Long term (2003–2012) spatio-temporal MODIS (Terra/Aqua level 3) derived climatic variations of aerosol optical depth and cloud properties over a semi arid urban tropical region of Northern India

2014 ◽  
Vol 83 ◽  
pp. 291-300 ◽  
Author(s):  
Adarsh Kumar
2014 ◽  
Vol 997 ◽  
pp. 843-846 ◽  
Author(s):  
Hao Liu ◽  
Xin Ming Tang ◽  
Wei Cao ◽  
Zhi Ying Xie ◽  
Jing Han Lei ◽  
...  

Based on the monthly data of MODIS Level 3, the spatio-temporal variabilities of Aerosol Optical Depth (AOD) over areas around Beijing have been analyzed from March 2000 to December 2013. The results presented that: (1) In the past 14 years , the annual mean AODs vary between 0.428 and 0.550; The recent 14 years can be divided into two stages, the first stage is 2000-2007, which shows an increasing trend with an increase rate of 1.349%, while the second stage is 2008-2013, which shows an decreasing trend with a decrease rate of 1.483%; Summer has the maximum AOD, but shows a decreasing trend, while winter has the minimum AOD, but shows an increasing trend. (2) AODs over the south are higher than the north, high AODs are mainly distributed along the southwest of Hebei and southwest of Shandong with an AOD of 0.72, while low AODs are mainly distributed along the north of Hebei and the north of Shanxi with an AOD of 0.23; The spatial distribution of AOD varies with the seasons, AODs are high in spring, and are maximized in summer, then show a significant decrease from summer to autumn, while are minimized in winter.


GEOgraphia ◽  
2021 ◽  
Vol 23 (51) ◽  
Author(s):  
Amaury de Souza ◽  
Guilherme Henrique Cavazzana ◽  
Débora Aparecida da Silva Santos ◽  
Marcel Carvalho Abreu ◽  
Widinei Alves Fernandes ◽  
...  

Os aerossóis atmosféricos influenciam a precipitação, alteram o balanço de energia da Terra e também as propriedades das nuvens. Este trabalho foi desenvolvido no estado de Mato Grosso do Sul com o objetivo de estudar as relações entre a profundidade óptica do aerossol e o nível de precipitação, levando em conta a umidade relativa do ar. Os dados mensais de profundidade óptica em 550 nm (AOD) foram adquiridos do sensor MODIS/Terra, e os dados climatológicos do CEMTEC-MS, para o período de 2002-2011. Os valores mensais de AOD 550 nm apresentam um padrão sazonal, com mínimos e máximos nas estações chuvosa e seca, respectivamente. As médias mensais de AOD 550nm foram correlacionadas com os registros mensais de precipitação e de umidade relativa do ar (UR) no MS. As análises de correlação de Pearson para as escalas mensais revelaram que a UR pode ser o fator de influência dominante na relação entre AOD e precipitação. Quando análises de correlação parcial são conduzidas para os dados mensais da precipitação, nota-se que a maioria das correlações negativas observadas diminuem ou não são significativas, isso ocorre sempre que a UR é usada como variável de controle. Palavras-chave: mudanças climáticas, impactos climáticos, variabilidade espaço-temporal, Giovanni NASA RELATIONSHIP BETWEEN AEROSOL OPTICAL DEPTH AND PRECIPITATION CONSIDERING THE RELATIVE HUMIDITY AS AN INFLUENCE FACTOR Abstract: Atmospheric aerosols influence precipitation, modify the balance of Earth's energy, and alter the cloud properties. This work has been developed in the state of South Mato Grosso to study the correlation between aerosol optical depth and precipitation index, considering the relative air humidity. The monthly data of optical depth at 550 nm (AOD) come from the MODIS/TERRA sensor, and the climatological data come from CEMTEC-MS. They are considered for the period 2002-2011. The monthly values of AOD 550 nm show seasonal patterns, with minimum and maximum during the rainy and dry seasons, respectively. The monthly averages of AOD 550nm have been correlated with the records of precipitation and relative humidity for the state of South Mato Grosso. The analysis of Pearson's correlation for the monthly scales reveals that the UR may be the dominant influence factor in the relationship between AOD and precipitation. When partial correlation analyses are conducted for monthly rainfall data, most of the resulting negative correlations decrease or are insignificant. It happens when the UR is used as a controlling variable. Keywords: climatic changes, climatic impacts, spatio-temporal variability, Giovanni NASA RELACIÓN ENTRE PROFUNDIDAD ÓPTICA DEL AEROSOL Y PRECIPITACIÓN CONSIDERANDO LA HUMEDAD RELATIVA COMO FACTOR DE INFLUENCIA Resumen: Los aerosoles atmosféricos influyen en la precipitación, alteran el equilibrio energético de la Tierra, y también las propiedades de las nubes. El trabajo se desarrolló en el estado de Mato Grosso del Sur con el objetivo de estudiar la relación entre la profundidad óptica del aerosol y la precipitación, teniendo en cuenta la humedad relativa del aire. Los datos mensuales de profundidad óptica a 550 nm (AOD) fueran adquiridos del sensor MODIS/TERRA, y los datos climatológicos del CEMTEC-MS, todos para lo período 2002-2011. Los valores mensuales de AOD 550 nm muestran un patrón estacional, con mínimos y máximos en las estaciones lluviosa y seca, respectivamente. Los promedios mensuales de 550 nm AOD se correlacionan con los registros mensuales de precipitación y humedad relativa en el estado de Mato Grosso del Sur. Los análisis de correlación de Pearson para las escalas mensuales revelan que UR puede ser el factor de influencia dominante en la relación entre AOD y precipitación. Cuando se realizan análisis de correlación parcial para los datos de lluvia mensual, se observa que la mayoría de las correlaciones negativas disminuyeron o no son significativas siempre que se utiliza UR como variable de control. Palabras clave: cambio climático, impactos climáticos, variabilidad espacio-temporal, Giovanni NASA  


