Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015

Abstract. Specific aerosols and cloud properties over large urban regions seem to generate an island, similar to the well-known urban heat island, leading to lower ultraviolet (UV) radiation intensity compared to the surrounding less polluted areas, thus creating a shield against excessive human exposure to UV radiation. The present study focuses on differences between erythemal and UVA (324 nm) doses measured by the Brewer spectrophotometers in Warsaw (52.3° N, 21.0° E) and Belsk (51.8° N, 20.8° E). The latter is a rural region located about 60 km south-west of the city. Ratios between erythemal and UVA partly daily doses, obtained during all-sky and cloudless-sky conditions for the period May 2013–December 2015, were analysed to infer a specific cloud and aerosol forcing on the surface UV doses over Warsaw. Radiative model simulations were carried out to find sources of the observed differences between the sites. It was found that Warsaw urban agglomeration induced 8 and 6 % attenuation of the erythemal and UVA doses respectively. This is mostly due to the lower sun elevation in Warsaw during the near-noon measurements and the larger optical depth of the city aerosols and increased cloudiness. It could be hypothesised that the expected stronger absorption of the solar UV radiation by urban aerosols is compensated for here by a higher surface reflectivity over the city.

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An urban agglomeration effect on surface UV doses: Comparison of the Brewer measurements in Warsaw and at Belsk, Poland, for the period 2013–2015

10.5194/acp-2016-366 ◽

2016 ◽

Author(s):

Agnieszka E. Czerwińska ◽

Janusz W. Krzyścin ◽

Janusz Jarosławski

Keyword(s):

Uv Radiation ◽

Total Ozone ◽

Surface Albedo ◽

Geographical Location ◽

Urban Agglomeration ◽

Aerosol Forcing ◽

Cloud Properties ◽

Aerosol Absorption ◽

The Mean ◽

The City

Abstract. The specific aerosols and cloud properties over large urban regions seem to generate an island, similar to the well- know city heat island, leading to lower UV radiation intensity compared to the surrounding cleaner areas, thus creating a shield against excessive human exposure to the UV radiation. The present study focuses on differences in the erythemal and UV-A1 (340–400 nm) doses measured by the Brewer spectrophotometers in Warsaw (52.3° N, 21.0° E) and at Belsk (51.8° N, 20.8° E), which is located in a rural region at a distance of about 60 km in the south-west direction from the city. The ratio between erythemal and UV-A1 partly daily doses, obtained during all-sky and cloudless-sky conditions in the period May 2013–December 2015, are analyzed to infer specific cloud and aerosol forcing on the surface UV doses over Warsaw. Radiative model simulations are carried out to assess impact of the Warsaw-Belsk differences in total ozone, geographical location and albedo, on the mean ratio between the doses. Higher surface albedo over the city compensates the effect of solar elevation differences due to latitude differences as the mean total ozone values appear almost the same over both sites. It is found that urban agglomeration induced 8 % and 5 % attenuation of the erythemal and UV-A1 doses, respectively, which could be caused by larger aerosol absorption. It appears that a slightly increased optical depth of the urban aerosols and properties of clouds generated over Warsaw are less important for the UV attenuation. In this work we are showing that the higher city surface albedo compensates for the solar UV attenuation caused by urban aerosol load in the city of Warsaw.

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Episode of unusual high solar ultraviolet radiation over central Europe due to dynamical reduced total ozone in May 2005

Atmospheric Chemistry and Physics ◽

10.5194/acp-6-1771-2006 ◽

2006 ◽

Vol 6 (7) ◽

pp. 1771-1776 ◽

Cited By ~ 24

Author(s):

C. Stick ◽

K. Krüger ◽

N. H. Schade ◽

H. Sandmann ◽

A. Macke

Keyword(s):

Ultraviolet Radiation ◽

Central Europe ◽

Uv Radiation ◽

Solar Ultraviolet Radiation ◽

Solar Uv ◽

The Tropics ◽

Sky Conditions ◽

Effective Radiation ◽

Ozone Episodes ◽

Solar Ultraviolet

Abstract. In late May 2005 unusual high levels of solar ultraviolet radiation were observed over central Europe. In Northern Germany the measured irradiance of erythemally effective radiation exceeded the climatological mean by more than about 20%. An extreme low ozone event for the season coincided with high solar elevation angles and high pressure induced clear sky conditions leading to the highest value of erythemal UV-radiation ever observed over this location in May since 1994. This hereafter called "ozone mini-hole" was caused by an elevation of tropopause height accompanied with a poleward advection of ozone-poor air from the tropics. The resultant increase in UV-radiation is of particular significance for human health. Dynamically induced low ozone episodes that happen in late spring can considerably enhance the solar UV-radiation in mid latitudes and therefore contribute to the UV-burden of people living in these regions.

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Diffuse Solar UV Radiation and Implications for Preventing Human Eye Damage¶

Photochemistry and Photobiology ◽

10.1562/0031-8655(2001)073<0135:dsurai>2.0.co;2 ◽

2001 ◽

Vol 73 (2) ◽

pp. 135 ◽

Cited By ~ 21

Author(s):

Alfio V. Parisi ◽

Adele Green ◽

Michael G. Kimlin

Keyword(s):

Uv Radiation ◽

Human Eye ◽

Solar Uv Radiation ◽

Eye Damage ◽

Solar Uv

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Local climate zones in the city of Nur-Sultan (Kazakhstan) and their connections with urban heat island and thermal comfort

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/611/1/012060 ◽

2020 ◽

Vol 611 ◽

pp. 012060

Author(s):

A A Berlessova ◽

P I Konstantinov

Keyword(s):

Thermal Comfort ◽

Urban Heat Island ◽

Heat Island ◽

Climate Zones ◽

Local Climate ◽

Local Climate Zones ◽

Urban Heat ◽

The City

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Temperature-Related Mortality in Helsinki Compared to Its Surrounding Region Over Two Decades, with Special Emphasis on Intensive Heatwaves

Atmosphere ◽

10.3390/atmos12010046 ◽

2020 ◽

Vol 12 (1) ◽

pp. 46

Author(s):

Reija Ruuhela ◽

Athanasios Votsis ◽

Jaakko Kukkonen ◽

Kirsti Jylhä ◽

Susanna Kankaanpää ◽

...

