scholarly journals Study of Low-Level Jet and Extremely Heavy Rainfall over Northern Taiwan in the Mei-Yu Season

1988 ◽  
Vol 116 (4) ◽  
pp. 884-891 ◽  
Author(s):  
George Tai-Jen Chen ◽  
Chia-Chung Yu
Keyword(s):  
Heavy Rainfall ◽  
Low Level ◽  
Low Level Jet ◽  
Northern Taiwan

The role of monsoon low-level jet in modulating heavy rainfall events

2017 ◽  
Vol 38 ◽  
pp. e569-e576 ◽  
Author(s):  
Anu Xavier ◽  
Ajil Kottayil ◽  
K. Mohanakumar ◽  
Prince K. Xavier
Keyword(s):  
Heavy Rainfall ◽  
Rainfall Events ◽  
Low Level ◽  
Low Level Jet ◽  
Heavy Rainfall Events

scholarly journals Impact of low level jet on heavy rainfall events over Mumbai

MAUSAM ◽  
2021 ◽  
Vol 58 (2) ◽  
pp. 229-240
Author(s):  
VINOD KUMAR ◽  
D. K. U. R. BHAGAT ◽  
M. SATYA KUMAR ◽  
SHIV GANESH
Keyword(s):  
Heavy Rainfall ◽  
Rainfall Events ◽  
Low Level ◽  
Low Level Jet ◽  
Heavy Rainfall Events

scholarly journals On the Relationship of a Low-Level Jet and the Formation of a Heavy-Rainfall-Producing Mesoscale Vortex over the Yangtze River Basin

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 156
Author(s):  
Shen-Ming Fu ◽  
Huan Tang ◽  
Yu Li ◽  
Hui Ma ◽  
Jian-Hua Sun
Keyword(s):  
River Basin ◽  
Yangtze River ◽  
Heavy Rainfall ◽  
Yangtze River Basin ◽  
The Yangtze River ◽  
Cyclonic Vorticity ◽  
Low Level ◽  
The Yangtze River Basin ◽  
Low Level Jet ◽  
Vorticity Transport

Dabie vortices (DBVs) are a type of heavy-rainfall-producing mesoscale vortices that appear with a high frequency around the Dabie Mountain over the Yangtze River Basin. For a long time, scholars have found that DBVs tend to form when a low-level jet (LLJ) appears in their neighboring regions. However, the underlying mechanisms of this phenomenon still remain vague. This study furthers the understanding of this type of event by conducting detailed analyses on a long-lived eastward-moving DBV that caused a severe flood in the 2020 summer. It is found that the LLJ in this event was belonged to a nocturnal LLJ type, with its maximum/minimum appeared around 2100/0600 UTC. The diurnal cycle of LLJ affected precipitation and intensity of the DBV notably: As the LLJ intensified, vortex’s precipitation and intensity both enhanced, and vice versa. The LLJ exerted two effects on the DBV’s formation that are opposite to each other. The more important effect is that the LLJ caused intense lower-level convergence around its northern terminus. This convergence directly produced cyclonic vorticity through vertical stretching, which dominates the DBV’s formation and enhances the convection-related upward cyclonic vorticity transport that acted as another favorable factor. The less important effect is that (i) the LLJ induced import of anticyclonic vorticity into the vortex’s central region, which decelerated the DBV’s formation; and (ii) the LLJ-related to strong ascending motions tilted horizontal vorticity into negative vertical vorticity, which reduced the growth rate of cyclonic vorticity.

Characteristics of Low-Level Jets over Northern Taiwan in Mei-Yu Season and Their Relationship to Heavy Rain Events

2005 ◽  
Vol 133 (1) ◽  
pp. 20-43 ◽  
Author(s):  
George Tai-Jen Chen ◽  
Chung-Chieh Wang ◽  
David Ta-Wei Lin
Keyword(s):  
Heavy Rainfall ◽  
Southern China ◽  
Heavy Rain ◽  
Maximum Wind ◽  
Low Level ◽  
Hourly Rainfall ◽  
Single Jet ◽  
Low Level Jets ◽  
Rain Events ◽  
Northern Taiwan

Abstract The present study investigates the characteristics of low-level jets (LLJs) (≥12.5 m s−1) below 600 hPa over northern Taiwan in the mei-yu season and their relationship to heavy rainfall events (≥50 mm in 24 h) through the use of 12-h sounding data, weather maps at 850 and 700 hPa, and hourly rainfall data at six surface stations during the period of May–June 1985–94. All LLJs are classified based on their height, appearance (single jet or double jet), and movement (migratory and nonmigratory). The frequency, vertical structure, and spatial and temporal distribution of LLJs relative to the onset of heavy precipitation are discussed. Results on the general characteristics of LLJs suggest that they occurred about 15% of the time in northern Taiwan, with a top speed below 40 m s−1. The level of maximum wind appeared mostly between 850 and 700 hPa, with highest frequency at 825–850 hPa. A single jet was observed more often (76%) than a double jet (24%), while in the latter case a barrier jet usually existed at 900–925 hPa as the lower branch. Migratory and nonmigratory LLJs each constituted about half of all cases, and there existed no apparent relationship between their appearance and movement. Migratory LLJs tended to be larger in size, stronger over a thicker layer, more persistent, and were much more closely linked to heavy rainfall than nonmigratory jets. They often formed over southern China between 20° and 30°N and moved toward Taiwan presumably along with the mei-yu frontal system. Before and near the onset of the more severe heavy rain events (≥100 mm in 24 h) in northern Taiwan, there was a 94% chance that an LLJ would be present over an adjacent region at 850 hPa, and 88% at 700 hPa, in agreement with earlier studies. Occurrence frequencies of LLJs for less severe events (50–100 mm in 24 h) were considerably lower, and the difference in accumulative rainfall amount was seemingly also affected by the morphology of the LLJs, including their strength, depth, elevation of maximum wind, persistence, proximity to northern Taiwan, source region of moisture, and their relative timing of arrival before rainfall. During the data period, about 40% of all migratory LLJs at 850 or 700 hPa passing over northern Taiwan were associated with heavy rainfall within the next 24 h. The figure, however, was much lower compared to earlier studies, and some possible reasons are offered to account for this deficit.

Understanding the influence of ENSO on the Great Plains low-level jet in CMIP5 models

2017 ◽  
Vol 51 (4) ◽  
pp. 1537-1558 ◽  
Author(s):  
James F. Danco ◽  
Elinor R. Martin
Keyword(s):  
Great Plains ◽  
Cmip5 Models ◽  
Low Level ◽  
Low Level Jet
Sign in / Sign up

Export Citation Format

Share Document