BC Absorption Research Articles

Attribution of Source Specific 370 nm UV Light Absorption from Dust, Brown Carbon, and Black Carbon at Two Locations in the San Joaquin Valley

Yearlong, one-in-three-day, source apportionment results were applied to literature values of source specific BrC, BC, and dust mass absorption cross-sections (MAC) to estimate the source contribution to 370 nm near-UV light absorption at Fresno and Bakersfield, San Joquin Valley (SJV), California. The reconstructed light absorption agreed well (r2 of 0.94 Fresno and 0.90 Bakersfield) with co-located AE33 aethalometer measurements. Near-UV absorption was attributed to total mobile, vegetative detritus, wood combustion, meat cooking, SOA, and dust sources. Winter BrC absorption was dominated by wood combustion, accounting for 67% (Fresno) and 53% (Bakersfield) of light absorption at the sites. In summer, wood combustion only accounted for approximately 7% of the near-UV absorption in the SJV. Summer absorption, while significantly lower than winter values, was dominated by SOA and vehicle emissions. In Fresno, summer absorption was comprised of 35% SOA, 39% vehicle BC and 15% vehicle BrC. Bakersfield’s summer absorption was 27% SOA, 44% vehicle BC, and 14% vehicle BrC. Total BrC absorption correlated well with OC concentrations, when segregated out by season, while the total BrC absorption was highly variable when compared to WSOC concentrations. The results indicate using source specific MAC values is an effective way to model near-UV light absorption associated with BrC sources and mitigation approaches that prioritize wood combustion in winter and vehicle emissions in summer would have the greatest effect in reducing near-UV light absorption in the SJV.

Wildfire Smoke Demonstrates Significant and Predictable Black Carbon Light Absorption Enhancements

AbstractBlack carbon (BC) is estimated to have the second largest anthropogenic radiative forcing in earth‐systems models (ESMs), but there is significant uncertainty in its impact due to complex mixing with organics. Laboratory‐generated particles show that co‐mixed non‐absorbing material enhances absorption by BC by a factor of 2–3.5 as predicted by optical models. However, weak or no enhancements are often reported for field studies. The cause of lower‐than‐expected absorption is not well understood and implies a lower radiative impact of BC compared to how many ESMs currently treat aerosols. By analyzing BC aerosol particle‐by‐particle we reconcile observed and expected absorption for ambient smoke plumes varying in geographic origin, fuel types, burn conditions, atmospheric age and transport. Although particle‐by‐particle tracking is computationally prohibitive for sophisticated ESMs we show that realistic BC absorption is reliably estimated by bulk properties of the plume providing a suitable parameterization to constrain black carbon radiative forcing.

Wildfire atmospheric chemistry: climate and air quality impacts

Wildfire atmospheric chemistry: climate and air quality impacts

Investigating Carbonaceous Aerosol and Its Absorption Properties From Fires in the Western United States (WE‐CAN) and Southern Africa (ORACLES and CLARIFY)

AbstractBiomass burning (BB) produces large quantities of carbonaceous aerosol (black carbon and organic aerosol, BC and OA, respectively), which significantly degrade air quality and impact climate. BC absorbs radiation, warming the atmosphere, while OA typically scatters radiation, leading to cooling. However, some OA, termed brown carbon (BrC), also absorbs visible and near UV radiation; although, its properties are not well constrained. We explore three aircraft campaigns from important BB regions with different dominant fuel and fire types (Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen [WE‐CAN] in the western United States and ObseRvations of Aerosols above CLouds and their intEractionS and Cloud‐Aerosol‐Radiation Interactions and Forcing for Year downwind of southern Africa) and compare them with simulations from the global chemical transport model, GEOS‐Chem using GFED4s. The model generally captures the observed vertical profiles of carbonaceous BB aerosol concentrations; however, we find that BB BC emissions are underestimated in southern Africa. Our comparisons suggest that BC and/or BrC absorption is substantially higher downwind of Africa than in the western United States and, while the Saleh et al. (2014, https://doi.org/10.1038/ngeo2220) and FIREX parameterizations based on the BC:OA ratio improve model‐observation agreement in some regions, they do not sufficiently differentiate absorption characteristics at short wavelengths. We find that photochemical whitening substantially decreases the burden and direct radiative effect of BrC (annual mean of +0.29 W m−2 without whitening and +0.08 W m−2 with). Our comparisons suggest that whitening is required to explain WE‐CAN observations; however, the importance of whitening for African fires cannot be confirmed. Qualitative comparisons with the OMI UV aerosol index suggest our standard BrC whitening scheme may be too fast over Africa.

