Intra-annual variations of regional total column ozone, aerosol optical depth, and water vapor from ground-based, satellite-based and model-based observations

2020 ◽  
Vol 237 ◽  
pp. 104860
Author(s):  
Dada P. Nade ◽  
Swapnil S. Potdar ◽  
Rani P. Pawar ◽  
Alok Taori ◽  
Gourihar Kulkarni ◽  
...  
Keyword(s):  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Total Column Ozone ◽  
Annual Variations ◽  
Model Based ◽  
Column Ozone ◽  
Total Column

scholarly journals STUDIES ON THE TOTAL COLUMN ATMOSPHERIC AEROSOL OPTICAL DEPTH, OZONE AND PRECIPITABLE WATER CONTENT IN THE TROPICS: A CASE STUDY OF MALAYSIA

2011 ◽  
Vol 1 (2) ◽  
pp. 55-62
Author(s):  
Said Fhazli
Keyword(s):  
Water Vapor ◽  
Water Content ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Precipitable Water ◽  
Mean Value ◽  
Total Column Ozone ◽  
Precipitable Water Content ◽  
The Mean ◽  
Total Column

A Multifilter Rotating Shadowband Radiometer has been used to monitor the directly transmitted solar irradiance at six wavelength regions (413.9 nm, 494.6 nm, 612.7 nm, 670.8 nm, 868.0 nm and 939.1 nm) for three clear stable days at Bangi. Extensive observations of the columnar aerosol optical depth (AOD), total column ozone (TCO) and precipitable water content (PWC) have been carried out using this instrument. The result shows that the maximum optical depth of aerosol at the shorter wavelength, especially on 24th February 2002 with mean value of 0.254 (24th February 2002), 0.095 (25th February 2002), and 0.072 (26th February 2002) while the ozone optical depth shows the mean value 0.0153 on 24th February 2002, 0.0174 on 25thFebruary 2002 and 0.0175 on 26th February 2002 with the avarage absorption coefficient (a), 0.2 (24th and 26th February 2002) and 0.1 (25th February 2002). The mean value of water vapor content shows that  = 0.356 cm and k = 0.301 cm for wavelength 939.1 nm. From the aerosol optical depth, it shows the existence of smoke type of aerosol on February, 24th to 25th 2002 with Ångström coefficient, , is 1.534 and 1.5513, respectively, and sea water vapor is 0.9889 on 26thFebruary 2002. From the Ångström coefficient, it shows that atmosphere layer of Bangi at that moment is similar to U.S. Standard Atmosphere, with maximum spectral irradiance on black body temperature is 5860 oK.

scholarly journals A 30-year climatology (1990-2020) of aerosol optical depth and total column water vapor and ozone over Texas

2021 ◽  
pp. 1-22
Author(s):  
Forrest M. Mims
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Precipitable Water ◽  
Texas History ◽  
Total Column Ozone ◽  
Annual Cycles ◽  
Total Column

AbstractA 30-year time series (4 Feb 1990 to 4 Feb 2020) of aerosol optical depth of the atmosphere (AOD), total precipitable water (TPW) and total column ozone has been conducted in Central Texas using simple, highly stable instruments. All three parameters in this ongoing measurement series exhibited robust annual cycles. They also responded to many atmospheric events, including the historic volcanic eruption of Mount Pinatubo (1991), a record El Niño (1998), an unprecedented biomass smoke event (1998) and the La Niña that caused the driest drought in recorded Texas history (2011). Reduced air pollution caused mean AOD to decline from 0.175 to 0.14. The AOD trend measured for 30 years by an LED sun photometer, the first of its kind, parallels the trend from 20 years of measurements by a modified Microtops II. While TPW responded to El Niño-Southern Oscillation conditions, TPW exhibited no trend over the 30 years. The TPW data compare favorably with 4.5 years of simultaneous measurements by a nearby NOAA GPS (r2 = 0.78). The 30 years of ozone measurements compare favorably with those from a series of NASA ozone satellites (r2 = 0.78). In 2016, 194 comparisons of Microtops II and world standard ozone instrument Dobson 83 at the Mauna Loa Observatory agreed within 1.9% (r2 = 0.81). The paper concludes by observing that students and citizen scientists can collect scientifically useful atmospheric data with simple sun photometers that use one or more LEDs as spectrally selective photodiodes.

