Oceanography and Atmospheric Sciences and Meteorology Commons^™

Changes At The Edge: Trends In Sea Ice, Ocean Temperature And Ocean Color At The Northwest Atlantic/Southern Arctic Interface, Ashley V. York, Karen E. Frey, Luisa N.C. Young

Geography

Spatial and temporal trends of remotely sensed sea-ice cover, sea surface temperatures, chlorophyll-a concentration and primary production in the Baffin Bay, Davis Strait and Labrador Sea were analyzed for the 1998-2017 period. We found spatial variability in the trends of these cryospheric, biologic and oceanographic phenomena. For example, in the northern Baffin Bay, we observed decreases in annual sea-ice persistence, yet increases along the Labrador Sea-ice edge during winter, with the latter having significant correlations with broader atmospheric patterns. In general, we observed increases in summer sea surface temperatures across the study region, except a small area of cooling along …

Change Points Detected In Decadal And Seasonal Trends Of Outlet Glacier Terminus Positions Across West Greenland, Ashley V. York, Karen E. Frey, Sadegh Jamali, Sarah B. Das

Geography

We investigated the change in terminus position between 1985 and 2015 of 17 marine-terminating glaciers that drain into Disko and Uummannaq Bays, West Greenland, by manually digitizing over 5000 individual frontal positions from over 1200 Landsat images. We find that 15 of 17 glacier termini retreated over the study period, with ~80% of this retreat occurring since 2000. Increased frequency of Landsat observations since 2000 allowed for further investigation of the seasonal variability in terminus position. We identified 10 actively retreating glaciers based on a significant positive relationship between glaciers with cumulative retreat >300 m since 2000 and their average …

Seasonal And Latitudinal Variations In Sea Ice Algae Deposition In The Northern Bering And Chukchi Seas Determined By Algal Biomarkers, Chelsea Wegner Koch, Lee W. Cooper, Catherine Lalande, Thomas A. Brown, Karen E. Frey, Jacqueline M. Grebmeier

Geography

An assessment of the production, distribution and fate of highly branched isoprenoid (HBI) biomarkers produced by sea ice and pelagic diatoms is necessary to interpret their detection and proportions in the northern Bering and Chukchi Seas. HBIs measured in surface sediments collected from 2012 to 2017 were used to determine the distribution and seasonality of the biomarkers relative to sea ice patterns. A northward gradient of increasing ice algae deposition was observed with localized occurrences of elevated IP25 (sympagic HBI) concentrations from 68–70N and consistently strong sympagic signatures from 71–72.5N. A declining sympagic signature was observed from 2012 to 2017 …

Instrumental Meteorological Records Before 1850, S. Brönnimann, R. Allan, L. Ashcroft, S. Baer, M. Barriendos, R. Brázdil, Y. Brugnara, M. Brunet, M. Brunetti, B. Chimani, R. Cornes, F. Domínguez-Castro, J. Filipiak, D. Found, Fiona Williamson, J. Gergis, S. Grab, L. Hannak, H. Huhtamaa, K. S. Jacobsen

Research Collection College of Integrative Studies

Climate data are part of our cultural heritage. Enlightenment scientists initiated regular meteorological measurements in the seventeenth and eighteenth centuries, providing modern scientists a wealth of early weather and climate information from across the world. Very long temperature and rainfall series are widely used as a baseline for current changes and to study past climatic variations at regional scale. But records like these constitute only a subset of all measurements taken. We provide here a partial inventory of meteorological measurements made prior to around 1850. Numerous efforts by individuals, weather services, international projects, and the Atmospheric Circulation Reconstructions over the …

Recent Disruptions In The Timing And Intensity Of Precipitation In Calakmul, Mexico, Sofia Mardero, Birgit Schmook, Zachary Christman, Sarah E. Metcalfe, Betsabé De La Barreda-Bautista

