Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
The weekly averages of near-surface 7 Be, 210 Pb, O 3 , and CO 2 concentrations at the Global Atmospheric Watch Observatory, Mt. Waliguan (101.98°E, 36.287°N, 3810 m a.s.l.), from October 2002 to January 2004 are presented. With the establishment of the new datasets of DCCW (Differential Concentrations in Contiguous Weeks) of 7 Be, 210 Pb, and O 3 , CO 2 (Δ 7 Be, Δ 210 Pb, ΔO 3 , ΔCO 2 , respectively, the impacts of upper-level downward transports and land-surface emissions on O 3 and CO 2 concentrations are implied by 7 Be and 210 Pb being as independent tracers. The relations among Δ 7 Be, Δ 210 Pb, and ΔO 3 , ΔCO 2 are examined statistically and compared. The results indicate that with the DCCWs, the interferences with the tracing significance of 7 Be and 210 Pb from the seasonal wet scavenging of atmospheric aerosol are greatly reduced, and the weighting sources of O 3 or CO 2 variations are more pronounced. Basically, the variability of surface O 3 is controlled predominately by air mass transported from the upper atmosphere levels while the emission from the Continent Boundary Layer (CBL) has an obvious input for CO 2 . The relation between Δ 210 Pb and ΔO 3 reflects that influences of CBL emission are generally positive/negative for surface O 3 budget in summer/winter, and the relation of Δ 7 Be and ΔCO 2 also reveals that upper level downward transport has positive/negative inputs for CO 2 in summer/winter. With the highly correlated relations between 7 Be and O 3 , a quantitative estimation is made of the stratospheric contributions to the budget of surface O 3 at WLG: the monthly averages of stratospheric O 3 range from 6 × 10 −9 to 8 × 10 −9 (volume mixing ratio) in April and from June to August, and 2 × 10 −9 to 4 × 10 −9 in the remaining months. For the ultimate sources of the baseline concentration of surface O 3 , which consist of only stratospheric transport and tropospheric photochemistry production, the contribution from stratospheric transport is estimated to be about 20 × 10 −9 from May to July, and (12-15) × 10 −9 in the remaining months, and the total relative contribution rate is about 35% to 40%. Differential Concentrations in Contiguous Weeks (DCCW), Continent Boundary Layer (CBL) emission, downward transport from stratosphere, natural trace, WLGCitation:
The weekly averages of near-surface 7 Be, 210 Pb, O 3 , and CO 2 concentrations at the Global Atmospheric Watch Observatory, Mt. Waliguan (101.98°E, 36.287°N, 3810 m a.s.l.), from October 2002 to January 2004 are presented. With the establishment of the new datasets of DCCW (Differential Concentrations in Contiguous Weeks) of 7 Be, 210 Pb, and O 3 , CO 2 (Δ 7 Be, Δ 210 Pb, ΔO 3 , ΔCO 2 , respectively, the impacts of upper-level downward transports and land-surface emissions on O 3 and CO 2 concentrations are implied by 7 Be and 210 Pb being as independent tracers. The relations among Δ 7 Be, Δ 210 Pb, and ΔO 3 , ΔCO 2 are examined statistically and compared. The results indicate that with the DCCWs, the interferences with the tracing significance of 7 Be and 210 Pb from the seasonal wet scavenging of atmospheric aerosol are greatly reduced, and the weighting sources of O 3 or CO 2 variations are more pronounced. Basically, the variability of surface O 3 is controlled predominately by air mass transported from the upper atmosphere levels while the emission from the Continent Boundary Layer (CBL) has an obvious input for CO 2 . The relation between Δ 210 Pb and ΔO 3 reflects that influences of CBL emission are generally positive/negative for surface O 3 budget in summer/winter, and the relation of Δ 7 Be and ΔCO 2 also reveals that upper level downward transport has positive/negative inputs for CO 2 in summer/winter. With the highly correlated relations between 7 Be and O 3 , a quantitative estimation is made of the stratospheric contributions to the budget of surface O 3 at WLG: the monthly averages of stratospheric O 3 range from 6 × 10 −9 to 8 × 10 −9 (volume mixing ratio) in April and from June to August, and 2 × 10 −9 to 4 × 10 −9 in the remaining months. For the ultimate sources of the baseline concentration of surface O 3 , which consist of only stratospheric transport and tropospheric photochemistry production, the contribution from stratospheric transport is estimated to be about 20 × 10 −9 from May to July, and (12-15) × 10 −9 in the remaining months, and the total relative contribution rate is about 35% to 40%. Differential Concentrations in Contiguous Weeks (DCCW), Continent Boundary Layer (CBL) emission, downward transport from stratosphere, natural trace, WLGCitation:
Indian cities are highly vulnerable to atmospheric pollution in recent years, due to exponential growth in urbanisation and industrialisation, and the increased pollution has been made to focus on the temporal variation analysis and forecasting of air pollutants over major Indian cities like Delhi and Bangalore. PM 2.5 concentrations are nearly 60.5% less than the annual average value during monsoon season while 76.3% more during the winter months. Ozone concentrations increase during the summer months (~ 46.3% more than the annual average) in Delhi, whereas in Bangalore, ozone concentrations are more (~ 75% more than the annual average) during the winter months. Variations of carbon monoxide and nitrogen oxides are significantly less comparatively. COVID-19 lockdown has a substantial positive impact on air pollution. Air pollutant concentrations are reduced during phase I and phase II of the lockdown. Pollutants, especially NOx and PM 2.5 concentrations, are drastically reduced compared to the previous years. NOx concentrations are reduced by ~ 20% in Bangalore, whereas ~ 50% in Delhi. PM 2.5 concentrations are reduced by ~ 41% in Delhi and ~ 55% in Bangalore. Forecasting of pollutants will be helpful in providing the valuable information for the optimal air pollution control strategies. It has been observed that linear model gives better results compared to ARIMA and Exponential Smoothening models. By forecasting, the concentration of NO 2 is 115.288 µg/m 3 , the ozone is 30.636 µg/m 3 , SO 2 is 11.798 µg/m 3 , and CO is 2.758 mg/m 3 over Delhi in 2021. All the pollutants during forecasting showed a rising trend except sulphur dioxide. Supplementary Information The online version contains supplementary material available at 10.1007/s12517-022-09996-2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.