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Articles 1 - 5 of 5
Full-Text Articles in Meteorology
Process-Based Evaluation Of Stochastic Perturbed Parameterization Tendencies On Ensemble Forecasts Of Heavy Rainfall Events, Kevin Michael Lupo
Process-Based Evaluation Of Stochastic Perturbed Parameterization Tendencies On Ensemble Forecasts Of Heavy Rainfall Events, Kevin Michael Lupo
Legacy Theses & Dissertations (2009 - 2024)
Stochastic model error schemes, such as the stochastic perturbed parameterization tendencies (SPPT) and independent SPPT (iSPPT) schemes, have become an increasingly utilized method to represent model error associated with uncertain subgrid-scale processes in ensemble prediction systems (EPSs). While much of the current literature focuses on how stochastic methods influence ensemble skill, relatively less attention is given to the processes by which these schemes lead to forecast variability. In this vein, this dissertation examines the physical processes by which the application of SPPT and iSPPT to the microphysics, planetary boundary layer (PBL), and radiation parameterization schemes yields rainfall forecast variability. These …
Developing Spatially Accurate Rainfall Predictions For The San Francisco Bay Area Through Case Studies Of Atmospheric River And Other Synoptic Events, Alison Bridger, Dung Nguyen, Sen Chiao
Developing Spatially Accurate Rainfall Predictions For The San Francisco Bay Area Through Case Studies Of Atmospheric River And Other Synoptic Events, Alison Bridger, Dung Nguyen, Sen Chiao
Faculty Publications, Meteorology and Climate Science
Rainfall patterns in the San Francisco Bay Area (SFBA) are highly influenced by local topography. It has been a forecasting challenge for the main US forecast models. This study investigates the ability of the Weather Research and Forecasting (WRF) model to improve upon forecasts, with particular emphasis on the rain shadow common to the southern end of the SFBA. Three rain events were evaluated: a mid-season atmospheric river (AR) event with copious rains; a typical non-AR frontal passage rain event; and an area-wide rain event in which zero rain was recorded in the southern SFBA. The results show that, with …
Numerical Investigations Of Atmospheric Rivers And The Rain Shadow Over The Santa Clara Valley, Dalton Behringer, Sen Chiao
Numerical Investigations Of Atmospheric Rivers And The Rain Shadow Over The Santa Clara Valley, Dalton Behringer, Sen Chiao
Faculty Publications, Meteorology and Climate Science
This study investigated precipitation distribution patterns in association with atmospheric rivers (ARs). The Weather Research and Forecasting (WRF) model was employed to simulate two strong atmospheric river events. The precipitation forecasts were highly sensitive to cloud microphysics parameterization schemes. Thus, radar observed and simulated ZH and ZDR were evaluated to provide information about the drop-size distribution (DSD). Four microphysics schemes (WSM-5, WSM-6, Thompson, and WDM-6) with nested simulations (3 km, 1 km, and 1/3 km) were conducted. One of the events mostly contained bright-band (BB) rainfall and lasted less than 24 h, while the other contained both BB and non-bright-band …
Cirrus Cloud Microphysics Over Darwin, Australia, Dorothea Ivanova, Matthew Johnson
Cirrus Cloud Microphysics Over Darwin, Australia, Dorothea Ivanova, Matthew Johnson
Publications
Ice clouds, crucial to the understanding of both short - and long - term climate trends, are poorly represented in global climate models (GCMs). Cirrus clouds, one of the largest uncertainties in the global radiation budget, have been inadequately studied at low latitudes. Parameterizations exist for mid - latitude and tropical cirrus ( Ivanova et al. 2001; McFarquhar et al. 1997). Due to climate sensitivity in the GCM with respect to cloud input, without robust parameterizations of cirrus clouds, the GCM is inaccurate over most output fields, including radiative forcing, temperature, albedo, and heat flux (Yao and Del Genio 1999). …
Effects Of Mid- And Upper-Level Dry Layers On Microphysics Of Simulated Supercell Storms, Matthew S. Van Den Broeke
Effects Of Mid- And Upper-Level Dry Layers On Microphysics Of Simulated Supercell Storms, Matthew S. Van Den Broeke
Department of Earth and Atmospheric Sciences: Faculty Publications
Conceptual differences are presented among supercell storms simulated with midlevel and deep dry layers of varying magnitude. Initial patterns are identified which should be studied more comprehensively using observed or simulated data. These initial results indicate that mixing ratios of small ice particles are most sensitive to the depth of a dry layer rather than to its magnitude, with fewer particles in simulations containing a deep dry layer. Hail from frozen drops may be most abundant when a deep layer is dried, and bursts of hail species reaching low levels may be followed 15–20 min later by an increase in …