Oceanography and Atmospheric Sciences and Meteorology Commons^™

An Agricultural Drought Risk-Assessment Model For Corn And Soybeans, Hong Wu, Kenneth G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

Copyright © 2004 Royal Meteorological Society. Published by Wiley InterScience. Used by permis-sion.

An Operational Agricultural Drought Risk Assessment Model For Nebraska, Usa, Hong Wu, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

Drought is a common occurrence in Nebraska and agriculture is the primary economic sector affected. Because of repeated and widespread severe drought impacts, more emphasis on drought risk management is warranted. This study develops an agricultural drought risk assessment model using multivariate techniques. The model is specific to corn and soybeans and is able to assess real-time agricultural drought risk associated with crop yield losses at critical phenological stages prior to and during the growing season. The assessment results are presented in a Geographic Information System to provide a better visualization. This model provides information in a timely manner about …

Drought Monitoring Using Data Mining Techniques: A Case Study For Nebraska, Usa, Tsegaye Tadesse, Donald A. Wilhite, Sherri K. Harms, Michael J. Hayes, Steve Goddard

National Drought Mitigation Center: Faculty Publications

Drought has an impact on many aspects of society. To help decision makers reduce the impacts of drought, it is important to improve our understanding of the characteristics and relationships of atmospheric and oceanic parameters that cause drought. In this study, the use of data mining techniques is introduced to find associations between drought and several oceanic and climatic indices that could help users in making knowledgeable decisions about drought responses before the drought actually occurs. Data mining techniques enable users to search for hidden patterns and find association rules for target data sets such as drought episodes. These techniques …

Biozonation On Deep-Water Carbonate Mounds And Associated Hardgrounds Along The Western Margin Of Little Bahama Bank, With Notes On The Caicos Platform Island Slope, Charles G. Messing

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Carbonate mounds found in a broad band from about 325 to 700 m along the western margin of Little Bahama Bank exhibit consistent faunal zonations characterized by assemblages of attached, suspension-feeding macroinvertebrates dominated by sponges, octocorals, crinoids and stylasterid and scleractinian corals. Biozonation on hard substrates appears chiefly dependent on depth (and associated parameters, e.g., temperature) and current flow. Mounds in 325-435 m with up to 30 m vertical relief reveal dense assemblages on gentler up current slopes and flanks, and an almost complete lack of macrofauna on steep downcurrent slopes. Macrofauna include stalked crinoids on upcurrent slopes and crest, …

Spatial And Temporal Recruitment Patterns Of Juvenile Grunts (Haemulon Spp.) In South Florida, L. K. B. Jordan, David S. Gilliam, Robin L. Sherman, Paul T. Arena, Fleur M. Harttung, Robert M. Baron, Richard E. Spieler

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Grunts (Haemulidae) are important fisheries species and represent a major component of reef fish communities in the Greater Caribbean region. To date, little is known about their recruitment pattems. Data from more than 2,000 visual fish counts from multiple natural and artificial reef studies in Broward County, Florida, over a seven-year period, were examined to identify both spatial and temporal trends in recruitment of juvenile (i.e., < 5cm TL) grunts of the genus Haemulon. In general, data from these studies indicate that juvenile Haemulon spp. recruitment increases in the spring and peaks in the early summer months (i.e., June and July). Data from natural reef surveys revealed a predominantly nearshore preference for recruitment in water depths less than 8 m. However, on artificial reefs, recruitment commoniy occurred at 20 m depths. The biotic and abiotic factors determining the settlement of grunts are not clear and will be examined in future studies.

Presence Of Juvenile Blackfin Snapper, Lutjanus Buccanella, And Snowy Grouper, Epinephelus Niveatus, On Shallow-Water Artificial Reefs, Paul T. Arena, Patrick Quinn, Lance K. B. Jordan, Robin L. Sherman, Fleur M. Harttung, Richard E. Spieler

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The inshore environment of Broward County, Florida consists of three reef tracts, each separated by sand substrate, running parallel to the coastline in sequentially deeper water. A wide variety of artificial reef designs have been deployed in Broward County, many lying in sand flats between the reeftracts. From 1995 through 2002, over 1,100 visual fish censuses (predominantly point-counts) were completed on the three natural reeftracts in water depths from 3 m to 30 m and over 1,100 censuses were done on artificial reefs at depths of 7 m to 23 m. Curiously, the juvenile stages of two deeper-water species of …

An Association Of Benthic Foraminifera And Gypsum In Holocene Sediments Of Estuarine Chesapeake Bay, Usa, John Cann, Thomas Cronin