Enhanced Light‐Absorption of Black Carbon in Rainwater Compared With Aerosols Over the Northern Indian Ocean

AbstractBlack carbon (BC) aerosols affect climate, especially in high aerosol loading regions such as South Asia. A key uncertainty for the climate effects of BC is the evolution of light‐absorbing properties in the atmosphere. Here, we present a year‐round comparison of the mass absorption cross section (MAC; 678 nm) of BC in air (PM10) and rain, for samples collected at the Maldives Climate Observatory at Hanimaadhoo. We develop a filter‐loading correction scheme for estimating BC absorption on filters used in high‐volume samplers. The year‐round average MAC678 of BC in the rain is almost twice (13.3 ± 4.2 m2/g) compared to the PM10 aerosol (7.2 ± 2.6 m2/g). A possible explanation is the elevated ratio of organic carbon (OC) to BC observed in rain particulate matter (9.4 ± 6.3) compared to in the aerosols (OC/BC 2.6 ± 1.4 and water‐insoluble organic carbon/BC 1.2 ± 0.8), indicating a coating‐enhancement effect. In addition to BC, we also investigated the MAC365 of water‐soluble brown carbon in PM10 (0.4 ± 0.4 m2/g, at 365 nm). In contrast to BC, MAC365brown carbon relates to air mass history, showing higher values for samples from air originating over the South Asian landmass. Furthermore, calculated washout ratios are much lower for BC compared to OC and inorganic ions such as sulfate, implying a longer atmospheric lifetime for BC. The wet deposition flux for BC during the high loading winter was 3 times higher than during the wet summer, despite much less precipitation in the winter.

Vertical evolution of black carbon characteristics and heating rate during a haze event in Beijing winter

Black carbon aerosol plays an important role on absorbing shortwave solar radiation. The absorption of BC in urban environment with intensive anthropogenic emissions may modify the atmospheric thermodynamics by heating the planetary boundary layer (PBL), however the exact impacts are still largely uncertain due to lack of in-situ observations. Here we report the detailed in-situ characterization on vertical profiles of BC-related properties including the BC mass, size distribution and mixing state over Beijing by successive flights, during which a full process of haze initialization, development and ceasing were captured and processes of BC properties during this typical haze event was in detail investigated. We found the shallow PBL and the temperature inversion importantly enhanced the BC mass loading in the polluted day and these BC particles were significantly coated with mass ratio of coating over refractory BC increasing from about 1 to 10, whereas when the capping was released the BC was dispersed throughout the column and the coating was reduced. The coatings may cause the enhancement of BC absorption by 95% and introduce additional heating rate as high as 0.1K/h during hazy day. The absorbing power efficiency and heat rate of BC showed positive vertical gradient during peak pollution, which may enhance the temperature inversion at upper level of the PBL. These results provide impacts of BC mixing state on atmospheric heating, and emphasize the importance of including BC mixing state, especially under highly polluted environment, to model the aerosol-boundary layer interaction over urban environment with high BC emission.

Are Changes in Atmospheric Circulation Important for Black Carbon Aerosol Impacts on Clouds, Precipitation, and Radiation?

