The relationship between surface data and satellite data

Rudy Husar

Erin Robinson

Abstract

The land surface has optical properties that can change significantly over time and can be affected by particles in the air. Using data extracted from SEAWiFS satellite images with Sean Raffuse's programs, we are now looking at the relationship between satellite data and data monitored from the ground. One specific way we are doing this is by creating a program that reads in a list of latitudes and longitudes for stations collecting PM data and the particular value for that day, this program then finds the correlating pixel on the Aerosol Optical Thickness image (AOT) for the same day. This value is then written out and further analysis can take place. It is interesting to study this relationship because some aerosols travel close to the surface like smog, while other particulate matter like smoke can travel very high up being seen by the satellite, but not by the PM stations on the ground. By looking at both from the ground up and from the satellite down a more complete picture of the aerosol can be obtained.

August 8, 2000:

Idaho Smoke Event

Using IDL

1. Compile PM2.5 Data into a text file

2. Read the text file into the program

3. Using the appropriate AOT file find the pixel that correlates to the appropriate latitude/longitude of the station

4. Write out the same file with AOT values included

Output from PM_AOTmatchLoc_code latitude longitude date PM_value line sample AOT_value 60190008 36.78 -119.77 8/8/2000 5.994481 960 360 2060290014 35.36 -119.04 8/8/2000 7.698114 1020 360 2060370002 34.14 -117.92 8/8/2000 27.68846 1080 480 2060658001 34.01 -117.43 8/8/2000 27.18831 1080 480 2060670010 38.56 -121.49 8/8/2000 4.994182 840 240 2060730003 32.79 -116.94 8/8/2000 14.09065 1200 540 2060731002 33.13 -117.07 8/8/2000 13.79368 1140 480 2060850004 37.34 -121.89 8/8/2000 8.088856 900 240 201.31E+08 33.69 -84.29 8/8/2000 18.38881 1140 2460 371.31E+08 33.9 -84.28 8/8/2000 17.38851 1140 2460 371.31E+08 33.81 -84.38 8/8/2000 15.38791 1140 2460 3780310002 39.75 -104.99 8/8/2000 13.99687 780 1260 4360371103 34.07 -118.24 8/8/2000 23.79667 1080 420 501.7E+08 42.14 -87.8 8/8/2000 8.292042 600 2280 54

10730023 33.55 -86.82 8/8/2000 14.49702 1140 2340 5810732003 33.5 -86.92 8/8/2000 16.88836 1140 2340 582.21E+08 29.99 -90.1 8/8/2000 10.49582 1380 2100 641.21E+08 28.55 -81.35 8/8/2000 15.1691 1440 2640 671.21E+08 28.6 -81.36 8/8/2000 12.99657 1440 2640 6760731007 32.71 -117.15 8/8/2000 15.5911 1200 480 781.2E+08 30.36 -81.55 8/8/2000 15.24724 1320 2640 100

1.92E+08 41.66 -93.61 8/8/2000 7.088557 660 1920 12451191008 34.68 -92.33 8/8/2000 17.99806 1080 1980 1542.4E+08 39.31 -76.47 8/8/2000 20.3894 780 2940 172

2.45E+08 39.23 -76.58 8/8/2000 21.49911 780 2940 1722.45E+08 39.3 -76.6 8/8/2000 21.68667 780 2940 1721.1E+08 38.92 -77.01 8/8/2000 20.49881 840 2880 2281.1E+08 38.9 -76.95 8/8/2000 21.59289 840 2940 355

2.71E+08 44.96 -93.26 8/8/2000 9.089155 480 1920 5212.71E+08 44.96 -93.04 8/8/2000 8.292042 480 1920 521

Pictorial OutputRelationship between PM 2.5 and AOT values in the blue wavelength

for August 8, 2000

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PM 2.5 Data

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Conclusions and Future Research