Physical Sciences and Mathematics Commons^™

Last Millennium Hurricane Activity Linked To Endogenous Climate Variability, Wenchang Yang, Elizabeth Wallace, Gabriel A. Vecchi, Jeffrey P. Donnelly, Julien Emile-Geay, Gregory J. Hakim, Larry W. Horowitz, Richard M. Sullivan, Robert Tardif, Peter J. Van Hengstum, Tyler S. Winkler

OES Faculty Publications

Despite increased Atlantic hurricane risk, projected trends in hurricane frequency in the warming climate are still highly uncertain, mainly due to short instrumental record that limits our understanding of hurricane activity and its relationship to climate. Here we extend the record to the last millennium using two independent estimates: a reconstruction from sedimentary paleohurricane records and a statistical model of hurricane activity using sea surface temperatures (SSTs). We find statistically significant agreement between the two estimates and the late 20th century hurricane frequency is within the range seen over the past millennium. Numerical simulations using a hurricane-permitting climate model suggest …

Precipitation Variability And Predictability Over The Arabian Peninsula, Central Southwest Asia, And Southern Africa, Matthew Francis Horan

Doctoral Dissertations

The Northern Hemisphere winter is the main rainy season for the Arabian Peninsula (AP), Central Southwest Asia (CSWA), and Southern Africa (SF), where precipitation predictability is limited or understudied. This dissertation research focuses on improving our understanding of these regions' wet-season precipitation characteristics and predictability.

First, I have identified the AP's key moisture sources through a Lagrangian back-trajectory algorithm. Mid-latitude land and water bodies, such as the Mediterranean and Caspian Seas, are the primary moisture sources in the northern region. Areas further south rely on moisture transport from the Western Indian Ocean and the African continent. A significant drying trend …

Acceleration Of U.S. Southeast And Gulf Coast Sea-Level Rise Amplified By Internal Climate Variability, Sönke Dangendorf, Noah Hendricks, Qiang Sun, John Klinck, Tal Ezer, Thomas Frederikse, Francisco M. Calafat, Thomas Wahl, Torbjörn E. Törnqvist

CCPO Publications

While there is evidence for an acceleration in global mean sea level (MSL) since the 1960s, its detection at local levels has been hampered by the considerable influence of natural variability on the rate of MSL change. Here we report a MSL acceleration in tide gauge records along the U.S. Southeast and Gulf coasts that has led to rates (>10 mm yr⁻¹ since 2010) that are unprecedented in at least 120 years. We show that this acceleration is primarily induced by an ocean dynamic signal exceeding the externally forced response from historical climate model simulations. However, when the …

Getting Ahead Of Flash Drought: From Early Warning To Early Action, Jason A. Otkin, Molly Woloszyn, Hailan Wang, Mark D. Svoboda, Marina Skumanich, Roger Pulwarty, Joel Lisonbee, Andrew Hoell, Mike Hobbins, Tonya Haigh, Amanda E. Cravens

Drought Mitigation Center: Faculty Publications

Flash droughts, characterized by their unusually rapid intensification, have garnered increasing attention within the weather, climate, agriculture, and ecological communities in recent years due to their large environmental and socioeconomic impacts. Because flash droughts intensify quickly, they require different early warning capabilities and management approaches than are typically used for slower-developing “conventional” droughts. In this essay, we describe an integrated research-and-applications agenda that emphasizes the need to reconceptualize our understanding of flash drought within existing drought early warning systems by focusing on opportunities to improve monitoring and prediction. We illustrate the need for engagement among physical scientists, social scientists, operational …

Impact Of Climate Oscillations/Indices On Hydrological Variables In The Mississippi River Valley Alluvial Aquifer., Meena Raju

