Effects of urban agglomeration on surface-UV doses: a comparison of Brewer measurements in Warsaw and Belsk, Poland, for the period 2013–2015
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 t...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-11-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/13641/2016/acp-16-13641-2016.pdf |
| _version_ | 1818143400050819072 |
|---|---|
| author | A. E. Czerwińska J. W. Krzyścin J. Jarosławski M. Posyniak |
| author_facet | A. E. Czerwińska J. W. Krzyścin J. Jarosławski M. Posyniak |
| author_sort | A. E. Czerwińska |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-11T11:31:04Z |
| format | Article |
| id | doaj.art-d59d4d5ce90948f6be0e5eea6035d6af |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-11T11:31:04Z |
| publishDate | 2016-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-d59d4d5ce90948f6be0e5eea6035d6af2022-12-22T01:08:53ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242016-11-0116136411365110.5194/acp-16-13641-2016Effects of urban agglomeration on surface-UV doses: a comparison of Brewer measurements in Warsaw and Belsk, Poland, for the period 2013–2015A. E. Czerwińska0J. W. Krzyścin1J. Jarosławski2M. Posyniak3Institute of Geophysics, Polish Academy of Sciences, 01452 Warsaw, PolandInstitute of Geophysics, Polish Academy of Sciences, 01452 Warsaw, PolandInstitute of Geophysics, Polish Academy of Sciences, 01452 Warsaw, PolandInstitute of Geophysics, Polish Academy of Sciences, 01452 Warsaw, PolandSpecific 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.https://www.atmos-chem-phys.net/16/13641/2016/acp-16-13641-2016.pdf |
| spellingShingle | A. E. Czerwińska J. W. Krzyścin J. Jarosławski M. Posyniak Effects of urban agglomeration on surface-UV doses: a comparison of Brewer measurements in Warsaw and Belsk, Poland, for the period 2013–2015 Atmospheric Chemistry and Physics |
| title | Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015 |
| title_full | Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015 |
| title_fullStr | Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015 |
| title_full_unstemmed | Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015 |
| title_short | Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015 |
| title_sort | effects of urban agglomeration on surface uv doses a comparison of brewer measurements in warsaw and belsk poland for the period 2013 2015 |
| url | https://www.atmos-chem-phys.net/16/13641/2016/acp-16-13641-2016.pdf |
| work_keys_str_mv | AT aeczerwinska effectsofurbanagglomerationonsurfaceuvdosesacomparisonofbrewermeasurementsinwarsawandbelskpolandfortheperiod20132015 AT jwkrzyscin effectsofurbanagglomerationonsurfaceuvdosesacomparisonofbrewermeasurementsinwarsawandbelskpolandfortheperiod20132015 AT jjarosławski effectsofurbanagglomerationonsurfaceuvdosesacomparisonofbrewermeasurementsinwarsawandbelskpolandfortheperiod20132015 AT mposyniak effectsofurbanagglomerationonsurfaceuvdosesacomparisonofbrewermeasurementsinwarsawandbelskpolandfortheperiod20132015 |