Related Experiment Video
Updated: Sep 27, 2025
06:27
Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer
Published on: May 29, 2019
8.1K
Decreasing Aerosol Loading in the North American Monsoon Region
Aishwarya Raman1, Avelino F Arellano1, Armin Sorooshian1,2
1Department of Hydrology and Atmospheric Sciences, Tucson, AZ 85721, USA.
Atmosphere
|May 12, 2017
Summary
Aerosol optical depth (AOD) over the North American Monsoon region decreased from 2005-2014, particularly from fires and human activity. Dust storms, however, complicate this trend in the NAM alley.
Area of Science:
- Atmospheric Science
- Environmental Science
- Remote Sensing
Background:
- Aerosol loading significantly impacts regional climate and air quality.
- Understanding spatio-temporal aerosol variability is crucial for climate modeling and environmental monitoring.
- The North American Monsoon (NAM) region exhibits complex aerosol dynamics influenced by diverse sources.
Purpose of the Study:
- To investigate the spatio-temporal variability of aerosol loading in the NAM region from 2005-2014.
- To identify and classify dominant aerosol sources and their impact on aerosol optical depth (AOD).
- To analyze aerosol trends across different seasons and source-specific clusters.
Main Methods:
- Utilized aerosol optical depth (AOD) retrievals from NASA's Terra Moderate Resolution Imaging Spectroradiometer (MODIS).
- Integrated satellite data on atmospheric and land-surface properties.
- Classified 20 aerosol hotspots into fire, anthropogenic, dust, and NAM alley clusters based on dominant drivers.
- Applied multivariate statistics to analyze anomalies during pre-, monsoon, and post-monsoon periods.
Main Results:
- Observed a general decrease in aerosol loading across the NAM region, consistent with declining AOD trends over the continental US.
- Fire and anthropogenic aerosol clusters showed significant decreases during pre-monsoon and monsoon seasons, linked to reduced fire counts and carbon monoxide.
- Aerosol trends in the NAM alley were modulated by monsoon precipitation and frequent dust storms, particularly during monsoon and post-monsoon periods.
- Dust cluster aerosol loading showed a slight decrease and was associated with vegetation index variations.
Conclusions:
- The study confirms a decreasing trend in overall aerosol loading within the North American Monsoon region.
- Fire and anthropogenic sources are key drivers of this decline, though their impact is complex.
- Dust events and monsoon precipitation significantly influence aerosol patterns in the NAM alley, creating regional heterogeneity.
- Continued monitoring is essential to understand the interplay of diverse aerosol sources and climatic factors in the NAM region.
Related Concept Videos
01:18Boundary Layer Characteristics
246
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
246
01:12Precipitation Processes
642
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...
642
01:17Precipitation and Co-precipitation
2.3K
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...
2.3K
01:18Variation of Atmospheric Pressure
2.9K
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
2.9K
03:28Vapor Pressure Lowering
28.4K
The equilibrium vapor pressure of a liquid is the pressure exerted by its gaseous phase when vaporization and condensation are occurring at equal rates:
Dissolving a nonvolatile substance in volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be explained by considering the effect of added solute molecules on the liquid's vaporization and condensation processes. To vaporize, solvent molecules must be present at the surface of the solution....
Dissolving a nonvolatile substance in volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be explained by considering the effect of added solute molecules on the liquid's vaporization and condensation processes. To vaporize, solvent molecules must be present at the surface of the solution....
28.4K
01:16What is Climate?
19.3K
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
19.3K