AbstractBlack carbon (BC) aerosols strongly absorb solar radiation, but their effective radiative forcing and impacts on regional climate remain highly uncertain owing to strong feedbacks of BC heating on clouds, convection, and precipitation. This study investigates the role of large‐scale circulation changes in governing such feedbacks. In the HadGEM3 climate model BC emissions were increased to 10 times present‐day values while keeping sea surface temperatures fixed, to assess the rapid adjustments to increased BC absorption. The BC perturbation led to an effective radiative forcing of 2.7 W/m2 and a 0.13‐mm/day reduction in global precipitation. There were also large shifts in the spatial distribution of tropical convection, increased low cloud over oceans, and a weakening and poleward shift of midlatitude storm tracks, especially in the Northern Hemisphere. In a parallel experiment, horizontal winds were nudged toward meteorological reanalyses to deliberately suppress circulation responses while allowing changes to the thermodynamic structure of the atmosphere. Surprisingly, BC had approximately the same impact on global‐mean radiation and global precipitation in the nudged experiment, even though regional changes in clouds and convection were not fully captured. The results show that large‐scale dynamical responses to BC are important for regional impacts but have a limited role in determining the effective radiative forcing and global‐mean climate response. The rapid adjustments of clouds, radiation, and global precipitation were primarily a response to increased radiative absorption and atmospheric stability. This implies that short nudged simulations may be sufficient to assess absorbing aerosol impacts on global‐mean radiation and precipitation.

Optical Properties and Radiative Forcing of Aged BC due to Hygroscopic Growth: Effects of the Aggregate Structure

AbstractBlack carbon (BC) particles become hydrophilic after mixing with soluble matter in the atmosphere, and their optical and radiative properties can be significantly modified accordingly. This study investigates the impact of aggregate structure on optical and radiative properties of aged BC, that is, BC coated by sulfate or organic aerosols, especially during hygroscopic growth. A more realistic BC morphology based on fractal aggregates is considered, and inhomogeneous mixtures of BC aggregates are treated more realistically (with respect to particle geometries) in the multiple sphere T‐matrix method for optical property simulations. As relative humidity increases, BC extinction is significantly enhanced due to an increase in scattering, and the enhancement depends on the amount and hydrophilicity of the coating. The absorption exhibits less variation during hygroscopic growth because the coating of aerosols already leads to BC absorption close to the maximum. Furthermore, hygroscopic growth not only results in negative radiative forcing (RF) at the top of the atmosphere but also slightly weakens the absorption in the atmosphere (inducing a negative RF in the atmosphere). Compared to the more realistic model with BC as aggregates, the currently popular core‐shell model reasonably approximates the top of the atmosphere RF but underestimates the atmospheric RF due to hygroscopic growth by up to 40%. Furthermore, for the RF caused by internal mixing, the core‐shell model overestimates the RFs at the surface and in the atmosphere by ~10%.

Citrus Flavanones Enhance β-Carotene Uptake in Vitro Experiment Using Caco-2 Cell: Structure-Activity Relationship and Molecular Mechanisms.

Flavonoids can interfere with the absorption of carotenoids. In this study, the inherent mechanisms of 12 citrus flavanones for β-carotene (Bc) cellular uptake and the structure-activity relationship were investigated. The results showed that multiple hydroxyl groups had the lowest promoting effect. O-Glycosylation at C7 of the A ring led to the greatest promoting effect on Bc absorption. O-Glycosylation at C7 exhibited a strong affinity with the cell membrane and subsequently fluidized the cell membrane. Aglycon molecules significantly induced transient increases of paracellular permeability by decreasing tight junction proteins (ZO-1, claudin-1) expression. In addition, citrus flavanones might enhance scavenger receptor class B type I (SR-BI) expression via their actions as agonists of peroxisome proliferator-activated receptor-gamma (PPARγ). Catechol structure in the B-ring attenuated the activate action of SR-BI expression. The structure-dependent membrane permeability and activation of specific membrane proteins are mechanistically associated with the promoting effect on Bc cellular uptake by citrus flavanones.

