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Full-Text Articles in Atmospheric Sciences

Biennial And Low-Frequency Components Of El Niño/Southern Oscillation, James Michael Ryan Aug 2020

Biennial And Low-Frequency Components Of El Niño/Southern Oscillation, James Michael Ryan

Theses and Dissertations

El Niño/Southern Oscillation (ENSO) is a coupled oscillation of sea surface temperatures (SSTs), winds, and air pressure in the eastern and central tropical Pacific, that repeats with quasi-regularity, every 2–7 years. Although the ENSO’s spectral peak is found at a 4–7-yr period, composite El Niño events, taken as the 84 months before and after the peak of each El Niño, show that the length of each event, and often the following La Niña if there is one, usually falls within a quasi-biennial (QB) range of around 18–42 months. We argue that the biennial range of ENSO events stems from the …


Lightning Activity In The Continental United States On An Enso Time Scale, 2002-2015, Tyler M. Gingrich May 2020

Lightning Activity In The Continental United States On An Enso Time Scale, 2002-2015, Tyler M. Gingrich

Senior Honors Projects, 2020-current

This investigation examined the frequency and spatial pattern of lightning in the continental United States from 2002 to 2015. Before analysis, flashes were grouped based on their El Niño Southern Oscillation (ENSO) phase and Spatial Synoptic Classification (SSC) type for the winter season (December, January, and February). The purpose of this study is to better understand the relationship between planetary teleconnections, synoptic scale air masses, and micro scale phenomena, specifically lightning, in the continental United States. Evidence suggests ENSO cold phase flashes tend to have a lower frequency in number of flashes and flash days, as well as a northward …


Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson May 2019

Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson

Graduate Theses and Dissertations

Earlywood (EW) and latewood (LW) ring-width chronologies have become an increasingly important proxy in paleoclimate reconstructions. These subannual variables can provide estimates of past hydroclimate variability for seasonal windows that total ring-widths cannot resolve. The strength of the relationship between EW and LW series may influence what type of paleoclimate information is embedded within the tree-ring series. High correlations (> 0.70) between EW and LW are recorded for much of the continent but the magnitude of correlation varies greatly across space and species boundaries. Using four LW chronologies from shortleaf pine, the North American conifer species displaying the lowest EW-LW …


Climate Fingerprints Of The Interdecadal Pacific Oscillation, Bo Dong Jan 2017

Climate Fingerprints Of The Interdecadal Pacific Oscillation, Bo Dong

Legacy Theses & Dissertations (2009 - 2024)

The Interdecadal Pacific Oscillation (IPO) is a multi-decadal quasi-oscillation seen primarily in tropical and extratropical Pacific sea surface temperatures (SSTs). Interacting with the atmosphere, the IPO has been shown to affect global and regional climate. However, a quantitative global synthesis of the IPO’s climate fingerprints and the underlying mechanisms are still lacking. Based on observational and reanalysis data and atmospheric model simulations, this dissertation investigates the IPO’s influence on regional climates over the globe, and its interactions with El Niño-Southern Oscillation (ENSO) and global warming.


A Southern Hemisphere Sea Level Pressure-Based Precursor For Enso Warm And Cold Events, B. D. Hamlington, R. F. Milliff, H. Van Loon, K.-Y. Kim Jan 2015

A Southern Hemisphere Sea Level Pressure-Based Precursor For Enso Warm And Cold Events, B. D. Hamlington, R. F. Milliff, H. Van Loon, K.-Y. Kim

CCPO Publications

Past studies have described large-scale sea level pressure (SLP) variations in the Southern Hemisphere that lead to El Nino-Southern Oscillation (ENSO) warm and cold events (WE and CE). By relying on this description and the importance of the related variability in the lead up to WE and CE, Southern Hemisphere SLP variations in May-June-July (MJJ) are shown here to be excellent predictors for the peak warm/cold events in sea-surface temperatures (SST) and sea level pressure that mark the mature phase of a warm/cold event in November-January of the same year. Cyclostationary empirical orthogonal functions (CSEOFs) are used to extract the …


Long Term Ground Based Precipitation Data Analysis: Spatial And Temporal Variability, Luciano Rodriguez, Cyril S. Rakovski, Hesham El-Askary, Mohamed Allali Dec 2014

Long Term Ground Based Precipitation Data Analysis: Spatial And Temporal Variability, Luciano Rodriguez, Cyril S. Rakovski, Hesham El-Askary, Mohamed Allali

Student Scholar Symposium Abstracts and Posters

California is an area of diverse topography and has what many scientists call a Mediterranean climate. Various precipitation patterns exist due to El Niño Southern Oscillation (ENSO) which can cause abnormal precipitation or droughts. As temperature increases mainly due to the increase of CO2 in the atmosphere, it is rapidly changing the climate of not only California but the world. An increase in temperature is leading to droughts in certain areas as other areas are experiencing heavy rainfall/flooding. Droughts in return are providing a foundation for fires harming the ecosystem and nearby population. Various natural hazards can be induced due …


An Analysis Of Surface Air Temperature Trends And Variability Along The Andes, Eric Franquist Jan 2013

An Analysis Of Surface Air Temperature Trends And Variability Along The Andes, Eric Franquist

Legacy Theses & Dissertations (2009 - 2024)

Climate change is difficult to study in mountainous regions such as the Andes since steep changes in elevation cannot always be resolved by climate models. However, it is important to examine temperature trends in this region as rises in surface air temperature are leading to the melting of tropical glaciers. Local communities rely on the glacier-fed streamflow to get their water for drinking, irrigation, and livestock. Moreover, communities also rely on the tourism of hikers who come to the region to view the glaciers. As the temperatures increase, these glaciers are no longer in equilibrium with their current climate and …


Review Of The Simulation Of The Precis Regional Climate Model Over Tropical South America Using Gcm And Reanalysis Lateral Boundary Conditions, Dana Mcglone Jan 2011

Review Of The Simulation Of The Precis Regional Climate Model Over Tropical South America Using Gcm And Reanalysis Lateral Boundary Conditions, Dana Mcglone

Legacy Theses & Dissertations (2009 - 2024)

High-resolution regional climate models (RCM) run over a limited domain are increasingly used to simulate seasonal to interannual climate variability over South America and to assess the spatiotemporal impact of future climate change under a variety of emission scenarios. Global climate models (GCM) are often too coarse to resolve local circulations and the topography of the Andes, leading to problems with simulation of temperature and precipitation patterns throughout the domain. A RCM model can also better represent the climate at a regional scale; however, they are subject to errors introduced by the driving global models. For this study, the Hadley …


Coupled Oceanic-Atmospheric Variability And U.S. Streamflow, Glenn A. Tootle, Thomas C. Piechota, Ashok Singh Dec 2005

Coupled Oceanic-Atmospheric Variability And U.S. Streamflow, Glenn A. Tootle, Thomas C. Piechota, Ashok Singh

Civil and Environmental Engineering and Construction Faculty Research

A study of the influence of interdecadal, decadal, and interannual oceanic-atmospheric influences on streamflow in the United States is presented. Unimpaired streamflow was identified for 639 stations in the United States for the period 1951–2002. The phases (cold/negative or warm/positive) of Pacific Ocean (El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO)) and Atlantic Ocean (Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation (NAO)) oceanic-atmospheric influences were identified for the year prior to the streamflow year (i.e., long lead time). Statistical significance testing of streamflow, based on the interdecadal, decadal, and interannual oceanic-atmospheric phase (warm/positive or cold/negative), was performed by …