scholarly journals Black Carbon Aerosol Characteristics and Its Radiative Impact over Nainital: A High-Altitude Station in the Central Himalayas

1970 ◽  
Vol 8 (3) ◽  
pp. 1-10 ◽  
Author(s):  
AK Srivastava ◽  
P Pant ◽  
UC Dumka ◽  
P Hegde
Keyword(s):  
High Altitude ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Lower Atmosphere ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Central Himalayas ◽  
Radiative Impact ◽  
Potential Factor ◽  
Black Carbon Aerosol

Ground-based measurements of aerosol black carbon (BC), from a high altitude location at Nainital in the central Himalayas (during June 2006 to May 2007), were used to study its temporal variability and impact on the atmospheric radiative forcing. Diurnal variation of BC mass concentration shows single enhanced peak in the late afternoon hour. The peak is rather pronounced in winter months due to shallow and stable boundary layer condition, which is largely associated with low surface temperature. The mean BC mass concentrations were found to be as ~0.6 (±0.2), 1.4 (±0.1), 1.2 (±0.3) and 1.5 (±0.2) μg m-3 during monsoon, post-monsoon, winter and spring periods, respectively while its maximum value was ~1.8 (±0.8) μg m-3 during April. The prevailing winds revealed to facilitates the transport of BC from the distant sources to the observing site. A radiative transfer model was used in conjunction with an aerosol optical model to estimate the BC radiative forcing over the station. Results show BC forcing at the top-of-atmosphere (TOA), surface and in the atmosphere varies between about +3 to +7, -6 to -14 and +8 to +21 Wm-2, respectively which is more pronounced during spring then during monsoon depending upon BC mass loading. The positive atmosphere forcing represents a considerable amount of heating to the lower atmosphere and has been conjectured as potential factor causing global warming. The estimated heating rate of the lower atmosphere over the station was found to be ranging from 0.24 Kday-1 during monsoon to 0.58 Kday-1 during spring season. DOI: http://dx.doi.org/10.3126/jie.v8i3.5926 JIE 2011; 8(3): 1-10

scholarly journals HAMP – the microwave package on the High Altitude and LOng range research aircraft HALO

2014 ◽  
Vol 7 (5) ◽  
pp. 4623-4657
Author(s):  
M. Mech ◽  
E. Orlandi ◽  
S. Crewell ◽  
F. Ament ◽  
L. Hirsch ◽  
...  
Keyword(s):  
High Altitude ◽  
Long Range ◽  
Microwave Remote Sensing ◽  
Passive Microwave ◽  
Lower Atmosphere ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Model Calculations ◽  
Cloud Radar ◽  
Research Aircraft

Abstract. An advanced package of microwave remote sensing instrumentation has been developed for the operation on the new German High Altitude LOng range research aircraft (HALO). The HALO Microwave Package, HAMP, consists of two nadir looking instruments: a cloud radar at 36 GHz and a suite of passive microwave radiometers with 26 frequencies in different bands between 22.24 and 183.31 ± 12.5 GHz. We present a description of HAMP's instrumentation together with an illustration of its potential. To demonstrate this potential synthetic measurements for the implemented passive microwave frequencies and the cloud radar based on cloud resolving and radiative transfer model calculations were performed. These illustrate the advantage of HAMP's chosen frequency coverage, which allows for improved detection of hydrometeors both via the emission and scattering of radiation. Regression algorithms compare HAMP retrieval with standard satellite instruments from polar orbiters and show its advantages particularly for the lower atmosphere with a reduced root mean square error by 5 and 15% for temperature and humidity, respectively. HAMP's main advantage is the high spatial resolution of about 1 km which is illustrated by first measurements from test flights. Together these qualities make it an exciting tool for gaining better understanding of cloud processes, testing retrieval algorithms, defining future satellite instrument specifications, and validating platforms after they have been placed in orbit.

scholarly journals HAMP – the microwave package on the High Altitude and LOng range research aircraft (HALO)

2014 ◽  
Vol 7 (12) ◽  
pp. 4539-4553 ◽  
Author(s):  
M. Mech ◽  
E. Orlandi ◽  
S. Crewell ◽  
F. Ament ◽  
L. Hirsch ◽  
...  
Keyword(s):  
High Altitude ◽  
Long Range ◽  
Microwave Remote Sensing ◽  
Passive Microwave ◽  
Lower Atmosphere ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Model Calculations ◽  
Cloud Radar ◽  
Research Aircraft

