Shouxian Aerosol Radiative Properties Measured by DOE AMF and Compared with CERES-MODIS

2012 ◽  
Vol 518-523 ◽  
pp. 1973-1976
Author(s):  
Yu Jun Qiu ◽  
Qiang Wang ◽  
Fang Chao Hu
Keyword(s):  
Radiation Flux ◽  
Eastern China ◽  
Department Of Energy ◽  
Radiative Properties ◽  
Early Winter ◽  
Radiative Effect ◽  
Late Autumn ◽  
Atmospheric Radiation Measurement ◽  
Field Campaigns ◽  
Aerosol Radiative

The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program held its first mobile facility (AMF) field campaigns in Shouxian in eastern China. Based on the AMF data, we studied the radiative properties of aerosols in late autumn and early winter. The results show that aerosols and clouds decreased the surface total radiation flux (RF) by 27.5% and the shortwave (SW) RF by 30.8%. The aerosol radiative effect (ARE) in late autumn and early winter calculated is about -24.9 W/m2. In addition, we compared the AMF data with MODIS datasets in a 1×1 degree box. The net SW errors of Terra and Aqua were 97.4 and 30.0 w/m2. The net LW errors were 17.4 W/m2and 21.4 W/m2, respectively. The differences of the errors between Terra and Aqua were caused by the different zenith angles and the different atmospheric aerosol and vapor backgrounds during the satellite overpasses.

scholarly journals Integrated impacts of synoptic forcing and aerosol radiative effect on boundary layer and pollution in the Beijing–Tianjin–Hebei region, China

2020 ◽  
Vol 20 (10) ◽  
pp. 5899-5909 ◽  
Author(s):  
Yucong Miao ◽  
Huizheng Che ◽  
Xiaoye Zhang ◽  
Shuhua Liu
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Large Scale ◽  
Eastern China ◽  
Radiative Effect ◽  
Synoptic Pattern ◽  
Rapid Urbanization ◽  
Synoptic Conditions ◽  
Aerosol Pollution ◽  
Aerosol Radiative

Abstract. Rapid urbanization and industrialization have led to deterioration of air quality in the Beijing–Tianjin–Hebei (BTH) region due to high loadings of PM2.5. Heavy aerosol pollution frequently occurs in winter, in close relation to the planetary boundary layer (PBL) meteorology. To unravel the physical processes that influence PBL structure and aerosol pollution in BTH, this study combined long-term observational data analyses, synoptic pattern classification, and meteorology–chemistry coupled simulations. During the winter of 2017 and 2018, Beijing and Tangshan often experienced heavy PM2.5 pollution simultaneously, accompanied by strong thermal inversion aloft. These concurrences of pollution in different cities were primarily regulated by the large-scale synoptic conditions. Using principal component analysis with geopotential height fields at the 850 hPa level during winter, two typical synoptic patterns associated with heavy pollution in BTH were identified. One pattern is characterized by a southeast-to-north pressure gradient across BTH, and the other is associated with high pressure in eastern China. Both synoptic types feature warmer air temperature at 1000 m a.g.l., which could suppress the development of the PBL. Under these unfavorable synoptic conditions, aerosols can modulate PBL structure through the radiative effect, which was examined using numerical simulations. The aerosol radiative effect can significantly lower the daytime boundary layer height through cooling the surface layer and heating the upper part of the PBL, leading to the deterioration of air quality. This PBL–aerosol feedback is sensitive to the aerosol vertical structure, which is more effective when the synoptic pattern can distribute more aerosols to the upper PBL.

scholarly journals Empirically-Derived Parameterizations of the Direct Aerosol Radiative Effect based on ORACLES Aircraft Observations

2020 ◽  
Author(s):  
Sabrina P. Cochrane ◽  
K. Sebastian Schmidt ◽  
Hong Chen ◽  
Peter Pilewskie ◽  
Scott Kittelman ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Single Scattering ◽  
Aerosol Layer ◽  
Radiative Effect ◽  
Limited Information ◽  
Study Region ◽  
Radiative Fluxes ◽  
Aircraft Observations ◽  
Field Campaigns ◽  
Aerosol Radiative

