Estimating daily ambient concentrations of PM2.5 composition using satellite remote sensing to refine mitigation strategies
Scope of Work
The objectives of this project are to (1) quantify California’s local and regional daily ambient particulate matter (PM2.5) composition (e.g. nitrate, sulfate, organic carbon, elemental carbon, and dust) using satellite remote sensing data collected over the last two decades, (2) track the long-term progress of PM2.5 reductions in regions underrepresented by ground-level air quality monitors, (3) evaluate the spatial disparities in these regions, and (4) recommend pathways that refine existing PM2.5 mitigation strategies with considerations for social equity.
Ambient PM2.5 concentrations often exceed the National Ambient Air Quality Standards (NAAQS) in many parts of California. CARB conducts regional air quality modeling to understand the spatial and temporal variabilities of PM2.5 composition in the regulatory decision-making process. The model outputs are evaluated by using limited ground-level air quality monitoring data that primarily describes the air quality over populated urban centers. Recent advancement in satellite remote sensing technology and data processing algorithms have demonstrated their ability in describing surface-level air quality at a relatively high spatial resolution, providing opportunities for the regional air quality models to be evaluated using an independent dataset. Taking advantage of such data resource is valuable for building additional confidence in the spatial and temporal representativeness of the regional air quality models where ground-level air quality monitoring is limited.
CARB previously collaborated with external researchers to estimate the daily ambient concentrations of PM2.5 composition using satellite remote sensing data from Multi-angle Imaging SpectroRadiometer (MISR; 4.4 km resolution) operated by NASA’s Jet Propulsion Laboratory (JPL). The study focused on the South Coast Air Basin (SoCAB) and the southern San Joaquin Valley (SJV) for years between 2001 and 2015. The satellite derivative enabled CARB to examine the effectiveness of PM2.5 mitigation strategies and prioritize PM2.5 components and their source types for future research.
Expanding the spatiotemporal coverage of PM2.5 composition to the rest of the state can help CARB evaluate opportunities for additional air pollutant emission control strategies, particularly in non-attainment areas and disadvantaged communities without ground-level monitors. Furthermore, spatially and temporally comprehensive PM2.5 composition data can also contribute to the multi-agency environmental justice efforts and health effect studies.
Scope of Work
Task 1. Estimating daily ambient concentrations of PM2.5 composition using satellite remote sensing
The project will estimate daily ambient concentrations of PM2.5 composition (i.e., nitrate, sulfate, organic carbon, elemental carbon, and dust) using the MISR data that spatially covers all of California at the spatial resolution of 4.4 km (further downscaling preferred) for the years 2000-2020. Statistical models or machine learning approaches are recommended to estimate the PM2.5 composition. The project will also process the data just beyond the California-Mexico border to understand the influence of interregional air pollution transport and its influences on California’s local and regional air quality. Additional data resources such as meteorology and land-use information shall be incorporated into the statistical or machine learning models to enhance the overall model predictability of PM2.5 composition.
Task 2. Imputation of missing satellite-based PM2.5 composition estimates
Satellite remote sensing data are retrieved in cloud-free conditions, resulting in days without ambient concentrations of PM2.5 composition that are estimated from Task 1. Therefore, the project will combine other modeling capabilities such as chemical transport models (CTMs; i.e., WRF-Chem or CMAQ) and reanalysis models (assimilation systems; e.g., NASA’s MERRA-2) to impute those missing concentrations. For the imputation, the fusing approaches of CTMs, reanalysis models, ground-level data, and/or ambient concentrations of PM2.5 composition from Task 1 among others. The spatial resolution of the imputed data must be consistent with that of Task 1. Validation of results between the measured and estimated concentrations of PM2.5 composition will be presented from Tasks 1 and 2.
Task 3. Reports
Quarterly reports will be submitted to CARB. A draft report and a final report will be due 30 and 36 months after the start date of the contract, respectively. The report will include a summary of the methodology, all calculations used to produce the results, and policy implications for the PM2.5 mitigation, as requested in the project. The report will also provide the following two datasets: (1) estimated daily ambient concentrations of PM2.5 composition from Task 1, and (2) estimated daily ambient concentrations of PM2.5 composition that are derived from both Tasks 1 and 2 collectively (i.e., all gap-filled PM2.5 composition estimates across California through the entire study period).
