Gravity Wave Phenomena Accompanying East Coast Cyclogenesis

Abstract

remarkable example of gravity wave propagation over the southeastern United States on Dec. 3, 1968, is described. The wave developed within the cold air north of a quasi-stationary front along the coast of the Gulf of Mexico in apparent responde to convective activity associated with a weak cyclonic disturbance on the front. The wave maintained its identity for 14 hr while propagating east-southeastward at 13 m/s in a direction nearly opposite t o the low-level flow. Gravity-wave-related pressure drops exceeded 7 mb over an average period of 1 hr. Strong and gusty winds blowing perpendicularly to the isobars toward lower pressure accompanied the waverelated pressure fall. Precipitation of several hours duration ceased abruptly with the wave passage, along with increases in the ceiling and horizontal visibility. Comparison is made with results from other papers dealing with wave propagation along frontal surfaces. May1973 BosartandCussen 1 447 FIQURE 3.-Detailed surface maps a t 3-hourly intervals for time aeriods indicated. Isobars are drawn for every 1 mb and winds a in knots, plotted according to the conventional station model.

The Internal Gravity Wave Observed in the Typhoon T8124 (Gay)

“…There appears a large precipitation area extending to the east of the PD line, but no precipitation is observed on and just west of it. This situation is very much similar to that analyzed by Bosart & Cussen (1973). A weak precipitation area was recognized to the north of 35.5*N in the western region of the PD line.…”

“…According to rainguage observations, the principal rain area is found to the east of PD line just as shown by Bosart & Cussen (1973). They pointed out that there appears to be a shutting off of precipitation associated with rapid decrease in convergence after the wave passage.…”

“…IGW characteristics are often revealed in Mesoscale D isturbances (hereafter denoted by MD) analyzed within severe snowstorm or heavy rainfall regions (Matsumoto & Ninomiya, 1965;Matsumoto & Akiyama, 1969;Uccellini, 1975;and others). Bosart & Cussen (1973) analyzed an IGW-related Pressure Drop-jump (hereafter denoted by PD) line of 500km length which moved north-eastwards in the Eastern United States and showed, like many others, a divergence area in front of this line and a convergence area in the rear of it. Eom (1975) investigated the relationship among surface pressure, surface wind, cloudiness field and their changes around a PD line within a MD which moved north-eastwards over the Midwest of USA, and explained their rela-* Present affiliation : Japan Weather Association , 4-5 Kojimachi, Chiyoda-ku, Tokyo, Japan.…”

Vertical structure of the stable boundary layer detected by RASS-SODAR and in-situ measurements in SABLES 2006 field campaign

“…It has been previously reported that pressure fluctuations related to waves range in average between 0.01 and 0.1 hPa, with time scales between 1 and 40 min (Stull 1988). Nevertheless, some intense mesoscale events have been documented with higher amplitudes (e.g., Bosart andCussen 1973, Viana et al 2009). Although the linear theory can sometimes be applied to study the atmospheric waves present in the SBL (Gossard andHooke 1975, Nappo 2002), most of these waves are far from a linear behaviour, and polarization relationships, as those between vertical Brought to you by | Universidad Complutense Madrid Authenticated Download Date | 1/27/16 11:07 AM velocity and temperature (π/2 out of phase) which means that the vertical heat flux due to gravity waves is zero, are not always found.…”

Continental shelf processes affecting the oceanography of the South Atlantic Bight. Progress report

“…Intense lows are frequently accompanied by trailing outbreaks of very cold polar air, causing sharp cold fronts which move southeastward over the southeastern states; and they can bring freezing weather and strong winds as far south as Florida. Smaller scale waves can develop along the polar front near the southeastern coast which exhibit highly variable stress and precipitation patterns on the subsynoptic (10-100 km) scale (Bosart, Vando, and Helsdon, 1972;Bosart, 1973). Bosart and Cussen (1973) have found surface pressure Gluctuatfons of 4-5 mb amplitude along the coast…”