2014 Progress Report: Improved Prediction of the Vertical Profile of Atmospheric Black Carbon: Development and Evaluation of WRF-CMAQ

EPA Grant Number: R835041
Title: Improved Prediction of the Vertical Profile of Atmospheric Black Carbon: Development and Evaluation of WRF-CMAQ
Investigators: Carlton, Annmarie
Institution: Rutgers, The State University of New Jersey
EPA Project Officer: Hunt, Sherri
Project Period: September 1, 2011 through August 31, 2014 (Extended to February 29, 2016)
Project Period Covered by this Report: September 1, 2013 through August 31,2014
Project Amount: $449,916
RFA: Black Carbon's Role In Global To Local Scale Climate And Air Quality (2010) RFA Text |  Recipients Lists
Research Category: Global Climate Change , Climate Change , Air

Objective:

The project goals for the last year are to implement the new solver approach, developed in year 2 for CMAQ’s aqueous cloud chemistry, into WRF-CMAQ simulations and explore the impact on predicted radiative impacts.

Progress Summary:

We have a Kinetic Pre Processor (KPP) version of an expanded aqueous phase chemical mechanism into WRF-CMAQ. To date, we have conducted eight 10-day sensitivity simulations for the SOAS (Southern Oxidant and Aerosol Study) time period (summer 2013) that includes new mechanisms (see Table 1). We plan to submit this work for publication in the coming year. We find that implementation of the new solver (RODAS3 in KPP) has an impact on secondary organic aerosol (SOAaq) production that is on par with 40 percent changes in cloud liquid water. Liu, et al. (2012) identified that cloud liquid water was the variable that had the largest impact on predicted SOAaq. Our work suggests the model’s internal solver impacts SOAaq mass predictions to a similar degree. 

We have evaluated predictions from the base case CMAQ simulation for particle phase liquid water (Figure 1) and total solubility for the volatile organic carbon (VOC) inventory (Figure 2) (analogous to VOC reactivity evaluations). These are the first such evaluations of CMAQ. We find that the method used in CMAQ to estimate particle phase liquid water cannot reproduce early morning values measured by SMPS during SOAS (Figure 1). In this evaluation, observed ion, temperature and RH are used as inputs to ISORROPIA for comparison with SMPS measurements. Interpretation and analysis of VOC solubility is under development (Figure 2). Future sensitivity simulations include exploring the effects of "salting in" and "salting out" on the amount glyoxal, methylglyoxal and IEPOX that can partition to aerosol liquid water. Preliminary, offline calculations are presented in Figure 3. 

In addition to the core solver and mechanism development work described, we have conducted synergistic activities. We studied inorganic chemistry on cloud ice to investigate the impact on particle concentrations aloft (100 mb+) (Marmo et al., 2013), where radiative impacts are suspected to be large because direct scattering calculations are altitude dependent. We collaborated with EPA scientists to understand how organic cloud chemistry impacts atmospheric mercury reduction (Bash et al., 2014). We have developed a method to improve representation of electricity sector emissions that has a dramatic impact on ambient black carbon mass concentrations at the surface and aloft (Farkas et al., 2015). At 800 mb, black carbon mass concentrations increase more than 300 percent (Figure 4). We have also evaluated trends in particle phase liquid water in the Southeast United States as an explanation for observed decreases in optically active particulate organic carbon. We find that aerosol water mass in the Southeast United States has decreased by approximately 70 percent (Figure 5) and that the sulfate to organic mass ratio remains nearly constant (Figure 6) when fires are screened from data in EPA’s IMPROVE network and EPRI’s SEARCH network data. This work is currently in preparation and we expect to submit a manuscript in the coming year. 

 

 

Future Activities:

Completion of the grant is focused on full CMAQ simulations and comparison with ambient observational data.

References:

Liu, X., et al. (2012), Toward a minimal repreetion of aerosols in climat models: Decriptionaevation in the Community Atmospere Model CAM5, Geosci. Mode Dev. Discuss., 5, 709-739, doi:10.5194/gmd-5-709-2012.


Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other project views: All 50 publications 17 publications in selected types All 17 journal articles
Type Citation Project Document Sources
Journal Article Bash JO, Carlton AG, Hutzell WT, Bullock Jr OR. Regional air quality model application of the aqueous-phase photo reduction of atmospheric oxidized mercury by dicarboxylic acids. Atmosphere 2014;5(1):1-15. R835041 (2014)
R835041 (2015)
R835041 (Final)
  • Full-text: Atmosphere-Full Text-HTML
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  • Abstract: Atmosphere-Abstract
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  • Other: Atmosphere-Full Text-PDF
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  • Journal Article Farkas CM, Moeller MD, Felder FA, Baker KR, Rodgers M, Carlton AG. Temporalization of peak electric generation particulate matter emissions during high energy demand days. Environmental Science & Technology 2015;49(7):4696-4704. R835041 (2014)
    R835041 (2015)
    R835041 (Final)
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  • Journal Article Hodas N, Sullivan AP, Skog K, Keutsch FN, Collett Jr JL, Decsesari S, Facchini MC, Carlton AG, Laaksonen A, Turpin BJ. Aerosol liquid water driven by anthropogenic nitrate: implications for lifetimes of water‐soluble organic gases and potential for secondary organic aerosol formation. Environmental Science & Technology 2014;48(19):11127‐11136. R835041 (2014)
    R835041 (2015)
    R835041 (Final)
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  • Journal Article Marmo BP, Carlton AG, Henderson BH. Partitioning of HNO3, H2O2 and SO2 to cloud ice: simulations with CMAQ. Atmospheric Environment 2013;88:239-246. R835041 (2014)
    R835041 (2015)
    R835041 (Final)
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  • Supplemental Keywords:

    Cloud processing, secondary organic aerosol, black carbon, atmospheric black carbon, cloud chemistry;

    Relevant Websites:

    Rutgers Department of Environmental Sciences: Annmarie Carlton Exit
    Rutgers: Southern Oxidant and Aerosol Study Exit

    Progress and Final Reports:

    Original Abstract
    2012 Progress Report
    2013 Progress Report
    2015 Progress Report
    Final Report