scholarly journals Contribution of Arctic seabird-colony ammonia to atmospheric particles and cloud-albedo radiative effect

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
B. Croft ◽  
G. R. Wentworth ◽  
R. V. Martin ◽  
W. R. Leaitch ◽  
J. G. Murphy ◽  
...  
Keyword(s):  
Atmospheric Particles ◽  
Radiative Effect ◽  
Cloud Albedo ◽  
Seabird Colony

scholarly journals An emulator approach to stratocumulus susceptibility

2019 ◽  
Vol 19 (15) ◽  
pp. 10191-10203 ◽  
Author(s):  
Franziska Glassmeier ◽  
Fabian Hoffmann ◽  
Jill S. Johnson ◽  
Takanobu Yamaguchi ◽  
Ken S. Carslaw ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Cloud Amount ◽  
Cloud Fraction ◽  
Surface Fluxes ◽  
Complex Data ◽  
Radiative Effect ◽  
Liquid Water Path ◽  
Cloud Albedo ◽  
Cloud Radiative Effect ◽  
Wide Range

Abstract. The climatic relevance of aerosol–cloud interactions depends on the sensitivity of the radiative effect of clouds to cloud droplet number N, and liquid water path LWP. We derive the dependence of cloud fraction CF, cloud albedo AC, and the relative cloud radiative effect rCRE=CF⋅AC on N and LWP from 159 large-eddy simulations of nocturnal stratocumulus. These simulations vary in their initial conditions for temperature, moisture, boundary-layer height, and aerosol concentration but share boundary conditions for surface fluxes and subsidence. Our approach is based on Gaussian-process emulation, a statistical technique related to machine learning. We succeed in building emulators that accurately predict simulated values of CF, AC, and rCRE for given values of N and LWP. Emulator-derived susceptibilities ∂ln⁡rCRE/∂ln⁡N and ∂ln⁡rCRE/∂ln⁡LWP cover the nondrizzling, fully overcast regime as well as the drizzling regime with broken cloud cover. Theoretical results, which are limited to the nondrizzling regime, are reproduced. The susceptibility ∂ln⁡rCRE/∂ln⁡N captures the strong sensitivity of the cloud radiative effect to cloud fraction, while the susceptibility ∂ln⁡rCRE/∂ln⁡LWP describes the influence of cloud amount on cloud albedo irrespective of cloud fraction. Our emulation-based approach provides a powerful tool for summarizing complex data in a simple framework that captures the sensitivities of cloud-field properties over a wide range of states.

scholarly journals The aerosol radiative effects of uncontrolled combustion of domestic waste

2016 ◽  
Vol 16 (11) ◽  
pp. 6771-6784 ◽  
Author(s):  
John K. Kodros ◽  
Rachel Cucinotta ◽  
David A. Ridley ◽  
Christine Wiedinmyer ◽  
Jeffrey R. Pierce
Keyword(s):  
Indirect Effect ◽  
Transport Model ◽  
Radiative Effect ◽  
Chemical Transport Model ◽  
Domestic Waste ◽  
Emissions Inventory ◽  
Aerosol Indirect Effect ◽  
Waste Combustion ◽  
Cloud Albedo ◽  
Aerosol Radiative

Abstract. Open, uncontrolled combustion of domestic waste is a potentially significant source of aerosol; however, this aerosol source is not generally included in many global emissions inventories. To provide a first estimate of the aerosol radiative impacts from domestic-waste combustion, we incorporate the Wiedinmyer et al. (2014) emissions inventory into GEOS-Chem-TOMAS, a global chemical-transport model with online aerosol microphysics. We find domestic-waste combustion increases global-mean black carbon and organic aerosol concentrations by 8 and 6 %, respectively, and by greater than 40 % in some regions. Due to uncertainties regarding aerosol optical properties, we estimate the globally averaged aerosol direct radiative effect to range from −5 to −20 mW m−2; however, this range increases from −40 to +4 mW m−2 when we consider uncertainties in emission mass and size distribution. In some regions with significant waste combustion, such as India and China, the aerosol direct radiative effect may exceed −0.4 W m−2. Similarly, we estimate a cloud-albedo aerosol indirect effect of −13 mW m−2, with a range of −4 to −49 mW m−2 due to emission uncertainties. In the regions with significant waste combustion, the cloud-albedo aerosol indirect effect may exceed −0.4 W m−2.

scholarly journals The aerosol radiative effects of uncontrolled combustion of domestic waste

