scholarly journals Adjoint inverse modeling of black carbon during the Asian Pacific Regional Aerosol Characterization Experiment

2005 ◽  
Vol 110 (D14) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. Hakami ◽  
D. K. Henze ◽  
J. H. Seinfeld ◽  
T. Chai ◽  
Y. Tang ◽  
...  
Keyword(s):  
Black Carbon ◽  
Inverse Modeling ◽  
Asian Pacific ◽  
Aerosol Characterization

Black carbon aerosol characterization in a coastal city in South China using a single particle soot photometer

2012 ◽  
Vol 51 ◽  
pp. 21-28 ◽  
Author(s):  
Xiao-Feng Huang ◽  
Tian-Le Sun ◽  
Li-Wu Zeng ◽  
Guang-He Yu ◽  
Sheng-Ji Luan
Keyword(s):  
Black Carbon ◽  
South China ◽  
Single Particle ◽  
Coastal City ◽  
Black Carbon Aerosol ◽  
Aerosol Characterization

scholarly journals Inverse modeling of black carbon emissions over China using ensemble data assimilation

2016 ◽  
Vol 16 (2) ◽  
pp. 989-1002 ◽  
Author(s):  
P. Wang ◽  
H. Wang ◽  
Y. Q. Wang ◽  
X. Y. Zhang ◽  
S. L. Gong ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Black Carbon ◽  
Atmospheric Chemistry ◽  
Inverse Modeling ◽  
Optimal Interpolation ◽  
Top Down ◽  
Bottom Up ◽  
Error Matrix ◽  
Ensemble Data Assimilation ◽  
Ensemble Data

Abstract. Emissions inventories of black carbon (BC), which are traditionally constructed using a bottom-up approach based on activity data and emissions factors, are considered to contain a large level of uncertainty. In this paper, an ensemble optimal interpolation (EnOI) data assimilation technique is used to investigate the possibility of optimally recovering the spatially resolved emissions bias of BC. An inverse modeling system for emissions is established for an atmospheric chemistry aerosol model and two key problems related to ensemble data assimilation in the top-down emissions estimation are discussed: (1) how to obtain reasonable ensembles of prior emissions and (2) establishing a scheme to localize the background-error matrix. An experiment involving 1-year-long simulation cycle with EnOI inversion of BC emissions is performed for 2008. The bias of the BC emissions intensity in China at each grid point is corrected by this inverse system. The inverse emission over China in January is 240.1 Gg, and annual emission is about 2539.3 Gg, which is about 1.8 times of bottom-up emission inventory. The results show that, even though only monthly mean BC measurements are employed to inverse the emissions, the accuracy of the daily model simulation improves. Using top-down emissions, the average root mean square error of simulated daily BC is decreased by nearly 30 %. These results are valuable and promising for a better understanding of aerosol emissions and distributions, as well as aerosol forecasting.

scholarly journals Inverse modeling of black carbon emissions over China using ensemble data assimilation

2015 ◽  
Vol 15 (15) ◽  
pp. 20851-20879
Author(s):  
P. Wang ◽  
H. Wang ◽  
Y. Q. Wang ◽  
X. Y. Zhang ◽  
S. L. Gong ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Black Carbon ◽  
Atmospheric Chemistry ◽  
Inverse Modeling ◽  
Optimal Interpolation ◽  
Top Down ◽  
Bottom Up ◽  
Error Matrix ◽  
Ensemble Data Assimilation ◽  
Ensemble Data

Abstract. Emissions inventories of black carbon (BC), which are traditionally constructed using a "bottom-up" approach based on activity data and emissions factors, are considered to contain a large level of uncertainty. In this paper, an ensemble optimal interpolation (EnOI) data assimilation technique is used to investigate the possibility of optimally recovering the spatially resolved emissions bias of BC. An inverse modeling system for emissions is established for an atmospheric chemistry aerosol model and two key problems related to ensemble data assimilation in the top-down emissions estimation are discussed: (1) how to obtain reasonable ensembles of prior emissions; and (2) establishing a scheme to localize the background-error matrix. An experiment involving a one month simulation cycle with EnOI inversion of BC emissions is performed for January 2008. The bias of the BC emissions intensity in China at each grid point is corrected by this inverse system. The inversed emission over China in January is 240.1 Gg, and annual emission is about 2750 Gg, which is over 1.8 times of bottom-up emission inventory. The results show that, even though only monthly mean BC measurements are employed to inverse the emissions, the accuracy of the daily model simulation improves. Using top-down emissions, the average root-mean-square error of simulated daily BC is decreased by nearly 30 %. These results are valuable and promising for a better understanding of aerosol emissions and distributions, as well as aerosol forecasting.

scholarly journals Analysis of transpacific transport of black carbon during HIPPO-3: implications for black carbon aging

2014 ◽  
Vol 14 (1) ◽  
pp. 505-540 ◽  
Author(s):  
Z. Shen ◽  
J. Liu ◽  
L. W. Horowitz ◽  
D. K. Henze ◽  
S. Fan ◽  
...  
Keyword(s):  
Black Carbon ◽  
Aging Time ◽  
Biomass Burning ◽  
Inverse Modeling ◽  
North Pacific ◽  
Time Scale ◽  
Aging Process ◽  
The North ◽  
Transpacific Transport ◽  
The North Pacific

