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Full-Text Articles in Physical Sciences and Mathematics
Seasonal Propagation Characteristics Of Mstids Observed At High Latitudes Over Central Alaska Using The Poker Flat Incoherent Scatter Radar, Michael R. Negale, Michael J. Taylor, M. J. Nicolls, Sharon L. Vadas, Kim Nielsen, Craig J. Heinselman
Seasonal Propagation Characteristics Of Mstids Observed At High Latitudes Over Central Alaska Using The Poker Flat Incoherent Scatter Radar, Michael R. Negale, Michael J. Taylor, M. J. Nicolls, Sharon L. Vadas, Kim Nielsen, Craig J. Heinselman
Publications
Near‐continuous electron density measurements obtained over a ∼3 year period, 2010–2013, using the Poker Flat Incoherent Scatter Radar (PFISR) in central Alaska (69°N, 147°W) have been analyzed to quantify the properties of over 650 high‐latitude medium‐scale traveling ionospheric disturbances (MSTIDs). Our analysis focused on the altitude range 100–300 km encompassing the lower ionosphere/thermosphere and yielded first full seasonal day/night distributions of MSTIDs at high northern latitudes with mean values: horizontal wavelength 446 km, horizontal phase speed 187 m/s, and period 41 min. These year‐round measurements fill an important summertime gap in existing MSTID measurements revealing predominantly eastward wave propagation during …
Multidecadal Variability In The Subseasonal Peak Of Low-Level Convergence Over The Pacific Warm Pool, Yen-Heng Lin, Shih-Yu (Simon) Wang
Multidecadal Variability In The Subseasonal Peak Of Low-Level Convergence Over The Pacific Warm Pool, Yen-Heng Lin, Shih-Yu (Simon) Wang
Plants, Soils, and Climate Faculty Publications
In the Western North Pacific (WNP), the atmospheric low-level convergence is one of the main factors that influences the genesis of tropical cyclones (TC). It has been observed that the timing of the seasonal maxima in the low-level convergence and TC genesis has shifted since the mid-1990s from mid-August to late-July, with this shift having also affected the number of TC. A multidecadal frequency of 20 years was revealed in the timing variation of the tropical intraseasonal oscillation (ISO) in the Western Pacific, in which a weak WNP low-level convergence in spring may trigger an advanced ISO phase in summer …
Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over South Pole (90°S), Pierre-Dominique Pautet, Michael J. Taylor, J. B. Snively, Christina Solorio
Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over South Pole (90°S), Pierre-Dominique Pautet, Michael J. Taylor, J. B. Snively, Christina Solorio
Publications
Since 2010, Utah State University has operated an infrared Advanced Mesospheric Temperature Mapper at the Amundsen–Scott South Pole station to investigate the upper atmosphere dynamics and temperature deep within the vortex. A surprising number of “frontal” gravity wave events (86) were recorded in the mesospheric OH(3,1) band intensity and rotational temperature images (typical altitude of ~87 km) during four austral winters (2012–2015). These events are gravity waves (GWs) characterized by a sharp leading wave front followed by a quasi-monochromatic wave train that grows with time. A particular subset of frontal gravity wave events has been identified in the past (Dewan …
Mid-Latitude Climatologies Of Mesospheric Temperature And Geophysical Temperature Variability Determined With The Rayleigh-Scatter Lidar At Alo-Usu, Joshua P. Herron, Vincent B. Wickwar
Mid-Latitude Climatologies Of Mesospheric Temperature And Geophysical Temperature Variability Determined With The Rayleigh-Scatter Lidar At Alo-Usu, Joshua P. Herron, Vincent B. Wickwar
All Physics Faculty Publications
From 1993-2004, 839 nights were observed with the Rayleigh-scatter lidar at Utah State University’s Atmospheric Lidar Observatory. They were reduced to obtain nighttime mesospheric temperatures between 45 and ~90 km, which were then combined to derive composite annual climatologies of mid-latitude temperatures and geophysical temperature variability. At 45 km, near the stratopause, there is a ~250 K temperature minimum in mid-winter and a 273 K maximum in mid-May. The variability behaves oppositely, being 7-10 K in winter and 2.5 K in summer. At 85 km, there is a 215 K temperature maximum at the end of December and a 170 …