Physical Sciences and Mathematics Commons^™

Ocean Temperatures Do Not Account For A Record-Setting Winter In The U.S. West, Matthew D. Laplante, Liping Deng, Luthiene Dalanhese, Shih-Yu Wang

Journalism and Communication Faculty Publications

The record-setting winter of 2022–2023 came as an answer to both figurative and literal prayers for political leaders, policy makers, and water managers reliant on snowpacks in the Upper Colorado River Basin, a vital source of water for tens of millions of people across the Western United States. But this “drought-busting” winter was not well-predicted, in part because while interannual patterns of tropical ocean temperatures have a well-known relationship to precipitation patterns across much of the American West, the Upper Colorado is part of a liminal region where these connections tend to be comparatively weak. Using historical sea surface temperature …

Hydroclimate Effects On Great Salt Lake Decline Since 1980, Siiri Joy Bigalke

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

As a terminal basin lake, the Great Salt Lake (GSL) is known to act as a barometer for low frequency climate variability for the Western United States. As thus, there are naturally occurring large changes to GSL elevation levels that vary on time scales from years to decades. However, amongst these naturally occurring interannual changes there has been a significant declining trend in the elevation levels since a string of anomalous pluvial years in the early 1980s. In the summer of 2022, the Great Salt Lake reached its lowest levels in recorded history, which coincided with a two-decades long regional …

Remote Ocean Forcing On Interannual-To-Decadal Climate Variability Through Inter-Basin Interactions, Zachary F. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation explores the connection between ocean basins through the atmosphere by employing observational data analyses and a climate modeling approach. Sea surface temperature changes in the tropical Pacific, known as the El Niño Southern Oscillation, can influence worldwide weather and sea surface temperatures in other ocean basins. For instance, tropical Pacific sea surface temperatures can impact the Atlantic and Indian Oceans through airflow changes along the equator. However, Atlantic and Indian Ocean sea surface temperature changes can also influence the tropical Pacific through similar processes. Therefore, it is challenging to identify the mechanisms of these remote connections between ocean …

Ocean Impacts On Australian Interannual To Decadal Precipitation Variability, Zachary F. Johnson, Yoshimitsu Chikamoto, Jing-Jia Luo, Takashi Mochizuki

Plants, Soils, and Climate Faculty Publications

In Australia, successful seasonal predictions of wet and dry conditions are achieved by utilizing the remote impact of sea surface temperature (SST) variability in tropical oceans, particularly the Pacific Ocean, on the seasonal timescale. Beyond seasonal timescales, however, it is still unclear which processes and oceans contribute to interannual-to-decadal wet/dry conditions in Australia. This research examines the interannual-to-decadal relationship between global SST anomalies (SSTAs) and Australian wet/dry variability by analyzing observational data and global climate model experiments conducted with the NCAR Community Earth System Model (CESM) and the Model for Interdisciplinary Research on Climate (MIROC). A 10-member ensemble simulation suite …

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 …

Observational And Synoptic Analyses Of The Winter Precipitation Regime Change Over Utah, Robert R. Gillies, Shih-Yu Wang, Marty R. Booth

Plants, Soils, and Climate Faculty Publications

Previous studies have indicated a widespread decline in snowpack over Utah accompanied by a decline in the snow–precipitation ratio while anecdotal evidence claims have been put forward that measured changes in Utah’s snowpack are spurious and do not reflect actual change. Using two distinct lines of investigation, this paper further analyzes the winter precipitation regime in the state of Utah. First, by means of observation-based, gridded daily temperature, precipitation, and remotely sensed data, as well as utilizing a climatological rain–snow threshold (RST) temperature method, the precipitation regime of Utah was scrutinized. Second, a comprehensive synoptic analysis was conducted as an …

Potential Regional Impacts Of Global Warming On Precipitation In The Western United States, United States Department Of The Interior, Bureau Of Reclamation

Meterology

Snow and melting of the snowpack provide the principal supply of water to much of the Western United States. Whether global warming threatens this water supply is the focus of this research. This study builds upon a previous Global Climate Change Response Program investigation. Charts were generated of four geopotential height parameters for a domain covering the eastern North Pacific Ocean and western North America. Out of 131 total winter months (from 1946-89), 35 were selected as analogues.

Monthly mean precipitation values for areas in western Montana, northern Utah, and east central Arizona were compared with median values for the …

Precipitation Gauge Testing On The Wasatch Plateau, Utah, During Early 1993, United States Department Of The Interior, Bureau Of Reclamation

Meterology

The Bureau of Reclamation performed an independent evaluation of an ETI (Electronic Techniques, Inc.) precipitation gauge at the High Altitude Site on the western slope of the Wasatch Plateau in central Utah. The ETI gauge could provide a desirable alternative to conventional recording gauges in several applications, including evaluation of cloud seeding projects, if it performs as advertised. The testing program was intended to determine its performance in a winter mountain environment. The ETI precipitation gauge proved to be reliable from time of installation in late November 1992 until removal in late March 1993. The only problem found was an …