United States Geological Survey: Staff Publications

Two cores of Holocene sediments recovered from the Cape Charles Channel of Chesapeake Bay yielded radiocarbon ages of about 6.8 to 5.8 ka for the lower intervals. Fossil foraminifera preserved in these lower sediments are dominated by species of Elphidium, which make up about 90% of the assemblage throughout, and probably signify deposition in hypersaline waters. Buccella frigida and Ammonia beccarii are the only other species commonly present. Hypersalinity of bottom waters seems to have been maintained by water-density stratification in a basin-like section of the channel. In core PTXT -4-P-I transition to modem Chesapeake conditions, in which numbers …

Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr.

United States Geological Survey: Staff Publications

Structure and composition of vegetation and abundance of breeding birds in grasslands seeded to Old World bluestem (Bothriochloa ischmaeum) were compared to native mixed prairie in the southern Great Plains of North America. Abundance of birds was determined using fixed-radius point counts. Detrended correspondence analysis was used to compare plant community composition and canonical correspondence analysis was used to examine the relationships between plant species composition and vegetation structure with the bird community. Plant species composition differed distinctly between seeded grassland and native mixed prairie, but the differences were not reflected in habitat structure, bird community composition, or …

Recent Advances In Drought Monitoring, Mark D. Svoboda, Michael J. Hayes, Donald A. Wilhite, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

Recent widespread, severe, and long-lasting droughts across North America have heightened awareness of and interest in how to better monitor drought and its impacts. Since its inception in 1999, the National Drought Mitigation Center (NDMC), United States Department of Agriculture (USDA) and NOAA’s Climate Prediction Center (CPC) and National Climatic Data Center (NCDC) have partnered to produce the weekly U.S. Drought Monitor (http://droug ht.unl.edu/m onitor/), a comprehensive drought assessment product based on a simple 5- category severity classification. On the heels of its widespread acceptance and usage, the NCDC, CPC, USDA, NDMC and scientists from Canada and Mexico have worked …

A Geospatial Decision Support System For Drought Risk Management, Steve Goddard, Jitender Deogun, Sherri K. Harms, Michael J. Hayes, Kenneth G. Hubbard, Stephen Reichenbach, Peter Revesz, W. J. Waltman, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

Drought affects virtually all regions of the world and results in significant economic, social, and environmental impacts. The Federal Emergency Management Agency estimates annual drought-related losses in the United States at $6-8 billion, which is more than any other natural hazard. Congress enacted the Agricultural Risk Protection Act of 2000 to encourage the United States Department of Agriculture (USDA) Risk Management Agency (RMA) and farmers to be more proactive in managing drought risk. Through the National Science Foundation (NSF) Digital Government program, the USDA RMA is working with the University of Nebraska−Lincoln Computer Science and Engineering (CSE) Department, National Drought …

Inorganic Nitrogen Transformations At High Loading Rates In An Oligohaline Estuary, R. Eugene Turner, Q. Dortch, Nancy N. Rabalais

Faculty Publications

A well-defined nitrogen retention and turnover budget was estimated for a shallow oligohaline lake (Lake Pontchartrain, Louisiana, USA). In 1997 a month-long diversion of the Mississippi River filled the Lake with highly concentrated river water (80 µM nitrate) and lowered the salinity to 0 psu within 2 weeks. After the spillway was closed the Lake mixed with estuarine tidal waters and came to equilibrium over 4 months with the riverine, atmospheric and offshore water nitrogen sources. A flushing rate of 1.78% d−1 was estimated by analyzing a plot of ln salinity versus time for the first 120 days after the …

Suspended Sediment, C, N, P, And Si Yields From The Mississippi River Basin, R. Eugene Turner, Nancy N. Rabalais

Faculty Publications

The annual loads of C,N,P, silicate, total suspended sediment (mass) and their yields (mass area−1) were estimated for six watersheds of the Mississippi River Basin (MRB) using water quality and water discharge records for 1973 to 1994. The highest load of suspended sediments is from the Missouri watershed (58 mt km2 yr−1), which is also the largest among the six major sub-basins. The Ohio watershed delivers the largest load of water (38%). The Upper Mississippi has the largest total nitrogen load (32%) and yield (1120 kg TN km2 yr−1). The loading of organic carbon, total phosphorus and silicate from the …

Below-Ground Biomass In Healthy And Impaired Salt Marshes, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee, Thomas A. Oswald