School of Earth & Environment Departmental Research

This study addresses changes in the timing and intensity of precipitation from 1982 to 2016 from three meteorological stations around Calakmul, Mexico, a landscape balancing biodiversity conservation and smallholder agricultural production. Five methods were used to assess changes in precipitation: the Mann-Kendall test of annual and wet season trends; a fuzzy-logic approach to determine the onset of the rainy season; the Gini Index and Precipitation Concentration Index (PCI) to evaluate the temporal distribution of precipitation; Simple Precipitation Intensity Index (SDII) to evaluate precipitation intensity; and the Rainfall Anomaly Index (RAI) to identify the deficit or surplus of rainfall compared with …

An Analysis Of The Atmospheric Propagation Of Underground-Explosion-Generated Infrasonic Waves Based On The Equations Of Fluid Dynamics: Ground Recordings, Roberto Sabatini, Jonathan B. Snively, Michael P. Hickey, J. L. Garrison

Publications

An investigation on the propagation of underground-explosion-generated infrasonic waves is carried out via numerical simulations of the equations of fluid dynamics. More specifically, the continuity, momentum, and energy conservation equations are solved along with the Herzfeld-Rice equations in order to take into account the effects of vibrational relaxation phenomena. The radiation of acoustic energy by the ground motion caused by underground explosions is initiated by enforcing the equality, at ground level, between the component of the air velocity normal to the Earth's surface and the normal velocity of the ground layer. The velocity of the ground layer is defined semi-empirically …

Land Cover Change Detection In The Urban Catchments Of Dar Es Salaam, Tanzania Using Remote Sensing And Gis Techniques, Philip Mzava, Joel Nobert, Patrick Valimba

Tanzania Journal of Science

In this study, the Maximum Likelihood (ML) classification, Normalized Difference Vegetation Index (NDVI) and Artificial Neural Network (ANN) methods were applied to three (3) Landsat images collected over time (1979, 1998 and 2014), that contained historical land cover features for the urban catchments of Dar es Salaam. Five major land cover classes were identified, mapped, and the land cover changes investigated. The major land cover changes observed from post-classification comparisons of the classified images are: the forest land losing 17.09% of its area in the period 1979-1998 to other land covers, mainly turning to grassland, and from 1998 to 2014, …

Diel Temperature And Ph Variability Scale With Depth Across Diverse Coral Reef Habitats, Tyler Cyronak, Yuichiro Takeshita, Travis A. Courtney, Eric H. Decarlo, Bradley D. Eyre, David I. Kline, Todd R. Martz, Heather Page, Nichole Price, Jennifer Smith, Laura Stoltenberg, Martin Tresguerres, Andreas J. Andersson

Marine & Environmental Sciences Faculty Articles

Coral reefs are facing intensifying stressors, largely due to global increases in seawater temperature and decreases in pH. However, there is extensive environmental variability within coral reef ecosystems, which can impact how organisms respond to global trends. We deployed spatial arrays of autonomous sensors across distinct shallow coral reef habitats to determine patterns of spatiotemporal variability in seawater physicochemical parameters. Temperature and pH were positively correlated over the course of a day due to solar heating and light‐driven metabolism. The mean temporal and spatial ranges of temperature and pH were positively correlated across all sites, with different regimes of variability …

Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl

OES Faculty Publications

Optical instruments can rapidly determine numbers and characteristics of water column particles with high sensitivity. Here we show the usefulness of optically assessed total particle volume below the main pycnocline to estimate carbon export in two systems: the open subarctic North Atlantic and the Ross Sea, Antarctica. Both regions exhibit seasonally high phytoplankton production and efficient export (i.e., a strong biological pump). Total particle volumes in the mesopelagic (200-300 m) were significantly correlated with those in the overlying surface mixed layer (50-60 m), indicating that most particles at depth reflect export from the surface. This connectivity, however, is modulated by …

The Vezo Communities And Fisheries Of The Coral Reef Ecosystem In The Bay Of Ranobe, Madagascar, Shane Abeare

