Oceanography and Atmospheric Sciences and Meteorology Commons^™

Can Mud (Silt And Clay) Concentration Be Used To Predict Soil Organic Carbon Content Within Seagrass Ecosystems?, Oscar Serrano, Paul Lavery, Carlos M. Duarte, Gary A. Kendrick, Antoni Calafat, Paul York, Andy Steven, Peter Macreadie

Research Datasets

The database compiles published data (in Serrano et al. 2016, Biogeosciences, doi:10.5194/bg-2015-598) on biogeochemical characteristics (%organic carbon, stable carbon isotopes and mud content) of sediments underneath seagrass meadows and bare sediments in Australia and Spain. Details on habitat characteristics (latitude/longitude, water depth, seagrass species and geomorphology) and sediment depth are also provided for each location studied. The data set includes 1345 data entries from 100 sediment cores, encompassing 10 seagrass species in estuarine and coastal habitats.

Impact Of Mooring Activities On Carbon Stocks In Seagrass Meadows, Oscar Serrano, Radhiyah Ruhon, Paul S. Lavery, Gary A. Kendrick, Sharyn Hickey, Pere Masque, Ariane Arias-Ortiz, Andy Steven, Carlos M. Duarte

Research Datasets

The database compiles published data (in Serrano et al. 2016, Scientific Reports, in press) on biogeochemical characteristics (density, organic carbon, calcium carbonate, stable carbon isotopes and sediment grain size) of sediments underneath seagrass meadows and adjacent un-vegetated patches after mooring disturbances in Rottnest Island (Perth, Western Australia). The dataset compiles data on biogeochemical sediment characteristics for a total of 16 cores, 50 cm-long (4 cores from seagrass meadows and 4 cores from adjacent bare sediments at Thompson Bay, and 4 cores from seagrass meadows and 4 cores from adjacent bare sediments at Stark Bay).

Seagrass Sediments Reveal The Long-Term Deterioration Of An Estuarine Ecosystem, Oscar Serrano, Paul S. Lavery, Pere Masque, Karina Inostroza, James Bongiovanni, Carlos Duarte

Research Datasets

The database compiles published data (in Serrano et al. 2016, Global Change Biology, doi:10.1111/gcb.13195) on temporal trends in biogeochemical variables in the Posidonia australis sediment core from Oyster Harbour, Western Australia. The core studied encompasses the last 500 years of history. Data on dry bulk density, carbonate content, sedimentso.

Variability In The Carbon Storage Of Seagrass Habitats And Its Implications For Global Estimates Of Blue Carbon Ecosystem Service, Paul Lavery, Miguel-Angel Mateo, Oscar Serrano, Mohammad Rozaimi

Research Datasets

The dataset compiles published data (in Lavery et al. 2013, PLoS ONE 8(9): e73748. doi:10.1371/journal.pone.0073748) on biogeochemical variables (organic matter, organic carbon and CO3 contents, and stable carbon isotope signatures of the organic carbon) in sediment core from seagrass meadows in Australia. The cores studied were up to 29 cm long, and ecompass tropical, subtropical and temperate seagrass meadows in intertidal and subtidal habitats.

Predicting The Impact Of Future Climate On Ecologically Important Macroalgae, Charlie Phelps

Theses: Doctorates and Masters

Macroalgae play an important role in coastal reef systems and are often referred to as ecosystem engineers. They serve as primary producers, supporting a diverse range of organisms, and are a sink for atmospheric CO2. Water acidification and ocean warming caused by anthropogenic activities are affecting many marine flora and fauna, potentially impacting the physical and chemical performance of macroalgae and the consumption rates of associated herbivores. Many studies have focused on ocean acidification or ocean warming individually but there is an overall lack of research investigating the combined effects and the ensuing repercussions on consumer-prey relationships.