Brown and Black Carbon Emitted by a Marine Engine Operated on Heavy Fuel Oil and Distillate Fuels: Optical Properties, Size Distributions, and Emission Factors

AbstractWe characterized the chemical composition and optical properties of particulate matter (PM) emitted by a marine diesel engine operated on heavy fuel oil (HFO), marine gas oil (MGO), and diesel fuel (DF). For all three fuels, ∼80% of submicron PM was organic (and sulfate, for HFO at higher engine loads). Emission factors varied only slightly with engine load. Refractory black carbon (rBC) particles were not thickly coated for any fuel; rBC was therefore externally mixed from organic and sulfate PM. For MGO and DF PM, rBC particles were lognormally distributed in size (mode at drBC≈120 nm). For HFO, much larger rBC particles were present. Combining the rBC mass concentrations with in situ absorption measurements yielded an rBC mass absorption coefficient MACBC,780nm of 7.8 ± 1.8 m2/g at 780 nm for all three fuels. Using positive deviations of the absorption Ångström exponent (AAE) from unity to define brown carbon (brC), we found that brC absorption was negligible for MGO or DF PM (AAE(370,880 nm)≈1.0 ± 0.1) but typically 50% of total 370‐nm absorption for HFO PM. Even at 590 nm, ∼20 of the total absorption was due to brC. Using absorption at 880 nm as a reference for BC absorption and normalizing to organic PM mass, we obtained a MACOM,370nm of 0.4 m2/g at typical operating conditions. Furthermore, we calculated an imaginary refractive index of (0.045 ± 0.025)(λ/370nm)−3 for HFO PM at 370 nm>λ > 660 nm, more than twofold greater than previous recommendations. Climate models should account for this substantial brC absorption in HFO PM.

Light Absorption Enhancement of Black Carbon Aerosol Constrained by Particle Morphology.

The radiative forcing of black carbon aerosol (BC) is one of the largest sources of uncertainty in climate change assessments. Contrasting results of BC absorption enhancement ( Eabs) after aging are estimated by field measurements and modeling studies, causing ambiguous parametrizations of BC solar absorption in climate models. Here we quantify Eabs using a theoretical model parametrized by the complex particle morphology of BC in different aging scales. We show that Eabs continuously increases with aging and stabilizes with a maximum of ∼3.5, suggesting that previous seemingly contrast results of Eabs can be explicitly described by BC aging with corresponding particle morphology. We also report that current climate models using Mie Core-Shell model may overestimate Eabs at a certain aging stage with a rapid rise of Eabs, which is commonly observed in the ambient. A correction coefficient for this overestimation is suggested to improve model predictions of BC climate impact.

Field Measurements for Quantifying Semi-Volatile Aerosol Influence on Physical and Optical Properties of Ambient Aerosols in the Kathmandu Valley, Nepal

ABSTRACT An intensive field campaign was conducted during the pre-monsoon season of 2015 in the urban atmosphere of the Kathmandu Valley to study the influence of the semi-volatile aerosol fraction on physical and optical properties of aerosols. Ambient air was siphoned through a specific ambient air inlet and then split into two parts. The first part connected directly with an ambient air sample while the second received the air sample through a thermodenuder (TDD). The aerosol properties, such as the aerosol number, size distribution, absorption, and scattering, were studied using Condensation Particle Counters (CPCs), Scanning Mobility Particle Sizers (SMPSs), Aethalometers (AE33) and Nephelometers, respectively. The differences in the properties of the aerosol fraction at room temperature and other TDD set temperatures (50°C, 100°C, 150°C, 200°C, 250°C, and 300°C) were calculated to study the influence of the semi-volatile aerosol fraction on ambient aerosols. The evaporated fraction of the semi-volatile aerosols increased with the TDD set temperature. The semi-volatile fraction of the aerosol number increased from 16% to 49% of ambient aerosol, while the peak mobility diameter of particles shifted from around 60 nm to 40 nm as the temperature increased from 50°C to 300°C. However, increasing the TDD set temperature had no influence on the effective diameter of the aerosol size distribution. Larger aerosol size bins of the SMPS experienced a significantly stronger influence (~70%) from temperature increments compared to smaller size bins (~20%). The semi-volatile aerosol fraction amplified BC absorption by up to 28%, while scattering by the semi-volatile aerosol fraction contributed up to 71% of the total.

