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Spatiotemporal variability and long-term trends of ocean acidification in the California Current System
(2012)Biogeosciences DiscussionsDue to seasonal upwelling, the upper ocean waters of the California Current System (CCS) have a naturally low pH and aragonite saturation state (Ωarag), making this region particularly prone to the effects of ocean acidification. Here, we use the Regional Oceanic Modeling System (ROMS) to conduct preindustrial and transient (1995–2050) simulations of ocean biogeochemistry in the CCS. The transient simulations were forced with increasing ...Working Paper -
Global ocean carbon uptake: Magnitude,variability and trends
(2012)Biogeosciences DiscussionsEstimates of the anthropogenic global-integrated sea-air carbon dioxide (CO2) fluxfrom 1990 to 2009, based on different models and measurements, range from−1.4to−2.6 PgC yr−1. The median values of anthropogenic CO2for each method showbetter agreement and are:−1.9 for Pg C yr−1for numerical ocean general circulation hind cast models (OGCMs) with parameterized biogeochemistry;−2.1 PgC yr−1for at-mospheric inverse models;−1.9 PgC yr−1for ...Working Paper -
Trends and drivers of regional sources and sinks of carbon dioxide over the past two decades
(2013)Biogeosciences DiscussionsThe land and ocean absorb on average just over half of the anthropogenic emissions of carbon dioxide (CO2) every year. These CO2 "sinks" are modulated by climate change and variability. Here we use a suite of nine dynamic global vegetation models (DGVMs) and four ocean biogeochemical general circulation models (OBGCMs) to estimate trends driven by global and regional climate and atmospheric CO2 in land and oceanic CO2 exchanges with the ...Working Paper -
Projected decreases in future marine export production: The role of carbon fluxes through the upper ocean ecosystem
(2015)Biogeosciences DiscussionsAccurate projections of marine particle export production (EP) are crucial for predicting the response of the marine carbon cycle to climate change, yet models show a wide range in both global EP and their responses to climate change. This is, in part, due to EP being the net result of a series of processes, starting with net primary production (NPP) in the sunlit upper ocean, followed by the formation of particulate organic matter and ...Working Paper -
Global ocean storage of anthropogenic carbon
(2012)Biogeosciences Discussionshe global ocean is a significant sink for anthropogenic carbon (Cant), absorbing roughly a third of human CO2 emitted over the industrial period. Robust estimates of the magnitude and variability of the storage and distribution of Cant in the ocean are therefore important for understanding the human impact on climate. In this synthesis we review observational and model-based estimates of the storage and transport of Cant in the ocean. We ...Working Paper -
Phytoplankton competition during the spring bloom in four Plankton Functional Type Models
(2012)Biogeosciences DiscussionsWe investigated the mechanisms of phytoplankton competition during the spring bloom,one of the most dramatic seasonal events in lower-trophic level ecosystems, in fourstate-of-the-art Plankton Functional Type (PFTs) models: PISCES, NEMURO, Plank-TOM5 and CCSM-BEC. In particular, we investigated the relative importance of dif-5ferent ecophysiological processes on the determination of the community structure,focusing both on the bottom-up ...Working Paper -
The distribution, dominance patterns and ecological niches of plankton functional types in Dynamic Green Ocean Models and satellite estimates
(2013)Biogeosciences DiscussionsWe compare the spatial and temporal representation of phytoplankton functional types (pPFTs) in four different Dynamic Green Ocean Models (DGOMs; CCSM-BEC, NEMURO, PISCES and PlankTOM5) to derived phytoplankton distributions from two independent satellite estimates, with a particular focus on diatom distributions. Global annual mean surface biomass estimates for diatoms vary between 0.23 mmol C m−3 and 0.77 mmol C m−3 in the models, and ...Working Paper -
MAREDAT: towards a world atlas of MARine Ecosystem DATa
(2012)Earth System Science Data DiscussionsWe present a summary of biomass data for 11 Plankton Functional Types (PFTs)plus phytoplankton pigment data, compiled as part of the MARine Ecosystem biomassDATa (MAREDAT) initiative. The goal of the MAREDAT initiative is to provide global gridded data products with coverage of all biological components of the global ocean ecosystem. This special issue is the first step towards achieving this. The PFTs presented here include picophytoplankton, ...Working Paper