The Deepwater Horizon (DWH) oil spill likely affected ecosystem services in the Gulf of Mexico. To test this hypothesis, we configured a “Ecopath with Ecosim” model and quantified the effects of commercial fisheries and particulate organic carbon (POC) sequestration from 2004 to 2014, encompassing DWH. Read more “The Effect of the Deepwater Horizon Oil Spill on two Ecosystem Services in the Northern Gulf of Mexico”
Major oil spills immensely impact the environment and society. Coastal fishery-dependent communities are especially at risk as their fishing grounds are susceptible to closure because of seafood contamination threat. Read more “Predicting the Impact of Future Oil-Spill Closures on Fishery-Dependent Communities—A Spatially Explicit Approach”
Coupling between the atmosphere and ocean is scale-dependent. For example, in the mid-latitudes and at oceanic mesoscales (spatial scales between 10 and hundreds of kilometers), the air–sea interactions are driven by the oceanic variability, and the atmosphere responds to the changes in the sea surface temperature anomalies (SSTA), which are created by fast oceanic advection. This study explores these interactions, using a regional high-resolution atmosphere–ocean coupled model with a realistic atmospheric component and a semi-idealized oceanic model of a zonal flow. Read more “A Study of Mesoscale Air–Sea Interaction in the Southern Ocean with a Regional Coupled Model”
Abstract Major oil spills are catastrophic events that immensely affect the environment and society, yet determining their spatial extent is a highly complex task. During the Deepwater Horizon (DWH) blowout, ~149,000 km2 of the Gulf of Mexico (GoM) was covered by oil slicks and vast areas of the Gulf were closed for fishing. Read more “Invisible Oil Beyond the Deepwater Horizon Satellite Footprint”
The depletion of readily accessible oil reservoirs in conjunction with the demand for fossil fuels leads to the exploration and production of remote deposits, esp. in the deep sea. Operations at hard-to-reach locations far beyond atmospheric conditions are challenging and associated with elevated risk, Read more “Deep Sea Oil Spills-Investigating Droplet Size Distributions and Oil Fate in Experiments and Modeling”
Paleoclimate proxies suggest that modern droughts in North America pale in comparison to those of the Early to Mid-Holocene and the Medieval Warm Period. Modeling studies show that both tropical SSTs and local dust feedbacks modulate drought conditions over North America. We hypothesize that Read more “Evaluating the Roles of Tropical North Atlantic SSTs and Local and Remote Dust Impacts on North American Dought”
Cloud radiative feedbacks are disabled via “cloud-locking” in the Community Earth System Model, version 1.2 (CESM1.2), to result in a shift in El Niño–Southern Oscillation (ENSO) periodicity from 2–7 years to decadal time scales. We hypothesize that cloud radiative feedbacks may impact the periodicity in three ways: by
1) modulating heat flux locally into the equatorial Pacific subsurface through negative shortwave cloud feedback on sea surface temperature anomalies (SSTA),
2) damping the persistence of subtropical southeast Pacific SSTA such that the South Pacific meridional mode impacts the duration of ENSO events, or
3) controlling the meridional width of off-equatorial westerly winds, which impacts the periodicity of ENSO by initiating longer Rossby waves.
The result of cloud-locking in CESM1.2 contrasts that of another study, which found that cloud-locking in a different global climate model led to decreased ENSO magnitude across all time scales due to a lack of positive longwave feedback on the anomalous Walker circulation. CESM1.2 contains this positive longwave feedback on the anomalous Walker circulation, but either its influence on the surface is decoupled from ocean dynamics or the feedback is only active on interannual time scales. The roles of cloud radiative feedbacks in ENSO in other global climate models are additionally considered. In particular, it is shown that one cannot predict the role of cloud radiative feedbacks in ENSO through a multimodel diagnostic analysis. Instead, they must be directly altered.
Read more . . .
