Mississippi River Flood Waters That Reached The Gulf Stream

Distributions of physical, biological, and chemical parameters in Florida Keys coastal waters seaward of the reef track were surveyed on September 9 to 13, 1993, as part of a coordinated multidisciplinary study of surface transport processes. A band of low-salinity water was observed along the shoreward side of the Florida Current over the downstream extent of the survey from Miami to Key West. Biological and chemical indicators within the band, together with its large volume, satellite imagery, and a surface drifter trajectory suggested the recent Mississippi River flood as the source

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Transport of anomalous low-salinity waters from the Mississippi River flood of 1993 to the Straits of Florida

Recent field studies in the southern Straits of Florida revealed the existence of Mississippi River outflow embedded in the Florida Current and adjacent coastal waters. Surface thermosalinograph measurements for the period of 10–13 September 1993 indicated a band of low-salinity water measuring approximately 40 km wide and 30 m in depth extending from south of Key West to Miami, a distance of 260 km. Surface salinity values as low as 31 psu were found. The estimated volume of the band is approximately 33.3 × 10 10 m 3 for the Key West to Miami region, thereby requiring roughly 1.2 × 10 10 m 3 of fresh water to mix with oceanic waters to produce this low-salinity band. The only nearby, dynamically viable, source for such a large volume of fresh water is the Mississippi River during its flood stage in 1993. The proposed transport mechanism for the transport of flood waters from the shelf in the northeastern Gulf of Mexico to the Straits of Florida is via the Loop Current through entrainment. Salinity records from offshore C-MAN towers indicate that the low-salinity band persisted off the lower Florida Keys for approximately 3 months. The variability in the flow field in the southern Straits occurs in a 30–70 day band due to the meandering of the Florida Current and the subsequent formation, and propagation, of cyclonic gyres off the Dry Tortugas. This variability in the flow field had a clear affect on the evolution of the low-salinity band, as observed by the salinity records from the C-MAN towers. Because the band traveled as a lens in the upper 30 m of the water column and because its evolution was highly dependent on the variability within the Gulf Stream System, it was a good indicator of the mixing and exchange of offshore waters with shallow waters of the Florida reef tract and Florida Bay

Practical Points for the Software Development of an Agent-Based Model of a Coupled Human-Natural System

Modeling complex natural and human systems to support policy or management decision making is becoming increasingly common. The resulting models are often designed and implemented by researchers or domain experts with limited software engineering expertise. To help this important audience, we present our experience and share lessons learned from the design and implementation of an agent-based model of agricultural production systems in the Argentine Pampas, emphasizing the software engineering perspective. We discuss the model's design including the model classes; the activity diagram, and data flow; the package and folder layout; the use of design patterns; performance optimization; initialization approaches; the analysis of results; and model measurement, validation, and verification

An agent based model to simulate structural and land use changes in agricultural systems of the argentine pampas

The Argentine Pampas, one of the main agricultural areas in the world, recently has undergone significant changes in land use and structural characteristics of agricultural production systems. Concerns about the environmental and societal impacts of the changes motivated development of an agent-based model (ABM) to gain insight on processes underlying recent observed patterns. The model is described following a standard protocol (ODD). Results are discussed for an initial set of simplified simulations performed to understand the processes that generated and magnified the changes in the Pampas. Changes in the structure of agricultural production and land tenure seem to be driven by differences among farmers’ ability to generate sufficient agricultural income to remain in business. In turn, as no off-farm or credit is modeled, economic sustainability is tied to initial resource endowment (area cropped). Farmers operating small areas are economically unviable and must lease out their farms to farmers operating larger areas. This leads to two patterns: (a) a concentration of production (fewer farmers operating larger areas) and, (b) an increase in the area operated by tenants. The simulations showed an increase of soybean area, linked to the higher profitability of this crop. Despite the stylized nature of initial simulations, all emerging patterns are highly consistent with changes observed in the Pampas.Fil: Bert, Federico Esteban. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Podesta, Guillermo P.. University Of Miami. Rosenstiel School Of Marine Atmospheric Science. Meteorology And Physical Oceanography; Estados UnidosFil: Rovere, Santiago L.. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Menendez, Angel N.. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: North, Michael. Argonne National Laboratory; Estados UnidosFil: Tatara, Eric. Argonne National Laboratory; Estados UnidosFil: Laciana, Carlos E.. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Weber, Elke. Columbia University; Estados UnidosFil: Ruiz Toranzo, Fernando. Asociación Argentina de Consorcios Regionales de Experimentación Agrícola ; Argentin

The Influence of Loop Current Perturbations on the Formation and Evolution of Tortugas Eddies in the Southern Straits of Florida

Large cyclonic eddies on the northern edge of the Florida Current are the dominant mesoscale features within the southern Straits of Florida. The most prominent of these features is a quasi-stationary eddy that forms near the Dry Tortugas. Our observations, compiled from 3 years of advanced very high resolution radiometer measurements in the Straits of Florida and Gulf of Mexico, demonstrate a strong relationship between the generation of anticyclonic rings from the Gulf of Mexico Loop Current and the evolution of Tortugas eddies within the southern Straits of Florida. In six cases, Tortugas eddies evolve from cyclonic frontal eddies which form along the boundary of the Loop Current. The eddies remain stationary near the Dry Tortugas until they are impacted by an approaching Loop Current frontal eddy. The length of time an eddy spends near the Dry Tortugas is increased when the Loop Current sheds an anticyclonic ring. The involvement of a Loop Current frontal eddy in the ring-shedding process results in a delay in its, and hence the Tortugas eddy\u27s, downstream propagation. Results suggest that the lifetime of a Tortugas eddy can be as long as 140 days when a ring-shedding event occurs, or as short as 50 days in the absence of any ring-shedding events. Upon entering the Straits of Florida, the Tortugas eddies are deformed by the narrowing topography and shrink to approximately 55% of their original size as they propagated downstream. The shrinking of these eddies is accompanied by an accelerated translation from 5 km/d in the western Straits of Florida to 16 km/d in the east