scholarly journals The global overturning diabatic circulation of the stratosphere as a metric for the Brewer-Dobson Circulation

2018 ◽  
Author(s):  
Marianna Linz ◽  
Marta Abalos ◽  
Anne Sasha Glanville ◽  
Douglas E. Kinnison ◽  
Alison Ming ◽  
...  
Keyword(s):  
Time Series ◽  
Water Vapor ◽  
Vertical Velocity ◽  
Recent Theory ◽  
Residual Circulation ◽  
Total Column Ozone ◽  
Upper Level ◽  
Column Ozone ◽  
The Tropics ◽  
Total Column

Abstract. The circulation of the stratosphere, also known as the Brewer-Dobson circulation, transports water vapor and ozone, with implications for radiative forcing and climate. This circulation is typically quantified from model output by calculating the tropical upwelling vertical velocity in the residual circulation framework, and it is estimated from observations by using time series of tropical water vapor to infer a vertical velocity. Recent theory has introduced a method to calculate the global mean diabatic circulation strength through isentropes from satellite measurements of long-lived tracers. In this paper, we explore this global diabatic circulation as it relates to the residual circulation vertical velocity, stratospheric water vapor, and ozone at interannual timescales. We use a comprehensive climate model, three reanalysis data products, and satellite ozone data. The different metrics for the circulation have different properties, especially with regards to the vertical autocorrelation. In the model, the different residual circulation metrics agree closely and are well correlated with the global diabatic circulation, except in the lowermost stratosphere. In the reanalysis products however, there are more differences throughout, indicating the dynamical inconsistencies of these products. The vertical velocity derived from the time series of water vapor in the tropics is significantly correlated with the diabatic circulation, but this relationship is not as strong as that between the diabatic circulation and the residual circulation vertical velocity. We find that the diabatic circulation in the lower to middle stratosphere (up to 500 K) is correlated with the total column ozone in the high latitudes and in the tropics. The upper level circulation is also correlated with the total column ozone, primarily in the subtropics, and we show that this is due to the correlation of both the circulation and the ozone with upper level temperatures.

scholarly journals Spatio-Temporal Variability of Aerosol Optical Depth, Total Ozone and NO2 Over East Asia: Strategy for the Validation to the GEMS Scientific Products

2020 ◽  
Vol 12 (14) ◽  
pp. 2256
Author(s):  
Sang Seo Park ◽  
Sang-Woo Kim ◽  
Chang-Keun Song ◽  
Jong-Uk Park ◽  
Kang-Ho Bae
Keyword(s):  
Seasonal Variation ◽  
East Asia ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Validation Study ◽  
Temporal Variability ◽  
Total Column Ozone ◽  
The North ◽  
Spatio Temporal ◽  
Total Column

In this study, the spatio-temporal variability of aerosol optical depth (AOD), total column ozone (TCO), and total column NO2 (TCN) was identified over East Asia using long-term datasets from ground-based and satellite observations. Based on the statistical results, optimized spatio-temporal ranges for the validation study were determined with respect to the target materials. To determine both spatial and temporal ranges for the validation study, we confirmed that the observed datasets can be statistically considered as the same quantity within the ranges. Based on the thresholds of R2>0.95 (temporal) and R>0.95 (spatial), the basic ranges for spatial and temporal scales for AOD validation was within 30 km and 30 min, respectively. Furthermore, the spatial scales for AOD validation showed seasonal variation, which expanded the range to 40 km in summer and autumn. Because of the seasonal change of latitudinal gradient of the TCO, the seasonal variation of the north-south range is a considerable point. For the TCO validation, the north-south range is varied from 0.87° in spring to 1.05° in summer. The spatio-temporal range for TCN validation was 20 min (temporal) and 20–50 km (spatial). However, the nearest value of satellite data was used in the validation because the spatio-temporal variation of TCN is large in summer and autumn. Estimation of the spatio-temporal variability for respective pollutants may contribute to improving the validation of satellite products.