2016 ◽  
Author(s):  
John K. Kodros ◽  
Rachel Cucinotta ◽  
David A. Ridley ◽  
Christine Wiedinmyer ◽  
Jeffrey R. Pierce
Keyword(s):  
Indirect Effect ◽  
Transport Model ◽  
Radiative Effect ◽  
Chemical Transport Model ◽  
Domestic Waste ◽  
Emissions Inventory ◽  
Aerosol Indirect Effect ◽  
Waste Combustion ◽  
Cloud Albedo ◽  
Aerosol Radiative

Abstract. Open, uncontrolled combustion of domestic waste is a potentially significant source of aerosol; however, this aerosol source is not generally included in many global emissions inventories. To provide a first estimate of the aerosol radiative impacts from domestic-waste combustion, we incorporate the Wiedinmyer et al. (2014) emissions inventory into GEOS-Chem-TOMAS, a global chemical-transport model with online aerosol microphysics. We find domestic-waste combustion increases global-mean black carbon and organic aerosol concentrations by 8 % and 6 %, respectively, and by greater than 40 % in some regions. Due to uncertainties regarding aerosol optical properties, we estimate the globally averaged aerosol direct radiative effect to range from −5 mW m−2 to −20 mW m−2; however, this range increases to −40 mW m−2 to +4 mW m−2 when we consider uncertainties in emission mass and size distribution. In some regions with significant waste combustion, such as India and China, the aerosol direct radiative effect may exceed −0.4 W m−2. Similarly, we estimate a cloud-albedo aerosol indirect effect of −13 mW m−2, with a range of −4 mW m−2 to −49 mW m−2 due to emission uncertainties. In the regions with significant waste combustion, the cloud-albedo aerosol indirect effect may exceed −0.4 W m−2.

scholarly journals An emulator approach to stratocumulus susceptibility

2019 ◽  
Author(s):  
Franziska Glassmeier ◽  
Fabian Hoffmann ◽  
Jill S. Johnson ◽  
Takanobu Yamaguchi ◽  
Ken S. Carslaw ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Cloud Amount ◽  
Cloud Fraction ◽  
Surface Fluxes ◽  
Complex Data ◽  
Radiative Effect ◽  
Liquid Water Path ◽  
Cloud Albedo ◽  
Cloud Radiative Effect ◽  
Wide Range

Abstract. The climatic relevance of aerosol-cloud interactions depends on the sensitivity of the radiative effect of clouds to cloud droplet number N and liquid water path LWP. We derive the dependence of cloud fraction CF, cloud albedo AC and the relative cloud radiative effect rCRE = CF · AC on N and LWP from 159 large-eddy simulations of nocturnal stratocumulus. These simulations vary in their initial conditions for temperature, moisture, boundary-layer height and aerosol concentration but share boundary conditions for surface fluxes and subsidence. Our approach is based on Gaussian process emulation, a statistical technique related to machine learning. We succeed in building emulators that accurately predict simulated values of CF, AC and rCRE for given values of N and LWP. Emulator-derived susceptibilities ∂ ln rCRE/∂ ln N and ∂ ln rCRE/∂ ln LWP cover the non-drizzling, fully-overcast regime as well as the drizzling regime with broken cloud cover. Theoretical results, which are limited to the non-drizzling regime, are reproduced. The susceptibility ∂ ln rCRE/∂ ln N captures the strong sensitivity of the cloud radiative effect to cloud fraction, while the susceptibility ∂ ln rCRE/∂ ln LWP describes the influence of cloud amount on cloud albedo irrespective of cloud fraction. Our emulation-based approach provides a powerful tool for summarizing complex data in a simple framework that captures the sensitivities of cloud field properties over a wide range of states.

scholarly journals Impacts of aviation fuel sulfur content on climate and human health

2015 ◽  
Vol 15 (13) ◽  
pp. 18921-18961 ◽  
Author(s):  
Z. Z. Kapadia ◽  
D. V. Spracklen ◽  
S. R. Arnold ◽  
D. J. Borman ◽  
G. W. Mann ◽  
...  
Keyword(s):  
Air Quality ◽  
Sulfur Content ◽  
Tropospheric Ozone ◽  
Tropospheric Chemistry ◽  
Aviation Fuel ◽  
Radiative Effect ◽  
Cloud Albedo ◽  
Albedo Effect ◽  
Aviation Emissions ◽  
The Impact