LSU New Orleans Theses and Dissertations

Madagascar, a country whose extraordinary levels of endemism and biodiversity are celebrated globally by scientists and laymen alike, yet historically has received surprisingly little research attention, is the setting of the present dissertation. Here, I contribute to the need for applied research by: 1) focusing on the most intensely fished section of the Toliara Barrier Reef, the Bay of Ranobe; 2) characterizing the marine environment, the human population, and the fisheries; and 3) collecting the longest known time-series of data on fisheries of Madagascar, thereby providing a useful baseline for future analyses. In Chapter 1, the bathymetry of the Bay …

On The Frontlines - The Fishermen Of Ibrahim Hyderi, Muhammad Haris Aslam Khan

MSJ Capstone Projects

Climate change has become a matter of recent debate for much of the world. According to a report published by a German watch, a non-governmental organization, in 2019, Pakistan among the five countries at severe risk of climate change disasters.

During the last two decades, Pakistan saw more than 141 extreme climatic catastrophes. Only in 2016, more than 566 people died due to these conditions.

A report published by Asian Development Bank in 2017 indicates Pakistan’s climate change profile. It states that more than 1,600 people have lost their lives in the super flood of 2010 alone. A loss of …

Beavers Alter Stream Macroinvertebrate Communities In Northeastern Utah, Susan E. Washko, Brett B. Roper, Trisha Brooke Atwood

Watershed Sciences Faculty Publications

1. Understanding changes in macroinvertebrate communities is important because they play a large role in stream ecosystem functioning, and they are an important food resource for fish. Beaver‐induced changes to stream morphology could alter macroinvertebrate communities, which in turn could affect food webs and ecosystem function. However, studies investigating the effects of North American beaver activities on macroinvertebrates are rare in the inter‐mountain west, an area with high potential for beaver‐assisted restoration.
2. The aim of this study was to quantify differences in the macroinvertebrate community between unaltered segments of streams and within beaver ponds in north‐eastern Utah, U.S.A. We assessed macroinvertebrate …

The Role Of Multi-Charged Responses: Construction And Application Of A Tandem Differential Mobility Analyzer (Tdma), Christopher Ray Oxford

McKelvey School of Engineering Graduate Student Theses & Dissertations

Atmospheric aerosols impact health outcomes, visibility, and the energy balance of the earth. The atmosphere contains a variety of compounds, and the volatility (phase change enthalpy and vapor pressure) of each compound determines its partitioning between the gas phase and the particle phase. The hygroscopicity (an aerosol’s affinity for water) of an atmospheric aerosol particle is determined by the many compounds present in the particle, and thus, the volatility impacts hygroscopicity. Changes in hygroscopicity alter the fraction of the aerosol deposited in the lungs and the fraction of the aerosol activated into cloud droplets. Thus, understanding the volatility and hygroscopicity …

Vintage Report 2019: North Willamette Valley, Gregory V. Jones

Linfield University Wine Studies Reports

This report describes the impacts of climate and phenology on vintage for the North Willamette Valley in Oregon in 2019. A relatively mild early winter in 2018 was followed by a cold and wet second half of winter in 2019 and then a wet, but warm, spring. The growing season saw a few mild frosts during late April, but started off warmer than average, moderating through mid-vintage with fewer than average heat spikes. Near-record precipitation amounts during late June and early July brought increased disease pressure to the region. The vintage will be remembered for the early rains in September …

Integrated Species–Phenon Trees: Visualizing Infraspecific Diversity Within Lineages, Abdullah Khan Zehady, Barry G. Fordham, James G. Ogg

