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Full-Text Articles in Physical Sciences and Mathematics

El Nino Southern Oscillation (Enso) Enhances Co2 Exchange Rates In Freshwater Marsh Ecosystems In The Florida Everglades, Sparkle L. Malone, Christina L. Staudhammer, Steven F. Oberbauer, Paulo Olivas, Michael G. Ryan, Jessica L. Schedlbauer, Henry W. Loescher, Gregory Starr Dec 2014

El Nino Southern Oscillation (Enso) Enhances Co2 Exchange Rates In Freshwater Marsh Ecosystems In The Florida Everglades, Sparkle L. Malone, Christina L. Staudhammer, Steven F. Oberbauer, Paulo Olivas, Michael G. Ryan, Jessica L. Schedlbauer, Henry W. Loescher, Gregory Starr

Biology Faculty Publications

No abstract provided.


The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown Dec 2014

The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regu­larly experience brief periods of severe weather–induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally smaller …


A Weather Monitoring System For The Study Of Precipitation Fields, Weather, And Climate In An Urban Area, Francesco Lo Conti, Dario Pumo, Antonia Incontrera, Antonio Francipane, Leonardo Valerio Noto, Goffredo La Loggia Aug 2014

A Weather Monitoring System For The Study Of Precipitation Fields, Weather, And Climate In An Urban Area, Francesco Lo Conti, Dario Pumo, Antonia Incontrera, Antonio Francipane, Leonardo Valerio Noto, Goffredo La Loggia

International Conference on Hydroinformatics

The possibility to study the precipitation dynamics with advanced and specific tools is an important task of the research activity addressing the understanding, the modeling, and the managing of rainfall events. Over the last years, the hydrology laboratory of the Department of Civil, Environmental, Aerospace Engineering, and Materials (DICAM) at the University of Palermo, has installed several instruments for the monitoring and the study of precipitation within the urban area of Palermo (Italy). The main instrument of this system is the X-band weather radar, which allows monitoring the precipitation fields with high resolution in space and time. This instrument is …


The Contribution Of Fine Scale Atmospheric Numerical Models In Improving The Quality Of Hydraulic Modelling Outputs, Rabia Merrouchi, Dalila Loudyi, Mohamed Chagdali Aug 2014

The Contribution Of Fine Scale Atmospheric Numerical Models In Improving The Quality Of Hydraulic Modelling Outputs, Rabia Merrouchi, Dalila Loudyi, Mohamed Chagdali

International Conference on Hydroinformatics

The atmospheric numerical models have known great advances with the ongoing development of numerical weather prediction and computing resources. The spatial and temporal resolution of the global atmospheric models has improved and therefore, the accuracy and reliability of their results have substantially increased. Emphasis was made on the improvement of models dynamics and physical aspects, but also on data assimilation and input data diversification using new numerical schemes and new physical parameterizations that better assess the small-scale weather phenomena. However, these models were not able to overcome their physical limitations and therefore, some small-scale processes are far from being thoroughly …


Statistically Downscaled North American Precipitation Using Support Vector Regression And The Big Brother Approach., Carlos F. Gaitan, Keith W. Dixon, Venkatramani Balaji, Renee Mcpherson Aug 2014

Statistically Downscaled North American Precipitation Using Support Vector Regression And The Big Brother Approach., Carlos F. Gaitan, Keith W. Dixon, Venkatramani Balaji, Renee Mcpherson

International Conference on Hydroinformatics

We implemented a hybrid downscaling model using classification and regression trees and support vector regression with evolutionary strategies to statistically downscale precipitation occurrences and amounts from 16 points across North America. All the selected points belong to different climate regions. In addition, to evaluate the downscaling model’s historical and future performances we used daily precipitation outputs (from a high resolution ~25km grid spacing global atmospheric model) as predictands, and coarsened versions of the same high-resolution outputs from the nearest nine gridpoints (interpolated to a ~100km grid), as predictors. This experimental setup, known as “Big-Brother” allows us to use the high-resolution …


