Climate Commons^™

Applications Of Satellite Geodesy In Environmental And Climate Change, Qian Yang

USF Tampa Graduate Theses and Dissertations

Satellite geodesy plays an important role in earth observation. This dissertation presents three applications of satellite geodesy in environmental and climate change. Three satellite geodesy techniques are used: high-precision Global Positioning System (GPS), the Gravity Recovery and Climate Experiment (GRACE) and Interferometric Synthetic Aperture Radar (InSAR). In the first study, I use coastal uplift observed by GPS to study the annual changes in mass loss of the Greenland ice sheet. The data show both spatial and temporal variations of coastal ice mass loss and suggest that a combination of warm atmospheric and oceanic condition drove these variations. In the second …

Understanding Climate Change And Sea Level: A Case Study Of Middle School Student Comprehension And An Evaluation Of Tide Gauges Off The Panama Canal In The Pacific Ocean And Caribbean Sea, Juan Carlos Millan-Otoya

USF Tampa Graduate Theses and Dissertations

The present study had two main objectives. The first was to determine the degree of understanding of climate change, sea level and sea level rise among middle school students. Combining open-ended questions with likert-scaled questions, we identified student conceptions on these topics in 86 students from 7^th and 8^th grades during 2012 and 2013 before and after implementing a Curriculum Unit (CU). Additional information was obtained by adding drawings to the open-ended questions during the second year to gauge how student conceptions varied from a verbal and a visual perspective. Misconceptions were identified both pre- and post-CU among …

A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary

USF Tampa Graduate Theses and Dissertations

Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ¹⁵N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …

Ocean Forcing Of Quaternary East Antarctic Ice Sheet Evolution: An Ice-Proximal Sedimentary Perspective, Michelle E. Guitard

USF Tampa Graduate Theses and Dissertations

Antarctica and the Southern Ocean play a critical role in Earth’s climate system. Antarctica’s ice sheets contain enough ice to raise global sea level by ~58 m, and the Southern Ocean distributes climate signals and nutrients to the major ocean basins and the deep ocean. Antarctica’s largest ice sheet, the East Antarctic Ice Sheet (EAIS), was considered stable compared to those in West Antarctica and the Antarctic Peninsula because it was thought to be grounded above sea level. However, subglacial topography now reveals vast submarine basins and measurements of ice velocity in the Pacific sector indicate marine-terminating outlet glacier thinning …

Timing Of Svalbard/Barents Sea Ice Sheet Decay During The Last Glacial Termination, Tasha Snow

USF Tampa Graduate Theses and Dissertations

The Arctic and North Atlantic underwent significant climactic changes since the Last Glacial Maximum (25,000 years before present (1950 AD); ka BP), but offsets in the timing of events between the two regions are poorly constrained due to age model uncertainties that arise from changing radiocarbon reservoir ages. Here, we use a relatively high-resolution, multi-proxy stable isotope and sedimentologic dataset from Eastern Fram Strait (ODP Leg 162 Site 986) marine sediments to constrain the timing of Svalbard/Barents Sea Ice Sheet decay and infer deglacial reservoir ages over the last 30 ka. We use magnetic susceptibility, inorganic and organic carbon, foraminiferal …

A Multi-Proxy Approach To Understanding Abrupt Climate Change And Laurentide Ice Sheet Melting History Based On Gulf Of Mexico Sediments, Clare Carlisle Williams

USF Tampa Graduate Theses and Dissertations

During the last deglaciation (ca. 24-10 ka thousand years ago (ka)), the North American Laurentide Ice Sheet (LIS) was a major source of meltwater to the Arctic Ocean, North Atlantic Ocean, and the Gulf of Mexico (GOM), and it is hypothesized that meltwater routing played an important role in regulating Late Quaternary millennial-scale climate variability, via its influence on Atlantic Meridional Overturning Circulation (AMOC). For example, the meltwater routing hypothesis predicts that a rerouting of meltwater from the GOM to the North Atlantic and/or Arctic Oceans resulted in a decrease of North Atlantic Deep Water (NADW) formation and subsequent cooling …

Flexible Urban Water Distribution Systems, Seneshaw Amare Tsegaye

USF Tampa Graduate Theses and Dissertations

With increasing global change pressures such as urbanization and climate change, cities of the future will experience difficulties in efficiently managing scarcer and less reliable water resources. However, projections of future global change pressures are plagued with uncertainties. This increases the difficulty in developing urban water systems that are adaptable to future uncertainty.

A major component of an urban water system is the distribution system, which constitutes approximately 80-85% of the total cost of the water supply system (Swamee and Sharma, 2008). Traditionally, water distribution systems (WDS) are designed using deterministic assumptions of main model input variables such as water …

Mangroves, Mudbanks And Seawalls: Political Ecology Of Adaptation To Sea Level Rise In Suriname, Ravic Nijbroek

USF Tampa Graduate Theses and Dissertations

This study seeks to understand how global discourses of sea level rise (SLR) and mangrove ecology influence national climate change adaptation policy to reduce coastal vulnerability in Suriname. A majority of the Surinamese population lives along the low elevation coastal zone and is highly exposed to projected SLR. Failure by the international community to reach agreement on climate change mitigation means that vulnerable coastal communities must adapt. The Suriname coast is predominantly shaped by mudbanks and mangroves which together provide protection against coastal erosion and trap sediments resulting in coastal accretion. Knowledge claims of mangrove ecology and utility in SLR …

Stable Isotope Studies Of Paleoenvironment And Paleoclimate From Afar, Ethiopia, Zelalem K. Bedaso

USF Tampa Graduate Theses and Dissertations

The sedimentary deposits of the Hadar Formation at Dikika and the Mount Galili Formation at Galili preserve a wealth of paleoenvironmental and paleoclimatic records spanning the last 5.29 Ma. Stable carbon and oxygen isotopic compositions of herbivore tooth enamel were analyzed for more than 600 specimens of 15 different taxa from 10 stratigraphic intervals. The application of carbon and oxygen isotopes here aims principally at reconstructing shifts in the relative abundance of C₄ grasses, and its implications for climate indicators including temperature, aridity, and seasonality. The full range of δ¹³C_enamel values throughout the Plio-Pleistocene signifies a …

Palaeoclimatic Significance Of Perennial Ice Accumulations In Caves: An Example From Scarisoara Ice Cave, Romania, Aurel Persoiu Tiritu

USF Tampa Graduate Theses and Dissertations

Stable isotopes in ice cores drilled in the polar and high-mountain region have been used intensively to reconstruct past climatic changes and atmospheric dynamics. However, no similar studies have been conducted on perennial ice accumulations in caves due to a limited understanding of the links between the external and cave environments, and the way in which the climatic signal can be recorded by the cave ice.

In this thesis, we successfully designed and build a research methodology for the reconstruction of past climatic changes based on perennial ice accumulation in caves, using as example the Scarisoara Ice Cave, Romania. The …