Climate Commons^™

Bay Of Bengal: Coupling Of Pre-Monsoon Tropical Cyclones With The Monsoon Onset In Myanmar, Boniface Opoku Fosu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Myanmar remained largely closed to the world through political instability for several years, when it continued to suffer terribly at the hands of nature that remained largely unknown. Of note is the period between 2008 and 2013, during which the country suffered at least eight major natural calamities that killed more than 141,000 people and affected 3.2 million. The worst of these was Cyclone Nargis in May 2008 that killed more than 130,000. With an estimated $4 billion in damages, Nargis remains the deadliest and most destructive named cyclone ever to have occurred in the North Indian Ocean. Recent studies …

Global Eastward Propagation Signals Associated With The 4-5-Year Enso Cycle, Shih-Yu (Simon) Wang, X. Jiang, B. Fosu

Plants, Soils, and Climate Faculty Publications

Longitude-time evolution of sea surface temperature anomalies (SSTA) reveals a slow southeastward propagation from the western North Pacific (WNP) around 20°N to the Niño-3.4 region in the equatorial Central Pacific. The propagation is manifested as a narrow, southwest-northeast oriented SSTA band across the subtropical North Pacific, and its journey takes about 2–3 years. The propagating SSTA appears to engage the initiation of the El Niño–Southern Oscillation (ENSO). The anomalies of surface winds, sea level pressure, outgoing longwave radiation, and velocity potential all exhibit a concurrent and distinct eastward propagation, one that appears to be circumglobal and is coupled with the …

Could The 2012 Drought In Central U. S. Have Been Anticipated?, Shih-Yu (Simon) Wang, Danny Barandiaran, Kyle Hilburn, Paul Houser

Plants, Soils, and Climate Faculty Publications

This paper summarizes research related to the 2012 record drought in the central United States conducted by members of the NEWS (NASA (National Aeronautics and Space Administration) Energy and Water cycle Study) Working Group. Past drought patterns were analyzed for signal coherency with latest drought and the contribution of long-term trends in the Great Plains low-level jet, an important regional circulation feature of the spring rainy season in the Great Plains. Long-term changes in the seasonal transition from rainy spring into dry summer were also examined. Potential external forcing from radiative processes, soil-air interactions, and ocean teleconnections were assessed as …

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 …

Coupling Of Pre-Monsoon Tropical Cyclones With The Monsoon Onset In Myanmar, B. O. Fosu, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

The pre-monsoon tropical cyclone (TC) activity and the monsoon evolution in the Bay of Bengal (BoB) are both influenced by the Madden–Julian Oscillation (MJO), but the two do not always occur in unison. This study examines the conditions that allow the MJO to modulate the monsoon onset in Myanmar and TC activity concurrently. Using the APHRODITE gridded precipitation and the ERA-Interim reanalysis datasets, composite evolutions of monsoon rainfall and TC genesis are constructed for the period of 1979–2010. It is found that the MJO exhibits a strong interannual variability in terms of phase and intensity, which in some years modulate …

Identification Of Extreme Precipitation Threat Across Midlatitude Regions Based On Short-Wave Circulations, Shih-Yu (Simon) Wang, Robert E. Davies, Robert R. Gillies

Plants, Soils, and Climate Faculty Publications

The most severe thunderstorms, producing extreme precipitation, occur over subtropical and midlatitude regions. Atmospheric conditions conducive to organized, intense thunderstorms commonly involve the coupling of a low-level jet (LLJ) with a synoptic short wave. The midlatitude synoptic activity is frequently modulated by the circumglobal teleconnection (CGT), in which meridional gradients of the jet stream act as a guide for short Rossby waves. Previous research has linked extreme precipitation events with either the CGT or the LLJ but has not linked the two circulation features together. In this study, a circulation-based index was developed by combining (a) the degree of the …

Rayleigh Lidar Temperature Studies In The Upper Mesosphere And Lower Thermosphere, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Matthew T. Emerick

