Absorption characteristics of aerosols over the northwestern region of India: Distinct seasonal signatures of biomass burning aerosols and mineral dust

Gogoi, Mukunda M.; Babu, S. Suresh; Moorthy, K. Krishna; Manoj, Mohanan R.; Chaubey, Jai Prakash

doi:10.1016/j.atmosenv.2013.03.009

Cited by 39 publications

(14 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[]). This feature occurs at several continental locations and has been discussed by other investigators also [ Gogoi et al ., ; Babu et al ., ; etc.]. In the present observational sites, these are mainly associated with the radiative cooling of the ground surface later in the evening and throughout the night, resulting in the suppression or weakening of the turbulent mixing and the shallow nocturnal boundary layer.…”

Section: Resultsmentioning

confidence: 99%

“…From the study of Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) extinction coefficient as well as depolarization profiles over Naliya in the western India, Gogoi et al . [] have revealed the presence of dust layers at elevated height.…”

Section: Resultsmentioning

confidence: 99%

“…In the context of the large spatial heterogeneity of sources and emission strengths of BC over the Indian region, it is essential that the model simulations are compared and validated with the high‐resolution, ground‐based observations. Based on multiyear measurements, very high values of BC in winter are reported over the urban/metropolitan city areas, viz., Delhi (~25 µg m −3 [ Bano et al ., ]), Hyderabad (~13 µg m −3 [ Jose et al ., 2016]), Chennai (~12 µg m −3 [ Aruna et al ., ]), and Kolkata (~27 µg m −3 [ Talukdar et al ., ]), while BC concentrations of very low magnitude are reported over the remote continental and Himalayan locations [ Gogoi et al ., ]. Over the northeastern part of India, the observed values of BC mass concentrations >20 µg m −3 are quite significant considering the remote nature of the region.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

et al. 2017

Self Cite

View full text Add to dashboard Cite

Multiyear measurements of spectral properties of aerosol absorption are examined over four geographically distinct locations of northeastern India. Results indicated significant spatiotemporal variation in aerosol absorption coefficients (σabs) with highest values in winter and lowest in monsoon. The western parts of the region, close to the outflow of Indo‐Gangetic Plains, showed higher values of σabs and black carbon (BC) concentration—mostly associated with fossil fuel combustion. But, the eastern parts showed higher contributions from biomass‐burning aerosols, as much as 20–25% to the total aerosol absorption, conspicuously during premonsoon season. This is attributed to a large number of burning activities over the Southeast Asian region, as depicted from Moderate Resolution Imaging Spectroradiometer fire count maps, whose spatial extent and magnitude peaks during March/April. The nearly consistent high values of aerosol index (AI) and layer height from Ozone Monitoring Instrument indicate the presence of absorbing aerosols in the upper atmosphere. The observed seasonality has been captured fairly well by Goddard Chemistry Aerosol Radiation and Transport (GOCART) as well as Weather Research and Forecasting–Chemistry (WRF‐Chem) model simulations. The ratio of column‐integrated optical depths due to particulate organic matter and BC from GOCART showed good coincidence with satellite‐based observations, indicating the increased vertical dispersion of absorbing aerosols, probably by the additional local convection due to higher fire radiative power caused by the intense biomass‐burning activities. In the WRF‐Chem though underperformed by different magnitude in winter, the values are closer or overestimated near the burnt areas. Atmospheric forcing due to BC was highest (~30 Wm−2) over the western part associated with the fossil fuel combustion.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…During the monsoon season and autumn, significant air mass contributions arrive from mainland India, as indicated by the contributions of the trajectories in each cluster (calculated according to Gogoi et al . []) shown in Figure (bottom). Conversely, the trajectories originating from the Indian subcontinent are insignificant during winter.…”