scholarly journals The global diabatic circulation of the stratosphere as a metric for the Brewer–Dobson circulation

2019 ◽  
Vol 19 (7) ◽  
pp. 5069-5090 ◽  
Author(s):  
Marianna Linz ◽  
Marta Abalos ◽  
Anne Sasha Glanville ◽  
Douglas E. Kinnison ◽  
Alison Ming ◽  
...  
Keyword(s):  
Time Series ◽  
Water Vapor ◽  
Vertical Velocity ◽  
Recent Theory ◽  
Residual Circulation ◽  
Total Column Ozone ◽  
Upper Level ◽  
Column Ozone ◽  
The Tropics ◽  
Total Column

Abstract. The circulation of the stratosphere, also known as the Brewer–Dobson circulation, transports water vapor and ozone, with implications for radiative forcing and climate. This circulation is typically quantified from model output by calculating the tropical upwelling vertical velocity in the residual circulation framework, and it is estimated from observations by using time series of tropical water vapor to infer a vertical velocity. Recent theory has introduced a method to calculate the strength of the global mean diabatic circulation through isentropes from satellite measurements of long-lived tracers. In this paper, we explore this global diabatic circulation as it relates to the residual circulation vertical velocity, stratospheric water vapor, and ozone at interannual timescales. We use a comprehensive climate model, three reanalysis data products, and satellite ozone data. The different metrics for the circulation have different properties, especially with regards to the vertical autocorrelation. In the model, the different residual circulation metrics agree closely and are well correlated with the global diabatic circulation, except in the lowermost stratosphere. In the reanalysis products, however, there are more differences throughout, indicating the dynamical inconsistencies of these products. The vertical velocity derived from the time series of water vapor in the tropics is significantly correlated with the global diabatic circulation, but this relationship is not as strong as that between the global diabatic circulation and the residual circulation vertical velocity. We find that the global diabatic circulation in the lower to middle stratosphere (up to 500 K) is correlated with the total column ozone in the high latitudes and in the tropics. The upper-level circulation is also correlated with the total column ozone, primarily in the subtropics, and we show that this is due to the correlation of both the circulation and the ozone with upper-level temperatures.

scholarly journals STUDIES ON THE CHARACTERISTICS OF SPECTRAL SOLAR IRRADIATION IN THE TROPICS: A CASE STUDY OF MALAYSIA

2011 ◽  
Vol 1 (2) ◽  
pp. 47-54
Author(s):  
Said Fhazli
Keyword(s):  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Sea Water ◽  
Mean Value ◽  
Primary Objective ◽  
Spectral Irradiance ◽  
Solar Irradiation ◽  
Total Column Ozone ◽  
The Mean

A Multifilter Rotating Shadowband Radiometer has been used to monitor the directly transmitted solar irradiance at six wavelength regions (413.9 nm, 494.6 nm, 612.7 nm, 670.8 nm, 868.0 nm and 939.1 nm) for three clear stable days at Bangi. The primary objective of this study is to determine the aerosol optical depth (AOD), total column ozone (TCO) and precipitable watercontent (PWC). The result shows that the maximum optical depth of aerosol at the shorter wavelength, especially on 24th February 2002 with mean value of 0.254 (24th February 2002), 0.095 (25th February 2002), and 0.072 (26th February 2002) while the ozone optical depth shows the mean value 0.0153 on 24th February 2002, 0.0174 on 25th February 2002 and 0.0175 on 26thFebruary 2002 with the avarage absorption coefficient (a), 0.2 (24th and 26th February 2002) and 0.1 (25th February 2002). The mean value of water vapor content shows that  = 0.356 cmand k = 0.301 cm for wavelength 939.1 nm. From the aerosol optical depth, it shows the existence of smoke type of aerosol on February, 24th to 25th 2002 with Ångström coefficient, , is 1.534 and 1.5513, respectively, and sea water vapor is 0.9889 on 26th February 2002. From the Ångström coefficient, it shows that atmosphere layer of Bangi at that moment is similar to U.S. Standard Atmosphere, with maximum spectral irradiance on black body temperature is 5860 oK.

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