Posters

Rayleigh lidar technology opened the middle atmosphere (from 30–90 km) to ground-based observations. The upgraded system at the Atmospheric Lidar Observatory (ALO) on the campus of Utah State University (41.74, 111.81) has shown that these ground-based observations can be extended to 109 km, with the goal of reaching 120 km. The resultant study of short and long-term temperature trends, using Rayleigh lidar, contributes immensely to the overall understanding of the properties and dominant physical processes in the middle atmosphere and Mesosphere-Lower Thermosphere (MLT) region. Temperature variations on short time scales, from minutes to days, give insight into the effects of …

Colorado River Cutthroat Trout Habitat Resistance And Resilience To Climate Change, Kate H. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Government agencies and private organizations spend large amounts of public money attempting to return ecosystems to a more natural state, which have often been harmed or even destroyed as a result of modern development. Colorado River cutthroat trout, Oncorhyncus clarki pleuriticus, are a subspecies of cutthroat trout. Cutthroat trout live in the Rocky Mountains of the western United States. The population of this particular subspecies has been severely reduced by human actions, and currently only 12% of its historic populations still exist. To improve the condition of cutthroat trout, fisheries professionals and biologists are working to restore natural populations. …

First Temperature Observations With The Usu Very Large Rayleigh Lidar: An Examination Of Mesopause Temperatures, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Marcus J. Bingham, Lance W. Petersen, Matthew T. Emerick

Posters

As the impetus for extended observational measurements throughout the middle atmosphere has increased1 , the limits of previous instrumentation need to be pushed. The Rayleigh lidar group at the Atmospheric Lidar Observatory (ALO) at Utah State University has pushed such limits on existing Rayleigh scatter lidar technology and, through major upgrades to the previous lidar system, has been able to gather temperature measurements in the upper mesosphere and lower thermosphere from approximately 70P109 km. A data campaign with the new system was conducted around the annual temperature minimum, centered on late June 2012, in this region. The temperatures from this …

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 …

Upgraded Alo Rayleigh Lidar System And Its Improved Gravity Wave Measurements, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Marcus J. Bingham

Graduate Student Posters

The Rayleigh-Scatter lidar system at the Atmospheric Lidar Observatory (ALO) on the Utah State campus is currently going through a series of upgrades to significantly improve its observational abilities. A specific objective of these upgrades is to expand the altitude range over which backscattered photons can be collected. A second objective is to increase the sensitivity of the instrument to be able to analyze the raw data at finer temporal and/or spatial resolutions. By measuring relative densities, the system will be able to produce absolute temperatures and relative density perturbations, which illustrate gravity wave structures. Gravity wave studies will significantly …

Observations With The Most Sensitive Rayleigh-Scatter Lidar, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Marcus J. Bingham

Graduate Student Posters

The mesosphere is the most unexplored region of the atmosphere. Its altitude range of 50-85 km lies in between the reaches of data collecting instruments like weather balloons and satellites. For this reason, remote sensing systems, such as lidar, which are able to employ ground-based instruments to make extensive measurements in this difficult to detect region. The Rayleigh-scatter lidar at USU is currently being redeveloped to be the most powerful and sensitive of its kind. This type of lidar exploits light and particle interactions, like those that account for the blue color of the sky, to make relative density and …

Connecting Subseasonal Movements Of The Winter Mean Ridge In Western North America To Inversion Climatology In Cache Valley, Utah, Shi-Yu (Simon) Wang, Robert R. Gillies, Randy Martin, Robert E. Davies, Marty R. Booth

Plants, Soils, and Climate Faculty Publications

A 10-yr record of PM2.5 (particulate matter of aerodynamic diameter ≤ 2.5 μm), collected in Cache Valley near downtown Logan, Utah, reveals a strong peak in the PM2.5 concentration climatology that is tightly localized in mid-January. The cause of this subseasonal variation in the PM2.5 climatology is investigated through dynamical downscaling and large-scale diagnostics. Climatological analysis of the U.S. winter mean ridge reveals a mid-January subseasonal shift in the zonal direction, likely in response to variations in the Rossby wave source over the central North Pacific Ocean. This displacement of the winter mean ridge, in turn, has an impact on …