Abstract. Long-range transport of black carbon (BC) is a growing concern as a result of the efficiency of BC in warming the climate and its adverse impact on human health. We study transpacific transport of BC during HIPPO-3 using a combination of inverse modeling and sensitivity analysis. We use the GEOS-Chem chemical transport model and its adjoint to constrain Asian BC emissions and estimate the source of BC over the North Pacific. We find that different sources of BC dominate the transport to the North Pacific during the southbound (29 March 2010) and northbound (13 April 2010) measurements in HIPPO-3. While biomass burning in Southeast Asia (SE) contributes about 60% of BC in March, more than 90% of BC comes from fossil fuel and biofuel combustion in East Asia (EA) during the April mission. GEOS-Chem simulations generally resolve the spatial and temporal variation of BC concentrations over the North Pacific, but are unable to reproduce the low and high tails of the observed BC distribution. We find that the optimized BC emissions derived from inverse modeling fail to improve model simulations significantly. This failure indicates that uncertainties in BC transport, rather than in emissions, account for the major biases in GEOS-Chem simulations of BC. The aging process, transforming BC from hydrophobic into hydrophilic form, is one of the key factors controlling wet scavenging and remote concentrations of BC. Sensitivity tests on BC aging suggest that the aging time scale of anthropogenic BC from EA is several hours, faster than assumed in most global models, while the aging process of biomass burning BC from SE may occur much slower, with a time scale of a few days. To evaluate the effects of BC aging and wet deposition on transpacific transport of BC, we develop an idealized model of BC transport. We find that the mid-latitude air masses sampled during HIPPO-3 may have experienced a series of precipitation events, particularly near the EA and SE source region. Transpacific transport of BC is sensitive to BC aging when the aging rate is fast; this sensitivity peaks when the aging time scale is in the range of 1–1.5 d. Our findings indicate that BC aging close to the source must be simulated accurately at a process level in order to simulate better the global abundance and climate forcing of BC.

scholarly journals Black carbon aerosol characterization in a remote area of Qinghai–Tibetan Plateau, western China

2014 ◽  
Vol 479-480 ◽  
pp. 151-158 ◽  
Author(s):  
Qiyuan Wang ◽  
J.P. Schwarz ◽  
Junji Cao ◽  
Rushan Gao ◽  
D.W. Fahey ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Black Carbon ◽  
Remote Area ◽  
Western China ◽  
Black Carbon Aerosol ◽  
Aerosol Characterization

scholarly journals Analysis of transpacific transport of black carbon during HIPPO-3: implications for black carbon aging

2014 ◽  
Vol 14 (12) ◽  
pp. 6315-6327 ◽  
Author(s):  
Z. Shen ◽  
J. Liu ◽  
L. W. Horowitz ◽  
D. K. Henze ◽  
S. Fan ◽  
...  
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
Inverse Modeling ◽  
North Pacific ◽  
Aging Process ◽  
Long Range Transport ◽  
The North ◽  
Range Transport ◽  
Transpacific Transport ◽  
The North Pacific

Abstract. Long-range transport of black carbon (BC) is a growing concern as a result of the efficiency of BC in warming the climate and its adverse impact on human health. We study transpacific transport of BC during HIPPO-3 using a combination of inverse modeling and sensitivity analysis. We use the GEOS-Chem chemical transport model and its adjoint to constrain Asian BC emissions and estimate the source of BC over the North Pacific. We find that different sources of BC dominate the transport to the North Pacific during the southbound (29 March 2010) and northbound (13 April 2010) measurements in HIPPO-3. While biomass burning in Southeast Asia (SE) contributes about 60% of BC in March, more than 90% of BC comes from fossil fuel and biofuel combustion in East Asia (EA) during the April mission. GEOS-Chem simulations generally resolve the spatial and temporal variation of BC concentrations over the North Pacific, but are unable to reproduce the low and high tails of the observed BC distribution. We find that the optimized BC emissions derived from inverse modeling fail to improve model simulations significantly. This failure indicates that uncertainties in BC removal as well as transport, rather than in emissions, account for the major biases in GEOS-Chem simulations of BC over the North Pacific. The aging process, transforming BC from hydrophobic into hydrophilic form, is one of the key factors controlling wet scavenging and remote concentrations of BC. Sensitivity tests on BC aging (ignoring uncertainties of other factors controlling BC long range transport) suggest that in order to fit HIPPO-3 observations, the aging timescale of anthropogenic BC from EA may be several hours (faster than assumed in most global models), while the aging process of biomass burning BC from SE may occur much slower, with a timescale of a few days. To evaluate the effects of BC aging and wet deposition on transpacific transport of BC, we develop an idealized model of BC transport. We find that the mid-latitude air masses sampled during HIPPO-3 may have experienced a series of precipitation events, particularly near the EA and SE source region. Transpacific transport of BC is sensitive to BC aging when the aging rate is fast; this sensitivity peaks when the aging timescale is in the range of 1–1.5 d. Our findings indicate that BC aging close to the source must be simulated accurately at a process level in order to simulate better the global abundance and climate forcing of BC.

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