Theses and Dissertations

The Mississippi River Valley Alluvial Aquifer (MRVAA) is one of the most productive agricultural regions in the United States. The main objectives of this research are to identify long term trends and change points in hydrological variables (streamflow and rainfall), to assess the relationship between hydrological variables, and to evaluate the influence of global climate indices on hydrological variables. Non-parametric tests, MMK and Pettitt’s tests were used to analyze trend and change points. PCC and Streamflow elasticity analysis were used to analyze the relationship between streamflow and rainfall and the sensitivity of streamflow to rainfall changes. PCC and MLR analysis …

Climate Adaptation For Tropical Island Land Stewardship: Adapting A Workshop Planning Process To Hawai'i, Ryan J. Longman, Courtney L. Peterson, Madeline Baroli, Abby G. Frazier, Zachary Cook, Elliott W. Parsons, Maude Dinan, Katie L. Kamelamela, Caitriana Steele, Reanna Burnett, Chris Swanston, Christian P. Giardina

Geography

No abstract provided.

Quantification Of Climate Variability And Extreme Events In The Great Plains, Angelinah Ntsieng Rasoeu

Electronic Theses and Dissertations

Climate variability and extreme events continue to worsen resulting in significant impacts to society and the environment. Quantifying precipitation variability, streamflow, and extreme events at local scale is crucial for local planning and management due to spatial and temporal precipitation variability which influences streamflow and thus, water resources. This study uses statistical tools to analyze 1895-2019 (125 years) of historical precipitation data to examine how long-term precipitation varies annually, seasonally, and monthly, and create climate classifications. The results show that annual precipitation is increasing linearly over time ranging from 13.2 in (1976) to 43.1 in (2010) and 5 climate classes …

Response Of Coastal Ichthyoplankton Assemblages Off Northern California To Seasonal Oceanographic And Climate Variability, Blair M. Winnacott

Cal Poly Humboldt theses and projects

This study analyzed samples collected along the Trinidad Head Line (41°N) to characterize variability in the ichthyoplankton assemblage in coastal waters off northern California from late 2007 through 2019, a period during which a major marine heatwave (MHW; late 2014-16) strongly perturbed the ecosystem. I augmented visual identification with genetic techniques to resolve the species composition of visually cryptic larval rockfishes (Sebastes spp.). While taxonomic composition off northern California was largely similar to studies off Oregon and Washington, and cross-shelf structure and seasonal patterns in species’ abundance were generally consistent with the distribution and phenology of parental stocks, interannual …

Dynamical Downscaling Of Near-Term Climate Variability And Change For The Main Hawaiian Islands Using Wrf, Katrina Marie Fandrich

Legacy Theses & Dissertations (2009 - 2024)

As climate models continue to improve, the demand from resource managers and decision-makers for more accurate climate projections is increasing. However, natural climate variability poses a limit to the confidence in regional climate change projections, particularly for the mid-21st century. The unique geographic location of the Hawaiian Islands and its regional climate provide a challenging opportunity for climate modelers. The goal of this project is to examine both the Pacific Decadal Oscillation (PDO) and anthropogenic climate change for their impacts on near-term rainfall and temperature projections for the Hawaiian Islands. Of primary interest are the questions 1) is there a …

Multiple Impact Pathways Of The 2015–2016 El Niño In Coastal Kenya, Matt Fortnam, Molly Atkins, Katrina Brown, Tomas Chaigneau, Ankje Frouws, Kemyline Gwaro, Mark Huxham, James Kairo, Amon Kimeli, Bernard Kirui, Katy Sheen

Research outputs 2014 to 2021

© 2020, The Author(s). The 2015–2016 El Niño had large impacts globally. The effects were not as great as anticipated in Kenya, however, leading some commentators to call it a ‘non-event’. Our study uses a novel combination of participatory Climate Vulnerability and Capacity Analysis tools, and new and existing social and biophysical data, to analyse vulnerability to, and the multidimensional impacts of, the 2015–2016 El Niño episode in southern coastal Kenya. Using a social-ecological systems lens and a unique dataset, our study reveals impacts overlooked by conventional analysis. We show how El Niño stressors interact with and amplify existing vulnerabilities …

