# Presentation: 527104

##     Assessment of U.S Particulate Air Quality Using Remote Sensing and EPA surface Aerosol Data via Giovanni 

**Ana I. Prados, Gregory Leptoukh,** **Andrey Savtchenko, Arun Gopalan, James Johnson, and ****Suraiya Ahmad**
**2008 National Air Quality Conference**

## About Giovanni

**About Giovanni**

- Giovanni is a Web-based application developed by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC).
- Giovanni provides a simple and easy way to explore, visualize, analyze, and access vast amounts of Earth science remote sensing and model data.
**http://giovanni.gsfc.nasa.gov/**

## http://giovanni.gsfc.nasa.gov

## The Power of Simplicity

**The Power of Simplicity**

-  Only a Web browser is needed.

- No need to learn data formats and programming.

- No need to download large amounts of data.

- Customized data and analyses can be obtained with only a few mouse clicks.

## Giovanni Air Quality Tools and Datasets

**Available Science Data Sets **
- PM2.5 station data - Acquired at DataFed from EPA AIRNow and then via WCS into Giovanni
- MODIS TERRA and AQUA total and fine mode Aerosol Optical Depth
- CALIOP Aerosol Feature Mask curtain plots
- OMI UV Aerosol Index
- OMI NO2 Tropospheric column (0.25x0.25 degree)
**Useful Tools for Air Quality Applications**
- AOD/ PM2.5 scatter plots, correlation maps, time series and difference plots
- AOD and PM2.5 loops for examining long range transport of aerosols

## Giovanni Air Quality (in testing mode)

## Giovanni Air Quality Parameters Available through existing instances (except PM2.5)

- Giovanni Air Quality Parameters Available through existing instances (except PM2.5)

## Click on ‘Generate Visualization’ and...

## Imagery and Datasets

- Download customized GIF images for the selected region/time period
- Download datasets :
-        - ASCII for easy import into Excel
-        - KMZs for Google Earth visualization

## Giovanni AIRNow PM2.5 Gridded Data

- Giovanni PM2.5 map Data from EPA AIRNow. Acquired from DataFed via WCS.

- Giovanni PM2.5 Map (ug/m3)

- AIRNow PM2.5 Air Quality Index Map

## MODIS Aerosol Optical Depth

-  MODIS Terra and    Aqua
-  Well validated over land
- Fine mode fraction
- Can capture both surface and mid to upper tropospheric aerosols

## Giovanni KMZ files: visualization through Google EarthMay 27, 2007

- Giovanni PM2.5 Map (ug/m3)

- Giovanni MODIS Terra AOD map

## MODIS AOD and AIRNow PM2.5 AQI(AQI from AIRNow web site)

- February 27th, 2008

- Giovanni KMZ files: visualization through Google Earth

## OMI UV Aerosol Index

-  Mostly sensitive to absorbing aerosols above the planetary boundary layer (i.e transported smoke plumes)
-  Work in progress to assess the utility of OMI UV Aerosol Index for understanding AOD/PM2.5 correlations

## PM2.5, MODIS and OMI Views of California Fires

**EPA  AIRNow PM****2.5**** (ug/m****3****)**

**OMI UV Aerosol Index**

** ****Level-3 MODIS  AQUA AOD**

- Oct. 24th

- Oct. 25th

## A-Train Instance: Select Orbit and date 

## Select A-Train Instance parameter(s) 

## Click on ‘Generate Visualization’ and...Calipso Curtain plot 

##  AIRNow PM2.5 map in background

 Yellow: aerosol flag 
  Blue: cloud flag

-  Yellow: aerosol flag
-   Blue: cloud flag

- Calipso Curtain PlotsJuly 31, 2007

##   AIRNow PM2.5 map in background

   Yellow: aerosol flag 
    Blue: cloud flag

-    Yellow: aerosol flag
-     Blue: cloud flag

- Calipso Curtain Plots July 31, 2007

## July 31st, 2007

**July 31****st****, 2007**

- In Canada and the north-central US, MODIS and OMI show thick aerosols plumes. CALIOP overpass has a plume above the boundary layer

## Calipso Curtain Plots (A-Train)July 31, 2007: Smoke and Haze over the U.S 

- Calipso Curtain Plots (A-Train)July 31, 2007: Smoke and Haze over the U.S

- OMI contours over MODIS AOD. White lines indicate CALIPSO overpass

- Calipso provides vertical aerosol and cloud information

## Not fully validated (in progress)
Qualitative agreement with high NOx regions (i.e urban areas)

- Qualitative agreement with high NOx regions (i.e urban areas)

- OMI Tropospheric NO2 Column

## Giovanni Air Quality Services:                  AOD/PM2.5 Correlation Maps and Time Series

- May 2007 AOD/PM2.5 correlation map over the U.S
- Moderate to good correlation in the eastern U.S
-     May 2007- AOD and PM2.5
-    Time series over the southeast