2016 ◽  
Vol 9 (1) ◽  
pp. 53-62 ◽  
Author(s):  
R. D. García ◽  
O. E. García ◽  
E. Cuevas ◽  
V. E. Cachorro ◽  
A. Barreto ◽  
...  

Abstract. This paper presents the reconstruction of a 73-year time series of the aerosol optical depth (AOD) at 500 nm at the subtropical high-mountain Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain). For this purpose, we have combined AOD estimates from artificial neural networks (ANNs) from 1941 to 2001 and AOD measurements directly obtained with a Precision Filter Radiometer (PFR) between 2003 and 2013. The analysis is limited to summer months (July–August–September), when the largest aerosol load is observed at IZO (Saharan mineral dust particles). The ANN AOD time series has been comprehensively validated against coincident AOD measurements performed with a solar spectrometer Mark-I (1984–2009) and AERONET (AErosol RObotic NETwork) CIMEL photometers (2004–2009) at IZO, obtaining a rather good agreement on a daily basis: Pearson coefficient, R, of 0.97 between AERONET and ANN AOD, and 0.93 between Mark-I and ANN AOD estimates. In addition, we have analysed the long-term consistency between ANN AOD time series and long-term meteorological records identifying Saharan mineral dust events at IZO (synoptical observations and local wind records). Both analyses provide consistent results, with correlations  >  85 %. Therefore, we can conclude that the reconstructed AOD time series captures well the AOD variations and dust-laden Saharan air mass outbreaks on short-term and long-term timescales and, thus, it is suitable to be used in climate analysis.


2007 ◽  
Vol 7 (8) ◽  
pp. 2091-2101 ◽  
Author(s):  
S. Kazadzis ◽  
A. Bais ◽  
V. Amiridis ◽  
D. Balis ◽  
C. Meleti ◽  
...  

Abstract. Spectral measurements of the aerosol optical depth (AOD) and the Ångström coefficient were conducted at Thessaloniki, Greece (40.5° N, 22.9° E) between January 1997 and December 2005 with a Brewer MKIII double-monochromator spectroradiometer. The dataset was compared with collocated measurements of a second spectroradiometer (Brewer MKII) and a CIMEL sun-photometer, showing correlations of 0.93 and 0.98, respectively. A seasonal variation of the AOD was observed at Thessaloniki, with AOD values at 340 nm of 0.52 and 0.28 for August and December respectively. Back trajectories of air masses for up to 4 days were used to assess the influence of long-range transport from various regions to the aerosol load over Thessaloniki. It is shown that part of the observed seasonality can be attributed to air masses with high AOD originating from North-Eastern and Eastern directions during summertime. The analysis of the long-term record (9 years) of AOD showed a downward tendency. A similar decreasing tendency was found in the record of the PM$_{10}$ aerosol measurements, which are conducted near the surface at 4 air-quality monitoring stations in the area of the city of Thessaloniki.


2019 ◽  
Vol 10 (2) ◽  
pp. 608-620 ◽  
Author(s):  
Shantikumar S. Ningombam ◽  
E.J.L. Larson ◽  
U.C. Dumka ◽  
Victor Estellés ◽  
M. Campanelli ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document