Aboozar Tabatabai | Rutgers, The State University of New Jersey (original) (raw)

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Papers by Aboozar Tabatabai

Handbook of Nanomaterials and Nanocomposites for Energy and Environmental Applications, 2021

Journal of Geophysical Research: Oceans, 2019

This study uses a neural network model trained with in situ data, combined with satellite data an... more This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large flux variability with highest fluxes in spring and lowest in fall as well as interannual flux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by all Mid-Atlantic Bight estuaries (1.2 Tg C/year), the DOC export (CB + DB) of 0.3 Tg C/year estimated here corresponds to 25% of the TOCexp. Spatial and temporal covariations of velocity and DOC concentration provide contributions to the flux, with larger spatial influence. Differences in the discharge of fresh water into the bays (74 billion m 3 /year for CB and 21 billion m 3 /year for DB) and their geomorphologies are major drivers of the differences in DOC fluxes for these two systems. Terrestrial DOC inputs are similar to the export of DOC at the bay mouths at annual and longer time scales but diverge significantly at shorter time scales (days to months). Future efforts will expand to the Mid-Atlantic Bight and Gulf of Maine, and its major rivers and estuaries, in combination with coupled terrestrial-estuarine-ocean biogeochemical models that include effects of climate change, such as warming and CO 2 increase. Plain Language Summary This study combines satellite data, field work observations, and statistical and numerical models to investigate the seasonal and interannual variability of dissolved organic carbon (DOC) export from two major East Coast estuaries, Chesapeake, and Delaware Bays. DOC is a food supplement, supporting growth of microorganisms and plays an important role in the global carbon cycle through the microbial loop, a marine pathway which incorporates DOC into the food chain. Using this novel methodology, we were able to better quantify the combined contribution of these estuaries to the East Coast carbon budget and contrast estuarine properties affecting the DOC export, such as riverine inputs, time scales of variability, and geomorphology. The combined DOC contribution of these two estuaries represents 25% of the total organic carbon exported by all Mid-Atlantic Bight (the coastal region running from Massachusetts to North Carolina) estuaries, and 27% of the total atmospheric carbon dioxide uptake in the Mid-Atlantic Bight.

2018 Ocean Sciences Meeting, Feb 13, 2018

Estuaries play an important role in the biogeochemistry of the global ocean, particularly the cyc... more Estuaries play an important role in the biogeochemistry of the global ocean, particularly the cycling of nitrogen (N) and carbon from natural and anthropogenic sources. Delaware Estuary is a temperate coastal plain estuary with a significant economic and ecological value. In this study, a coupled three-dimensional physical and biogeochemical (BGC) modeling framework based on the Regional Ocean Modeling System (ROMS) was utilized to investigate hydrodynamic and BGC characteristics in Delaware Estuary. Freshwater dynamics, transport pathways, and dispersal time scales are presented in Chapter 2. The model simulated water level, velocity, salinity, and temperature with a minimum correlation coefficient of 0.78, and a maximum centered root mean squared difference of 72% of one standard deviation of the observations. We found that total transport and mean age of freshwater were more sensitive to discharge changes on the Delaware side than the New Jersey side. The mean flushing time (FT) of freshwater was estimated to be 40-125 days depending on discharge. A method introduced to estimate spatial FT highlighted increased FT on the lower NJ flank with higher discharge. In Chapter 3, the physical model was used to investigate a large oyster mortality event in the upper reaches of Delaware Bay following Hurricane Irene and Tropical Storm Lee in 2011. Monthly mortality rates of 10-55% were associated with a continuous low salinity (<7 psu) exposure for longer than 20 days. Population recovery projections predicted that recovery would take approximately 10 years. The configuration, parametrization, and evaluation of a process-based coupled BGC model are presented in Chapter 4. The simulation during 2009-2011 reproduced physical and BGC fields such as dissolved inorganic nitrogen (DIN), dissolved organic nitrogen, particulate organic nitrogen, and dissolved oxygen within one standard deviation of long-term mean values. In Chapter 5, major monthly and annual N fluxes were quantified with a positive net ecosys [...]

Journal of Geophysical Research: Oceans

Estuarine, Coastal and Shelf Science, 2013

One predicted consequence of climate change is increasing variability of local weather extremes s... more One predicted consequence of climate change is increasing variability of local weather extremes such as the frequency and intensity of storms. In August and September of 2011, Hurricane Irene and Tropical Storm Lee generated extreme flooding in the Delaware River watershed that produced prolonged baywide low salinity and consequent historically-high mortalities for the oyster stock in the upper reaches of Delaware Bay. The dynamics, consequences, and projections for recovery from the anomalously high oyster mortality that occurred as a consequence are reported using a combination of physical modeling, field sampling, and metapopulation dynamics modeling. Monthly mortality of 10% and 55% on the upper bay beds (Arnolds and Hope Creek respectively) exceeded the longer-term average at those locations and was associated with a continuous low salinity (<7) exposure of greater than 20 days. Population recovery projections based on metapopulation modeling suggests that recovery will take approximately 10 years for the uppermost beds. Clear understanding of the circumstances leading to this high population-level impact on oysters is important because anticipated future conditions of increased storm frequency will intensify the challenge such events pose for the management of fishery and aquaculture resources, and the siting of restoration efforts.