Faculty Publications

Twelve salt marshes in south Louisiana (USA) were classified as either ‘impaired’ or ‘healthy’ before a summer sample collection of above- and below-ground biomass and determination of sediment accretion rates. The above-ground biomass of plant tissues was the same at both impaired and healthy salt marshes and was not a good predictor of marsh health. However, below-ground root biomass in the upper 30 cm was much lower in the impaired marshes compared to the healthy marshes. Compromises to root production apparently occur before there is an obvious consequence to the above-ground biomass, which may quickly collapse before remedial action can …

Water Quality Assessment: A Hands-On Approach To Environmental Education, Tracy Lynn Royse

All Graduate Projects

A water quality assessment lab manual has been created to assist secondary educators using the HACH water quality testing kits. It consists of ten chemical tests, a geological survey and a biological assessment largely based upon Washington State University's lab format and the Walla Walla County Conservation District's water study protocol. The lab manual also contains safety guidelines, a scoring rubric and an action plan research project. The environmental approach to science education used in the lab manual meets the Essential Academic Learning Requirements adopted by the Washington State Commission on Student Learning as well as the National Science Education …

Mudfish On The Menu? Rise Of The Much-Maligned Bowfin, Ken Sulak

United States Geological Survey: Staff Publications

Cajuns call it “choupique” (say “shoe-pick”), from its Choctaw name. Elsewhere, it’s the dogfish, blackfish, grindle, cottonfish, or cypress trout. Its official common name is “Bowfin” (Amia calva)1. But to most anglers, this is the “mudfish,” a strange, unusual, and much-maligned fish, most everywhere considered a useless trash fish. One look and the words relict, prehistoric, primitive, and living fossil come to mind. Indeed, the bowfin is the last of its line, the sole-surviving species of a very ancient group of fishes. Its predecessors flourished in the Jurassic and Cretaceous periods during the Mesozoic (= Middle-Animal) Era, a …

Habitat Preferences And Diving Behavior Of White Marlin (Tetrapturus Albidus) Released From The Recreational Rod-And-Reel And Commercial Pelagic Longline Fisheries In The Western North Atlantic Ocean: Implications For Habitat-Based Stock Assessment Models, Andrij Horodysky, David W. Kerstetter, John E. Graves

Marine & Environmental Sciences Faculty Reports

To improve billfish assessments, researchers have applied habitat-based models that incorporate behavioral and oceanographic parameters to standardize historical catch-per-uniteffort time -series data, accounting for significant gear changes over time. However, there has been little behavioral data from Atlantic billfishes to support these models. We provide information on habitat preferences of white marlin released from recreational and commercial fisheries in the western North Atlantic. White marlin were tagged with pop-up satellite archival tags (PSATs) from recreational rod and reel (n=22) and commercial pelagic longline (n=2) fisheries between May-November 2002. Our data indicate that each surviving white marlin spent the majority of …

Sea Turtle Conservation Program, Broward County, Fl 2004 Report, Curtis M. Burney, Stefanie Ouellette

Marine & Environmental Sciences Faculty Reports

No abstract provided.

Microfauna As Tracers Of Sediment Transport: Ft. Pierce Dredge Spoils Sediment Study, Patricia Blackwelder, Carlos Alvares Zarikian, Terry Hood, Charles M. Featherstone, John Proni, Jules Craynock

Marine & Environmental Sciences Faculty Reports

No abstract provided.

Diel Activity Patterns, Space Utilization, Seasonal Distribution And Population Structure Of The Yellow Stingray, Urobatis Jamaicensis (Cuvier, 1817) In South Florida With Comments On Reproduction., Daniel P. Fahy

HCNSO Student Theses and Dissertations

The yellow stingray, Urobatis jamaicensis is the most common elasmobranch in the coastal waters of Southeast Florida. Despite their common occurrence the ecology of yellow stingrays remains poorly understood. In particular, yellow stingray daily movements, space utilization, seasonal distribution and population structure have not been described. This study was conducted to address the lack of knowledge of these fundamental life history parameters and to provide further information on the ecology of U. jamaicensis in coastal waters of Broward County, Florida.