Three species of …

Intermittency Of Gravity Wave Momentum Flux In The Mesopause Region Observed With An All-Sky Airglow Imager, Bing Cao, Alan Z. Liu

Publications

The intermittency of gravity wave momentum flux (MF) near the OH airglow layer (∼87 km) in the mesopause region is investigated for the first time using observation of all-sky airglow imager over Maui, Hawaii (20.7∘N, 156.3∘W), and Cerro Pachón, Chile (30.3∘S, 70.7∘W). At both sites, the probability density function (pdf) of gravity wave MF shows two distinct distributions depending on the magnitude of the MF. For MF smaller (larger) than ∼16 m2 s−2 (0.091 mPa), the pdf follows a lognormal (power law) distribution. The intermittency represented by the Bernoulli proxy and the percentile ratio shows that gravity waves have higher …

First Measurement Of Horizontal Wind And Temperature In The Lower Thermosphere (105–140 Km) With A Na Lidar At Andes Lidar Observatory, Alan Liu, Yafang Guo, Fabia A. Vargas, Gary Swenson,

Publications

We report the first measurement of nighttime atmospheric temperature and horizontal wind profiles in the lower thermosphere up to 140 km with the Na lidar at Andes Lidar Observatory in Cerro Pachón, Chile (30.25°S, 70.74°W), when enhanced thermospheric Na was observed. Temperature and horizontal wind were derived up to 140 km using various resolutions, with the lowest resolution of about 2.7 hr and 15 km above 130 km. Thus, the measurements span 60 km in vertical, more than double the traditional 25 km. On the night of 17 April 2015, the horizontal wind magnitude in the thermosphere exceeds 150 ms−1, …

Evidence Of The Excitation Of A Ring-Like Gravity Wave In The Mesosphere Over The Andes Lidar Observatory, Fabio Vargas, Gary Swenson,, Alan Liu, Dominique Pautet

Publications

On 23 March 2012, our all-sky imager recorded a concentric, ring-like gravity wave pattern. The wave arose within the area covered by images of both OH and O(1S) nightglow emissions taken at the Andes Lidar Observatory (ALO), Chile (30.3°S, 70.7°W). We have estimated the observed and intrinsic parameters of the event and located the wave source within the lower mesosphere altitude range using a reverse ray tracing method. By the analysis of GOES and LIS satellite images, we have not found evidence of neither convective nor lightning activity nearby ALO, indicating that the source of the ring-like wave …

Turbulence And Overturning Gravity Wave Effects Deduced From Mesospheric Na Density Between 100-105 Km At Andes Lidar Observatory, Chile, Alan Z. Liu, Channing P. Philbrick, Gary R. Swenson, Fabio A. Vargas

Publications

Atmospheric turbulence activity in the mesosphere and lower thermosphere (MLT) region is determined from narrowband Na lidar measurements obtained over 27 nights between 85-105 km altitude at the Andes Lidar Observatory (ALO) in Cerro Pachón, Chile (30.3ºS, 70.7ºW). Photocount perturbations in the applicable spectral subrange are used as a tracer of turbulence activity. Mean altitude profiles reveal a log-scale linear increase in turbulence perturbation amplitude above 95 km. The observed trend is compared against global mean constituent transport profiles derived from SABER and SCIAMACHY satellite borne measurements.

Chemical Transport Of Neutral Atmospheric Constituents By Waves And Turbulence: Theory And Observations, Chester S. Gardner, Alan Liu

Publications

Vertical chemical transport occurs when the density fluctuations of a species, caused by perturbations of its chemistry, are strongly correlated with the vertical wind fluctuations. Chemical transport can exceed dynamical and eddy transport of chemically active species. Theoretical expressions are derived for the chemical fluxes and transport velocities and used to characterize the vertical transport of mesospheric O3 and meteoric Na and Fe between 85 and 100 km. Chemical transport is dependent on the intrinsic frequency spectrum of the temperature fluctuations and on the chemical cutoff periods of the species. For O3 only high-frequency fluctuations contribute to chemical transport because …

Southern Hemisphere Summer Mesopause Responses To El Niño–Southern Oscillation, Tao Li, Natalia Calvo, Jia Yue, James Russell Iii, Alan Liu