Abstract. Aviation emissions impact both air quality and climate. Using a coupled tropospheric chemistry-aerosol microphysics model we investigate the effects of varying aviation fuel sulfur content (FSC) on premature mortality from long-term exposure to aviation-sourced PM2.5 (particulate matter with a dry diameter of < 2.5 μm) and on the global radiation budget due to changes in aerosol and tropospheric ozone. We estimate that present-day non-CO2 aviation emissions with a typical FSC of 600 ppm result in 3597 (95 % CI: 1307–5888) annual mortalities globally due to increases in cases of cardiopulmonary disease and lung cancer, resulting from increased surface PM2.5 concentrations. We quantify the global annual mean combined radiative effect (REcomb) of non-CO2 aviation emissions as −13.3 mW m−2; from increases in aerosols (direct radiative effect and cloud albedo effect) and tropospheric ozone. Ultra-low sulfur jet fuel (ULSJ; FSC =15 ppm) has been proposed as an option to reduce the adverse health impacts of aviation-induced PM2.5. We calculate that swapping the global aviation fleet to ULSJ fuel would reduce the global aviation-induced mortality rate by 624 (95 % CI: 227–1021) mortalities a−1 and increase REcomb by +7.0 mW m−2. We explore the impact of varying aviation FSC between 0–6000 ppm. Increasing FSC increases annual mortality, while enhancing climate cooling through increasing the aerosol cloud albedo effect (aCAE). We explore the relationship between the injection altitude of aviation emissions and the resulting climate and air quality impacts. Compared to the standard aviation emissions distribution, releasing aviation emissions at the ground increases global aviation-induced mortality and produces a net warming effect, primarily through a reduced aCAE. Aviation emissions injected at the surface are 5 times less effective at forming cloud condensation nuclei, reducing the aviation-induced aCAE by a factor of 10. Applying high FSCs at aviation cruise altitudes combined with ULSJ fuel at lower altitudes result in reduced aviation-induced mortality and increased negative RE compared to the baseline aviation scenario.

scholarly journals Impacts of aviation fuel sulfur content on climate and human health

2016 ◽  
Vol 16 (16) ◽  
pp. 10521-10541 ◽  
Author(s):  
Zarashpe Z. Kapadia ◽  
Dominick V. Spracklen ◽  
Steve R. Arnold ◽  
Duncan J. Borman ◽  
Graham W. Mann ◽  
...  
Keyword(s):  
Air Quality ◽  
Sulfur Content ◽  
Tropospheric Ozone ◽  
Tropospheric Chemistry ◽  
Aviation Fuel ◽  
Radiative Effect ◽  
Cloud Albedo ◽  
Albedo Effect ◽  
Aviation Emissions ◽  
The Impact

Abstract. Aviation emissions impact both air quality and climate. Using a coupled tropospheric chemistry-aerosol microphysics model we investigate the effects of varying aviation fuel sulfur content (FSC) on premature mortality from long-term exposure to aviation-sourced PM2.5 (particulate matter with a dry diameter of  <  2.5 µm) and on the global radiation budget due to changes in aerosol and tropospheric ozone. We estimate that present-day non-CO2 aviation emissions with a typical FSC of 600 ppm result in  ∼  3600 [95 % CI: 1310–5890] annual premature mortalities globally due to increases in cases of cardiopulmonary disease and lung cancer, resulting from increased surface PM2.5 concentrations. We quantify the global annual mean combined radiative effect (REcomb) of non-CO2 aviation emissions as −13.3 mW m−2; from increases in aerosols (direct radiative effect and cloud albedo effect) and tropospheric ozone. Ultra-low sulfur jet fuel (ULSJ; FSC  =  15 ppm) has been proposed as an option to reduce the adverse health impacts of aviation-induced PM2.5. We calculate that swapping the global aviation fleet to ULSJ fuel would reduce the global aviation-induced mortality rate by  ∼  620 [95 % CI: 230–1020] mortalities a−1 and increase REcomb by +7.0 mW m−2. We explore the impact of varying aviation FSC between 0 and 6000 ppm. Increasing FSC increases aviation-induced mortality, while enhancing climate cooling through increasing the aerosol cloud albedo effect (CAE). We explore the relationship between the injection altitude of aviation emissions and the resulting climate and air quality impacts. Compared to the standard aviation emissions distribution, releasing aviation emissions at the ground increases global aviation-induced mortality and produces a net warming effect, primarily through a reduced CAE. Aviation emissions injected at the surface are 5 times less effective at forming cloud condensation nuclei, reducing the aviation-induced CAE by a factor of 10. Applying high FSCs at aviation cruise altitudes combined with ULSJ fuel at lower altitudes results in reduced aviation-induced mortality and increased negative RE compared to the baseline aviation scenario.