Section: Resultsmentioning

confidence: 99%

Optical properties and CCN activity of aerosols in a high‐altitude Himalayan environment: Results from RAWEX‐GVAX

et al. 2015

Self Cite

View full text Add to dashboard Cite

The seasonality and mutual dependence of aerosol optical properties and cloud condensation nuclei (CCN) activity under varying meteorological conditions at the high-altitude Nainital site (~2 km) in the Indo-Gangetic Plains were examined using nearly year-round measurements (June 2011 to March 2012 at the Atmospheric Radiation Measurement mobile facility as part of the Regional Aerosol Warming Experiment-Ganges Valley Aerosol Experiment of the Indian Space Research Organization and the U.S. Department of Energy. The results from collocated measurements provided enhanced aerosol scattering and absorption coefficients, CCN concentrations, and total condensation nuclei concentrations during the dry autumn and winter months. The CCN concentration (at a supersaturation of 0.46) was higher during the periods of high aerosol absorption (single scattering albedo (SSA) < 0.80) than during the periods of high aerosol scattering (SSA > 0.85), indicating that the aerosol composition seasonally changes and influences the CCN activity. The monthly mean CCN activation ratio (at a supersaturation of 0.46) was highest (>0.7) in late autumn (November); this finding is attributed to the contribution of biomass-burning aerosols to CCN formation at high supersaturation conditions.

show abstract

“…However, in the case where NO 2 and aerosols are co-located near the surface, the aerosol correction factor sensitivity to cloud radiance fraction increases with AOD. As a result, for an AODs > 1, which is commonly measured over biomass burning events (Gogoi et al, 2013), we see from Fig. 5 that the aerosol correction can vary from +20 to +100 % between clear-sky and cloudy (cloud fraction of 20 %) conditions.…”

Section: Aerosol Correction Factor Sensitivity Analysismentioning

confidence: 95%

Space-based retrieval of NO<sub>2</sub> over biomass burning regions: quantifying and reducing uncertainties

Bousserez

2014

Atmos. Meas. Tech.

View full text Add to dashboard Cite

Abstract. The accuracy of space-based nitrogen dioxide (NO 2 ) retrievals from solar backscatter radiances critically depends on a priori knowledge of the vertical profiles of NO 2 and aerosol optical properties. This information is used to calculate an air mass factor (AMF), which accounts for atmospheric scattering and is used to convert the measured line-of-sight "slant" columns into vertical columns. In this study we investigate the impact of biomass burning emissions on the AMF in order to quantify NO 2 retrieval errors in the Ozone Monitoring Instrument (OMI) products over these sources. Sensitivity analyses are conducted using the Linearized Discrete Ordinate Radiative Transfer (LI-DORT) model. The NO 2 and aerosol profiles are obtained from a 3-D chemistry-transport model (GEOS-Chem), which uses the Fire Locating and Monitoring of Burning Emissions (FLAMBE) daily biomass burning emission inventory. Aircraft in situ data collected during two field campaigns, the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) and the Dust and Biomassburning Experiment (DABEX), are used to evaluate the modeled aerosol optical properties and NO 2 profiles over Canadian boreal fires and West African savanna fires, respectively. Over both domains, the effect of biomass burning emissions on the AMF through the modified NO 2 shape factor can be as high as −60 %. A sensitivity analysis also revealed that the effect of aerosol and shape factor perturbations on the AMF is very sensitive to surface reflectance and clouds. As an illustration, the aerosol correction can range from −20 to +100 % for different surface reflectances, while the shape factor correction varies from −70 to −20 %. Although previous studies have shown that in clear-sky conditions the effect of aerosols on the AMF was in part implicitly accounted for by the modified cloud parameters, here it is suggested that when clouds are present above a surface layer of scattering aerosols, an explicit aerosol correction would be beneficial to the NO 2 retrieval. Finally, a new method that uses slant column information to correct for shape-factor-related AMF error over NO x emission sources is proposed, with possible application to near-real-time OMI retrievals.

show abstract

Absorption characteristics of aerosols over the northwestern region of India: Distinct seasonal signatures of biomass burning aerosols and mineral dust

Cited by 39 publications

References 43 publications

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

Optical properties and CCN activity of aerosols in a high‐altitude Himalayan environment: Results from RAWEX‐GVAX

Space-based retrieval of NO<sub>2</sub> over biomass burning regions: quantifying and reducing uncertainties

Contact Info

Product

Resources

About

Absorption characteristics of aerosols over the northwestern region of India: Distinct seasonal signatures of biomass burning aerosols and mineral dust

Cited by 39 publications

References 43 publications

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

Optical properties and CCN activity of aerosols in a high‐altitude Himalayan environment: Results from RAWEX‐GVAX

Space-based retrieval of NO&lt;sub&gt;2&lt;/sub&gt; over biomass burning regions: quantifying and reducing uncertainties

Contact Info

Product

Resources

About

Space-based retrieval of NO<sub>2</sub> over biomass burning regions: quantifying and reducing uncertainties