Grantee Research Project Results
2015 Progress Report: Improved Prediction of the Vertical Profile of Atmospheric Black Carbon: Development and Evaluation of WRF-CMAQ
EPA Grant Number: R835041Title: Improved Prediction of the Vertical Profile of Atmospheric Black Carbon: Development and Evaluation of WRF-CMAQ
Investigators: Carlton, Annmarie
Institution: Rutgers
EPA Project Officer: Chung, Serena
Project Period: September 1, 2011 through August 31, 2014 (Extended to February 29, 2016)
Project Period Covered by this Report: September 1, 2014 through August 31,2015
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: Climate Change , Air
Objective:
To improve the model predictions of the vertical profile of particulate carbon through better representation of condensed phase organic chemistry in the 3-dimensional photochemical model "CMAQ."
Progress Summary:
The project goals for the final year were to test the new solver approach for CMAQ’s aqueous cloud chemistry in CMAQ. We developed a more explicit aqueous phase chemical mechanism and benchmarked CMAQ predictions from: (1) base CMAQv5.01 (“base”), (2) CMAQv5.01 with the kinetic mass transfer via KPP solver (“AQchem-KMT”), and (3) CMAQv.5.01 with KPP and expanded chemistry (“explicit”). The aqueous chemical mechanism developed with Kinetic Pre Processor (KPP) reduced the number operators required to solving the chemistry and is a more accurate representation of atmospheric processing by clouds. The KPP implementation required some structural changes to the chemistry. For example, bulk mass transfer through phase transition (in base CMAQ) is now calculated simultaneously in the forward (gas to liquid) and backward (liquid to gas) directions and is dependent on cloud droplet size. Note, cloud droplets are consistent with WRF-predicted values. The new reaction forms, used in CMAQ simulations for cases 2 and 3 (above) are listed in Table 1.
CMAQ aqueous chemistry is the base version of the model and in case 2 is shown as “Current SOA reaction in CMAQ” in Table 2. The expanded mechanism is shown as “Explicit reactions in new box model” in Table 2 and graphically in Figure 1. In case 3 simulations (“explicit”), cloud-produced species such as carboxylic acids partition to the gas phase depending on their vapor pressure (specific to acid or base form).
In general, we find that the explicit chemistry does not perturb domain-wide averages (left of Figure 2), but increases variability (right of Figure 2).
Implementation of the explicit chemistry for organic species in clouds changed cloud-produced SOA (SOAAQ) and total SOA mass (Figures 3 and 4). Changes in total SOA are a consequence of more organic mass (i.e., SOAAQ) available for semi-volatile partitioning (Figure 5). Largest average changes were observed in the eastern U.S. (Figure 6).
We are preparing these results for publication in collaboration with Kathleen Fahey of EPA’s Office of Research and Development.
Future Activities:
Year 3 activities are focused on full CMAQ simulations and comparison with ambient observational data.
Journal Articles on this Report : 7 Displayed | Download in RIS Format
| Other project views: | All 51 publications | 18 publications in selected types | All 18 journal articles |
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Baker KR, Carlton AG, Kleindienst TE, Offenberg JH, Beaver MR, Gentner DR, Goldstein AH, Hayes PL, Jimenez JL, Gilman JB, de Gouw JA, Woody MC, Pye HOT, Kelly JT, Lewandowski M, Jaoui M, Stevens PS, Brune WH, Lin Y-H, Rubitschun CL, Surratt JD. Gas and aerosol carbon in California: comparison of measurements and model predictions in Pasadena and Bakersfield. Atmospheric Chemistry and Physics 2015;15(9):5243-5258. |
R835041 (2015) R835041 (Final) |
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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) |
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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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Guo H, Xu L, Bougiatioti A, Cerully KM, Capps SL, Hite Jr. JR, Carlton AG, Lee S-H, Bergin MH, Ng NL, Nenes A, Weber RJ. Fine-particle water and pH in the southeastern United States. Atmospheric Chemistry and Physics 2015;15(9):5211-5228. |
R835041 (2015) R835041 (Final) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2015) R834799C001 (Final) R835410 (2013) R835410 (2014) R835410 (2015) R835410 (Final) |
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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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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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Nguyen TKV, Capps SL, Carlton AG. Decreasing aerosol water is consistent with OC trends in the southeast U.S. Environmental Science & Technology 2015;49(13):7843-7850. |
R835041 (2015) R835041 (Final) |
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Supplemental Keywords:
Cloud processing, secondary organic aerosol;Relevant Websites:
Annmarie Carlton ExitSouthern Oxidant & Aerosol Study (SOAS) Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.