Related Experiment Video
Updated: Jul 2, 2026
06:27
Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer
Published on: May 29, 2019
Spatiotemporal associations between GOES aerosol optical depth retrievals and ground-level PM2.5
Christopher J Paciorek1, Yang Liu, Hortensia Moreno-Macias
1Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts 02115, USA. paciorek@alumni.cmu.edu
Environmental Science & Technology
|August 30, 2008
Summary
Aerosol optical depth (AOD) from the GOES aerosol/smoke product (GASP) shows potential as a proxy for fine particulate matter (PM2.5) in the U.S. Despite limitations, its high data density and long record offer value for exposure assessments.
Area of Science:
- Environmental Science
- Atmospheric Science
- Remote Sensing
Background:
- Fine particulate matter (PM2.5) monitoring is crucial for public health, but ground-level data is sparse.
- Satellite-derived aerosol optical depth (AOD) offers a broader spatial and temporal coverage.
- The Geostationary Aerosol/Smoke Product (GASP) provides frequent AOD retrievals.
Purpose of the Study:
- To evaluate the GOES aerosol/smoke product (GASP) AOD as a proxy for ground-level PM2.5 in the United States.
- To assess the strengths and limitations of GASP AOD compared to other satellite products.
- To determine the utility of GASP AOD for improving exposure estimates in epidemiological studies.
Main Methods:
- Correlation analysis between daily GASP AOD and ground-level PM2.5 at fixed locations over time.
- Spatial correlation analysis of GASP AOD and PM2.5 at fixed times.
- Statistical calibration applied to time-averaged data.
- Comparison of data density and temporal coverage with other satellite AOD products (MODIS, MISR).
Main Results:
- Daily correlations between GASP AOD and PM2.5 are reasonably high, particularly outside of winter and the western U.S.
- Spatial correlations are generally lower than temporal correlations.
- Statistical calibration improves correlations when averaging over time.
- GASP AOD exhibits significantly higher data density (39% of days) compared to MODIS (11%) and MISR (5%).
- GASP AOD provides a long-term data record dating back to 1994.
Conclusions:
- GASP AOD shows potential as a valuable proxy for PM2.5, especially for epidemiological studies requiring extensive data.
- Its high temporal resolution and long historical record are significant advantages over other satellite products.
- Further research and statistical calibration are recommended to optimize its use in air quality assessments.
Related Concept Videos
01:17Precipitation and Co-precipitation
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
01:03Precipitation Gravimetry
Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
01:23Measurement of Air Content in Concrete
Air content measurement in concrete is critical for ensuring structural integrity and durability of concrete structures, especially in environments prone to severe weather conditions. Accurate air content analysis optimizes concrete's resistance to freeze-thaw cycles and enhances its workability and strength. Several methods are standardized under ASTM guidelines to measure the air content in fresh concrete, each suitable for different concrete types and conditions.
The pressure method,...
The pressure method,...
01:12Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...