contributor author | Gebauer, Joshua G.;Fedorovich, Evgeni;Shapiro, Alan | |
date accessioned | 2018-01-03T11:02:34Z | |
date available | 2018-01-03T11:02:34Z | |
date copyright | 8/9/2017 12:00:00 AM | |
date issued | 2017 | |
identifier other | jas-d-16-0333.1.pdf | |
identifier uri | http://138.201.223.254:8080/yetl1/handle/yetl/4246467 | |
description abstract | AbstractThe forcing of northerly low-level jets over the eastward-sloped terrain of the U.S. Great Plains was studied using a one-dimensional (1D) nonstationary analytical model based on the Boussinesq-approximated equations of motion and thermal energy. For northerly low-level jets, the forcing from diurnal changes in surface heating of the sloped terrain (Holton mechanism) is out of phase with the nocturnal inertial oscillation resulting from the cessation of turbulent mixing at sunset (Blackadar mechanism), which results in weaker northerly nocturnal low-level jets when compared to southerly nocturnal low-levels jets with the same-magnitude background pressure gradient forcing. Because of the Blackadar and Holton mechanisms acting out of phase, nocturnal northerly low-level jets cannot solely explain the northerly low-level jet maximum over the Great Plains found in climatological studies. It is shown that negative buoyancy values over the eastward-sloped terrain enhance the low-level northerly geostrophic wind, which can cause low-level jetlike wind profiles that do not necessarily depend on the diurnal cycle. However, nocturnal northerly low-level jets primarily caused by an inertial oscillation still occur when daytime mixing is strong and buoyancy is small at sunset. These conditions are possible when strong capping inversions are present in the daytime convective boundary layer. The occurrence of both types of northerly low-level jets, those caused by negative buoyancy values over the sloped terrain and those driven by an inertial oscillation, better explains the findings of previous low-level jet climatologies. | |
publisher | American Meteorological Society | |
title | A 1D Theoretical Analysis of Northerly Low-Level Jets over the Great Plains | |
type | Journal Paper | |
journal volume | 74 | |
journal issue | 10 | |
journal title | Journal of the Atmospheric Sciences | |
identifier doi | 10.1175/JAS-D-16-0333.1 | |
journal fristpage | 3419 | |
journal lastpage | 3431 | |
tree | Journal of the Atmospheric Sciences:;2017:;Volume( 074 ):;issue: 010 | |
contenttype | Fulltext | |