Abstract. An advanced package of microwave remote sensing instrumentation has been developed for the operation on the new German High Altitude LOng range research aircraft (HALO). The HALO Microwave Package, HAMP, consists of two nadir-looking instruments: a cloud radar at 36 GHz and a suite of passive microwave radiometers with 26 frequencies in different bands between 22.24 and 183.31 ± 12.5 GHz. We present a description of HAMP's instrumentation together with an illustration of its potential. To demonstrate this potential, synthetic measurements for the implemented passive microwave frequencies and the cloud radar based on cloud-resolving and radiative transfer model calculations were performed. These illustrate the advantage of HAMP's chosen frequency coverage, which allows for improved detection of hydrometeors both via the emission and scattering of radiation. Regression algorithms compare HAMP retrieval with standard satellite instruments from polar orbiters and show its advantages particularly for the lower atmosphere with a root-mean-square error reduced by 5 and 15% for temperature and humidity, respectively. HAMP's main advantage is the high spatial resolution of about 1 km, which is illustrated by first measurements from test flights. Together these qualities make it an exciting tool for gaining a better understanding of cloud processes, testing retrieval algorithms, defining future satellite instrument specifications, and validating platforms after they have been placed in orbit.

Black Carbon aerosol characteristics and radiative forcing over the high altitude glacier region of Himalaya-Karakorum-Hindukush

2020 ◽  
Vol 238 ◽  
pp. 117711
Author(s):  
Bahadar Zeb ◽  
Khan Alam ◽  
Jawad Nasir ◽  
Muhammad Mansha ◽  
Ifthikhar Ahmad ◽  
...  
Keyword(s):  
High Altitude ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Black Carbon Aerosol

scholarly journals Spatial-Temporal Variation of Snow Black Carbon Concentration in Snow Cover in Northeast China from 2001 to 2016 Based on Remote Sensing

2022 ◽  
Vol 14 (2) ◽  
pp. 959
Author(s):  
Yanjiao Zheng ◽  
Lijuan Zhang ◽  
Wenliang Li ◽  
Fan Zhang ◽  
Xinyue Zhong
Keyword(s):  
Black Carbon ◽  
Human Activities ◽  
Northeast China ◽  
Radiative Forcing ◽  
Surface Albedo ◽  
Global Climate ◽  
Atmospheric Stability ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Snow Surface

The amount of black carbon (BC) on snow surface can significantly reduce snow surface albedo in the visible-light range and change the surface radiative forcing effect. Therefore, it is key to study regional and global climate changes to understand the BC concentration on snow. In this study, we simulated the BC concentration on the surface snow of northeast China using an asymptotic radiative transfer model. From 2001 to 2016, the BC concentration showed no significant increase, with an average increase of 82.104 ng/g compared with that in the early 21st century. The concentration of BC in December was the largest (1344.588 ng/g) and decreased in January and February (1248.619 ng/g and 983.635 ng/g, respectively). The high black carbon content centers were concentrated in the eastern and central regions with dense populations and concentrated industries, with a concentration above 1200 ng/g, while the BC concentration in the southwest region with less human activities was the lowest (below 850 ng/g), which indicates that human activities played an important role in snow BC pollution. Notably, Heilongjiang province has the highest concentration, which may be related to its atmospheric stability in winter. These findings suggest that the BC pollution in northeast China has been aggravated from 2001 to 2016. It is estimated that the snow surface albedo will decrease by 16.448% due to the BC pollution of snow in northeast China. The problem of radiative forcing caused by black carbon to snow reflectivity cannot be ignored.

scholarly journals The direct and indirect radiative effects of biogenic secondary organic aerosol

2013 ◽  
Vol 13 (6) ◽  
pp. 16961-17019 ◽  
Author(s):  
C. E. Scott ◽  
A. Rap ◽  
D. V. Spracklen ◽  
P. M. Forster ◽  
K. S. Carslaw ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Radiative Transfer Model ◽  
Anthropogenic Emissions ◽  
Transfer Model ◽  
Particle Nucleation ◽  
Radiative Effect ◽  
Radiative Impact ◽  
Global Mean

