The website philadelphianeighborhoods.com provides news coverage about more than 30 underreported and underserved communities in Philadelphia. Affiliated with Temple University, the website and bimonthly printed editi...The website philadelphianeighborhoods.com provides news coverage about more than 30 underreported and underserved communities in Philadelphia. Affiliated with Temple University, the website and bimonthly printed editions focus on hyperlocal journalism, or journalism at the street-by-street level. The website has won numerous state, regional, and national awards for its coverage. The goals focus on many aspects of journalism, but this paper will address the successes and failures of this hyperlocal approach and the potential applicability for other organizations.展开更多
Sun-photometer measurements at Hefei,an urban site located in central East China,were examined to investigate the variations of aerosol loading and optical properties.It is found that aerosol optical thickness(AOT)kee...Sun-photometer measurements at Hefei,an urban site located in central East China,were examined to investigate the variations of aerosol loading and optical properties.It is found that aerosol optical thickness(AOT)keeps higher in winter/spring and gets relatively lower in summer/autumn.The large AOT in winter is caused by anthropogenic sulfate/nitrate aerosols,while in spring dust particles elevate the background aerosol loading and the excessive fine-mode particles eventually lead to severe pollution.There is a dramatic decline of AOT during summer,with monthly averaged AOT reaching the maximum in June and soon the minimum in August.Meanwhile,aerosol size decreases consistently and single scattering albedo(SSA)reaches its minimum in July.During summertime large-sized particles play a key role to change the air from clean to mild-pollution situation,while the presence of massive small-sized particles makes the air being even more polluted.These complicated summer patterns are possibly related to the three key processes that are active in the high temperature/humidity environment concentrating on sulfate/nitrate aerosols,i.e.,gas-to-particle transformation,hygroscopic growth,and wet scavenging.Regardless of season,the increase of SSA with increasing AOT occurs across the visible and near-infrared bands,suggesting the dominant negative/cooling effect with the elevated aerosol loading.The SSA spectra under varying AOT monotonically decrease with wavelength.The relatively large slope arises in summer,reinforcing the dominance of sulfate/nitrate aerosols that induce severe pollution in summer season around this city.展开更多
文摘The website philadelphianeighborhoods.com provides news coverage about more than 30 underreported and underserved communities in Philadelphia. Affiliated with Temple University, the website and bimonthly printed editions focus on hyperlocal journalism, or journalism at the street-by-street level. The website has won numerous state, regional, and national awards for its coverage. The goals focus on many aspects of journalism, but this paper will address the successes and failures of this hyperlocal approach and the potential applicability for other organizations.
基金support on PREDE data and the two reviewers for their valuable suggestionssupported by the National Natural Science Foundation of China(Grant Nos.41175032&41575019)
文摘Sun-photometer measurements at Hefei,an urban site located in central East China,were examined to investigate the variations of aerosol loading and optical properties.It is found that aerosol optical thickness(AOT)keeps higher in winter/spring and gets relatively lower in summer/autumn.The large AOT in winter is caused by anthropogenic sulfate/nitrate aerosols,while in spring dust particles elevate the background aerosol loading and the excessive fine-mode particles eventually lead to severe pollution.There is a dramatic decline of AOT during summer,with monthly averaged AOT reaching the maximum in June and soon the minimum in August.Meanwhile,aerosol size decreases consistently and single scattering albedo(SSA)reaches its minimum in July.During summertime large-sized particles play a key role to change the air from clean to mild-pollution situation,while the presence of massive small-sized particles makes the air being even more polluted.These complicated summer patterns are possibly related to the three key processes that are active in the high temperature/humidity environment concentrating on sulfate/nitrate aerosols,i.e.,gas-to-particle transformation,hygroscopic growth,and wet scavenging.Regardless of season,the increase of SSA with increasing AOT occurs across the visible and near-infrared bands,suggesting the dominant negative/cooling effect with the elevated aerosol loading.The SSA spectra under varying AOT monotonically decrease with wavelength.The relatively large slope arises in summer,reinforcing the dominance of sulfate/nitrate aerosols that induce severe pollution in summer season around this city.
