Ozone data for "Ozone-related asthma exacerbation emergency department visits
in the US in a warming climate" by Nassikas et al.

These data are output from the Community Multiscale Air Quality (CMAQ) model,
version 5.2.  They are a subset of the data that were used for the Air Quality 
chapter of U.S. EPA (2017).

The meteorological input data for CMAQ were derived from outputs of the 
Community Earth System Model (CESM) following two Representative Concentration 
Pathways (RCPs): RCP4.5 and RCP8.5.  The CESM fields were downscaled to 
36-km grid cells over North America using the Weather Research and Forecasting
model version 3.4.1. The downscaling and air quality modeling procedure are
described in Spero et al. (2016) and Nolte et al. (2018).

The anthropogenic emissions used for the CMAQ simulations were 2040 projections
developed for analysis of the Heavy Duty Greenhouse Gas Rule. These represent
significant reductions relative to present-day of pollutant emissions, including
nitrogen oxides (NOx), sulfur dioxide, and volatile organic compounds (VOCs).
Climate-sensitive VOCs emitted from vegetation, e.g., isoprene, were modeled
within CMAQ using the downscaled meteorological projections from WRF.

Nolte CG, Spero TL, Bowden JH, Mallard MS, Dolwick PD (2018), The potential 
effects of climate change on air quality across the conterminous US at 2030 
under three Representative Concentration Pathways, Atmos. Chem. Phys., 
18, 15471-15489, doi:10.5194/acp-18-15471-2018.

Spero TL, Nolte CG, Bowden JH, Mallard MS, Herwehe JA (2016), The impact of
incongruous lake temperatures on regional climate extremes downscaled from
the CMIP5 archive using the WRF model, J. Clim., 29, 839-853, 
doi:10.1175/JCLI-D-15-0233.1.

U.S. EPA (2017), Multi-Model Framework for Quantitative Sectoral Risk Analysis: 
A Technical Report for the Fourth National Climate Assessment, U.S. Environmental 
Protection Agency, EPA 430-R-17-001, available at 
https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryId=335095.

Dataset manifest
README.txt (this file)
brown.zip  - ZIP file containing grid.csv and max8-brown.csv
  grid.csv - contains latitude (degrees_N) and longitude (degrees_E) for the
             center of the indicated grid cell, as indexed by the cell column and row.
             Cells outside of the contiguous United States are excluded from this
             data set.

  max8-brown.csv - Contains maximum daily 8-h average surface-layer ozone 
             concentrations (parts per billion by volume, ppb) modeled for each 
             indicated grid cell and day for the two future climate scenarios.
             Data are reported only for the May-September ozone season.
             Values are labeled by Julian day, so that 121 indicates 1 May,
             and 273 indicates 30 September.  
             There are no leap years in this climate model, so that February always
             has 28 days.
             Data are reported for May-September over the 20-year period 2036-2055.


These data provided to Nicholas Nassikas and Gregory Willenius of Brown University
for analysis of the extent to which a climate change mitigation scenario also 
mitigates asthma attributable to ozone.


This file prepared by:
Christopher G. Nolte
Office of Research and Development
U.S. Environmental Protection Agency
nolte.chris@epa.gov
10 June 2018