Optical Properties of Wintertime Aerosols from Residential Wood Burning in Fresno, CA: Results from DISCOVER-AQ 2013.

The optical properties, composition and sources of the wintertime aerosols in the San Joaquin Valley (SJV) were characterized through measurements made in Fresno, CA during the 2013 DISCOVER-AQ campaign. PM2.5 extinction and absorption coefficients were measured at 405, 532, and 870 nm along with refractory black carbon (rBC) size distributions and concentrations. BC absorption enhancements (Eabs) were measured using two methods, a thermodenuder and mass absorption coefficient method, which agreed well. Relatively large diurnal variations in the Eabs at 405 nm were observed, likely reflecting substantial nighttime emissions of wood burning organic aerosols (OA) from local residential heating. Comparably small diurnal variations and absolute nighttime values of Eabs were observed at the other wavelengths, suggesting limited mixing-driven enhancement. Positive matrix factorization analysis of OA mass spectra from an aerosol mass spectrometer resolved two types of biomass burning OA, which appeared to have different chemical composition and absorptivity. Brown carbon (BrC) absorption was estimated to contribute up to 30% to the total absorption at 405 nm at night but was negligible (<10%) during the day. Quantitative understanding of retrieved BrC optical properties could be improved with more explicit knowledge of the BC mixing state and the distribution of coating thicknesses.

Enhanced light absorption by mixed source black and brown carbon particles in UK winter.

Black carbon (BC) and light-absorbing organic carbon (brown carbon, BrC) play key roles in warming the atmosphere, but the magnitude of their effects remains highly uncertain. Theoretical modelling and laboratory experiments demonstrate that coatings on BC can enhance BC's light absorption, therefore many climate models simply assume enhanced BC absorption by a factor of ∼1.5. However, recent field observations show negligible absorption enhancement, implying models may overestimate BC's warming. Here we report direct evidence of substantial field-measured BC absorption enhancement, with the magnitude strongly depending on BC coating amount. Increases in BC coating result from a combination of changing sources and photochemical aging processes. When the influence of BrC is accounted for, observationally constrained model calculations of the BC absorption enhancement can be reconciled with the observations. We conclude that the influence of coatings on BC absorption should be treated as a source and regionally specific parameter in climate models.

Aerosol optical absorption by dust and black carbon in Taklimakan Desert, during no-dust and dust-storm conditions

Abstract Aerosol absorption coefficient σap involves the additive contribution of both black carbon aerosol (BC) and dust aerosol. The linear statistical regression analysis approach introduced by Fialho et al. (2005) is used to estimate the absorption exponents of BC and dust aerosol absorption coefficients, and further to separate the contributions of these two types of aerosols from the total light absorption coefficient measured in the hinterland of Taklimakan Desert in the spring of 2006. Absorption coefficients are measured by means of a 7-wavelength Aethalometer from 1 March to 31 May and from 1 November to 28 December, 2006. The absorption exponent of BC absorption coefficient α is estimated as (−0.95 ± 0.002) under background weather (supposing the observed absorption coefficient is due only to BC); the estimated absorption exponent of dust aerosol absorption coefficient β during the 6 dust storm periods (strong dust storm) is (−2.55 ± 0.009). Decoupling analysis of the measured light absorption coefficients demonstrates that, on average, the light absorptions caused by dust aerosol and BC make up about 50.5% and 49.5% respectively of the total light absorption at 520 nm; during dust weather process periods (dust storm, floating dust, blowing dust), the contribution of dust aerosol to absorption extinction is 60.6% on average; in the hinterland of desert in spring, dust aerosol is also the major contributor to the total aerosol light absorption, more than that of black carbon aerosol.

