scholarly journals SURFACE WIND SYSTEMS OVER CENTRAL JAPAN IN THE WARM SEASON-WITH SPECIAL REFERENCE TO THE SOUTHWESTERLY FLOW PATTERN

1970 ◽  
Vol 43 (4) ◽  
pp. 203-210 ◽  
Author(s):  
Takeshi KAWAMURA
Keyword(s):  
Special Reference ◽  
Flow Pattern ◽  
Surface Wind ◽  
Warm Season ◽  
Central Japan

scholarly journals Warm Season Afternoon Thunderstorm Characteristics under Weak Synoptic-Scale Forcing over Taiwan Island

2011 ◽  
Vol 26 (1) ◽  
pp. 44-60 ◽  
Author(s):  
Pin-Fang Lin ◽  
Pao-Liang Chang ◽  
Ben Jong-Dao Jou ◽  
James W. Wilson ◽  
Rita D. Roberts
Keyword(s):  
Surface Wind ◽  
Warm Season ◽  
Warning Systems ◽  
Synoptic Scale ◽  
Narrow Strip ◽  
Dewpoint Temperature ◽  
Surface Data ◽  
Hourly Rainfall ◽  
Taiwan Island ◽  
Moisture Conditions

Abstract The spatial and temporal characteristics and distributions of thunderstorms in Taiwan during the warm season (May–October) from 2005 to 2008 and under weak synoptic-scale forcing are documented using radar reflectivity, lightning, radiosonde, and surface data. Average hourly rainfall amounts peaked in midafternoon (1500–1600 local solar time, LST). The maximum frequency of rain was located in a narrow strip, parallel to the orientation of the mountains, along the lower slopes of the mountains. Significant diurnal variations were found in surface wind, temperature, and dewpoint temperature between days with and without afternoon thunderstorms (TSA and non-TSA days). Before thunderstorms occurred, on TSA days, the surface temperature was warmer (about 0.5°–1.5°C) and the surface dewpoint temperature was moister (about 0.5°–2°C) than on non-TSA days. Sounding observations from northern Taiwan also showed warmer and higher moisture conditions on TSA days relative to non-TSA days. The largest average difference was in the 750–550-hPa layer where the non-TSA days averaged 2.5°–3.5°C drier. These preconvective factors associated with the occurrences of afternoon thunderstorms could be integrated into nowcasting tools to enhance warning systems and decision-making capabilities in real-time operations.

scholarly journals Features of Urban Heat Island in Mountainous Chongqing from a Dense Surface Monitoring Network

Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 67 ◽  
Author(s):  
Ping Jiang ◽  
Xiaoran Liu ◽  
Haonan Zhu ◽  
Yonghua Li
Keyword(s):  
Urban Heat Island ◽  
Urban Areas ◽  
Surface Wind ◽  
Warm Season ◽  
Monitoring Network ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Near Surface ◽  
Urban Heat ◽  
Surface Monitoring

The spatial and temporal features of urban heat island (UHI) intensity in complex urban terrain are barely investigated. This study examines the UHI intensity variations in mountainous Chongqing using a dense surface monitoring network. The results show that the UHI intensity is closely related to underlying surfaces, and the strongest UHI intensity is confined around the central urban areas. The UHI intensity is most prominent at night and in warm season, and the magnitude could reach ~4.5 °C on summer night. Our quantitative analysis shows a profound contribution of urbanization level to UHI intensity both at night and in summer, with regression coefficient b = 4.31 and 6.65, respectively. At night, the urban extra heat such as reflections of longwave radiation by buildings and release of daytime-stored heat from artificial materials, is added into the boundary layer, which compensates part of urban heat loss and thus leads to stronger UHI intensity. In summer, the urban areas are frequently controlled by oppressively hot weather. Due to increased usage of air conditioning, more anthropogenic heat is released. As a result, the urban temperatures are higher at night. The near-surface wind speed can serve as an indicator predicting UHI intensity variations only in the diurnal cycle. The rural cooling rate during early evening transition, however, is an appropriate factor to estimate the magnitude of UHI intensity both at night and in summer.

Spring red snow phenomenon ‘Akashibo’ in the Ozegahara mire, Central Japan, with special reference to the distribution of invertebrates in red snow

2002 ◽  
Vol 28 (4) ◽  
pp. 1645-1652
Author(s):  
Haruo Fukuhara ◽  
Akifumi Ohtaka ◽  
Naoya Kimura ◽  
Manabu Fukui ◽  
Yoshiaki Kikuchi ◽  
...  
Keyword(s):  
Special Reference ◽  
Central Japan

scholarly journals On the Diurnal Variation of Mountain Waves

2008 ◽  
Vol 65 (4) ◽  
pp. 1360-1377 ◽  
Author(s):  
Qingfang Jiang ◽  
James D. Doyle
Keyword(s):  
Diurnal Variation ◽  
Froude Number ◽  
Flow Pattern ◽  
Surface Wind ◽  
Wave Drag ◽  
Prediction System ◽  
Wind Maximum ◽  
Mountain Waves ◽  
Ridge Crest ◽  
Deep Well

Abstract The diurnal variation of mountain waves and wave drag associated with flow past mesoscale ridges has been examined using the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) and an analytical boundary layer (BL) model. The wave drag exhibits substantial diurnal variation in response to the change in the atmospheric BL characteristics, such as the BL depth, shape factor, and stability. During daytime, a convective BL develops, characterized by a shallow shear layer near the surface and a deep well-mixed layer aloft, both of which tend to decrease the wave drag. As a result, the convective BL could significantly weaken mountain waves and reduce the momentum flux by up to 90%. Near the surface, the flow pattern resembles a potential flow with a surface wind maximum located near the ridge crest. During nighttime, a shallow stable BL develops, and the modulation of wave drag by the stable nocturnal BL is governed by the BL Froude number (Fr). If the BL flow is supercritical, the drag increases as Fr decreases toward unity and reaches the maximum around Fr = 1, where the drag could be several times larger than the corresponding free-slip hydrostatic wave drag. If the BL flow is subcritical because of excessive cooling, the drag decreases with decreasing Froude number and the flow pattern near the surface resembles a typical subcritical solution with the wind maximum located near the ridge crest.

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