Abstract. This work establishes an observationally-driven link from mid-visible aerosol optical depth (AOD) and other scene parameters to broadband shortwave irradiance (and by extension, the direct aerosol radiative effect, DARE), based on observations from the 2016 and 2017 field campaigns of ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS). Specifically, this is done by two parameterizations, one spanned by the mid-visible AOD and scene albedo below the aerosol layer, and another one with a third input, the mid-visible aerosol single scattering albedo (SSA). These parameterizations build on the earlier concept of radiative forcing efficiency, which describes the dependence of DARE on the AOD, and extend it to make the dependence on the other two scene parameters explicit. The parameterizations are founded on 9 cases from the campaigns, for which we retrieve the spectral aerosol properties of SSA and asymmetry parameter (g) directly from the radiative fluxes, based on the method presented in Cochrane et al. (2019). These properties are used as the basis of the parameterizations, capturing the natural variability of the study region as sampled. The majority of the case-to-case variability within the ORACLES DARE dataset is attributable to the dependence on AOD and scene albedo. This is captured by the first parameterization, which is advantageous when satellite retrievals provide only limited information such as AOD and scene albedo. However, the second parameterization explains even more of the case-to-case variability by introducing the mid-visible SSA as third parameter. For both parameterizations, we provide the necessary coefficients, uncertainties, and code required for the user to reconstruct the parameterization for their use.

Long-term changes in aerosol radiative properties at Armilla (Spain)

2004 ◽  
Vol 38 (35) ◽  
pp. 5935-5943 ◽  
Author(s):  
H. Lyamani ◽  
F.J. Olmo ◽  
L. Alados-Arboledas
Keyword(s):  
Radiative Properties ◽  
Long Term Changes ◽  
Aerosol Radiative

scholarly journals Resurrection, revenance, and exhumation: the problematics of the dead body in songs and laments

2011 ◽  
Vol 23 ◽  
pp. 28-54
Author(s):  
Madis Arukask
Keyword(s):  
Human Body ◽  
Fairy Tales ◽  
Fairy Tale ◽  
Field Trips ◽  
Dead Body ◽  
Early Winter ◽  
Late Autumn ◽  
Different Types ◽  
Familiar Environment ◽  
Folk Tradition

Different types of folklore texts differ from each other by their function. We can distinguish between genres meant to be believed (like legend) and genres recognized in advance as fiction (fairy-tale). At the same time, textual fiction may also have served practical purposes—such as the telling of fairy-tales during the late autumn and early winter for purposes of fertility magic—as used to be the case in the Estonian folk tradition. There are folklore genres that have functioned, among other things, as an accompaniment, comment on, or support to rituals or practices being carried out—for instance, an incantation during a cure, or a lament in death-related procedures, when a person must be separated from his familiar environment. The same textual formulae fulfil different tasks in different genres, which means that they also carry a different meaning. The present paper considers some themes related to the bodily aspect of humanity in various genres of folklore, particularly in songs and laments, as well as in practices related to death and commemoration. As expected, the problems connected with the human body have in these genres undergone transformations of meaning, the understanding and interpretation of which may vary considerably. The mater­ial discussed in the article derives mainly from the Balto-Finnic and north Russian cultural area, partly from the author's own experience during his field trips.

scholarly journals Aerosol absorption and radiative forcing

2007 ◽  
Vol 7 (3) ◽  
pp. 7171-7233 ◽  
Author(s):  
P. Stier ◽  
J. H. Seinfeld ◽  
S. Kinne ◽  
O. Boucher
Keyword(s):  
Optical Depth ◽  
Radiative Forcing ◽  
Radiative Properties ◽  
Refractive Indices ◽  
Anthropogenic Aerosol ◽  
Clear Sky ◽  
Aerosol Absorption ◽  
Long Wave ◽  
Aerosol Radiative ◽  
Cloud Radiative Properties

Abstract. We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the short-wave anthropogenic aerosol top-of-atmosphere (TOA) radiative forcing clear-sky from –0.79 to –0.53 W m−2 (33%) and all-sky from –0.47 to –0.13 W m−2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19 W m−2 (36%) clear-sky and of 0.12 W m−2 (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05 W m−2 and a positive TOA forcing perturbation of 0.02 W m−2. The long-wave aerosol radiative effects are small for anthropogenic aerosols but become of relevance for the larger natural dust and sea-salt aerosols.

scholarly journals The efficacy of aerosol–cloud radiative perturbations from near-surface emissions in deep open-cell stratocumuli