Publications

In the Southern Hemisphere (SH) polar region, satellite observations reveal a significant uppermesosphere cooling and a lower-thermosphere warming during warm ENSO events in December. An opposite pattern is observed in the tropical mesopause region. The observed upper-mesosphere cooling agrees with a climate model simulation. Analysis of the simulation suggests that enhanced planetary wave (PW) dissipation in the Northern Hemisphere (NH) high-latitude stratosphere during El Niño strengthens the Brewer–Dobson circulation and cools the equatorial stratosphere. This increases the magnitude of the SH stratosphere meridional temperature gradient and thus causes the anomalous stratospheric easterly zonal wind and early breakdown of the SH …

Examining The Potential Impact Of Swot Observations In An Ocean Analysis-Forecasting System, Matthew Carrier, Hans E. Ngodock, Scott R. Smith, Innocent Souopgui, Brent Bartels

Faculty Publications

NASA's Surface Water and Ocean Topography (SWOT) satellite, scheduled for launch in 2020, will provide observations of sea surface height anomaly (SSHA) at a significantly higher spatial resolution than current satellite altimeters. This new observation type is expected to improve the ocean model mesoscale circulation. The potential improvement that SWOT will provide is investigated in this work by way of twin-data assimilation experiments using the Navy Coastal Ocean Model four-dimensional variational data assimilation (NCOM-4DVAR) system in its weak constraint formulation. Simulated SWOT observations are sampled from an ocean model run (referred to as the "nature" run) using an observation-simulator program …

Sea Surface Temperature Variability In The Central-Western Mediterranean Sea During The Last 2700 Years: A Multi-Proxy And Multi-Record Approach, Merce Cisneros, Isabel Cacho, Jaime Frigola, Miquel Canals, Pere Masque, Belen Martrat, Marta Casado, Joan Grimalt, Leopoldo Pena, Giulia Margaritelli, Fabrizio Lirer

Research outputs 2014 to 2021

This study presents the reconstructed evolution of sea surface conditions in the central-western Mediterranean Sea during the late Holocene (2700 years) from a set of multi-proxy records as measured on five short sediment cores from two sites north of Minorca (cores MINMC06 and HER-MC-MR3). Sea surface temperatures (SSTs) from alkenones and Globigerina bulloides Mg / Ca ratios are combined with δ¹⁸O measurements in order to reconstruct changes in the regional evaporation–precipitation (E–P) balance. We also revisit the G. bulloides Mg / Ca–SST calibration and re-adjusted it based on a set of core-top measurements from the western Mediterranean Sea. …

Fine Particulate Air Pollution And Hospital Emergency Room Visits For Respiratory Disease In Urban Areas In Beijing, China, In 2013, Qin Xu, Xia Li, Shuo Wang, Chao Wang, Fangfang Huang, Qi Gao, Lijuan Wu, Lixin Tao, Jin Guo, Wei Wang, Xiuhua Guo

Research outputs 2014 to 2021

Background

Heavy fine particulate matter (PM_2.5) air pollution occurs frequently in China. However, epidemiological research on the association between short-term exposure to PM_2.5 pollution and respiratory disease morbidity is still limited. This study aimed to explore the association between PM_2.5 pollution and hospital emergency room visits (ERV) for total and cause-specific respiratory diseases in urban areas in Beijing. Methods Daily counts of respiratory ERV from Jan 1 to Dec 31, 2013, were obtained from ten general hospitals located in urban areas in Beijing. Concurrently, data on PM_2.5 were collected from the Beijing Environmental Protection Bureau, …

Responses Of Marine Organisms To Climate Change Across Oceans, Elvira S. Poloczanska, Michael T. Burrows, Christipher J. Brown, Jorge G. Molinos, Benjamin S. Halpern, Ove Hoegh-Guldberg, Carrie V. Kappel, Philippa J. Moore, Anthony Richardson, David S. Schoeman, William J. Sydeman

