Analysis of seven-year moderate resolution imaging spectroradiometer vegetation water indices for drought and fire activity assessment over Georgia of the United States

2009 ◽  
Vol 3 (1) ◽  
pp. 033555 ◽  
Author(s):  
Lingli Wang
Keyword(s):  
United States ◽  
The United States ◽  
Activity Assessment ◽  
Fire Activity ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Vegetation Water ◽  
Water Indices

scholarly journals US particulate matter air quality improves except in wildfire-prone areas

2018 ◽  
Vol 115 (31) ◽  
pp. 7901-7906 ◽  
Author(s):  
Crystal D. McClure ◽  
Daniel A. Jaffe
Keyword(s):  
United States ◽  
Particulate Matter ◽  
Fine Particulate Matter ◽  
The United States ◽  
Total Carbon ◽  
Positive Trend ◽  
Modis Aod ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Using Data

Using data from rural monitoring sites across the contiguous United States, we evaluated fine particulate matter (PM2.5) trends for 1988–2016. We calculate trends in the policy-relevant 98th quantile of PM2.5 using Quantile Regression. We use Kriging and Gaussian Geostatistical Simulations to interpolate trends between observed data points. Overall, we found positive trends in 98th quantile PM2.5 at sites within the Northwest United States (average 0.21 ± 0.12 µg·m−3·y−1; ±95% confidence interval). This was in contrast with sites throughout the rest of country, which showed a negative trend in 98th quantile PM2.5, likely due to reductions in anthropogenic emissions (average −0.66 ± 0.10 µg·m−3·y−1). The positive trend in 98th quantile PM2.5 is due to wildfire activity and was supported by positive trends in total carbon and no trend in sulfate across the Northwest. We also evaluated daily moderate resolution imaging spectroradiometer (MODIS) aerosol optical depth (AOD) for 2002–2017 throughout the United States to compare with ground-based trends. For both Interagency Monitoring of Protected Visual Environments (IMPROVE) PM2.5 and MODIS AOD datasets, we found positive 98th quantile trends in the Northwest (1.77 ± 0.68% and 2.12 ± 0.81% per year, respectively) through 2016. The trend in Northwest AOD is even greater if data for the high-fire year of 2017 are included. These results indicate a decrease in PM2.5 over most of the country but a positive trend in the 98th quantile PM2.5 across the Northwest due to wildfires.

scholarly journals Impact of data quality and surface-to-column representativeness on the PM<sub>2.5</sub>/satellite AOD relationship for the Continental United States

2013 ◽  
Vol 13 (12) ◽  
pp. 31635-31671 ◽  
Author(s):  
T. D. Toth ◽  
J. Zhang ◽  
J. R. Campbell ◽  
E. J. Hyer ◽  
J. S. Reid ◽  
...  
Keyword(s):  
United States ◽  
Data Quality ◽  
Dry Mass ◽  
Orthogonal Polarization ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Total Column ◽  
Particle Mass Concentration

Abstract. Satellite-derived aerosol optical depth (AOD) observations have been used to estimate particulate matter less than 2.5 μm (PM2.5). However, such a relationship could be affected by the representativeness of satellite-derived AOD to surface aerosol particle mass concentration and satellite AOD data quality. Using purely measurement-based methods, we have explored the impacts of data quality and representativeness on the AOD inferred PM2.5/AOD relationship for the Continental United States (CONUS). This is done through temporally and spatially collocated datasets of PM2.5 and AOD retrievals from Aqua/Terra Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging Spectroradiometer (MISR), and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). These analyses show that improving data quality of satellite AOD, such as done with data assimilation-grade retrievals, increases their correlation with PM2.5. However, overall correlation is relatively low across the CONUS. Also, integrated extinction observed within the 500 m above groud level (a.g.l.), as measured by CALIOP, is not well representative of the total column AOD. Surface aerosol in the Eastern CONUS is better correlated than in the Western CONUS. The best correlation values are found for estimated dry mass CALIOP extinction at 200–300 m a.g.l. and PM2.5, but additional work is needed to address the ability of using actively sensed AOD as a proxy for PM2.5 concentrations.

scholarly journals Alterações na eficiência do uso da água relacionadas com fatores climáticos e uso e ocupação do solo, na região do MATOPIBA