2018 ◽  
Vol 18 (23) ◽  
pp. 17475-17488 ◽  
Author(s):  
Anna Possner ◽  
Hailong Wang ◽  
Robert Wood ◽  
Ken Caldeira ◽  
Thomas P. Ackerman
Keyword(s):  
Emission Line ◽  
Radiative Properties ◽  
Radiative Effect ◽  
Radiative Effects ◽  
Near Surface ◽  
Open Cell ◽  
Detection And Attribution ◽  
Cloud Radiative Effects ◽  
Ship Tracks ◽  
Cloud Radiative Properties

Abstract. Aerosol–cloud radiative effects are determined and quantified in simulations of deep open-cell stratocumuli observed during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) campaign off the west coast of Chile. The cloud deck forms in a boundary layer 1.5 km deep, with cell sizes reaching 50 km in diameter. Global databases of ship tracks suggest that these linear structures are seldom found in boundary layers this deep. Here, we quantify the changes in cloud radiative properties to a continuous aerosol point source moving along a fixed emission line releasing 1017 particles per second. We show that a spatially coherent cloud perturbation is not evident along the emission line. Yet our model simulates an increase in domain-mean all-sky albedo of 0.05, corresponding to a diurnally averaged cloud radiative effect of 20 W m−2, given the annual mean solar insolation at the VOCALS-REx site. Therefore, marked changes in cloud radiative properties in precipitating deep open cells may be driven by anthropogenic near-surface aerosol perturbations, such as those generated by ships. Furthermore, we demonstrate that these changes in cloud radiative properties are masked by the naturally occurring variability within the organised cloud field. A clear detection and attribution of cloud radiative effects to a perturbation in aerosol concentrations becomes possible when sub-filtering of the cloud field is applied, using the spatio-temporal distribution of the aerosol perturbation. Therefore, this work has implications for the detection and attribution of effective cloud radiative forcing in marine stratocumuli, which constitutes one of the major physical uncertainties within the climate system. Our results suggest that ships may sometimes have a substantial radiative effect on marine clouds and albedo, even when ship tracks are not readily visible.

Aerosol radiative effect in UV, VIS, NIR, and SW spectra under haze and high-humidity urban conditions

2017 ◽  
Vol 166 ◽  
pp. 9-21 ◽  
Author(s):  
Ming Zhang ◽  
Yingying Ma ◽  
Wei Gong ◽  
Lunche Wang ◽  
Xiangao Xia ◽  
...  
Keyword(s):  
High Humidity ◽  
Radiative Effect ◽  
Urban Conditions ◽  
Aerosol Radiative

scholarly journals The influence of local oil exploration and regional wildfires on summer 2015 aerosol over the North Slope of Alaska

2018 ◽  
Vol 18 (2) ◽  
pp. 555-570 ◽  
Author(s):  
Jessie M. Creamean ◽  
Maximilian Maahn ◽  
Gijs de Boer ◽  
Allison McComiskey ◽  
Arthur J. Sedlacek ◽  
...  
Keyword(s):  
Cloud Microphysics ◽  
Department Of Energy ◽  
The Arctic ◽  
North Slope ◽  
The North ◽  
The Us ◽  
Range Transport ◽  
North Slope Of Alaska ◽  
Atmospheric Radiation Measurement ◽  
Arctic Atmosphere

Abstract. The Arctic is warming at an alarming rate, yet the processes that contribute to the enhanced warming are not well understood. Arctic aerosols have been targeted in studies for decades due to their consequential impacts on the energy budget, both directly and indirectly through their ability to modulate cloud microphysics. Even with the breadth of knowledge afforded from these previous studies, aerosols and their effects remain poorly quantified, especially in the rapidly changing Arctic. Additionally, many previous studies involved use of ground-based measurements, and due to the frequent stratified nature of the Arctic atmosphere, brings into question the representativeness of these datasets aloft. Here, we report on airborne observations from the US Department of Energy Atmospheric Radiation Measurement (ARM) program's Fifth Airborne Carbon Measurements (ACME-V) field campaign along the North Slope of Alaska during the summer of 2015. Contrary to previous evidence that the Alaskan Arctic summertime air is relatively pristine, we show how local oil extraction activities, 2015's central Alaskan wildfires, and, to a lesser extent, long-range transport introduce aerosols and trace gases higher in concentration than previously reported in Arctic haze measurements to the North Slope. Although these sources were either episodic or localized, they serve as abundant aerosol sources that have the potential to impact a larger spatial scale after emission.

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