Abstract. We use a global aerosol microphysics model in combination with an offline radiative transfer model to quantify the radiative effect of biogenic secondary organic aerosol (SOA) in the present day atmosphere. Through its role in particle growth and ageing, the presence of biogenic SOA increases the global annual mean concentration of cloud condensation nuclei (CCN; at 0.2% supersaturation) by 3.6–21.1%, depending upon the yield of SOA production, and the nature and treatment of concurrent primary carbonaceous emissions. This increase in CCN causes a rise in global annual mean cloud droplet number concentration (CDNC) of 1.9–5.2%, and a global mean first aerosol indirect effect (AIE) of between +0.01 W m−2 and −0.12 W m−2. The radiative impact of biogenic SOA is far greater when it also contributes to particle nucleation; using two organically-mediated mechanisms for new particle formation we simulate global annual mean AIEs of −0.22 W m−2 and −0.77 W m−2. The inclusion of biogenic SOA substantially improves the simulated seasonal cycle in the concentration of CCN sized particles observed at three forested sites. The best correlation is found when the organically-mediated nucleation mechanisms are applied, suggesting that the AIE of biogenic SOA could be as large as −0.77 W m−2. The radiative impact of SOA is sensitive to the presence of anthropogenic emissions. Lower background aerosol concentrations simulated with anthropogenic emissions from 1750 give rise to a greater fractional CCN increase and a more substantial indirect radiative effect from biogenic SOA. Consequently, the anthropogenic indirect radiative forcing between 1750 and the present day is sensitive to assumptions about the amount and role of biogenic SOA. We also calculate an annual global mean direct radiative effect (DRE) of between −0.08 W m−2 and −0.78 W m−2 in the present day, with uncertainty in the amount of SOA produced from the oxidation of biogenic volatile organic compounds (BVOCs) accounting for most of this range.

Black carbon aerosol and its radiative impact at a high-altitude remote site on the southeastern Tibet Plateau

2017 ◽  
Vol 122 (10) ◽  
pp. 5515-5530 ◽  
Author(s):  
Zhuzi Zhao ◽  
Qiyuan Wang ◽  
Baiqing Xu ◽  
Zhenxing Shen ◽  
Rujin Huang ◽  
...  
Keyword(s):  
High Altitude ◽  
Black Carbon ◽  
Tibet Plateau ◽  
Remote Site ◽  
Radiative Impact ◽  
Black Carbon Aerosol ◽  
Southeastern Tibet

scholarly journals Measurement report: Quantifying source contribution and radiative forcing of fossil fuel and biomass burning black carbon aerosol in the southeastern margin of Tibetan Plateau

2020 ◽  
Author(s):  
Huikun Liu ◽  
Qiyuan Wang ◽  
Li Xing ◽  
Yong Zhang ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Black Carbon ◽  
Biomass Burning ◽  
Radiative Forcing ◽  
Fossil Fuel ◽  
Sampling Site ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Southeastern Margin ◽  
Fuel Source

Abstract. Black carbon (BC) aerosol plays a vital role in disturbing the balance of ecosystem and climate stability of Tibetan Plateau (TP). An intensive campaign was carried out from 14th March to 12th May 2018 in the southeastern margin of TP to investigate the sources of BC and their radiative effects. To do so, an improved aethalometer model was used to distinguish and apportion BC into fossil fuel combustion source and biomass burning source. To minimize the uncertainty associated with the aethalometer model, a receptor model coupling multi-wavelength absorption with chemical species was used to retrieve the site-dependent Ångström exponent (AAE) and BC mass absorption cross-section (MAC). The results show that the AAEs and BC MACs at wavelength of 880 nm were 0.9 and 12.3 m2 g−1 for fossil fuel source and 1.7 and 10.4 m2 g−1 for biomass burning, respectively. Based on these parameters, the fossil fuel source-related BC (BCfossil) was estimated 43 % of the total BC and the rest 57 % was from biomass burning (BCbiomass) during the campaign. The results from a regional chemical dynamical model reveal that high BCbiomass was contributed from the northeastern India and northern Burma, and the Southeast Asia can explain 40 % of BCbiomass. The high BCfossil was mainly identified from the southeast of sampling site. A radiative transfer model estimated that the atmospheric directive radiative forcing of BC was +4.6 ± 2.4 W m−2 on average, including +2.5 ± 1.8 W m−2 from BCbiomass, and +2.1 ± 0.9 W m−2 from BCfossil, which correspond to and heating rates of 0.07 ± 0.05 and 0.06 ± 0.02 K day−1, respectively. Our study will be useful for improving our understanding in BC sources on the TP and their climatic effect.