2021 ◽  
Vol 10 (9) ◽  
pp. e3010917891
Author(s):  
Dimas de Barros Santiago ◽  
Humberto Alves Barbosa ◽  
Washington Luiz Félix Correia Filho
Keyword(s):  
United States ◽  
Water Use Efficiency ◽  
Water Use ◽  
Geological Survey ◽  
United States Geological Survey ◽  
Station Data ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Use Efficiency ◽  
Moderate Resolution Imaging Spectroradiometer

O estudo tem por objetivos: estimar e analisar as mudanças espaço-temporais da Eficiência do Uso da Água (Water Use Efficiency - WUE) no MATOPIBA e avaliar a influência de fatores climáticos e do uso e ocupação do solo na variação do WUE. No estudo serão utilizados os produtos MOD17A2 (GPP) e MOD16A2 (ET) derivados do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) obtidos no United States Geological Survey (USGS), com resolução espacial 1 km x 1km, para as computo da WUE anual no período entre 2001 e 2019. Em relação a avaliação do uso da terra será realizado com as imagens do MAPBIOMAS, com resolução de 30m x 30m. Já os dados de precipitação serão provenientes do Climate Hazard Group InfraRed Precipitation with Station data (CHIRPS) com resolução espacial de 5,6 km por 5,6 km. As realizações dos cálculos matemáticos serão executadas nos softwares ambiente R versão 3.6-3 e Quantum GIS versão 3.4-6. Os resultados apontam que os maiores (menores) valores de WUE ocorrem em regiões agrícolas e áreas de vegetação nativa amazônica (áreas de superfícies não vegetadas). Este padrão da WUE está associado à crescente expansão agrícola sobre as regiões (Oeste Baiano e na porção Piauí), motivados principalmente pelo plantio de soja. Além disso, constatou-se que as anomalias positivas (negativas) da WUE ocorrem em anos secos (chuvosos). Concluindo assim que, áreas agrícolas são propensas aos maiores valores da WUE devido ao manejo cultural auxiliando no desenvolvimento das culturas agrícolas. As respostas da vegetação aos eventos secos e chuvosos foram mais sensíveis em áreas agrícolas que em áreas de vegetação nativa.

scholarly journals Impact of data quality and surface-to-column representativeness on the PM<sub>2.5</sub> / satellite AOD relationship for the contiguous United States

2014 ◽  
Vol 14 (12) ◽  
pp. 6049-6062 ◽  
Author(s):  
T. D. Toth ◽  
J. Zhang ◽  
J. R. Campbell ◽  
E. J. Hyer ◽  
J. S. Reid ◽  
...  
Keyword(s):  
United States ◽  
Data Quality ◽  
Ground Level ◽  
Dry Mass ◽  
Orthogonal Polarization ◽  
Data Sets ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Total Column

Abstract. Satellite-derived aerosol optical depth (AOD) observations have been used to estimate particulate matter smaller than 2.5 μm (PM2.5). However, such a relationship could be affected by the representativeness of satellite-derived AOD to surface aerosol particle mass concentration and satellite AOD data quality. Using purely measurement-based methods, we have explored the impacts of data quality and representativeness on the AOD-inferred PM2.5 / AOD relationship for the contiguous United States (CONUS). This is done through temporally and spatially collocated data sets of PM2.5 and AOD retrievals from Aqua/Terra Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging Spectroradiometer (MISR), and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). These analyses show that improving data quality of satellite AOD, such as done with data assimilation-grade retrievals, increases their correlation with PM2.5. However, overall correlation is relatively low across the CONUS. Also, integrated extinction observed within 500 m above ground level (a.g.l.), as measured by CALIOP, is not well representative of the total column AOD. Surface aerosol in the eastern CONUS is better correlated with total column AOD than in the western CONUS. The best correlation values are found for estimated dry mass CALIOP extinction at 200–300 m a.g.l. and PM2.5, but additional work is needed to address the ability of using actively sensed AOD as a proxy for PM2.5 concentrations.