scholarly journals Exploring Relations between Cloud Morphology, Cloud Phase, and Cloud Radiative Properties in Southern Ocean Stratocumulus Clouds

2021 ◽  
Author(s):  
Jessica Danker ◽  
Odran Sourdeval ◽  
Isabel L. McCoy ◽  
Robert Wood ◽  
Anna Possner
Keyword(s):  
Southern Ocean ◽  
Austral Summer ◽  
Supercooled Liquid ◽  
Mixed Phase ◽  
Radiative Properties ◽  
Radiative Effect ◽  
Open Cell ◽  
Cloud Albedo ◽  
Organizational Patterns ◽  
Cloud Radiative Properties

Abstract. Marine stratocumuli are the most dominant cloud type by area coverage in the Southern Ocean (SO). They can be divided into different self-organized cellular morphological regimes known as open and closed mesoscale-cellular convec- tive (MCC) clouds. Open and closed cells are the two most frequent types of organizational regimes in the SO. Using the liDAR- raDAR (DARDAR) version 2 retrievals, we quantify 59 % of all MCC clouds in this region as mixed-phase clouds (MPCs) during a 4-year time period from 2007 to 2010. The net radiative effect of SO MCC clouds is governed by changes in cloud albedo. Both, cloud morphology and phase, have previously been shown to impact cloud albedo individually, but their interac- tions and their combined impact on cloud albedo remain unclear. Here, we investigate the relationships between cloud phase, organizational patterns, and their differences regarding their cloud radiative properties in the SO. The mixed-phase fraction, which is defined as the number of MPCs divided by the sum of MPC and supercooled liquid cloud (SLC) pixels, of all MCC clouds at a given cloud-top temperature (CTT) varies considerably between austral summer and winter. We further find that seasonal changes in cloud phase at a given CTT across all latitudes are largely independent of cloud morphology and are thus seemingly constrained by other external factors. Overall, our results show a stronger dependence of cloud phase on cloud-top height (CTH) than CTT for clouds below 2.5 km in altitude. Preconditioning through ice-phase processes in MPCs has been observed to accelerate individual closed to open cell transitions in extratropical stratocumuli. The hypothesis of preconditioning has been further substantiated in large-eddy simulations of open and closed MPCs. In this study, we do not find preconditioning to primarily impact climatological SO cloud mor- phology statistics. Meanwhile, in-cloud albedo analysis reveals stronger changes in open and closed cell albedo in SLCs than MPCs. In particular few optically thick (cloud optical thickness > 10) open cell stratocumuli are characterized as ice-free SLCs. Theses differences in in-cloud albedo are found to alter the cloud radiative effect in the SO by 12 W m−2 to 39 W m−2 depending on season and cloud phase.

Habitat constraints and spatial bias in seabird colony distributions

Ecography ◽  
2000 ◽  
Vol 23 (5) ◽  
pp. 575-578 ◽  
Author(s):  
L. Scott Forbes ◽  
Martin Jajam ◽  
Gary W. Kaiser
Keyword(s):  
Spatial Bias ◽  
Seabird Colony

Contribution of brown carbon and lensing to the direct radiative effect of carbonaceous aerosols from biomass and biofuel burning emissions

2015 ◽  
pp. n/a-n/a ◽  
Author(s):  
Rawad Saleh ◽  
Marguerite Marks ◽  
Jinhyok Heo ◽  
Peter J. Adams ◽  
Neil M. Donahue ◽  
...  
Keyword(s):  
Carbonaceous Aerosols ◽  
Radiative Effect ◽  
Brown Carbon

The radiative effect of an aged, internally mixed Arctic aerosol originating from lower-latitude biomass burning

Tellus B ◽  
2009 ◽  
Vol 61 (4) ◽  
Author(s):  
Ann-Christine Engvall ◽  
Johan Ström ◽  
Peter Tunved ◽  
Radovan Krejci ◽  
Hans Schlager ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Lower Latitude ◽  
Radiative Effect ◽  
Arctic Aerosol
Sign in / Sign up

Export Citation Format

Share Document