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Full-Text Articles in Physical Sciences and Mathematics

Observing The Quantumbehavior Of Light In An Undergraduate Laboratory, M. S. Neel, J. J. Thorn, V. W. Donato, G. S. Bergreen, Robert E. Davies, M. Beck Sep 2014

Observing The Quantumbehavior Of Light In An Undergraduate Laboratory, M. S. Neel, J. J. Thorn, V. W. Donato, G. S. Bergreen, Robert E. Davies, M. Beck

Plants, Soils, and Climate Faculty Publications

While the classical, wavelike behavior of light (interference and diffraction) has been easily observed in undergraduate laboratories for many years, explicit observation of the quantum nature of light (i.e., photons) is much more difficult. For example, while well-known phenomena such as the photoelectric effect and Compton scattering strongly suggest the existence of photons, they are not definitive proof of their existence. Here we present an experiment, suitable for an undergraduate laboratory, that unequivocally demonstrates the quantum nature of light. Spontaneously downconverted light is incident on a beamsplitter and the outputs are monitored with single-photon counting detectors. We observe a near …


Probable Causes Of The Abnormal Ridge Accompanying The 2013-14 California Drought: Enso Precursor And Anthropogenic Warming Footprint, Shih-Yu (Simon) Wang May 2014

Probable Causes Of The Abnormal Ridge Accompanying The 2013-14 California Drought: Enso Precursor And Anthropogenic Warming Footprint, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

The 2013–2014 California drought was initiated by an anomalous high-amplitude ridge system. The anomalous ridge was investigated using reanalysis data and the Community Earth System Model (CESM). It was found that the ridge emerged from continual sources of Rossby wave energy in the western North Pacific starting in late summer and subsequently intensified into winter. The ridge generated a surge of wave energy downwind and deepened further the trough over the northeast U.S., forming a dipole. The dipole and associated circulation pattern is not linked directly with either El Niño–Southern Oscillation (ENSO) or Pacific Decadal Oscillation; instead, it is correlated …


Coupling Of Pre-Monsoon Tropical Cyclones With The Monsoon Onset In Myanmar, B. O. Fosu, Shih-Yu (Simon) Wang Jan 2014

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 …


Global Eastward Propagation Signals Associated With The 4-5-Year Enso Cycle, Shih-Yu (Simon) Wang, X. Jiang, B. Fosu Jan 2014

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 Jan 2014

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 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 …