Morning-to-Afternoon Evolution of Marine Stratus Polluted by Underlying Ships: Implications for the Relative Lifetimes of Polluted and Unpolluted Clouds

2009 ◽  
Vol 66 (7) ◽  
pp. 2097-2106 ◽  
Author(s):  
Matthew W. Christensen ◽  
James A. Coakley ◽  
William R. Tahnk
Keyword(s):  
Liquid Water ◽  
The United States ◽  
Marine Stratus ◽  
The Pacific ◽  
Modis Imagery ◽  
Moderate Resolution ◽  
The Pacific Ocean ◽  
Resolution Imaging ◽  
Ship Tracks ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract Ship tracks appearing in both the morning and afternoon Moderate Resolution Imaging Spectroradiometer (MODIS) imagery for the Pacific Ocean off the west coast of the United States were used to study the morning-to-afternoon evolution of marine stratus polluted by underlying ships and nearby uncontaminated stratus. Analyzed 925-hPa winds were used to predict the afternoon positions of ship tracks found in the morning imagery. Droplet effective radii, visible optical depths, and liquid water amounts were analyzed for morning and afternoon clouds that, based on the low-level winds, were taken to be the same clouds. As found in a previous study by Segrin et al., both morning and afternoon polluted clouds had smaller droplet radii, larger optical depths, and smaller liquid water amounts than the nearby unpolluted clouds. In contrast to the Segrin et al. study, however, the droplet effective radii decreased significantly from morning to afternoon in both the polluted and unpolluted clouds, with the rate of decrease being twice as large for the unpolluted clouds. The larger decrease in the unpolluted clouds is thought to be caused by drizzle, which is probably absent in the polluted clouds. The observations suggest that, with their slower rate of liquid loss, polluted clouds could have longer lifetimes than their unpolluted counterparts. Of interest is that clouds with similar droplet radii but smaller optical depths, and thus smaller droplet number concentrations and liquid water amounts, exhibited higher sensitivities to the effects of elevated particle concentrations and a greater likelihood of appearing in both the morning and afternoon satellite overpasses.

scholarly journals Differences in Fine Particle Chemical Composition on Clear and Cloudy Days

2020 ◽  
Author(s):  
Amy E. Christiansen ◽  
Annmarie G. Carlton ◽  
Barron H. Henderson
Keyword(s):  
Chemical Composition ◽  
Fine Particulate Matter ◽  
The United States ◽  
Chemical Constituent ◽  
Clear Sky ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Aerosol Cloud Interactions

Abstract. Clouds are prevalent and alter fine particulate matter (PM2.5) mass and chemical composition. Cloud-affected satellite retrievals are subject to higher uncertainty and are often removed from data products, hindering quantitative estimates of tropospheric chemical composition during cloudy times. We examine surface PM2.5 chemical constituent concentrations in the Interagency Monitoring of PROtected Visual Environments (IMPROVE) network in the United States during Cloudy and Clear Sky times defined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud flags from 2010-2014 with a focus on differences in particle hygroscopicity and aerosol liquid water (ALW). Cloudy and Clear Sky periods exhibit significant differences in PM2.5 mass and chemical composition that vary regionally and seasonally. In the eastern US, relative humidity alone cannot explain differences in ALW, suggesting emissions and in situ chemistry exert determining impacts. An implicit clear sky bias may hinder efforts to quantitatively understand and improve representation of aerosol-cloud interactions, which remain dominant uncertainties in models.

Effects of Additional Particles on Already Polluted Marine Stratus

2012 ◽  
Vol 69 (6) ◽  
pp. 1975-1993 ◽  
Author(s):  
B. Sechrist ◽  
J. A. Coakley ◽  
W. R. Tahnk
Keyword(s):  
The United States ◽  
Western Coast ◽  
Particle Loading ◽  
Marine Stratocumulus ◽  
Cloud Properties ◽  
Marine Stratus ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Ship Tracks ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract The response of already polluted marine stratocumulus to additional particles was examined by studying the clouds where two ship tracks cross. Nearly 100 such crossings were collected and analyzed using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) multispectral imagery for the daytime passes off the western coast of the United States during the summer months of 4 years. To reduce biases in the retrieved cloud properties caused by the subpixel spatial structure of the clouds, results are presented only for ship tracks found in regions overcast by extensive layers of marine stratus. When two ship tracks cross, one of the tracks exhibits much larger changes in droplet radii when compared with the surrounding unpolluted clouds and is referred to as the dominant ship track. The clouds at the crossing typically exhibit properties that are closer to those of the dominant than to those of the subordinate ship track. To determine whether the additional particles at the crossing affect the dominant track, local gradients in the retrieved cloud properties near the crossing were determined for both ship tracks. Based on the gradients, the clouds at the junction were found to have significantly smaller droplet radii and significantly larger column droplet number concentrations than were predicted based on their values in both ship tracks on either side of the crossing. Comparing the effects of particle loading at the crossings and elsewhere along the ship tracks revealed that the effects decreased as the column droplet number concentration of the clouds being affected increased.

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