Transparency of Antarctic ice‐covered lakes to solar UV radiation
Depth profiles of solar ultraviolet radiation (UVR), photosynthetically available radiation (PAR), and related variables were measured beneath the thick, permanent ice cover of four lakes in the McMurdo Dry Valleys (77°S, 162°E). These lakes span a range of phytoplankton concentrations (0.1–10 μg Ch...
Published in: | Limnology and Oceanography |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1998
|
Subjects: | |
Online Access: | http://dx.doi.org/10.4319/lo.1998.43.4.0618 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1998.43.4.0618 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1998.43.4.0618 |
id |
crwiley:10.4319/lo.1998.43.4.0618 |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.4319/lo.1998.43.4.0618 2024-06-23T07:46:17+00:00 Transparency of Antarctic ice‐covered lakes to solar UV radiation Vincent, Warwick F. Rae, Rowena Laurion, Isabelle Howard‐Williams, Clive Priscu, John C. 1998 http://dx.doi.org/10.4319/lo.1998.43.4.0618 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1998.43.4.0618 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1998.43.4.0618 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Limnology and Oceanography volume 43, issue 4, page 618-624 ISSN 0024-3590 1939-5590 journal-article 1998 crwiley https://doi.org/10.4319/lo.1998.43.4.0618 2024-06-04T06:38:23Z Depth profiles of solar ultraviolet radiation (UVR), photosynthetically available radiation (PAR), and related variables were measured beneath the thick, permanent ice cover of four lakes in the McMurdo Dry Valleys (77°S, 162°E). These lakes span a range of phytoplankton concentrations (0.1–10 μg Chl a liter −1 ) but receive little input of chromophoric dissolved organic matter (CDOM) from their barren, polar desert catchments. The diffuse attenuation coefficients for downwelling radiation ( K d ) in the upper water column of the lakes were at or below those for clear natural waters elsewhere, with minimum values in Lake Vanda of 0.080 (305 nm), 0.055 (320 nm), 0.036 (340 nm), 0.023 (380 nm) and 0.034 (PAR) m −1 . The attenuation lengths (l/ K d ) for these lakes and for a set of high latitude lakes in the northern hemisphere (tundra and boreal forest catchments) showed a close log‐log relationship with dissolved organic carbon (DOC) concentrations ( r 2 ≥ 0.90; n = 20); dry valley lakes were at the high transparency end of this polar‐subpolar continuum. Phytoplankton exposure to UVR relative to PAR is known to rise steeply with decreasing DOC in the concentration range 2–4 g m −3 the addition of the dry valley lakes data shows the continuation of this upward, markedly nonlinear trend at lower DOC concentrations. Calculation of the biologically effective UVR dosage rate for the upper phytoplankton community of Lake Vanda indicated that sufficient UVR penetrates through the 3.5‐m‐thick lake ice to cause inhibition of algal growth. These results show that polar desert lakes are optical extremes in terms of their water‐column transparency to UVR, and that their dilute, mostly autochthonous CDOM offers little protection against the ultraviolet‐B radiation flux that is continuing to increase over the polar regions. Article in Journal/Newspaper Antarc* Antarctic McMurdo Dry Valleys polar desert Tundra Wiley Online Library Antarctic Four Lakes ENVELOPE(-126.826,-126.826,54.858,54.858) Lake Vanda ENVELOPE(161.600,161.600,-77.517,-77.517) McMurdo Dry Valleys Vanda ENVELOPE(161.550,161.550,-77.533,-77.533) Limnology and Oceanography 43 4 618 624 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Depth profiles of solar ultraviolet radiation (UVR), photosynthetically available radiation (PAR), and related variables were measured beneath the thick, permanent ice cover of four lakes in the McMurdo Dry Valleys (77°S, 162°E). These lakes span a range of phytoplankton concentrations (0.1–10 μg Chl a liter −1 ) but receive little input of chromophoric dissolved organic matter (CDOM) from their barren, polar desert catchments. The diffuse attenuation coefficients for downwelling radiation ( K d ) in the upper water column of the lakes were at or below those for clear natural waters elsewhere, with minimum values in Lake Vanda of 0.080 (305 nm), 0.055 (320 nm), 0.036 (340 nm), 0.023 (380 nm) and 0.034 (PAR) m −1 . The attenuation lengths (l/ K d ) for these lakes and for a set of high latitude lakes in the northern hemisphere (tundra and boreal forest catchments) showed a close log‐log relationship with dissolved organic carbon (DOC) concentrations ( r 2 ≥ 0.90; n = 20); dry valley lakes were at the high transparency end of this polar‐subpolar continuum. Phytoplankton exposure to UVR relative to PAR is known to rise steeply with decreasing DOC in the concentration range 2–4 g m −3 the addition of the dry valley lakes data shows the continuation of this upward, markedly nonlinear trend at lower DOC concentrations. Calculation of the biologically effective UVR dosage rate for the upper phytoplankton community of Lake Vanda indicated that sufficient UVR penetrates through the 3.5‐m‐thick lake ice to cause inhibition of algal growth. These results show that polar desert lakes are optical extremes in terms of their water‐column transparency to UVR, and that their dilute, mostly autochthonous CDOM offers little protection against the ultraviolet‐B radiation flux that is continuing to increase over the polar regions. |
format |
Article in Journal/Newspaper |
author |
Vincent, Warwick F. Rae, Rowena Laurion, Isabelle Howard‐Williams, Clive Priscu, John C. |
spellingShingle |
Vincent, Warwick F. Rae, Rowena Laurion, Isabelle Howard‐Williams, Clive Priscu, John C. Transparency of Antarctic ice‐covered lakes to solar UV radiation |
author_facet |
Vincent, Warwick F. Rae, Rowena Laurion, Isabelle Howard‐Williams, Clive Priscu, John C. |
author_sort |
Vincent, Warwick F. |
title |
Transparency of Antarctic ice‐covered lakes to solar UV radiation |
title_short |
Transparency of Antarctic ice‐covered lakes to solar UV radiation |
title_full |
Transparency of Antarctic ice‐covered lakes to solar UV radiation |
title_fullStr |
Transparency of Antarctic ice‐covered lakes to solar UV radiation |
title_full_unstemmed |
Transparency of Antarctic ice‐covered lakes to solar UV radiation |
title_sort |
transparency of antarctic ice‐covered lakes to solar uv radiation |
publisher |
Wiley |
publishDate |
1998 |
url |
http://dx.doi.org/10.4319/lo.1998.43.4.0618 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1998.43.4.0618 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1998.43.4.0618 |
long_lat |
ENVELOPE(-126.826,-126.826,54.858,54.858) ENVELOPE(161.600,161.600,-77.517,-77.517) ENVELOPE(161.550,161.550,-77.533,-77.533) |
geographic |
Antarctic Four Lakes Lake Vanda McMurdo Dry Valleys Vanda |
geographic_facet |
Antarctic Four Lakes Lake Vanda McMurdo Dry Valleys Vanda |
genre |
Antarc* Antarctic McMurdo Dry Valleys polar desert Tundra |
genre_facet |
Antarc* Antarctic McMurdo Dry Valleys polar desert Tundra |
op_source |
Limnology and Oceanography volume 43, issue 4, page 618-624 ISSN 0024-3590 1939-5590 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.4319/lo.1998.43.4.0618 |
container_title |
Limnology and Oceanography |
container_volume |
43 |
container_issue |
4 |
container_start_page |
618 |
op_container_end_page |
624 |
_version_ |
1802644989053763584 |