Middlemas, E. A., Clement, A. C., Medeiros, B., & Kirtman, B. (2019). Cloud Radiative Feedbacks and El Niño–Southern Oscillation, Journal of Climate, 32(15), 4661-4680. Retrieved Mar 29, 2021, from https://journals.ametsoc.org/view/journals/clim/32/15/jcli-d-18-0842.1.xml
Environmental sensitivity indices (ESIs) have long been used to identify coastal and shoreline resources particularly vulnerable to oil spills and ensuing mitigation measures. In the Gulf of Mexico, oil production by the United States and Mexico has increasingly focused on deepwater sources. As oil exploration and production continue further offshore, deepwater and open ocean pelagic resources increasingly become the focus of susceptibility to oil well blowouts. Methodologies are proposed to spatially quantify ESIs specifically for offshore living marine resources. A multi-attribute utility model is proposed to integrate biological resource sensitivity measures and measures of potential economic losses to define spatially explicit environmental sensitivity. Model sensitivity is examined using three weighting schemes for various environmental attributes. The relative environmental sensitivities of four simulated deepwater blowouts in the Gulf of Mexico were analyzed and compared. While differences were found between four oil well blowout scenarios in terms of the overall sensitivity and to the individual attributes, results were relatively insensitive to the weights assigned to various attributes. The uses of ESIs in optimizing oil production locations to minimize potential impacts on sensitive ecological resources and economic uses are discussed.
Read more . . .
Chancellor E., Murawski S.A., Paris C.B., Perruso L., Perlin N. (2020) Comparative Environmental Sensitivity of Offshore Gulf of Mexico Waters Potentially Impacted by Ultra-Deep Oil Well Blowouts. In: Murawski S. et al. (eds) Scenarios and Responses to Future Deep Oil Spills. Springer, Cham. https://doi.org/10.1007/978-3-030-12963-7_26
The ever-growing increase in deep-sea oil explorations in the Gulf of Mexico (GoM) has been raising concerns with regard to future oil spills. Major oil spills in the GoM such as the Deepwater Horizon (DWH 2010) and the Ixtoc 1 (1979) resulted in extensive pollution of the pelagic, sea-floor, and coastal ecosystems. Oil spill transport and fate models are effective tools that allow a spatiotemporally explicit reconstruction of oil spills while accounting for key processes such as evaporation, sedimentation, biodegradation, and dissolution. Oil transport data can be fed into an ecosystem model to help estimate system-scale changes in biodiversity and impacts on the delivery of ecosystem services. The increase in deep-sea oil-drilling endeavors warrants an evaluation of the potential outcomes and effects of oil spills. However, each spill scenario is a complex 4-D problem, spanning over wide spatiotemporal dimensions, affecting various media (water, sediments, coast, air); hence it is difficult to effectively evaluate the differences between various oil spill scenarios.
In the current chapter, we examine quantifiable variables, which enable effective comparison of the outcomes of four different scenarios: the DWH (DB_control), the DWH occurring during the fall (DB_Fall), east GoM scenario (DB_AL2), and west GoM scenario (DB_AL3). Specifically, we evaluate the total area and volume of oil-affected waters, the total water area and volume affected by toxic oil concentrations, the length of the shoreline affected by oil, and the total area of the sedimented oil. The oil transport model is coupled to Atlantis, a biogeochemical ecosystem model, to examine changes in the ecosystem biota. The depth and location of the oil vary with each scenario and so affect different habitats, species, and life stages. We consider relative impacts on pelagic and demersal food webs, shifts in age structure, changes in diet, and impacts on the sustainability of exploited species. We report the differences between the different oil spills and discuss their implications. Overall, the results differed slightly and not significantly between the four scenarios, ranked from most to least impactful: DB_AL2 > DB_control > DWH_Fall > DB_AL3. This work suggests that a “DWH” occurring at a different time or place in the GoM would result in an impact fairly similar to that that occurred during the actual DWH. This is relevant given the extensive petroleum-related activity in the GoM.
Read more . . .
Berenshtein I., Perlin N., Ainsworth C.H., Ortega-Ortiz J.G., Vaz A.C., Paris C.B. (2020) Comparison of the Spatial Extent, Impacts to Shorelines, and Ecosystem and Four-Dimensional Characteristics of Simulated Oil Spills. In: Murawski S. et al. (eds) Scenarios and Responses to Future Deep Oil Spills. Springer, Cham. https://doi.org/10.1007/978-3-030-12963-7_20
We are happy to announce the first seminar as part of the Lunch-bytes Seminar Series this semester at RSMAS. Lunch-bytes were a series of informal seminars that existed from 2010 to 2012, with a focus on various computing topics. Lunch-bytes aims to provide an informal forum for RSMAS students, researchers, and faculty to discuss and exchange knowledge on various computational tools, techniques, and programming languages. Read more “Lunch-Bytes Seminar 10/14/2015 RSMAS Campus”