Assessing Particulate matter Air pollution: Background and case studies

1
Assessing Particulate matter Air pollution
Background and case studies
Sundar A. Christopher Department of Atmospheric
Science UAHuntsville, AL AMS Giovanni
Short Course
2
Purpose

• Purpose of this session Provide guidelines for
  using satellite remote sensing tools for
  particulate matter (PM) air quality analysis.
• Some hands-on perspective is also included.

Satellites are the only viable method for
monitoring global pollution
3
How particulate matter is measured?

• PM2.5 Mass Concentration and particulate matter
  Air Quality Index are traditionally assessed from
  ground monitors.
• Ground monitors are almost non existent in many
  countries.

1500
4
Air Quality Index

• Based on 24 hour PM2.5 mass concentrations air
  quality indices are derived.
• However, these ground monitors lack spatial
  coverage.

5
Satellite imagery
Satellite imagery provide large-scale snapshots
and are reliable also available globally!
Figure courtesy, Engel-Cox
6
September8, 2002
September 10, 2002
September 12, 2002
Strengths of Satellite Remote Sensing Monitoring
Pollution Transport
Figure courtesy, Engel-Cox
7
The satellite ground monitor problem?
Multi-spectral satellite data
Surface measurement
Satellite measured radiances are converted to
columnar Aerosol Optical Thickness
8
How good is a column measurement for assessing
ground level pollution?

• Column satellite measurements coupled with
  space/ground-based lidars and meteorological
  information are critical for assessing PM2.5

9
Quite good actually!
Time Series shows agreement of hourly PM2.5
Concentrations (Surface Monitor) and Aerosol
Optical Depth in Coincident MODIS pixel.
Correlation Coefficient gt 0.88.
Pollution that is well mixed in the boundary
layer provides a good AOD-PM2.5 relationship
10
Air Quality Index
Use AOT PM2.5 relationship and get AQI
PM2.5 (µgm-3) (27.5 x MODIS AOT) 15.63
11
Air Quality Event Analysis
First things first, Interpreting satellite
imagery
True Color imagery Cloud versus aerosol AOD
maps Meteorology Ground-based info Air quality
assessment
Clouds
Smoke
Fires
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
Where did the pollution come from?
Web resources For examining Meteorology Are
available
17
Meteorology - Example
Met. Reports are always helpful
18
Air Quality Index
PM2.5 (µgm-3) (27.5 x MODIS AOT) 15.63
19
A Case Study Smoke pollution in southeastern
United States
20
Map of the Air Quality Event Region
Region of Air Quality Event
Massive fires during Spring, 2007
21
MODIS-Terra True Color Image 1635 GMT, May 02,
2007
Wheres the Cloud? Aerosol? Fires
(Red?) Sunglint?
Its one thing for the eye to separate features.
Teaching the computer to do that trick .
22
MODIS-Terra Aerosol Optical Thickness (AOT)
Colored circles represent air quality categories
derived from surface PM2.5 mass concentration
using EPA AirNow network
23
Terra-Aqua Daily Composite
24
Terra-Aqua Weekly Composite (May 27-Jun 02)
25
True Color Time Series Images MODIS-Terra Southeas
tern United States
May 11, 2007
May 12, 2007
May 13, 2007
May 14, 2007
May 15, 2007
May 16, 2007
26
AOT Time Series Images MODIS-Terra Southeastern
United States
May 11, 2007
May 12, 2007
May 13, 2007
May 14, 2007
May 15, 2007
May 16, 2007
27
True Color and AOT Images Available on the
Internet

• True Color Images
• MODIS instrument http//rapidfire.sci.gsfc.nasa
  .gov/subsets/
• Click on region of interest.
• Click on the display alternate dates available
  for this subset link.
• Select date of interest (dates are in Julian date
  format).
• Repeat for all overlapping regions of interest.
• True Color and AOD Images
• Parasol satellite http//www-icare.univ-lille1.f
  r/parasol/browse/
• Click the box next to Aerosol Optical Thickness
  over land and 865 nm Optical Thickness over
  ocean to view aerosol images.
• MODIS AOT images http//ladsweb.nascom.nasa.gov/b
  rowse_images/l2_browser.html
• AI Images
• OMI instrument http//toms.gsfc.nasa.gov/aerosol
  s/aerosols_v8.html
• Scroll to the bottom of the page to select
  images.
• Select global image from Choose output
  pull-down menu.
• Select OMI 8/17/2004 Present from coverage
  satellite pull-down menu.
• Select appropriate Date to be studied.

Some of this data is also available in GIOVANNI
28
Meteorological Information Available on the
Internet

• National Weather Services
• http//www.srh.noaa.gov/forecast/MapClick.php?City
  NameHuntsvillestateALsitehun
• Radar
• http//radar.weather.gov/radar.php?ridhtxproduct
  N0Roverlay11101111loopno
• Satellite
• http//www.goes.noaa.gov/ECIR4.html

29
Ground-Based Particulate Measurements
PM2.5 Mass Concentration and Air Quality Index
http//cfpub.epa.gov/airnow/index.cfm?actionairno
w.showmappollutantPM2.5
30
Hybrid Single-Particle Lagrangian Integrated
Trajectory (HYSPLIT) Analysis

• NOAA Air Resources Laboratory HYSPLIT Model
• http//www.arl.noaa.gov/ready/open/hysplit4.html
  
• Under the HYSPIT pull-down menu, select run
  with archived data.
• Select compute trajectories.
• Choose the GDAS (global, 2005-present) archived
  meteorological dataset.
• Select the gdsl.may07.w1 archive file.
• Choose 1 trajectory starting location.
• Enter the WMO code for the city where you would
  like to base the trajectory
• Or Click on the map to select your location of
  interest
• Model Run Time Options
• Select a forward or back trajectory.
• Select the appropriate start or end time.
• Type in 1000 for Start height 2 and 1500
  for Start height 3.
• LEAVE EVERYTHING ELSE UNCHANGED.
• Scroll to the bottom and click request
  trajectory.
• Wait for your results when they are done, click
  on your trajectory plot.

31
Sources of Satellite Data and Imagery
Moderate Resolution Imaging Spectroradiometer
(MODIS) description http//modis-atmos.gsfc.nasa
.gov/ MODIS Rapid Response System
http//rapidfire.sci.gsfc.nasa.gov/ MODIS direct
broadcast site http//eosweb.ssec.wisc.edu/ The
Smog Blog http//alg.umbc.edu/usaq/ NASA Earth
Observatory http//earthobservatory.nasa.gov/ NAS
A Visible Earth http//visibleearth.nasa.gov/ NAS
A Giovanni http//daac.gsfc.nasa.gov/techlab/giov
anni IDEA http//idea.ssec.wisc.edu/ CALIPSO
http//www-calipso.larc.nasa.gov/products/lidar/ U
SEPA http//cfpub.epa.gov/airnow/index.cfm?action
airnow.showmappollutantPM2.5 NSW
http//www.srh.noaa.gov/forecast/MapClick.php?City
NameHuntsvillestateALsitehun GOES
http//www.goes.noaa.gov/ECIR4.html