Impacts Of Basin-Scale Climate Modes On Coastal Sea Level: A Review, Weiqing Han, Detlef Stammer, Philip Thompson, Tal Ezer, Hindu Palanisamy, Xuebin Zhang, Catia M. Domingues, Lei Zhang, Dongliang Yuan

CCPO Publications

Global sea level rise (SLR) associated with a warming climate exerts significant stress on coastal societies and low-lying island regions. The rates of coastal SLR observed in the past few decades, however, have large spatial and temporal differences from the global mean, which to a large part have been attributed to basin-scale climate modes. In this paper, we review our current state of knowledge about climate modes’ impacts on coastal sea level variability from interannual-to-multidecadal timescales. Relevant climate modes, their impacts and associated driving mechanisms through both remote and local processes are elaborated separately for the Pacific, Indian and Atlantic …

Exploring The Relationship Between Climate And Forest Conditions In Forest Classee De La Mondah (Gabon) Using Remote Sensing Data, Mariano Mboumba

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

This study aims to examine the relationship between temperature and precipitation as climatic factors and the vegetation characteristics in Forêt Classée de la Mondah (Gabon). A pixel based spatial analysis procedure with QGIS was used to extract vegetation characteristics from MODIS on Terra, NDVI band, data from February 2000 to December 2015, while temperature and precipitation were monitored from January 1980 to December 2015 to highlight climate fluctuations in the study area. Two regression analyses were conducted : one between temperature and NDVI and the other one between precipitation and NDVI. Results showed that temperature and precipitation did not vary …

Total And Extreme Precipitation Changes Over The Northeastern United States, Huanping Huang, Jonathan M. Winter, Erich C. Osterberg, Radley M. Horton, Brian Beckage

College of Agriculture and Life Sciences Faculty Publications

The northeastern United States has experienced a large increase in precipitation over recent decades. Annual and seasonal changes of total and extreme precipitation from station observations in the Northeast were assessed over multiple time periods spanning 1901-2014. Spatially averaged, both annual total and extreme precipitation across the Northeast increased significantly since 1901, with changepoints occurring in 2002 and 1996, respectively. Annual extreme precipitation experienced a larger increase than total precipitation; extreme precipitation from 1996 to 2014 is 53% higher than from 1901 to 1995. Spatially, coastal areas receive more total and extreme precipitation on average, but increases across the changepoints …

On The Relationship Between Spring Nao And Snowmelt In The Upper Southwestern United States, Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study examines the relationship between the North Atlantic Oscillation (NAO) and snowmelt in spring in the upper southwestern states of the United States (UP_SW) including California, Nevada, Utah, and Colorado, using SNOTEL datasets for 34 yr (1980–2014). Statistically significant negative correlations are found between NAO averages in the snowmelt period and timings of snowmelt (i.e., positive NAO phases in spring enhance snowmelt, and vice versa). It is also found that correlations between El Niño–Southern Oscillation and snowmelt are negligible in the region. The NAO–snowmelt relationship is most pronounced below the 2800-m level; above this level, the relationship becomes weaker. …

Gridded Snow Water Equivalent Reconstruction For Utah Using Forest Inventory And Analysis Tree-Ring Data, Daniel Barandiaran, Shih-Yu (Simon) Wang, R. Justin Derose

Plants, Soils, and Climate Faculty Publications

Snowpack observations in the Intermountain West are sparse and short, making them difficult for use in depicting past variability and extremes. This study presents a reconstruction of April 1 snow water equivalent (SWE) for the period of 1850–1989 using increment cores collected by the U.S. Forest Service, Interior West Forest Inventory and Analysis program (FIA). In the state of Utah, SWE was reconstructed for 38 snow course locations using a combination of standardized tree-ring indices derived from both FIA increment cores and publicly available tree-ring chronologies. These individual reconstructions were then interpolated to a 4-km grid using an objective analysis …

Is The Detection Of Accelerated Sea Level Rise Imminent?, J. T. Fasullo, R. S. Nerem, B. Hamlington