The influence of a south Asian dust storm on aerosol radiative forcing at a high-altitude station in central Himalayas

2011 ◽  
Vol 32 (22) ◽  
pp. 7827-7845 ◽  
Author(s):  
Atul K. Srivastava ◽  
P. Pant ◽  
P. Hegde ◽  
Sachchidanand Singh ◽  
U. C. Dumka ◽  
...  
Keyword(s):  
High Altitude ◽  
South Asian ◽  
Dust Storm ◽  
Radiative Forcing ◽  
Asian Dust ◽  
Central Himalayas ◽  
Aerosol Radiative Forcing ◽  
Asian Dust Storm ◽  
Aerosol Radiative

Radiative forcing over the Arctic of aerosols from the August 2017 Canadian and Greenlandic wildfires

2021 ◽  
Author(s):  
Filippo Calì Quaglia ◽  
Daniela Meloni ◽  
Alcide Giorgio di Sarra ◽  
Tatiana Di Iorio ◽  
Virginia Ciardini ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Radiative Forcing ◽  
Solar Zenith Angle ◽  
Surface Albedo ◽  
High Arctic ◽  
The Arctic ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Aerosol Layer ◽  
Radiative Effect

<p>Extended and intense wildfires occurred in Northern Canada and, unexpectedly, on the Greenlandic West coast during summer 2017. The thick smoke plume emitted into the atmosphere was transported to the high Arctic, producing one of the largest impacts ever observed in the region. Evidence of Canadian and Greenlandic wildfires was recorded at the Thule High Arctic Atmospheric Observatory (THAAO, 76.5°N, 68.8°W, www.thuleatmos-it.it) by a suite of instruments managed by ENEA, INGV, Univ. of Florence, and NCAR. Ground-based observations of the radiation budget have allowed quantification of the surface radiative forcing at THAAO. </p><p>Excess biomass burning chemical tracers such as CO, HCN, H2CO, C2H6, and NH3 were  measured in the air column above Thule starting from August 19 until August 23. The aerosol optical depth (AOD) reached a peak value of about 0.9 on August 21, while an enhancement of wildfire compounds was  detected in PM10. The measured shortwave radiative forcing was -36.7 W/m2 at 78° solar zenith angle (SZA) for AOD=0.626.</p><p>MODTRAN6.0 radiative transfer model (Berk et al., 2014) was used to estimate the aerosol radiative effect and the heating rate profiles at 78° SZA. Measured temperature profiles, integrated water vapour, surface albedo, spectral AOD and aerosol extinction profiles from CALIOP onboard CALIPSO were used as model input. The peak  aerosol heating rate (+0.5 K/day) was  reached within the aerosol layer between 8 and 12 km, while the maximum radiative effect (-45.4 W/m2) is found at 3 km, below the largest aerosol layer.</p><p>The regional impact of the event that occurred on August 21 was investigated using a combination of atmospheric radiative transfer modelling with measurements of AOD and ground surface albedo from MODIS. The aerosol properties used in the radiative transfer model were constrained by in situ measurements from THAAO. Albedo data over the ocean have been obtained from Jin et al. (2004). Backward trajectories produced through HYSPLIT simulations (Stein et al., 2015) were also employed to trace biomass burning plumes.</p><p>The radiative forcing efficiency (RFE) over land and ocean was derived, finding values spanning from -3 W/m2 to -132 W/m2, depending on surface albedo and solar zenith angle. The fire plume covered a vast portion of the Arctic, with large values of the daily shortwave RF (< -50 W/m2) lasting for a few days. This large amount of aerosol is expected to influence cloud properties in the Arctic, producing significant indirect radiative effects.</p>

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