- Quarterly progress reports and conference calls;
- Draft final report;
- Final report;
- Research seminar in Sacramento (live broadcasting and archived recordings will be available);
- Peer-reviewed publication(s), as appropriate;
- Daily ambient concentrations of PM2.5 composition from Task 1;
- Daily ambient concentrations of PM2.5 composition that are derived from both Tasks 1 and 2 collectively (i.e., all gap-filled PM2.5 composition across California for the entire study period);
- Detailed descriptions of the data processing methods
- Data processing and modeling software/codes to estimate ambient concentrations of PM2.5 composition;
- In addition to the above deliverables, the project must incorporate equity components that could include but are not limited to the following:
- Equity implications section in the final report;
- Encourage non-academic partners, such as non-profits or community advocates; and/or encourage academic partners new to CARB contracting and/or from smaller universities;
- Peer-reviewed publications should be publicly available (please budget for this expense);
- Work with CARB to create plain-language outreach deliverables for public (available in multiple languages and formats)
- Additional deliverables to be determined in consultation with CARB staff.
It is anticipated this project will be completed in 36 months from the start date. This allows 30 months for completion of all work through delivery of a draft final report. The last 6 months are for review of the draft final report by CARB staff and the Research Screening Committee (RSC), modification of the report by the contractor in response to CARB staff and RSC comments, and delivery of a revised final report and data files to the CARB. The estimated budget for this project is $300,000.
In order to increase transparency of how winning pre-proposals are chosen, scoring criteria have been included for each project. Please note that scoring criteria is tailored to each project included in CARB's fiscal year 2021-2022 solicitation. If you are submitting pre-proposals for more than one project in the solicitation, please be sure to review the scoring criteria to get a better understanding of what components of the project are most valued for selection.
- Responsiveness to the Goals and Objectives Outlined in the Proposal Solicitation(15 points) Proposers should demonstrate a clear understanding of the policy objectives and research needs that CARB seeks to address with this project, and should convey their knowledge of the subject. The proposal should spell out, in adequate detail, exactly what the Proposer proposes to do to satisfy the requirements of the Solicitation. The draft proposal must propose work that would satisfy the objective(s) stated in the Research Solicitation: The objectives of this project are to (1) quantify California’s local and regional daily ambient particulate matter (PM2.5) composition (e.g., nitrate, sulfate, organic carbon, elemental carbon, and dust) using satellite remote sensing data collected over the last two decades, (2) track the long-term progress of PM2.5 reductions in regions underrepresented by ground-level air quality monitors, (3) evaluate the spatial disparities in these regions, and (4) recommend pathways that refine existing PM2.5 mitigation strategies with considerations for social equity.
- POLICY RELEVANCE/BENEFITS TO THE STATE(10 points) – Does the proposal describe how the project will provide data, information, and/or products to help CARB accomplish its mission? Under the Federal Clean Air Act, the California Air Resources Board (CARB) is tasked with the development of State Implementation Plans (SIPs) to meet the health-based national ambient air quality standards (NAAQS) for PM2.5.
- PREVIOUS WORK (10 points) – Do the researchers have relevant experience in this area? Do they discuss how they will build upon previous relevant work that was funded by CARB, other state/federal agencies (e.g., NASA, NOAA, and U.S. EPA), and universities?
- EXPANDING EXPERTISE (10 points) – Does the team bring in new talent that has not worked with CARB previously? Is the team composed of a multidisciplinary team of experts? Researchers new to CARB are encouraged to apply and partner with multidisciplinary teams.
- TECHNICAL MERIT (25 points) - Describe the submission's technical strengths and/or weaknesses. Proposers should demonstrate the logic and feasibility of the methodology and technical approach to the project, spell out the sequence and relationships of major tasks, and explain methods for performing the actual work. Please factor in how well the draft proposal describes these areas:
- Give specifics of each task that the Proposer plans to address (e.g., data resources, statistical model, machine learning, and other modeling capabilities).
- Provide the significance of the proposal that makes advancement over previous research and overcomes previous challenges and limitations.
- Demonstrate the feasibility of obtaining the objectives of this project (e.g., Is the method reasonable to generate high predictive power of daily PM2.5 composition? Does the project employ appropriate methodologies to fill in the data gaps?).
- The review team will be selecting only one draft proposal for development into a full proposal. If this draft proposal has potential, what areas or topics should be prioritized or better explained in the full proposal
- LEVEL AND QUALITY OF EFFORT TO BE PROVIDED(15 points) – Does the proposal allocate time and resources in such a way that the objectives of the study will be met? Is supervision and oversight adequate for ensuring that the project will remain on schedule? Is the distribution of workload appropriate for activities such as research, evaluation and analysis, data reduction, computer simulation, report preparation, meetings, and travel?
- COST EFFECTIVENESS (15 points) - Does the cost seem appropriate for the proposed work? Does the proposed work seem feasible within the requested budget? Projects that provide co-funding should be evaluated more favorably.