The activity patterns and space utilization of U. jamaicensis were assessed by manual tracking with ultrasonic telemetry. Telemetry tracking of …

Atmospheric Variability Of Methyl Chloride During The Last 300 Years From An Antarctic Ice Core And Firn Air, M. Aydin, Eric S. Saltzman, Warren J. De Bruyn, S. A. Montzka, J. H. Butler, M. Battle

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Measurements of methyl chloride (CH3Cl) in Antarctic polar ice and firn air are used to describe the variability of atmospheric CH3Cl during the past 300 years. Firn air results from South Pole and Siple Dome suggest that the atmospheric abundance of CH3Cl increased by about 10% in the 50 years prior to 1990. Ice core measurements from Siple Dome provide evidence for a cyclic natural variability on the order of 10%, with a period of about 110 years in phase with the 20th century rise inferred from firn air. Thus, the CH3Cl increase measured in firn air may largely be …

Estimation Of Primary Production And Carbon Flux In Antarctic Coastal Waters: A Modeling Study, Hae-Cheol Kim

OES Theses and Dissertations

This study presents results from models that are designed to simulate the underwater light field, to simulate phytoplankton primary production, and to estimate the fate of phytoplankton carbon in continental shelf waters of the west Antarctic Peninsula (WAP) and Ross Sea. Simulation of the underwater light field required derivation of new coefficient sets for power function-type cloud cover correction algorithms, which were found to be influenced by multiple reflections between the bottom of clouds and the surface. The coefficient sets indicate that the spectral effect of clouds on the properties of the surface irradiance was spectrally-neutral for wavelengths greater than …

Inner Shelf Circulation In Coastal Virginia: A Data Assimilation Approach, Hector Hito Sepulveda

OES Theses and Dissertations

The primary objective of this dissertation is to describe the tidal and subtidal flow patterns over the inner shelf of the Delmarva Peninsula, located in the Mid-Atlantic Bight of the United States (36.6–38.0 N), north of the Chesapeake Bay. The objective is pursued with a combination of direct measurements and numerical assimilative techniques. The dynamic balance of the study area is little known, and the distribution of tidal properties has not been described for this area since very rough descriptions in the 1950's. Hydrographic and current velocity profiles from four regional cruises in the inner shelf were used to study …

Sources And Cycling Of Carbonyl Sulfide In The Sargasso Sea, Gregory A. Cutter, Lynda S. Cutter, Katherine C. Filippino

OES Faculty Publications

The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L^-1, showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L^-1) and increased with depth. The photoproduction rate of OCS from in situ incubations averaged 9.6 pmol L^-1 h^-1, whereas dark production was 7.0 pmol L^-1 h^-1. Apparent quantum yields were 10^-5-10^-7 from 313-436 …

Light Dependence Of Selenium Uptake By Phytoplankton And Implications For Predicting Selenium Incorporation Into Food Webs, Stephen B. Baines, Nicholas S. Fisher, Martina A. Doblin, Gregory A. Cutter, Lynda S. Cutter, Brian Cole

OES Faculty Publications

The potentially toxic element selenium is first concentrated from solution to a large but highly variable degree by algae and bacteria before being passed on to consumers. The large loads of abiotic and detrital suspended particles often present in rivers and estuaries may obscure spatial and temporal patterns in Se concentrations at the base of the food web. We used radiotracers to estimate uptake of both selenite (Se(IV)) and C by intact plankton communities at two sites in the Sacramento/San Joaquin River Delta. Our goals were to determine (1) whether C and Se(IV) uptake were coupled, (2) the role of …

Analytical Intercomparison Between Flow Injection-Chemiluminescence And Flow Injection-Spectrophotometry For The Determination Of Picomolar Concentrations Of Iron In Seawater, Andrew R. Bowie, Peter N. Sedwick, Paul J. Worsfold

OES Faculty Publications

A lab- and ship-based analytical intercomparison of two flow injection methods for the determination of iron in seawater was conducted, using three different sets of seawater samples collected from the Southern Ocean and South Atlantic. In one exercise, iron was determined in three different size-fractions (< 0.03 &μm, < 0.4 μm, and unfiltered) in an effort to better characterize the operational nature of each analytical technique with respect to filter size. Measured Fe concentrations were in the range 0.19 to 1.19 nM using flow injection with luminol chemiluminescence detection (FI-CL), and 0.07 to 1.54 nM using flow injection with catalytic spectrophotometric detection with N, N-dimethyl-p-phenylenediamine dihydrochloride (FI-DPD). The arithmetic mean for the FI-CL method was higher (by 0.09 nM) than the FI-DPD method for dissolved (< 0.4 μm) Fe, a difference that is comparable to the analytical blanks, which were as high as 0.13 nM ( CL) and 0.09 nM (DPD). There was generally good agreement between the FI-CL determinations for the < 0.03 μm size fraction and the FI-DPD determinations for the < 0.4 μm size fraction in freshly collected samples. Differences in total-dissolvable ( unfiltered) Fe concentrations determined by the two FI methods were more variable, reflecting the added complexity associated with the analysis of partially digested particulate material in these samples. Overall, however, the FI-CL determinations were significantly (P = 0.05) lower than the FI-DPD determinations for the unfiltered samples. Our results suggest that the observed, systematic inter-method differences reflect measurement of different physicochemical fractions of Fe present in seawater, such that colloidal and/or organic iron species are better determined by the FI-CL method than the FI-DPD method. This idea is supported by our observation that inter-method differences were largest for freshly collected acidified seawater, which suggests extended storage (>6 months) of acidified samples as a possible protocol for the determination of dissolved iron in seawater.

