Difference in the Past Trends and Future Projections of Marine Primary Productivity in between the CMIP6 and CMIP5 Models
Abstract
Marine primary production is a key process in the marine ecosystem, central to the aquatic food web and the global biogeochemical cycles. Recent decades have experienced an unprecedented warming of the Earths climate, with the oceans accounting for 93% of this increased energy uptake. Amongst the tropical oceans, the Indian Ocean has undergone the largest warming (0.15 C/decade) in the ocean surfacewith projections of a stronger warming (>1 C) by 2070 and (>1.5 C) by 2100 across the CMIP5 models. In the low-latitude regions, a warmer ocean surface enhances the ocean stratification thereby reducing the vertical mixing and inhibiting the nutrients (required for photosynthesis) into the sunlit zone of the ocean. This limits the marine primary production subsequently impacting the biodiversity of the ocean. The CMIP5 earth system models (ESMs) suggested a decline of 30% in the marine primary productivity of the most biologically active region of the basinthe western Indian Ocean (left panel of Figure)driven by the ocean surface warming, and also projects a further decline in the primary productivity and its limiting nutrients by 2100. The CMIP6 models are improved biogeochemical ESMs and are expected to present a more realistic representation of our changing climate (Figure). Hence, this study evaluates the trends and future simulations of CMIP6 and provide a comparison with CMIP5 models to understand the key improvements in the current generation of ESMs. This is necessary to understand the changes and variability in biophysical indicators in response to the changing physical variables with a changing climate.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.A45F1910M