03 Characteristics Of The Quasi-16 Day Wave In The Mesosphere And Lower Thermosphere (Mlt): A Review Over An Equatorial Station Thumba (8.50n, 76.50e), Siddarth Shankar Das

Modern Climatology

To understand the climate variability and weather prediction in the Earth’s atmosphere, measurements of winds, temperature and wave activities are very crucial. The Earth’s atmosphere is believed to act as a source and sink for the waves of a broader spectrum with periods from few seconds to years. Generally, the Earth’s atmosphere is stably stratified except the planetary boundary layer and thus makes a reasonable assumption for the presence of atmospheric waves. A barotropic atmosphere in a resting basic state is able to support these spectra of waves. These waves move diagonally upward or downward and horizontally. The mean zonal …

01 Southern Hemisphere Tropical Cyclone Climatology, Yuriy Kuleshov

Modern Climatology

Southern Hemisphere Tropical Cyclone Climatology:

Each year, around 80 tropical cyclones (TCs) form around the world, with about one-third of them in the Southern Hemisphere (SH) (Gray, 1979). Tropical cyclones within the South Indian Ocean (SIO) and the South Pacific Ocean (SPO) are frequent and intense, and they dramatically affect maritime navigation and the lives of communities in coastal areas. Australia and the island nations are affected each year by TCs. In extreme cases they can have devastating consequences on life, property and the economic well-being of the communities directly affected and the country as a whole, as in the …

12 On The Relationship Between Boundary Layer Convergence And Cloud-To-Ground Lightning, Michael L. Gauthier

Modern Climatology

It is generally accepted that significant electrification, and subsequent lightning generation, in clouds is attained via non-inductive charging (NIC) when sufficient numbers of ice crystals collide with graupel particles in the presence of supercooled liquid water [e.g. Saunders et al., 1991; Jayaratne et al., 1983; Takahashi, 1978]. As these particle scale interactions are driven by vertical motions it can be argued that, under appropriate thermodynamical and microphysical conditions, any process that enhances updraft strength should also enhance the storms ability to generate lightning. Constrained by mass continuity, updrafts leading to deep moist convection are necessarily associated with sub-cloud horizontal mass …

14 Rainfall Prediction Using Teleconnection Patterns Through The Application Of Artificial Neural Networks, Gholam Abbas Fallah-Ghalhari

Modern Climatology

All aspects of human life are, directly or indirectly, affected by climatic processes. This effect is especially noticeable in such fields as agriculture, irrigation, economy, telecommunications, transportation, traffic, air pollution and military industries (Haltiner & Williams 1980). A number of researchers have studied the possibility of forecasting rainfall several months in advance using climate indices such as SOI, PDOI and NPI (e.g. Silverman and Dracup 2000). A well-known atmospheric phenomenon is the Southern Oscillation (SO). The SO is an atmospheric see-saw process in the tropical Pacific sea level pressure between the eastern and western hemispheres associated with the El Niño …

13 Synthesizing High-Resolution Climatological Wind Fields With A Mesoscale Atmospheric Boundary Layer Model Forced With Local Weather Observations, Guillermo J. Berri

Modern Climatology

The region of the La Plata River in southeastern South America (see Fig. 1) concentrates important economic and social activities since one third of the population of Argentina and more than one half the population of Uruguay live there. Large urban complexes, different commercial activities and important industries are located along its shores. In addition, the La Plata River and its tributary the Paraná River are main ship tracks with some of the largest ports of the southern cone of South America. Therefore, the region is of vital importance for the two countries. The La Plata River is a large …

