Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites
Snow algae are an important group of terrestrial photosynthetic organisms in Antarctica, where they mostly grow in low lying coastal snow fields. Reliable observations of Antarctic snow algae are difficult owing to the transient nature of their blooms and the logistics involved to travel and work th...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2021-06-01
|
| Series: | Frontiers in Plant Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2021.671981/full |
| _version_ | 1818919062205366272 |
|---|---|
| author | Andrew Gray Andrew Gray Monika Krolikowski Peter Fretwell Peter Convey Lloyd S. Peck Monika Mendelova Alison G. Smith Matthew P. Davey Matthew P. Davey |
| author_facet | Andrew Gray Andrew Gray Monika Krolikowski Peter Fretwell Peter Convey Lloyd S. Peck Monika Mendelova Alison G. Smith Matthew P. Davey Matthew P. Davey |
| author_sort | Andrew Gray |
| collection | DOAJ |
| description | Snow algae are an important group of terrestrial photosynthetic organisms in Antarctica, where they mostly grow in low lying coastal snow fields. Reliable observations of Antarctic snow algae are difficult owing to the transient nature of their blooms and the logistics involved to travel and work there. Previous studies have used Sentinel 2 satellite imagery to detect and monitor snow algal blooms remotely, but were limited by the coarse spatial resolution and difficulties detecting red blooms. Here, for the first time, we use high-resolution WorldView multispectral satellite imagery to study Antarctic snow algal blooms in detail, tracking the growth of red and green blooms throughout the summer. Our remote sensing approach was developed alongside two Antarctic field seasons, where field spectroscopy was used to build a detection model capable of estimating cell density. Global Positioning System (GPS) tagging of blooms and in situ life cycle analysis was used to validate and verify our model output. WorldView imagery was then used successfully to identify red and green snow algae on Anchorage Island (Ryder Bay, 67°S), estimating peak coverage to be 9.48 × 104 and 6.26 × 104 m2, respectively. Combined, this was greater than terrestrial vegetation area coverage for the island, measured using a normalized difference vegetation index. Green snow algae had greater cell density and average layer thickness than red blooms (6.0 × 104 vs. 4.3 × 104 cells ml−1) and so for Anchorage Island we estimated that green algae dry biomass was over three times that of red algae (567 vs. 180 kg, respectively). Because the high spatial resolution of the WorldView imagery and its ability to detect red blooms, calculated snow algal area was 17.5 times greater than estimated with Sentinel 2 imagery. This highlights a scaling problem of using coarse resolution imagery and suggests snow algal contribution to net primary productivity on Antarctica may be far greater than previously recognized. |
| first_indexed | 2024-12-20T00:59:53Z |
| format | Article |
| id | doaj.art-b29ba86788734e1092b1f72bcd60e91a |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-20T00:59:53Z |
| publishDate | 2021-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-b29ba86788734e1092b1f72bcd60e91a2022-12-21T19:59:01ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2021-06-011210.3389/fpls.2021.671981671981Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView SatellitesAndrew Gray0Andrew Gray1Monika Krolikowski2Peter Fretwell3Peter Convey4Lloyd S. Peck5Monika Mendelova6Alison G. Smith7Matthew P. Davey8Matthew P. Davey9Department of Plant Sciences, University of Cambridge, Cambridge, United KingdomField Spectroscopy Facility (Natural Environment Research Council), University of Edinburgh, Edinburgh, United KingdomDepartment of Plant Sciences, University of Cambridge, Cambridge, United KingdomBritish Antarctic Survey, Natural Environment Research Council, Cambridge, United KingdomBritish Antarctic Survey, Natural Environment Research Council, Cambridge, United KingdomBritish Antarctic Survey, Natural Environment Research Council, Cambridge, United KingdomDepartment of Plant Sciences, University of Cambridge, Cambridge, United KingdomDepartment of Plant Sciences, University of Cambridge, Cambridge, United KingdomDepartment of Plant Sciences, University of Cambridge, Cambridge, United KingdomThe Scottish Association for Marine Science, Oban, United KingdomSnow algae are an important group of terrestrial photosynthetic organisms in Antarctica, where they mostly grow in low lying coastal snow fields. Reliable observations of Antarctic snow algae are difficult owing to the transient nature of their blooms and the logistics involved to travel and work there. Previous studies have used Sentinel 2 satellite imagery to detect and monitor snow algal blooms remotely, but were limited by the coarse spatial resolution and difficulties detecting red blooms. Here, for the first time, we use high-resolution WorldView multispectral satellite imagery to study Antarctic snow algal blooms in detail, tracking the growth of red and green blooms throughout the summer. Our remote sensing approach was developed alongside two Antarctic field seasons, where field spectroscopy was used to build a detection model capable of estimating cell density. Global Positioning System (GPS) tagging of blooms and in situ life cycle analysis was used to validate and verify our model output. WorldView imagery was then used successfully to identify red and green snow algae on Anchorage Island (Ryder Bay, 67°S), estimating peak coverage to be 9.48 × 104 and 6.26 × 104 m2, respectively. Combined, this was greater than terrestrial vegetation area coverage for the island, measured using a normalized difference vegetation index. Green snow algae had greater cell density and average layer thickness than red blooms (6.0 × 104 vs. 4.3 × 104 cells ml−1) and so for Anchorage Island we estimated that green algae dry biomass was over three times that of red algae (567 vs. 180 kg, respectively). Because the high spatial resolution of the WorldView imagery and its ability to detect red blooms, calculated snow algal area was 17.5 times greater than estimated with Sentinel 2 imagery. This highlights a scaling problem of using coarse resolution imagery and suggests snow algal contribution to net primary productivity on Antarctica may be far greater than previously recognized.https://www.frontiersin.org/articles/10.3389/fpls.2021.671981/fullsnow algaeAntarcticaremote sensingsnowsatellitesWorldView |
| spellingShingle | Andrew Gray Andrew Gray Monika Krolikowski Peter Fretwell Peter Convey Lloyd S. Peck Monika Mendelova Alison G. Smith Matthew P. Davey Matthew P. Davey Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites Frontiers in Plant Science snow algae Antarctica remote sensing snow satellites WorldView |
| title | Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites |
| title_full | Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites |
| title_fullStr | Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites |
| title_full_unstemmed | Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites |
| title_short | Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites |
| title_sort | remote sensing phenology of antarctic green and red snow algae using worldview satellites |
| topic | snow algae Antarctica remote sensing snow satellites WorldView |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2021.671981/full |
| work_keys_str_mv | AT andrewgray remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT andrewgray remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT monikakrolikowski remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT peterfretwell remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT peterconvey remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT lloydspeck remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT monikamendelova remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT alisongsmith remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT matthewpdavey remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites AT matthewpdavey remotesensingphenologyofantarcticgreenandredsnowalgaeusingworldviewsatellites |