Reducing uncertainties associated with filter-based optical measurements of light absorbing carbon particles with chemical information

Abstract. The presented filter-based optical method for determination of soot (light absorbing carbon or Black Carbon, BC) can be implemented in the field under primitive conditions and at low cost. This enables researchers with small economical means to perform monitoring at remote locations, especially in the Asia where it is much needed. One concern when applying filter-based optical measurements of BC is that they suffer from systematic errors due to the light scattering of non-absorbing particles co-deposited on the filter, such as inorganic salts and mineral dust. In addition to an optical correction of the non-absorbing material this study provides a protocol for correction of light scattering based on the chemical quantification of the material, which is a novelty. A newly designed photometer was implemented to measure light transmission on particle accumulating filters, which includes an additional sensor recording backscattered light. The choice of polycarbonate membrane filters avoided high chemical blank values and reduced errors associated with length of the light path through the filter. Two protocols for corrections were applied to aerosol samples collected at the Maldives Climate Observatory Hanimaadhoo during episodes with either continentally influenced air from the Indian/Arabian subcontinents (winter season) or pristine air from the Southern Indian Ocean (summer monsoon). The two ways of correction (optical and chemical) lowered the particle light absorption of BC by 63 to 61 %, respectively, for data from the Arabian Sea sourced group, resulting in median BC absorption coefficients of 4.2 and 3.5 Mm−1. Corresponding values for the South Indian Ocean data were 69 and 97 % (0.38 and 0.02 Mm−1). A comparison with other studies in the area indicated an overestimation of their BC levels, by up to two orders of magnitude. This raises the necessity for chemical correction protocols on optical filter-based determinations of BC, before even the sign on the radiative forcing based on their effects can be assessed.

Absorbing aerosol in the troposphere of the Western Arctic during the 2008 ARCTAS/ARCPAC airborne field campaigns

Abstract. In the spring of 2008 NASA and NOAA funded the ARCTAS and ARCPAC field campaigns as contributions to POLARCAT, a core IPY activity. During the campaigns the NASA DC-8, P-3B and NOAA WP-3D aircraft conducted over 160 h of in-situ sampling between 0.1 and 12 km throughout the Western Arctic north of 55° N (i.e. Alaska to Greenland). All aircraft were equipped with multiple wavelength measurements of aerosol optics, trace gas and aerosol chemistry measurements, as well as direct measurements of the aerosol size distributions and black carbon mass. Late April of 2008 proved to be exceptional in terms of Asian biomass burning emissions transported to the Western Arctic. Though these smoke plumes account for only 11–14 % of the samples within the Western Arctic domain, they account for 42–47 % of the total burden of black carbon. Dust was also commonly observed but only contributes to 4–12 % and 3–8 % of total light absorption at 470 and 530 nm wavelengths above 6 km. Below 6 km, light absorption by carbonaceous aerosol derived from urban/industrial and biomass burning emissions account for 97–99 % of total light absorption by aerosol. Stratifying the data to reduce the influence of dust allows us to determine mass absorption efficiencies for black carbon of 11.2±0.8, 9.5±0.6 and 7.4±0.7 m2 g−1 at 470, 530 and 660 nm wavelengths. These estimates are consistent with 35–80 % enhancements in 530 nm absorption due to clear or slightly absorbing coatings of pure black carbon particulate. Assuming a 1/λ wavelength dependence for BC absorption, and assuming that refractory aerosol (420 °C, τ = 0.1 s) in low-dust samples is dominated by brown carbon, we derive mass absorption efficiencies for brown carbon of 0.83±0.15 and 0.27±0.08 m2 g−1 at 470 and 530 nm wavelengths. Estimates for the mass absorption efficiencies of Asian dust are 0.034 m2 g−1 and 0.017 m2 g−1. However the absorption efficiency estimates for dust are highly uncertain due to the limitations imposed by PSAP instrument noise. In-situ ARCTAS/ARCPAC measurements during the IPY provide valuable constraints for absorbing aerosol over the Western Arctic, species which are currently poorly simulated over a region that is critically under-sampled.

