Climate change enhances primary production in the western Antarctic Peninsula |
| |
Authors: | Sébastien Moreau Behzad Mostajir Simon Bélanger Irene R Schloss Martin Vancoppenolle Serge Demers Gustavo A Ferreyra |
| |
Institution: | 1. Georges Lema?tre Centre for Earth and Climate Research, Earth and Life Institute, Université catholique de Louvain, Louvain‐La‐Neuve, Belgium;2. Institut des sciences de la mer de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), Rimouski, QC, Canada;3. Laboratoire d'ECOlogie des SYstèmes Marins c?tiers (ECOSYM), UMR 5119 (Universités Montpellier 2 et 1– CNRS – IFREMER – IRD), Montpellier Cedex 05, France;4. Groupe BORéAS – Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski (UQAR), Rimouski, G5L 3A1, Canada;5. Instituto Antártico Argentino, Ciudad de Buenos Aires, Argentina;6. CONICET, Av. Rivadavia 1917 (C1033AAV), Buenos Aires, Argentina;7. LOCEAN‐IPSL, CNRS/IRD/MNHN, Sorbonne Universités (UPMC Paris 06), Paris, France |
| |
Abstract: | Intense regional warming was observed in the western Antarctic Peninsula (WAP) over the last 50 years. Here, we investigate the impact of climate change on primary production (PP) in this highly productive region. This study is based on temporal data series of ozone thickness (1972–2010), sea ice concentration (1978–2010), sea‐surface temperature (1990–2010), incident irradiance (1988–2010) and satellite‐derived chlorophyll a concentration (Chl‐a, 1997–2010) for the coastal WAP. In addition, we apply a photosynthesis/photoinhibition spectral model to satellite‐derived data (1997–2010) to compute PP and examine the separate impacts of environmental forcings. Since 1978, sea ice retreat has been occurring earlier in the season (in March in 1978 and in late October during the 2000s) while the ozone hole is present in early spring (i.e. August to November) since the early 1990s, increasing the intensity of ultraviolet‐B radiation (UVBR, 280–320 nm). The WAP waters have also warmed over 1990–2010. The modelled PP rates are in the lower range of previously reported PP rates in the WAP. The annual open water PP in the study area increased from 1997 to 2010 (from 0.73 to 1.03 Tg C yr?1) concomitantly with the increase in the production season length. The coincidence between the earlier sea ice retreat and the presence of the ozone hole increased the exposure to incoming radiation (UVBR, UVAR and PAR) and, thus, increased photoinhibition during austral spring (September to November) in the study area (from 0.014 to 0.025 Tg C yr?1). This increase in photoinhibition was minor compared to the overall increase in PP, however. Climate change hence had an overall positive impact on PP in the WAP waters. |
| |
Keywords: | ozone hole photoinhibition primary production regional warming sea ice seawater temperature ultraviolet radiation |
|
|