A5049544123- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Marine and fisheries research
- Oceanographic and Atmospheric Processes
- Microbial Community Ecology and Physiology
- Fish Ecology and Management Studies
- Atmospheric and Environmental Gas Dynamics
- Isotope Analysis in Ecology
- Ocean Acidification Effects and Responses
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Calibration and Measurement Techniques
- Climate variability and models
- Arctic and Antarctic ice dynamics
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Mercury impact and mitigation studies
- Cryospheric studies and observations
- Marine Bivalve and Aquaculture Studies
- Geochemistry and Elemental Analysis
- Evolution and Genetic Dynamics
- Arctic and Russian Policy Studies
- Physiological and biochemical adaptations
- Wastewater Treatment and Nitrogen Removal
- Geomagnetism and Paleomagnetism Studies
Massachusetts Institute of Technology
2016-2025
Planetary Science Institute
2013-2025
Moscow Institute of Thermal Technology
2018-2024
United States Global Change Research Program
2023
National Oceanography Centre
2021
IIT@MIT
2020
University of New Mexico
2011
Lehigh University
2009-2010
Pennsylvania State University
2009-2010
Engineering Systems (United States)
2009-2010
A marine ecosystem model seeded with many phytoplankton types, whose physiological traits were randomly assigned from ranges defined by field and laboratory data, generated an emergent community structure biogeography consistent observed global distributions. The modeled organisms included types analogous to the cyanobacterium Prochlorococcus . Their distributions properties simultaneously correspond observations. This flexible representation of can be used explore relations between...
We synthesize estimates of the contemporary net air‐sea CO 2 flux on basis an inversion interior ocean carbon observations using a suite 10 general circulation models (Mikaloff Fletcher et al., 2006, 2007) and compare them to based new climatology difference partial pressure ( p ) (Takahashi 2008). These two independent reveal consistent description regional distribution annual mean sources sinks atmospheric for decade 1990s early 2000s with differences at level generally less than 0.1 Pg C...
There is increasing concern that accelerating environmental change attributed to human-induced warming of the planet may substantially alter patterns, distribution and intensity Harmful Algal Blooms (HABs). Changes in temperature, ocean acidification, precipitation, nutrient stress or availability, physical structure water column all influence productivity, composition, global range phytoplankton assemblages, but large uncertainty remains about how integration these climate drivers might...
Abstract Numerical models of ocean biogeochemistry are relied upon to make projections about the impact climate change on marine resources and test hypotheses regarding drivers past changes in ecosystems. In large areas ocean, iron availability regulates functioning ecosystems hence carbon cycle. Accordingly, our ability quantify impacts fluctuations cycling space time relies first achieving an appropriate representation modern cycle models. When distributions from 13 global compared against...
We present a model of diverse phytoplankton and zooplankton populations embedded in global ocean circulation model. Physiological ecological traits the organisms are constrained by relationships with cell size. The qualitatively reproduces distributions nutrients, biomass, primary productivity, captures power‐law relationship between size numerical density, which has realistic slopes −1.3 −0.8. use to explore structure marine ecosystems, highlighting importance both nutrient grazer controls....
Spatial diversity gradients are a pervasive feature of life on Earth. We examined global ocean circulation, biogeochemistry, and ecosystem model that indicated decrease in phytoplankton with increasing latitude, consistent observations many marine terrestrial taxa. In the modeled subpolar oceans, seasonal variability environment led to competitive exclusion slower growth rates lower diversity. The relatively weak seasonality stable subtropical tropical oceans enabled long time scales...
Rivers are an important source of mercury (Hg) to marine ecosystems. Based on analysis compiled observations, we estimate global present-day Hg discharges from rivers ocean margins 27 ± 13 Mmol a–1 (5500 2700 Mg a–1), which 28% reaches the open and rest is deposited margin sediments. Globally, amounts 30% atmospheric inputs. This larger than previously estimated due accounting for elevated concentrations in Asian variability offshore transport across different types estuaries. Riverine...
The shape of the productivity–diversity relationship (PDR) for marine phytoplankton has been suggested to be unimodal, that is, diversity peaking at intermediate levels productivity. However, there are few observations and little attempt understand mechanisms would lead such a planktonic organisms. Here we use ecosystem model together with community assembly theory explain unimodal PDR obtain global scale. positive slope from low productivity is due grazer control selective feeding, which...