10 Cenozoic Climatic Record For Monsoonal Rainfall Over The Indian Region, Mohan Kuppusamy, Prosenjit Ghosh

Modern Climatology

Atmospheric carbon dioxide level is one of the major drivers responsible for the global temperature change (Lacis et al., 2010). The role of carbon dioxide as an important greenhouse gas, and its contribution towards regulation of global surface temperature has been recognized for over a century (Arrhenius, 1896; Chamberlin, 1899; Royer, 2006). The ice core records along with other proxy based records provides an evidence signifying a strong coupling between CO2 and global temperature for at least the last ~65 m.y. (million years) (Petit et al., 1999; Siegenthaler et al., 2005, Zachos et al., 2001). The intensification of convective hydrological …

09 Paleotempestology: Reconstructing Atlantic Tropical Cyclone Tracks In The Pre-Hurdat Era, Jill S.M. Coleman, Steven A. Lavoie

Modern Climatology

The study of past tropical cyclone activity by means of geological proxies and/or historical documentary records is known as paleotempestology. This scientific discipline has become prominent over the course of the last decade partially in response to the recent increase in tropical cyclone count and intensity in the North Atlantic basin witnessed since 1995. The field has also developed due to the socioeconomic impacts of tropical cyclones particularly along vulnerable coastal regions. During the twenty-five years prior to the start of the most recent increase in hurricane activity, major (Category 3, 4, or 5) hurricanes were less frequent than in …

08 Spatial And Temporal Variability Of Sea Surface Temperature In The Yellow Sea And East China Sea Over The Past 141 Years, Daji Huang, Xiaobo Ni, Qisheng Tang, Xiaohua Zhu, Dongfeng Xu

Modern Climatology

The Yellow Sea and East China Sea (YES) are marginal seas in the northwest Pacific. There is in fact a smaller sea, the Bohai Sea, to the north of the Yellow Sea. For most discussions in the chapter, we shall treat the Bohai Sea as part of the Yellow Sea. The YES is one of the mostly intensively utilized sea in the world, for example, heavy fishery and marine aquaculture. The use of the YES is closely related to its climate variability, though it is not well-know because until now there has been a lack of adequate observational data. To …

07 Climatology Of The Northern-Central Adriatic Sea, Aniello Russo, Sandro Carniel, Mauro Sclavo, Maja Krzelj

Modern Climatology

It is well know that the ocean processes exert a great influence on global climate as well as affect the local climate of coastal areas (Russo et al., 2002). Within the Mediterranean region (see Fig. 1a), the presence of the Adriatic Sea influences the atmospheric properties of the surrounding regions over long and short time-scales, and has obviously a relevant influence on human activities and ecosystems (Boldrin et al., 2009).

06 Climatology Of The U.S. Inter-Mountain West, Shih-Yu (Simon) Wang, Robert R. Gillies

Modern Climatology

The Inter-Mountain West (IMW) of North America is a region that lies between the Rocky Mountains to the east and the Cascades and Sierra Nevada to the west (Fig. 1). The climate of the IMW is generally semi-arid but this varies by location and elevation. An estimated 50- 80% of the IMW’s streams and rivers are fed by mountain snowpack (Marks and Winstral 2001), while the majority of the streams and rivers flow into desert sinks or closed-basin lakes such as the Great Salt Lake (Fig. 1). These streams and rivers create some agriculturally productive areas in the otherwise dry …

05 The South American Monsoon System: Climatology And Variability, Viviane B.S. Silva, Vernon E. Kousky

Modern Climatology

A typical Monsoon System is characterized by a reversal in the low-level wind direction between summer and winter seasons, and distinct wet (summer) and dry (winter) periods. The changes in low-level atmospheric circulation are related to changes in the thermal contrast between oceans and continents. During summer, the air over continents is warmer and more convectively unstable than air over adjacent oceanic regions. Consequently, lower pressure occurs over land and higher pressure occurs over nearby oceanic areas. This pressure pattern causes low-level moist air to converge onto the land, resulting in precipitation, especially during the late afternoon and evening hours. …

