1. AIRNow Web Services Data to Go! Prepared by Steven A. Ludewig, Timothy S. Dye Sonoma Technology, Inc. Petaluma, CA John E. White U.S. Environmental Protection Agency Research Triangle Park, NC Presented at the 2010 National Air Quality Conferences Raleigh, NC March 15-18, 2010 3800

2. 2 AIRNow Web Services: Why Are They Needed? Web Services provide a way to retrieve data and information ‘on demand’ from the AIRNow system. –Forecasts –Action days –Observed data –Multiple format options including maps –Agency, reporting area, and monitoring site information Uses –Agency websites, web developer access –Local news organizations –Other agencies –Schools and researchers –Spreadsheets and other applications –The public

3. 3 A few potential uses AIRNow Web Services

4. 4 AIRNow System Desktop Apps Websites Mobile Apps Web Services enable the AIRNow repository to become the data source behind many types of software programs. It meets the needs of web developers, news organizations, researchers, and the public. It saves agency time – no need to deliver custom data sets or provide specific feeds to those requesting data. Web Services

5. 5 AIRNow Web Services Where we’ve been –Simple Object Access Protocol (SOAP): not as simple or clean as it sounds Progress in 2009 –A RESTful approach The future – an AIRNow Application Programming Interface (API) –Additional services, data sets, and formats useful for building applications –An easier to use, well-documented interface

6. 6 AIRNow Web Services: A RESTful Approach (1 of 2) REST = “REpresentational State Transfer” –The RESTful AIRNow Web Services use the URL – the web address that we are all familiar with, e.g., http://www.airnow.gov” –The URL represents a question asked of a computer system. –Example: Typing www.airnow.gov in the address line is asking AIRNow to show us their home page. The web page is then returned and displayed on-screen. Web Service questions can be much more specific than just “show me your web page” and the results can be more than just a display in the browser.

7. 7 AIRNow Web Services: A RESTful Approach (2 of 2) Example question: “What is the current air quality forecast for my home town ZIP Code?” –URL: http://ws.airnowgateway.org/GatewayWebService REST/Gateway.svc/forecastbyzipcode?key=43321E- F56Q-B612-68FBN&zipcode=95401&format=csv Looks complicated, but let’s break it down –ForecastByZIPCode = the name of this request* –Key = unique user key –ZIPCode = ZIP Code of interest –Format = payload options (CSV, JSON, KML, XML, etc.) –Optional: Date = any date of interest (defaults to the current date) *a companion service exists for observed data: ObservedByZIPCode

8. 8 AIRNow Web Services Use of ForecastByZIPCode and ObservedByZIPCode services by the EPA MyEnvironment website: www.epa.gov/myenvironment

9. 9 AIRNow Web Services Question: “What are the current observed PM 2.5 values for a geographic area in northern California?” –URL: http://ws.airnowgateway.org/demo/wcs/wcs.asmx/wcs?service=wcs& Request=GetCoverage&identifier=point&aqsparamcode=44201&aqsdurati oncode=1&poc=1&time_sequence=2010-02-27 00:00:00&bbox=40,- 124,42,-122&format=csv&key=1A112F55-9B32-4C54-A81B-78D9C03A5 –Identifier = point (other options include time series and gridded data) –AQSParamCode = 44201 (AQS parameter code for ozone) –AQSDurationCode = 1 (one hour) –POC = 1 (parameter occurrence code) –Time_Sequence = date/time of data –BBox = the geographic bounding box of the data (latitude/longitude) –Format = payload format (CSV, AQCSV, KML, NetCDF ) –Key = unique user key

10. 10 AIRNow Web Services Use of a geospatial Web Coverage Service (WCS) by Shasta County, CA: http://www.co.shasta.ca.us/html/ResMgmt/AQ/aq_map.aspx KML file

11. 11 AIRNow Web Services ForecastByZIPCode ObservedByZIPCode ForecastsByIssueDate ActionDaysByDate Ozone24HourAQI PM25Mid24HrAQI ReportingAreaMax- AverageAQI SiteMaxAverageAQI SiteInfoByAQSCode AgencyGetSites GetReportingAreas Geospatial: WCS – point WCS – time series Coming Soon: WCS – grid WMS – mapping service Demonstration Tool

12. 12 AIRNow Web Services – The Future AIRNow API –Expanded library of services –Additional geospatial services –More payload options –Improved standardization –Extensive documentation –Online query generator tools

13. 13 AIRNow Web Services Thank You! Contact: Steven A. LudewigJohn E. White (707) 665-9900(919) 541-2306 steve@sonomatech.comwhite.johne@epa.gov