The future response of marine ecosystem diversity to continued anthropogenic forcing is poorly constrained. Phytoplankton are a diverse set organisms that form the base ecosystem. Currently, ocean biogeochemistry and models used for climate change projections typically include only 2-3 phytoplankton types are, therefore, too simple adequately assess potential changes in plankton community structure. Here, we analyse complex model with 35 evaluate composition, turnover size structure over...
Abstract. The element silicon (Si) is required for the growth of silicified organisms in marine environments, such as diatoms. These consume vast amounts Si together with N, P, and C, connecting biogeochemical cycles these elements. Thus, understanding cycle ocean critical wider issues carbon sequestration by ocean's biological pump. In this review, we show that recent advances process studies indicate total inputs outputs, to from world ocean, are 57 % 37 higher, respectively, than previous...
Monitoring changes in marine phytoplankton is important as they form the foundation of food web and are crucial carbon cycle. Often Chlorophyll-a (Chl-a) used to track phytoplankton, since there global, regular satellite-derived estimates. However, satellite sensors do not measure Chl-a directly. Instead, estimated from remote sensing reflectance (RRS): ratio upwelling radiance downwelling irradiance at ocean's surface. Using a model, we show that RRS blue-green spectrum likely have stronger...
Abstract Mercury is a potent neurotoxin that poses health risks to the global population. Anthropogenic mercury emissions atmosphere are projected decrease in future due enhanced policy efforts such as Minamata Convention, legally-binding international treaty entered into force 2017. Here, we report development of comprehensive climate-atmosphere-land-ocean-ecosystem and exposure-risk model framework for its application project effects atmospheric emissions. Our results show accumulated...
Strong natural variability has been thought to mask possible climate-change-driven trends in phytoplankton populations from Earth-observing satellites. More than 30 years of continuous data were be needed detect a trend driven by climate change
Abstract Eight earth system models of intermediate complexity (EMICs) are used to project climate change commitments for the recent Intergovernmental Panel on Climate Change’s (IPCC’s) Fourth Assessment Report (AR4). Simulations run until year 3000 a.d. and extend substantially farther into future than conceptually similar simulations with atmosphere–ocean general circulation (AOGCMs) coupled carbon cycle models. In this paper following investigated: 1) commitment in response stabilized...
Abstract The Massachusetts Institute of Technology (MIT) Integrated Global System Model is used to make probabilistic projections climate change from 1861 2100. Since the model’s first were published in 2003, substantial improvements have been made model, and improved estimates probability distributions uncertain input parameters become available. new are considerably warmer than 2003 projections; for example, median surface warming 2091–2100 5.1°C compared 2.4°C earlier study. Many changes...
Carbon uptake by marine phytoplankton, and its export as organic matter to the ocean interior (i.e., "biological pump"), lowers partial pressure of carbon dioxide (pCO(2)) in upper facilitates diffusive drawdown atmospheric CO(2). Conversely, precipitation calcium carbonate planktonic calcifiers such coccolithophorids increases pCO(2) promotes outgassing "alkalinity pump"). Over past approximately 100 million years, these two fluxes have been modulated relative abundance diatoms...
We examine the interplay between ecology and biogeochemical cycles in context of a global three‐dimensional ocean model where self‐assembling phytoplankton communities emerge from wide set potentially viable cell types. consider complex solutions light resource competition theory. The emergent community structures ecological regimes vary across different physical environments ocean: Strongly seasonal, high‐nutrient regions are dominated by fast growing bloom specialists, while stable,...
The marine nitrogen fixing microorganisms (diazotrophs) are a major source of to open ocean ecosystems and predicted be limited by iron in most environments. Here we use global targeted proteomic analyses on key unicellular diazotroph Crocosphaera watsonii reveal large scale diel changes its proteome, including substantial variations concentrations metalloproteins involved fixation photosynthesis, as well nocturnal flavodoxin production. daily synthesis degradation enzymes coordination with...
We use an inverse method to estimate the global‐scale pattern of air‐sea flux natural CO 2 , i.e., component due carbon cycle that already existed in preindustrial times, on basis ocean interior observations dissolved inorganic ( DIC ) and other tracers, from which we Δ C gasex observed is gas exchange . employ a suite 10 different Ocean General Circulation Models (OGCMs) quantify error arising uncertainties modeled transport required link surface fluxes. The results contributing OGCMs are...