Purdue University Libraries Open Access Publishing Fund

The unprecedented detail with which contemporary molecular phylogenetics are visualizing infraspecific relationships within living species and species complexes cannot as yet be reliably extended into deep time. Yet paleontological systematics has routinely dealt in (mainly) morphotaxa envisaged in various ways to have been components of past species lineages. Bridging these perspectives can only enrich both. We present a visualization tool that digitally depicts infraspecific diversity within species through deep time. Our integrated species–phenon tree merges ancestor–descendant trees for fossil morphotaxa (phena) into reconstructed phylogenies of lineages (species) by expanding the latter into “species boxes” and placing the phenon trees inside. …

A Climatology Of Snowpack In The Southern Rocky Mountains And Snow To Liquid Ratio Forecasting Techniques Using Model Generated Soundings From The Rapid Refresh Model, Carson Jones

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Mountainous snowpack represents up to 70% of the total water resources for areas in the western United States. Temperature and precipitation control the accumulation and ablation of the snowpack throughout the cold season, both of which are subject to a changing climate. This study will use a network of snow telemetry (SNOTEL) stations to investigate changes in the snowpack season, snow water equivalent (SWE), and temperature in the southern Rocky Mountain region. Additionally, this study will use model generated soundings from the Rapid Refresh (RAP) model to establish relationships between the depth and cloud proportion of ice crystal growth layers, …

Steve And The Picket Fence: Evidence Of Feedback-Unstable Magnetosphere-Ionosphere Interaction, Evgeny Mishin, Anatoly Streltsov

Publications

This paper aims to extend the understanding of Strong Thermal Emission VelocityEnhancement (STEVE) and the Picket Fence related to strong subauroral ion drifts (SAID). Wenumerically demonstrated that precipitating energetic electrons are critical for the structuring of the PicketFence. It is created by feedback-unstable magnetosphere-ionosphere interactions driven by the SAIDelectric field when the Hall conductance created by energetic (≥1 keV) electrons exceeds the Pedersenconductance. We show that thermal excitation of the red-line emission in STEVE is inhibited by inelasticcollisions with molecular nitrogen. Suprathermal (≤500 eV) electrons coming from the turbulentplasmasphere appear to be the major source. We also show that the …

A Risk Analysis Of Microplastic Consumption In Filter Feeders, Sheri Rahman

HCNSO Student Capstones

Microplastics (plastic particles < 5 mm) pose a serious threat to marine organisms, as researchers have documented such particles in the gut contents of numerous species. In particular, filter feeders are at risk of consuming microplastics because they may accidentally consume the particulates when feeding or they may prey on species that have already consumed them. The goals of this research were to evaluate the risks that different filter feeders face in regards to microplastic consumption through the analysis of the calculated Microplastic Consumption Rates for numerous species of filter feeders. Factors that could potentially affect this risk were also considered, including ocean basin, environment type, salinity, life stage, IUCN status, and filtration technique. Initial analysis showed that body size greatly impacted a species’ risk of microplastic consumption and further tests were completed to evaluate overall microplastic contamination for each species. Microplastic consumption and microplastic contamination values were evaluated and analyzed to determine which filter feeding species were most at risk of experiencing ecological effects from microplastic pollution. From a resource management perspective, this research highlights the filter feeding species most at risk, contributing to the development of more effective plastic waste management policies.

Life In Hampton Roads Survey No. 4: Neighborhood Flooding And Insurance, News @ Odu

News Items

No abstract provided.

Spatial And Temporal Trends Of Southeastern Florida's Octocoral Comunity, Alexandra Hiley

HCNSO Student Theses and Dissertations

In the Caribbean, local and global stressors have driven significant declines in scleractinian coral cover up to 80% in only three decades. Following these declines, phase shifts in benthic community composition have been reported. Shifts towards macroalgal dominance has been the most widely observed case, however, shifts towards octocoral and sponge dominance have also been reported. In Florida, USA, the Florida Reef Tract is an extensive barrier reef system that contains diverse assemblages of corals, sponges, fish, and other taxa. The Southeast Florida Reef Tract (SEFRT) within the Southeast Florida Coral Reef Conservation Area is the northern portion of this …