Handbook of Nanomaterials and Nanocomposites for Energy and Environmental Applications, 2021

Journal of Geophysical Research: Oceans, 2019

This study uses a neural network model trained with in situ data, combined with satellite data an... more This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large flux variability with highest fluxes in spring and lowest in fall as well as interannual flux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by all Mid-Atlantic Bight estuaries (1.2 Tg C/year), the DOC export (CB + DB) of 0.3 Tg C/year estimated here corresponds to 25% of the TOCexp. Spatial and temporal covariations of velocity and DOC concentration provide contributions to the flux, with larger spatial influence. Differences in the discharge of fresh water into the bays (74 billion m 3 /year for CB and 21 billion m 3 /year for DB) and their geomorphologies are major drivers of the differences in DOC fluxes for these two systems. Terrestrial DOC inputs are similar to the export of DOC at the bay mouths at annual and longer time scales but diverge significantly at shorter time scales (days to months). Future efforts will expand to the Mid-Atlantic Bight and Gulf of Maine, and its major rivers and estuaries, in combination with coupled terrestrial-estuarine-ocean biogeochemical models that include effects of climate change, such as warming and CO 2 increase. Plain Language Summary This study combines satellite data, field work observations, and statistical and numerical models to investigate the seasonal and interannual variability of dissolved organic carbon (DOC) export from two major East Coast estuaries, Chesapeake, and Delaware Bays. DOC is a food supplement, supporting growth of microorganisms and plays an important role in the global carbon cycle through the microbial loop, a marine pathway which incorporates DOC into the food chain. Using this novel methodology, we were able to better quantify the combined contribution of these estuaries to the East Coast carbon budget and contrast estuarine properties affecting the DOC export, such as riverine inputs, time scales of variability, and geomorphology. The combined DOC contribution of these two estuaries represents 25% of the total organic carbon exported by all Mid-Atlantic Bight (the coastal region running from Massachusetts to North Carolina) estuaries, and 27% of the total atmospheric carbon dioxide uptake in the Mid-Atlantic Bight.

2018 Ocean Sciences Meeting, Feb 13, 2018

Estuaries play an important role in the biogeochemistry of the global ocean, particularly the cyc... more Estuaries play an important role in the biogeochemistry of the global ocean, particularly the cycling of nitrogen (N) and carbon from natural and anthropogenic sources. Delaware Estuary is a temperate coastal plain estuary with a significant economic and ecological value. In this study, a coupled three-dimensional physical and biogeochemical (BGC) modeling framework based on the Regional Ocean Modeling System (ROMS) was utilized to investigate hydrodynamic and BGC characteristics in Delaware Estuary. Freshwater dynamics, transport pathways, and dispersal time scales are presented in Chapter 2. The model simulated water level, velocity, salinity, and temperature with a minimum correlation coefficient of 0.78, and a maximum centered root mean squared difference of 72% of one standard deviation of the observations. We found that total transport and mean age of freshwater were more sensitive to discharge changes on the Delaware side than the New Jersey side. The mean flushing time (FT) of freshwater was estimated to be 40-125 days depending on discharge. A method introduced to estimate spatial FT highlighted increased FT on the lower NJ flank with higher discharge. In Chapter 3, the physical model was used to investigate a large oyster mortality event in the upper reaches of Delaware Bay following Hurricane Irene and Tropical Storm Lee in 2011. Monthly mortality rates of 10-55% were associated with a continuous low salinity (<7 psu) exposure for longer than 20 days. Population recovery projections predicted that recovery would take approximately 10 years. The configuration, parametrization, and evaluation of a process-based coupled BGC model are presented in Chapter 4. The simulation during 2009-2011 reproduced physical and BGC fields such as dissolved inorganic nitrogen (DIN), dissolved organic nitrogen, particulate organic nitrogen, and dissolved oxygen within one standard deviation of long-term mean values. In Chapter 5, major monthly and annual N fluxes were quantified with a positive net ecosys [...]

Journal of Geophysical Research: Oceans

Estuarine, Coastal and Shelf Science, 2013

One predicted consequence of climate change is increasing variability of local weather extremes s... more One predicted consequence of climate change is increasing variability of local weather extremes such as the frequency and intensity of storms. In August and September of 2011, Hurricane Irene and Tropical Storm Lee generated extreme flooding in the Delaware River watershed that produced prolonged baywide low salinity and consequent historically-high mortalities for the oyster stock in the upper reaches of Delaware Bay. The dynamics, consequences, and projections for recovery from the anomalously high oyster mortality that occurred as a consequence are reported using a combination of physical modeling, field sampling, and metapopulation dynamics modeling. Monthly mortality of 10% and 55% on the upper bay beds (Arnolds and Hope Creek respectively) exceeded the longer-term average at those locations and was associated with a continuous low salinity (<7) exposure of greater than 20 days. Population recovery projections based on metapopulation modeling suggests that recovery will take approximately 10 years for the uppermost beds. Clear understanding of the circumstances leading to this high population-level impact on oysters is important because anticipated future conditions of increased storm frequency will intensify the challenge such events pose for the management of fishery and aquaculture resources, and the siting of restoration efforts.