOPCON for Jan/Jul 2011 36/12 km

• Perform annual 2011 36/12 km BC sensitivity test– Annual MPE to make sure no new issues related to BC– Adopt BCs for 2011b platform by end of May/early Jun

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MOVES2014 Sensitivity• Objective

– Quantify the emissions and simulated air quality changes resulting from estimating on-road mobile emissions with MOVES2014 (relative to MOVES2010b)

– Perform due diligence on a significant update to the model of a major source of emissions

• Design– MOVES2014 Sensitivity off of CAMx Base11a (MZ BCs)– Use EPA NEI2011v2 modeling platform MOVES2014 CB6 emission rate

look up tables and inputs– Prepare these data for 15-day spin-up+January/July 2011 – CAMx MPE for January July

• CAMx simulations will finish in early May, results available mid-May

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MOVES2014 Sensitivity• Sensitivity Wiki• NOx Emissions Results

– Slightly higher NOx in the summer than winter months

– Utah county total MOVES NOx emissions

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MOVES2014 Sensitivity

• NOx Emissions Results– Monthly total NOx emissions

differences (MOVES2014-MOVES2010b)

– NOx emissions ratios (MOVES2014/MOVES2010b)

– General decrease in onroad NOx in MOVES2014 relative MOVES2010b

– Differences also reflect change in spatial surrogates (extended idle and starts/stops)

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MOVES2014 Sensitivity• TOG Emissions Results

– >25% higher TOG in the summer than winter months

– Wyoming county total TOG emissions

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MOVES2014 Sensitivity• TOG Emissions Results

– Monthly total TOG emissions differences (MOVES2014-MOVES2010b)

– TOG emissions ratios (MOVES2014/MOVES2010b)

– Increases in onroad TOG in MOVES2014 relative MOVES2010b