Precipitation Sensor Network Optimal Design Using Time-Space Varying Correlation Structure, Juan Carlos Chacon-Hurtado, Leonardo Alfonso, Dimitri P. Solomatine Aug 2014

Precipitation Sensor Network Optimal Design Using Time-Space Varying Correlation Structure, Juan Carlos Chacon-Hurtado, Leonardo Alfonso, Dimitri P. Solomatine

International Conference on Hydroinformatics

Design of optimal precipitation sensor networks is a common topic in hydrological literature, however this is still an open problem due to lack of understanding of some spatially variable processes, and assumptions that often cannot be verified. Among these assumptions lies the homoscedasticity of precipitation fields, common in hydrological practice. To overcome this, it is proposed a local intensity-variant covariance structure, which in the broad extent, provides a fully updated correlation structure as long as new data are coming into the system. These considerations of intensity-variant correlation structure will be tested in the design of a precipitation sensor network for …


Springtime Atmospheric Responses To North Atlantic Sst Anomalies In Idealized Gcm Experiments: Northern Hemisphere Circulation And North American Precipitation, Michael C. Veres Jul 2014

Springtime Atmospheric Responses To North Atlantic Sst Anomalies In Idealized Gcm Experiments: Northern Hemisphere Circulation And North American Precipitation, Michael C. Veres

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

In this study, a series of experiments using idealized sea surface temperatures (SST), land and orography are performed to examine the interactions between the Atlantic Multidecadal Oscillation (AMO), continents and major orography. Three sets of experiments are done using an increasingly realistic surface boundary (aqua-planet, land without orography and land with orography) and run using perpetual equinox conditions. For each land surface boundary, the model is forced with a zonally symmetric SST, with additional experiments with an imposed positive or negative SST anomalies in the North Atlantic. The experiments are then compared to determine how these forcings interact and what …


Decaf: A New Event Detection Logic For The Purpose Of Fusing Delineated-Continuous Spatial Information, Kerry Q. Hart May 2014

Decaf: A New Event Detection Logic For The Purpose Of Fusing Delineated-Continuous Spatial Information, Kerry Q. Hart

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Geospatial information fusion is the process of synthesizing information from complementary data sources located at different points in space and time. Spatial phenomena are often measured at discrete locations by sensor networks, technicians, and volunteers; yet decisions often require information about locations where direct measurements do not exist. Traditional methods assume the spatial phenomena to be either discrete or continuous, an assumption that underlies and informs all subsequent analysis. Yet certain phenomena defy this dichotomy, alternating as they move across spatial and temporal scales. Precipitation, for example, appears continuous at large scales, but it can be temporally decomposed into discrete …


Synoptic Typing And Precursors Of Heavy Warm-Season Precipitation Events At Montreal, Québec, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum, Giselle Dookhie Apr 2014

Synoptic Typing And Precursors Of Heavy Warm-Season Precipitation Events At Montreal, Québec, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum, Giselle Dookhie

Publications

A precipitation climatology is compiled for warm-season events at Montreal, Québec, Canada, using 6-h precipitation data. A total of 1663 events are recorded and partitioned into three intensity categories (heavy, moderate, and light), based on percentile ranges. Heavy (top 10%) precipitation events (n = 166) are partitioned into four types, using a unique manual synoptic typing based on the divergence of Q-vector components. Type A is related to cyclones and strong synoptic-scale quasigeostrophic (QG) forcing for ascent, with high-θe air being advected into the Montreal region from the south. Types B and C are dominated by frontogenesis (mesoscale QG forcing …


Influence Of Regional Precipitation Patterns On Stable Isotopes In Ice Cores From The Central Himalayas, H. Pang, S. Hou, Susan Kaspari, P. A. Mayewski Feb 2014

Influence Of Regional Precipitation Patterns On Stable Isotopes In Ice Cores From The Central Himalayas, H. Pang, S. Hou, Susan Kaspari, P. A. Mayewski