Keyword(s):

Heat Stress ◽

The Elderly ◽

Land Uses ◽

Hospital District ◽

Distributed Lag ◽

Temperature Ranges ◽

Distributed Lag Nonlinear Model ◽

Urban Heat ◽

The City ◽

Related Mortality

Urbanization and ongoing climate change increase the exposure of the populations to heat stress, and the urban heat island (UHI) effect may magnify heat-related mortality, especially during heatwaves. We studied temperature-related mortality in the city of Helsinki—with urban and suburban land uses—and in the surrounding Helsinki-Uusimaa hospital district (HUS-H, excluding Helsinki)—with more rural types of land uses—in southern Finland for two decades, 2000–2018. Dependence of the risk of daily all-cause deaths (all-age and 75+ years) on daily mean temperature was modelled using the distributed lag nonlinear model (DLNM). The modelled relationships were applied in assessing deaths attributable to four intensive heatwaves during the study period. The results showed that the heat-related mortality risk was substantially higher in Helsinki than in HUS-H, and the mortality rates attributable to four intensive heatwaves (2003, 2010, 2014 and 2018) were about 2.5 times higher in Helsinki than in HUS-H. Among the elderly, heat-related risks were also higher in Helsinki, while cold-related risks were higher in the surrounding region. The temperature ranges recorded in the fairly coarse resolution gridded datasets were not distinctly different in the two considered regions. It is therefore probable that the modelling underestimated the actual exposure to the heat stress in Helsinki. We also studied the modifying, short-term impact of air quality on the modelled temperature-mortality association in Helsinki; this effect was found to be small. We discuss a need for higher resolution data and modelling the UHI effect, and regional differences in vulnerability to thermal stress.

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The Early Days of Personal Solar Ultraviolet Dosimetry

Atmosphere ◽

10.3390/atmos11020125 ◽

2020 ◽

Vol 11 (2) ◽

pp. 125 ◽

Cited By ~ 3

Author(s):

Brian Diffey

Keyword(s):

Uv Radiation ◽

Human Exposure ◽

Ground Level ◽

Uv Exposure ◽

Population Exposure ◽

Atmospheric Ozone ◽

Quantitative Understanding ◽

Solar Uv ◽

The Impact ◽

Solar Ultraviolet

In the early 1970s, environmental conservationists were becoming concerned that a reduction in the thickness of the atmospheric ozone layer would lead to increased levels of ultraviolet (UV) radiation at ground level, resulting in higher population exposure to UV and subsequent harm, especially a rise in skin cancer. At the time, no measurements had been reported on the normal levels of solar UV radiation which populations received in their usual environment, so this lack of data, coupled with increasing concerns about the impact to human health, led to the development of simple devices that monitored personal UV exposure. The first and most widely used UV dosimeter was the polymer film, polysulphone, and this review describes its properties and some of the pioneering studies using the dosimeter that led to a quantitative understanding of human exposure to sunlight in a variety of behavioral, occupational, and geographical settings.

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Assessing Inequitable Urban Heat Islands and Air Pollution Disparities with Low-Cost Sensors in Richmond, Virginia

Sustainability ◽

10.3390/su122310089 ◽

2020 ◽

Vol 12 (23) ◽

pp. 10089

Author(s):

Andre M. Eanes ◽

Todd R. Lookingbill ◽

Jeremy S. Hoffman ◽

Kelly C. Saverino ◽

Stephen S. Fong

Keyword(s):

Air Pollution ◽

Low Income ◽

Green Space ◽

Low Cost ◽

Early Morning ◽

Urban Heat Islands ◽

Urban Heat ◽

Adverse Environmental Conditions ◽

East End ◽

The City

Air pollution and the urban heat island effect are consistently linked to numerous respiratory and heat-related illnesses. Additionally, these stressors disproportionately impact low-income and historically marginalized communities due to their proximity to emissions sources, lack of access to green space, and exposure to other adverse environmental conditions. Here, we use relatively low-cost stationary sensors to analyze PM2.5 and temperature data throughout the city of Richmond, Virginia, on the ten hottest days of 2019. For both hourly means within the ten hottest days of 2019 and daily means for the entire record for the year, the temperature was found to exhibit a positive correlation with PM2.5. Analysis of hourly means on the ten hottest days yielded a diurnal pattern in which PM2.5 levels peaked in the early morning and reached their minima in the mid-afternoon. Spatially, sites exhibiting higher temperatures consistently had higher PM2.5 readings, with vulnerable communities in the east end and more intensely developed parts of the city experiencing significantly higher temperatures and PM2.5 concentrations than the suburban neighborhoods in the west end. These findings suggest an uneven distribution of air pollution in Richmond during extreme heat events that are similar in pattern but less pronounced than the temperature differences during these events, although further investigation is required to verify the extent of this relationship. As other studies have found both of these environmental stressors to correlate with the distribution of green space and other land-use factors in cities, innovative and sustainable planning decisions are crucial to the mitigation of these issues of inequity going forward.

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