C065-04
Altered Ice Algal Phenology In A Changing Cryosphere
Altered Ice Algal Phenology In A Changing Cryosphere
Wednesday, 16 December 2020: 05:39
Virtual
Abstract:
The Arctic decline in the past decades is being well reproduced by CMIP5 and CMIP6 models (Tedesco et al 2019; Tedesco et al In preparation). In contrast, CMIP6 models largely underestimate the Antarctic sea-ice extent trend for all months (Vichi et al In preparation). Also, while the decline of Artic sea ice is being undergoing largely on a pan-Arctic scale (Tedesco et al In preparation), we will show that regional and seasonal differences in the Southern Ocean are often represented by models in a opposite way (Vichi et al In preparation).
Recent studies (Tedesco et al 2019) combining sea-ice biogeochemical modelling with CMIP5 model data present future scenarios of largely altered Arctic ice algal primary production and phenology. The expected increase in production turns limited by the diminished seasonal areas, while blooms in areas with expanding first-year ice become limited by narrower growth windows. Disruption of the seasonality of the algal blooms have already created mismatches for the timing of zooplankton production, which in turn may lead to the possibility of phenological uncoupling with secondary and tertiary consumers. We will deliver a set of predictions for key productivity indicators, and propose a semi-quantitative model of the expected future changes in primary production in the ice-covered Arctic Ocean.
The large disagreement between model simulations and satellite observations of Antarctic sea-ice extent trends raises the fundamental question whether CMIP6 models can be used for hindcasts and projections of ice algae dynamics as done for the Arctic. While an understanding of the discrepancies is a fundamental step forward, climate models remain the only available tools to quantitatively assess long-term changes in sea-ice biogeochemical dynamics also in the Southern Ocean.
Recent studies (Tedesco et al 2019) combining sea-ice biogeochemical modelling with CMIP5 model data present future scenarios of largely altered Arctic ice algal primary production and phenology. The expected increase in production turns limited by the diminished seasonal areas, while blooms in areas with expanding first-year ice become limited by narrower growth windows. Disruption of the seasonality of the algal blooms have already created mismatches for the timing of zooplankton production, which in turn may lead to the possibility of phenological uncoupling with secondary and tertiary consumers. We will deliver a set of predictions for key productivity indicators, and propose a semi-quantitative model of the expected future changes in primary production in the ice-covered Arctic Ocean.
The large disagreement between model simulations and satellite observations of Antarctic sea-ice extent trends raises the fundamental question whether CMIP6 models can be used for hindcasts and projections of ice algae dynamics as done for the Arctic. While an understanding of the discrepancies is a fundamental step forward, climate models remain the only available tools to quantitatively assess long-term changes in sea-ice biogeochemical dynamics also in the Southern Ocean.