## AOD/PM2.5 Correlations over the Southeastern US  July 31, 2007

-  In the southeast (Tennessee, Mississippi, Alabama and Arkansas) MODIS and PM2.5 show good spatial agreement and have moderately good correlation
- Low OMI UV Aerosol Index and CALIPSO Aerosol flag also indicate aerosols are primarily confined to the boundary layer in these states

## July 31st, 2007

**July 31****st****, 2007**

- In Canada and the north-central US, MODIS and OMI show thick aerosols plumes. CALIOP overpass has a plume above the boundary layer

## Giovanni Air Quality tools:                                  Understanding AOD/PM2.5 correlations

**EPA PM****2.5**** (ug/m3)**

- May 22nd, 2007: Smoke over north Carolina. High AOD and low PM2.5 (r=0.54). There is also haze in the southeast

-  Improved correlation over this region when excluding smoke areas (r=0.80)

- Giovanni Air Quality tools:                                  Understanding AOD/PM2.5 correlations

## Giovanni Air Quality tools:                                 Understanding AOD/PM2.5 correlations

** ****Level-3 MODIS AOD**

**EPA PM****2.5**** (ug/m3)**

-  CALIOP Aerosol Flag (yellow) for examining the vertical aerosol  distribution.
-  Aerosols in Georgia and Alabama from the surface to 4 km, AOD/PM2.5 correlation is moderately good
-  Aerosols in the northeast are above boundary layer,  AOD/PM2.5 correlation is poor

- Giovanni Air Quality tools:                                 Understanding AOD/PM2.5 correlations

## Smoke over the eastern U.S Aug 13-15, 2007

- AIRNow PM2.5(ug/m3)

- MODIS AQUA AOD

- OMI AI

- OMI UV Aerosol Index-  helps identify regions with aerosols above the boundary layer
- When aerosols are above the boundary we expect the AOD/PM2.5 correlation to be poor

## Improving the PM2.5/AOD Correlationwith the OMI UV Aerosol Index (AI)

- AOD/PM2.5 correlation r=0.4

- AOD/PM2.5 correlation after eliminating AODs where AI >1
- r= 0.56

- Screened MODIS data points

## Examine AOD and PM2.5 maps, correlation maps and time series plots. Fine Mode AOD also available
High AOD/PM2.5 correlation indicates the MODIS algorithm is capturing aerosols at the surface; elevated aerosol layers may still be present – check OMI AI
 High AOD and low PM2.5 may indicate the presence of aerosol plumes above the boundary layer – check OMI AI
CALIPSO overpass (if available) together with AOD/PM2.5 correlations and scatter plots to qualitatively assess the vertical distribution of aerosols
 MODIS algorithm issues (e.g. retrieval problems over bright surfaces) affect correlations

**High AOD/PM****2.5**** correlation** indicates the MODIS algorithm is capturing aerosols at the surface; elevated aerosol layers may still be present – check OMI AI
-  **High AOD and low PM****2.5** may indicate the presence of aerosol plumes above the boundary layer – check OMI AI
**CALIPSO overpass** (if available) together with **AOD/PM****2.5** correlations and scatter plots to qualitatively assess the vertical distribution of aerosols
-  **MODIS algorithm issues** (e.g. retrieval problems over bright surfaces) affect correlations

**Analysis of U.S Air Quality Via Giovanni**

##    NASA Gocart Model Particle Speciation

-    NASA Gocart Model Particle Speciation

- California and Southwestern US

- Eastern US

-  Global chemical transport model with gas phase and aerosol chemistry
-  Monthly data at 1x1.25 degree resolution
-  Giovanni allows colocation with EPA AIRNow data
-  Source attribution for pollution events

**Sea salt     ****Organic Carbon****        ****Dust****          ****Black carbon**        **Sulfate**

##    NASA GOCART Model Particle Speciation

- Texas

- North-Central US

- Southeastern US

**Sea salt     ****Organic Carbon****        ****Dust****       ****Black carbon**     **Sulfate**

-    NASA GOCART Model Particle Speciation

##    NASA GOCART Model Particle Speciation

-    NASA GOCART Model Particle Speciation

- Black Carbon

- Sulfate

- Organic Carbon

-          Dust

##    NASA GOCART Model Particle Speciation

-    NASA GOCART Model Particle Speciation

- Sea Salt

## Summary

-  **Giovanni Air Quality** (currently in testing)
-      - Addition of EPA gridded PM2.5 AIRNow data
-      - Simultaneous visualization and comparisons between EPA surface data and NASA remote sensing data for the assessment of the origin, distribution, and evolution of smoke and industrial pollution plumes over the continental U.S

**Summary**