Research outputs 2014 to 2021

Climate change is driving changes in the physical and chemical properties of the ocean that have consequences for marine ecosystems. Here, we review evidence for the responses of marine life to recent climate change across ocean regions, from tropical seas to polar oceans. We consider observed changes in calcification rates, demography, abundance, distribution, and phenology of marine species. We draw on a database of observed climate change impacts on marine species, supplemented with evidence in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We discuss factors that limit or facilitate species' responses, such as fishing pressure, the …

Laboratory Measurements Of Contact Nucleation By Mineral Dusts, Bacteria, And Soluble Salts, Joseph Niehaus

Dissertations, Master's Theses and Master's Reports

We present results from experiments that emulate atmospheric ice nucleation by aerosols. We have refined experimental techniques to improve measurements of ice forming nuclei in the contact mode. Our results show that atmospherically relevant dusts such as kaolinite, feldspar, rhyolitic ash, and Arizona Test Dust have efficiencies in the contact mode that are higher than the immersion mode. Experiments with bacteria show that biological material has the potential to contribute significantly to ice concentrations, but has large variability. By choosing a soluble compound as an ice nucleus, we are able to place bounds on the timescale for contact freezing and …

Testing Lidar-Radar Derived Drop Sizes Against In Situ Measurements, Mary Amanda Shaw

Dissertations, Master's Theses and Master's Reports

How well can a co-located lidar and radar retrieve a drop size distribution in drizzling clouds? To answer, we mimic scattering from a laboratory cloud to retrieve a lidar-radar effective diameter. Using only the shape parameter of the gamma-distributed drops, the mean diameter of the drops can be estimated from lidar-radar effective diameter to within a few percent of the true mean. In practice, the shape parameter of the gamma distribution is not known. To set bounds, mean diameters were calculated from the lidar-radar effective diameter using a range of in situ measured gamma shape parameters. The estimated means varied …

Interactions Among Hydrology, Sediment And Vegetation In Accreting Wax Lake Delta: Physical And Biogeochemical Implications For Coastal Louisiana Restoration, Courtney Erin Elliton

LSU Master's Theses

River discharge pulses, wind, waves, tides, and the presence of dense vegetation are factors that interact and regulate the transport and retention of sediment in coastal regions. In particular, vegetation structural and physiognomic traits promote fine sediment trapping during tidal and river flow, maintaining the balance between soil elevation and relative sea level rise on coastline stability and land building. Mike Island, located within Wax Lake Delta, Louisiana, USA, is part of a deltaic system created by a man-made freshwater diversion (1941) and one of few coastal areas where land is expanding in coastal Louisiana as result of pulsing river …

The Role Of Upper Ocean Heat Content And Sea Surface Temperature On Northeast Pacific Hurricane Evolution During Average And Active Years, Victoria Lauren Ford

LSU Master's Theses

Upon comparison to typical neutral-ENSO conditions in the Northeast Pacific Ocean, the 2014 hurricane season has been identified as highly anomalous in both tropical cyclone frequency and intensity. This thesis seeks to investigate the influence of sea surface temperatures (SSTs) and upper ocean heat content (UOHC), defined as the excess of heat present above 26°C, upon the upper ocean thermal structure, mesoscale features, and anomalies that led to an active hurricane season in the Northeast Pacific. The 2012 Northeast Pacific hurricane season was selected as a ‘normal’ season to fully quantify the anomalous 2014 hurricane season. Data sets utilized in …

Everglades Mangrove Forest Response To Large-Scale Disturbance: Long-Term Assessment Of Structural And Functional Properties, Tess Marie Danielson

LSU Master's Theses

The impact (i.e., defoliation and mortality) associated with large-scale natural disturbance events is capable of significantly altering ecosystem structure (e.g., biomass) and function (e.g., productivity) in mangrove wetlands. These pulsing events provide an opportunity to assess ecosystem resilience (i.e., recovery to pre-disturbance conditions) by evaluating the immediate and long-term ecosystem response trajectory (i.e., disturbance magnitude, recovery time). I hypothesized that 1) there are specific properties of disturbance that can be characterized and fit to a general forest disturbance model, and that 2) a mangrove forest recovery trajectory (i.e. recovery duration and rate) is dependent on the disturbance magnitude and initial …