CCPO Publications

Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking …

Slides: Water Allocation And Water Markets In Spain, Nuria Hernández-Mora

Coping with Water Scarcity in River Basins Worldwide: Lessons Learned from Shared Experiences (Martz Summer Conference, June 9-10)

Presenter: Nuria Hernández Mora, Universidad de Sevilla, Spain

22 slides

Long-Term Trend Analysis Of Precipitation And Air Temperature For Kentucky, United States, Somsubhra Chattopadhyay, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Variation in quantities such as precipitation and temperature is often assessed by detecting and characterizing trends in available meteorological data. The objective of this study was to determine the long-term trends in annual precipitation and mean annual air temperature for the state of Kentucky. Non-parametric statistical tests were applied to homogenized and (as needed) pre-whitened annual series of precipitation and mean air temperature during 1950–2010. Significant trends in annual precipitation were detected (both positive, averaging 4.1 mm/year) for only two of the 60 precipitation-homogenous weather stations (Calloway and Carlisle counties in rural western Kentucky). Only three of the 42 temperature-homogenous …

Regional Variations Of Optimal Sowing Dates Of Maize For The Southwestern U.S., Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Sowing date (SD) is sensitive to regional climate characteristics; thus, it is critical to systematically examine the effects of SD on crop yields for various temperature regimes. We performed a sensitivity study of SD for maize in the southwestern U.S. using the regionally extended version of the Agricultural Production Systems sIMulator (APSIM) model. The model was run utilizing North American Regional Reanalysis at a 32 km resolution from 1991 to 2011, with an irrigation threshold at 95% of the soil water-holding capacity. Two types of SD optimizations maximizing yield potential (Yp), varying spatially or interannually, revealed that the optimal SD …

The Effect Of The El Nino-Southern Oscillation On U.S. Regional And Coastal Sea Level, B. D. Hamlington, R. R. Leben, K. -Y. Kim, R. S. Nerem, L. P. Atkinson, P. R. Thompson

CCPO Publications

Although much of the focus on future sea level rise concerns the long-term trend associated with anthropogenic warming, on shorter time scales, internal climate variability can contribute significantly to regional sea level. Such sea level variability should be taken into consideration when planning efforts to mitigate the effects of future sea level change. In this study, we quantify the contribution to regional sea level of the El Niño-Southern Oscillation (ENSO). Through cyclostationary empirical orthogonal function analysis (CSEOF) of the long reconstructed sea level data set and of a set of U.S. tide gauges, two global modes dominated by Pacific Ocean …

Navigating A Pathway Toward Colorado's Water Future: A Review And Recommendations On Colorado's Draft Water Plan, Lawrence J. Macdonnell, Colorado Water Working Group

Books, Reports, and Studies

40 pages (includes color illustrations).

Effects Of Climate Oscillations On Wind Resource Variability In The United States, B. D. Hamlington, P. E. Hamlington, S. G. Collins, S. R. Alexander, K.-Y. Kim

CCPO Publications

Natural climate variations in the United States wind resource are assessed by using cyclostationary empirical orthogonal functions (CSEOFs) to decompose wind reanalysis data. Compared to approaches that average climate signals or assume stationarity of the wind resource on interannual time scales, the CSEOF analysis isolates variability associated with specific climate oscillations, as well as their modulation from year to year. Contributions to wind speed variability from the modulated annual cycle (MAC) and the El Nino-Southern Oscillation (ENSO) are quantified, and information provided by the CSEOF analysis further allows the spatial variability of these effects to be determined. The impacts of …

A Historical Perspective On Nebraska’S Variable And Changing Climate, Martha Shulski, William Baule, Crystal J. Stiles, Natalie A. Umphlett

High Plains Regional Climate Center: Personnel Publications

Nebraska is situated at the intersection of the northern and southern Great Plains, exhibiting a dramatic longitudinal gradient for precipitation and humidity, and benefiting from groundwater resources. The continental climate is highly variable temporally both for temperature and precipitation. Our assessment of long-term meteorological observations shows that over the last century the annual average temperature in Nebraska has warmed approximately 0.6°C, which is similar to the increase in the global average temperature over the same time period. Furthermore, we found minimum temperatures have warmed more than maximum temperatures, and winter and spring show the strongest warming. We found no significant …