04 Thunderstorm And Lightning Climatology Of Australia, Yuriy Kuleshov

Modern Climatology

Thunderstorms are spectacular but hazardous weather phenomena and the associated lightning and wind gusts can be very hazardous to people, buildings, and industry and utility assets. The thunderstorm hazards in Australia are in most respects similar to those in other countries, but some are worthy of special comment. In some instances, the effects of lightning initiated bushfires are so extreme that they are classified as natural disasters. The wildfires started by lightning are known locally in Australia as bushfire and grass fires, and these can cause extensive damage and loss of life. The ignition is caused by the lightning current …

02 Indian Monsoon Depression: Climatology And Variability, Jin-Ho Yoon, Wan-Ru Huang

Modern Climatology

The monsoon climate is traditionally characterized by large amount of seasonal rainfall and reversal of wind direction (e.g., Krishnamurti 1979). Most importantly this rainfall is the major source of fresh water to various human activities such as agriculture. The Indian subcontinent resides at the core of the Southeast Asian summer monsoon system with the monsoon trough extended from northern India across Indochina to the Western Tropical Pacific (WTP). Large fraction of annual rainfall occurs during the summer monsoon season, i.e., June – August1, with two distinct maxima. One is located over the Bay of Bengal with rainfall extending northwestward into …

Modern Climatology - Full Text, Shih-Yu (Simon) Wang, Robert R. Gillies

Modern Climatology

Climatology, the study of climate, is no longer regarded as a single discipline that treats climate as something that fluctuates only within the unchanging boundaries described by historical statistics. The field has recognized that climate is something that changes continually under the influence of physical and biological forces and so, cannot be understood in isolation but rather, is one that includes diverse scientific disciplines that play their role in understanding a highly complex coupled “whole system” that is the Earth’s climate. The modern era of climatology is echoed in this book. On the one hand it offers a broad synoptic …

11 Climate Change: Is It More Predictable Than We Think?, Rafail V. Abramov

Modern Climatology

The global climate systemties togethermany physical variables, such as flow velocity, density, pressure, temperature, to name a few. The core equations of the climate system are the primitive evolution equations of the atmosphere and ocean (Lions et al., 1992a;b; 1993a;b; 1995; Majda, 2003), which directly involve the flow velocity (or, alternatively, streamfunction and vorticity), density and pressure. To incorporate the effects of other relevant physical processes which supply the energy to or draw it from the motion of the flow, the primitive equations are coupled to other physical processes through temperature, water vapor, ocean surface pressure, and other variables. The …

Pakistan's Two-Stage Monsoon And Links With The Recent Climate Change, Shih-Yu (Simon) Wang, Robert Davies, Wan Ru Huang, Robert R. Gillies

Plants, Soils, and Climate Faculty Publications

Meteorological conditions related to the Pakistan floods of 2010 were examined in the context of monsoon dynamics and large‐scale circulations. Case and climatological analyses suggest that summer precipitation in northern Pakistan comprises two distinct phases: (1) a premonsoon trough phase (July) whose rainfall is more episodic and intense, occurring prior to arrival of the monsoon trough, and (2) a monsoon trough phase (August) whose rainfall is persistent, yet less episodic, driven by northward migration of the monsoon trough. Analyses of conditional instability, moisture flux, and circulation features support a persistent increase in conditional instability during the July premonsoon trough phase, …

Individualistic Response Of Piñon And Juniper Tree Species Distributions To Climate Change In North America's Arid Interior West, Jacob R. Gibson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Piñon and juniper tree species have species-specific climatic requirements, resulting in unique distributions and differential responses to climate change. Piñons and junipers co-dominate the arid woodlands of North America as groups with widespread hybridization. Two piñons, Pinus edulis; P. monophylla, and four junipers, Juniperus deppeana var. deppeana; J. monosperma; J. occidentalis; J. osteosperma, are endemic to the midlatitude interior west and form three groups of hybridizing sister species, P. edulis-P. monophylla; J. deppeana var. deppeana-J. monosperma; J. occidentalis-J. osteosperma. Recent droughts have caused widespread mortality among piñons, but have had less impact on …