Influence Of Short-Term Variations In Food On Survival Of Crassotrea Gigas Larvae: A Modeling Study, Eric N. Powell, Eleanor A, Bochenek, John M. Klinck, Eileen E. Hofmann

OES Faculty Publications

A biochemically-based model was developed to simulate the growth, development, and metamorphosis of larvae of the Pacific oyster, Crassostrea gigas. The model defines larvae in terms of their protein, lipid, carbohydrate, and ash content and includes variation in growth efficiency and egg quality to better simulate cohort population dynamics. Changes in tissue composition occur as the larva grows and in response to the biochemical composition of the food. The premise behind this modeling study was that certain periods of larval life are more critical than others with respect to the availability of food and that food quality is as …

Physical Forcing Of Phytoplankton Community Structure And Primary Production In Continental Shelf Waters Of The Western Antarctic Peninsula, Barbara B. Prézelin, Eileen E. Hofmann, Mark Moline, John M. Klinck

OES Faculty Publications

Analyses of a multidisciplinary data set, collected in continental shelf waters of the Western Antarctic Peninsula (WAP) during austral summer of January 1993, identified a previously unrecognized forcing mechanism that sets up a physical and chemical structure that supports and assures site-specific diatom-dominated communities and enhanced biological production (Prézelin et al., 2000). This forcing is active when the southern boundary of the Antarctic Circumpolar Current (ACC) flows along the shelf edge, thereby facilitating onshelf bottom intrusions of nutrient-rich Upper Circumpolar Deep Water (UCDW), which then is upwelled or mixed into the upper water column. At times or locations where UCDW …

Black Carbon In Estuarine And Coastal Ocean Dissolved Organic Matter, Antonio Mannino, H. Rodger Harvey

OES Faculty Publications

We measured black carbon (BC) in ultrafiltered, high-molecular weight dissolved organic matter (UDOM) in surface waters of Delaware Bay, Chesapeake Bay, and the adjacent Atlantic Ocean (U.S.A.) to investigate the importance of riverine and estuarine dissolved organic matter (DOM) as a source of BC to the ocean. BC was 5-72% of UDOM-C (27 ± 17%), which corresponds to 8.9 ± 6.5% of dissolved organic carbon (DOC), with higher values in the heavily urbanized midbay region of the Delaware Estuary and lower yields in the river and coastal ocean. The spatial and seasonal distributions of BC along the salinity gradient of …

Relevant Scales In Zooplankton Ecology: Distribution, Feeding, And Reproduction Of The Copepod Acartia Hudsonica In Response To Thin Layers Of The Diatom Skeletonema Costatum, Alexander B. Bochdansky, Stephen M. Bollens

OES Faculty Publications

We investigated the interaction of the copepod Acartia hudsonica in relation to thin layers of the diatom Skeletonema costatum. Thin layers have recently received much attention, since they are common and persistent features in the water column, often overlooked by traditional sampling methods. Their frequent abundance in coastal oceans and the high biomass associated with them has led to the assumption that they are important grazing sites of calanoid copepods. We employed 2-m tall tower tanks that allowed us to simulate thin layers. Three variables representative of three time scales were considered: the distribution of copepods in the tanks …

Interactive Regulation Of Dissolved Copper Toxicity By An Estuarine Microbial Community, Christina L. Dryden, Andrew S. Gordon, John R. Donat

OES Faculty Publications

Cultured marine microorganisms under copper stress produce extracellular compounds having a high affinity for copper (copper-complexing ligands). These ligands are similar in binding strength to those found in natural waters, but few studies have examined the relationship between copper, copper-complexing ligand concentrations, and natural microbial populations. A series of in situ experiments in the Elizabeth River, Virginia, revealed that an intact estuarine microbial community responded to copper stress by production of extracellular, high-affinity copper-complexing ligands. The rate of ligand production was dependent on copper concentration and resulted in a reduction of the concentration of free cupric ions, Cu²⁺, …