Bioefficacy of β-carotene is improved in rats after solubilized as equimolar dose of β-carotene and lutein in phospholipid-mixed micelles

beta-Carotene (BC) is a potent dietary source of vitamin A for populations at risk of vitamin A deficiency, yet its bioavailability is influenced by several factors such as dietary fat, carotenoids type, and other components. We hypothesize that type of micellar phospholipids influence bioefficacy of carotenoids and activity of carotenoid metabolizing enzymes. This study determined the BC bioefficacy in rats (n = 5/time point) after an equimolar dose of BC and lutein (Lut) solubilized in micelles containing either phosphatidylcholine (PC) or lysophosphatidylcholine (LPC), or no phospholipid (NoPL). Results show that no BC and Lut was detected in the plasma of rats at 0 hour, but after gavage, the mean (SD) area under the curve (AUC; in picomoles per milliliter) of plasma BC for 6 hours in PC, LPC, and NoPL groups were 1145 (132), 965 (199), and 2136 (112), respectively. The AUC value of plasma Lut in LPC group (183 +/- 23 pmol mL(-1) h(-1)) was higher than the other 2 groups. Similarly, liver BC and Lut levels in the LPC group were significantly higher than the other groups. The activity of BC 15,15'-monooxygenase in the intestinal mucosa of LPC and PC groups was higher than NoPL group. Plasma retinyl palmitate level in LPC (AUC, 647 +/- 89 pmol mL(-1) h(-1)) group was 2-fold higher than that of PC and NoPL groups. Results indicate that phospholipids enhanced the BC and Lut absorption. beta-Carotene uptake was not affected by Lut when given with micellar phospholipids, but reduced plasma Lut level was observed, which may be due to the conversion of absorbed Lut into its metabolites.

Climate response of fossil fuel and biofuel soot, accounting for soot's feedback to snow and sea ice albedo and emissivity

The first three‐dimensional global model in which time‐dependent spectral albedos and emissivities over snow and sea ice are predicted with a radiative transfer solution, rather than prescribed, is applied to study the climate response of fossil fuel plus biofuel black carbon plus organic matter (ff+bf BC+OM) when BC absorption in snow and sea ice is accounted for. The model treats the cycling of size‐resolved BC+OM between emission and removal by dry deposition and precipitation from first principles. Particles produce and enter size‐resolved clouds and precipitation by nucleation scavenging and aerosol‐hydrometeor coagulation. Removal brings BC to the surface, where internally and externally mixed BC in snow and sea ice affects albedo and emissivity through radiative transfer. Climate response simulations were run with a ff+bf BC+OC emission inventory lower than that used in a previous study. The 10‐year, globally averaged ff+bf BC+OM near‐surface temperature response due to all feedbacks was about +0.27 K (+0.32 in the last 3 years), close to those from the previous study (5‐year average of +0.3 K and fifth‐year warming of +0.35 K) and its modeled range (+0.15 to +0.5 K) because warming due to soot absorption in snow and sea ice here (10‐year average of +0.06 K with a modeled range of +0.03 to +0.11 K) offset reduced warming due to lower emission. BC was calculated to reduce snow and sea ice albedo by ∼0.4% in the global average and 1% in the Northern Hemisphere. The globally averaged modeled BC concentration in snow and sea ice was ∼5 ng/g; that in rainfall was ∼22 ng/g. About 98% of BC removal from the atmosphere was due to precipitation; the rest was due to dry deposition. The results here support previous findings that controlling ff+bf BC+OM and CO2 emission may slow global warming.