All Faculty Scholarship for the College of the Sciences

Several ice cores have been recovered from the Dasuopu (DSP) Glacier and the East Rongbuk (ER) Glacier in the central Himalayas since the 1990s. Although the distance between the DSP and the ER ice core drilling sites is only 125 km, the stable isotopic record (18O or D) of the DSP core is interpreted in previous studies as a temperature proxy, while the ER core is interpreted as a precipitation proxy. Thus, the climatological significance of the stable isotopic records of these Himalayan ice cores remains a subject of debate. Based on analysis of regional precipitation patterns over the region, …


Are Climate Model Simulations Useful For Forecasting Precipitation Trends? Hindcast And Synthetic-Data Experiments, Nir Y. Krakauer, Balázs M. Fekete Feb 2014

Are Climate Model Simulations Useful For Forecasting Precipitation Trends? Hindcast And Synthetic-Data Experiments, Nir Y. Krakauer, Balázs M. Fekete

Publications and Research

Water scientists and managers currently face the question of whether trends in climate variables that affect water supplies and hazards can be anticipated. We investigate to what extent climate model simulations may provide accurate forecasts of future hydrologic nonstationarity in the form of changes in precipitation amount. We compare gridded station observations (GPCC Full Data Product, 1901–2010) and climate model outputs (CMIP5 Historical and RCP8.5 simulations, 1901–2100) in real and syntheticdata hindcast experiments. The hindcast experiments show that imputing precipitation trends based on the climate model mean reduced the root mean square error of precipitation trend estimates for 1961–2010 by …


Changing Forest Water Yields In Response To Climate Warming: Results From Long-Term Experimental Watershed Sites Across North America, Irena F. Creed, Adam T. Spargo, Julia A. Jones, Jim M. Buttle, Mary B. Adams, Fred D. Beall, Eric G. Booth, John L. Campbell, Dave Clow, Kelly Elder, Mark B. Green, Nancy B. Grimm, Chelcy Miniat, Patricia Ramlal, Amartya Saha, Stephen Sebestyen, Dave Spittlehouse, Shannon Sterling, Mark W. Williams, Rita Wrinkler, Huaxia Yao Jan 2014

Changing Forest Water Yields In Response To Climate Warming: Results From Long-Term Experimental Watershed Sites Across North America, Irena F. Creed, Adam T. Spargo, Julia A. Jones, Jim M. Buttle, Mary B. Adams, Fred D. Beall, Eric G. Booth, John L. Campbell, Dave Clow, Kelly Elder, Mark B. Green, Nancy B. Grimm, Chelcy Miniat, Patricia Ramlal, Amartya Saha, Stephen Sebestyen, Dave Spittlehouse, Shannon Sterling, Mark W. Williams, Rita Wrinkler, Huaxia Yao

USDA Forest Service / UNL Faculty Publications

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment’s change in actual ET divided by P …


Significant Impacts Of Radiation Physics In The Wrf Model On The Precipitation And Dynamics Of The West African Monsoon, R. Li, J. Jin, Shih-Yu (Simon) Wang, R. R. Gillies Jan 2014

Significant Impacts Of Radiation Physics In The Wrf Model On The Precipitation And Dynamics Of The West African Monsoon, R. Li, J. Jin, Shih-Yu (Simon) Wang, R. R. Gillies

Plants, Soils, and Climate Faculty Publications

Precipitation from the West African Monsoon (WAM) provides food security and supports the economy in the region. As a consequence of the intrinsic complexities of the WAM’s evolution, accurate simulations of the WAM and its precipitation regime, through the application of regional climate models, are challenging. We used the coupled Weather Research and Forecasting (WRF) and Community Land Model (CLM) to explore impacts of radiation physics on the precipitation and dynamics of the WAM. Our results indicate that the radiation physics schemes not only produce biases in radiation fluxes impacting radiative forcing, but more importantly, result in large bias in …