The Hard Winter Of 1880-1881: Climatological Context And Communication Via A Laura Ingalls Wilder Narrative, Barbara Boustead

School of Natural Resources: Dissertations, Theses, and Student Research

The Hard Winter of 1880-1881 was featured in the Laura Ingalls Wilder historical fiction account, The Long Winter, as well as in several town histories across the region. Both meteorological records and historical accounts indicate that the winter was particularly long, snowy, and cold. The question of how “hard” a winter is for a given location depends on the climatological context, which relies on an objective characterization of winter severity. The Accumulated Winter Season Severity Index (AWSSI) allows comparison of the winter of 1880-1881 among sites across the region, as well as in the context of the period of …

Slides: Is There A Dust Bowl In Our Future?: Projections For The Eastern Rockies And Central Great Plains, Dennis Ojima

Water, Climate and Uncertainty: Implications for Western Water Law, Policy, and Management (Summer Conference, June 11-13)

Presenter: Dennis Ojima, Senior Research Scientist, Natural Resource Ecology Laboratory, Colorado State University (NREL/CSU)

30 slides

Slides: A History Of Climate Variability And Change In The American West, Kelly T. Redmond

Water, Climate and Uncertainty: Implications for Western Water Law, Policy, and Management (Summer Conference, June 11-13)

Presenter: Kelly T. Redmond, Regional Climatologist, Western Regional Climate Center (WRCC), Desert Research Institute

65 slides

Contribution Of The Pacific Decadal Oscillation To Global Mean Sea Level Trends, B. D. Hamlington, R. R. Leben, M. W. Strassburg, R. S. Nerem, K-Y. Kim

CCPO Publications

Understanding and explaining the trend in global mean sea level (GMSL) have important implications for future projections of sea level rise. While measurements from satellite altimetry have provided accurate estimates of GMSL, the modern altimetry record has only now reached 20 years in length, making it difficult to assess the contribution of decadal to multidecadal climate signals to the global trend. Here, we use a sea level reconstruction to study the 20 year trends in sea level since 1950. In particular, we show that the Pacific Decadal Oscillation (PDO) contributes significantly to the 20 year trends in GMSL. We estimate …

Agenda: Navigating The Future Of The Colorado River, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Competition for scarce Colorado River water resources is nothing new, but the conflicts that prompted the seven basin states to negotiate the 1922 Colorado River Compact have grown considerably fiercer and more complex in recent decades. In 2007, responding to the challenges of increasing demand and sustained drought, the seven basin states and a number of other affected interests agreed to a set of interim guidelines for allocating Colorado River water in the event of shortages. This agreement represents an important evolution in the governance of the Colorado River, suggesting that the many interests in the basin can work together …

Ice Layers As An Indicator Of Summer Warmth And Atmospheric Blocking In Alaska, Eric P. Kelsey, Cameron P. Wake, Karl Kreutz, Erich Osterberg

Dartmouth Scholarship

No abstract provided.

U.S.-Globec: Nep Phase Iiib-Cgoa: A Synthesis Of Climate-Forced Variability On Mesoscale Structure In The Cgoa With Direct Comparisons To The Ccs, Andrew C. Thomas

University of Maine Office of Research Administration: Grant Reports

A variety of extreme climate events occurred during the period of US GLOBEC monitoring and process studies in the NEP (1997-2004). These provide an unprecedented opportunity to examine a range of climate variability experienced by the coastal Gulf of Alaska (CGOA). By relating these climate events to regional physical and biological observations, using multiple and diverse data sources (GLOBEC observations, historical data sets and reanalyses, satellites, models), we can determine how these events affect mesoscale ocean variability in the CGOA and its related target populations (the primary goal of the NEP program). We can then directly compare these responses to …