scholarly journals Numerical Study of the Effects of Topography and Urbanization on the Local Atmospheric Circulations over the Beijing-Tianjin-Hebei, China

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Yucong Miao ◽  
Shuhua Liu ◽  
Yijia Zheng ◽  
Shu Wang ◽  
Bicheng Chen
Keyword(s):  
Numerical Study ◽  
Wrf Model ◽  
Sea Breeze ◽  
Land Breeze ◽  
Bohai Bay ◽  
Breeze Circulation ◽  
Thermally Induced ◽  
Atmospheric Circulations ◽  
Mountain Valley ◽  
Bth Region

The effects of the topography and urbanization on the local atmospheric circulations over the Beijing-Tianjin-Hebei (BTH) region were studied by the weather research and forecasting (WRF) model, as well as the interactions among these local atmospheric circulations. It was found that, in the summer day time, the multiscale thermally induced local atmospheric circulations may exist and interact in the same time over the BTH region; the topography played a role in the strengthening of the sea breeze circulations; after sunset, the inland progress of sea breeze was slowed down by the opposite mountain breeze; when the land breeze circulation dominated the Bohai bay, the mountain breeze circulation can couple with the land breeze circulation to form a large circulation ranging from the coastline to the mountains. And the presence of cities cannot change the general state of the sea-land breeze (SLB) circulation and mountain-valley breeze (MVB) circulation but acted to modify these local circulations slightly. Meanwhile, the development of the urban heat island (UHI) circulation was also strongly influenced by the nearby SLB circulation and MVB circulation.

scholarly journals Numerical Study on the Effect of Urbanization and Coastal Change on Sea Breeze over Qingdao, China

Atmosphere ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 345 ◽  
Author(s):  
Shangfei Hai ◽  
Yucong Miao ◽  
Lifang Sheng ◽  
Linbo Wei ◽  
Qing Chen
Keyword(s):  
Human Activities ◽  
Urban Areas ◽  
Numerical Study ◽  
Wrf Model ◽  
Sea Breeze ◽  
Air Pollutant ◽  
Land Breeze ◽  
Coastal Change ◽  
Conversion Time ◽  
The Impact

During the past few decades, rapid economic development occurred in Qingdao. Inevitably, human activities have caused great changes to the underlying surface, including urbanization and coastal change. Coastal change mainly refers to the expansion of the coastline to increase coastal land area. Sea-land breeze (SLB) is important for local weather and the transport of air pollutant. However, the impact of human activities on the SLB over Qingdao is not yet clear. Thus, the weather research and forecasting (WRF) model is applied to study the effect of urbanization and coastal change on SLB. The study shows that urbanization strengthens the urban heat island (UHI) effect. Due to the expansions of urban area during past decades, sea breeze is strengthened before it passes through the urban areas. When it penetrates into the city, the inland progress of sea breeze is slowed down due to the UHI effect and stronger frictional force. Besides, the expansions of coastline can delay the SLB conversion time, lead to the changes in the sea breeze penetration path and the weakening of SLB intensity.

scholarly journals A numerical study of the effect of sea breeze circulation on photochemical pollution over a highly industrialized peninsula

2009 ◽  
Vol 17 (1) ◽  
pp. 19-31 ◽  
Author(s):  
Cristina Mangia ◽  
Ilenia Schipa ◽  
Annalisa Tanzarella ◽  
Dario Conte ◽  
Gian Paolo Marra ◽  
...  
Keyword(s):  
Numerical Study ◽  
Sea Breeze ◽  
Breeze Circulation ◽  
Photochemical Pollution

scholarly journals Study on the Air Dispersion Characteristics along the West Coast of Korean Peninsula

1970 ◽  
Vol 8 (3) ◽  
pp. 94-104
Author(s):  
Rajib Pokhrel ◽  
Inhyeong Cho ◽  
Ram K Sharma ◽  
Heekwan Lee
Keyword(s):  
Potential Temperature ◽  
Coastal Region ◽  
Sea Breeze ◽  
Early Morning ◽  
Land Breeze ◽  
Maximum Speed ◽  
Study Region ◽  
Thermally Induced ◽  
Transition Stage ◽  
Meso Scale

When the temperature difference between land and sea surface along coastline is large enough, thermally induced circulation is likely developed in the coastal region, called as Sea/Land (S/L) breeze. It has been an important issue in coastal region because of its significant role for the transport, dispersion of air pollutants generated in coastal regions. Meso-scale modeling was carried out using the commercial modeling tool ‘A2C flow / A2C t&d (A2C represents the Atmospheric to Computational fluid dynamics and t&d represents the transport and diffusion)’ to characterize the meso-scale circulation of pure breeze in the study region (125.22E, 36.32N to 127.95E, 38.39N) in late July for typical summer conditions of Korea. Maximum potential temperature differences were approximately 5K and 14K in early morning and mid day, respectively in the study domain. Strong land breeze was observed around 6AM and it was neutralized to transition stage between 9AM ~ 10AM then the sea breeze started. Maximum speed of sea breeze, approximately 2.5m/s was found around 3PM which is about double of land breeze (1.5m/s). With the declination of sun energy with the passing of time, sea breeze lost its momentum and reached to transition stage between (9PM ~ 10PM). The penetration lengths of sea breeze and land breeze are approximately 25km~30km and 20km~25km, respectively while the suction lengths of sea breeze and land breeze are approximately 15km~20km each. In addition, the maximum depths of the S/L breeze are approximately 400m and 1200m, respectively in early morning and sometimes in mid day along the coastal area. DOI: http://dx.doi.org/10.3126/jie.v8i3.5936 JIE 2011; 8(3): 94-104

scholarly journals Numerical Simulation of Sea Breeze Convergence over Antarctic Peninsula

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Alcimoni Nelci Comin ◽  
Otávio Costa Acevedo
Keyword(s):  
Antarctic Peninsula ◽  
Large Scale ◽  
Potential Temperature ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Sea Breeze ◽  
Circulation System ◽  
Breeze Circulation ◽  
Synoptic Wind ◽  
Cold Anomaly

The convergence zone induced by sea breeze systems over Antarctic Peninsula is analyzed for the summer season of 2013–2015. 59 days, selected by satellite images for the absence of major synoptic forcing, are simulated using the WRF model. Sea breeze convergence has been detected in 21 of these days, mostly during evening hours and under large-scale winds. Breeze events are associated with a cold anomaly at the peninsula with respect to the climatology. This condition favors the onset of the necessary horizontal thermal gradients to trigger the breeze circulation. At the same time, no anomaly of the average pressure at sea level is found, indicating that events are favored when the average synoptic flow is present. Case studies indicate that the convergence location over the peninsula is controlled by the synoptic wind. An average convergence over the peninsula happens from 14:00 to 22:30 UTC, with a maximum at 18:00 UTC. There is a strong potential temperature gradient between the surface of the peninsula and the sea, with the sea breeze circulation system extending up to 1.2 km or higher. The sensible heat flux reaches 80 W/m2at the top of mountains and 10 W/m2near the coast.

scholarly journals The influence of sea- and land-breeze circulations on the diurnal variability in precipitation over a tropical island

2017 ◽  
Vol 17 (21) ◽  
pp. 13213-13232 ◽  
Author(s):  
Lei Zhu ◽  
Zhiyong Meng ◽  
Fuqing Zhang ◽  
Paul M. Markowski
Keyword(s):  
Diurnal Variation ◽  
Numerical Simulations ◽  
Diurnal Cycle ◽  
Wrf Model ◽  
Lower Troposphere ◽  
Sea Breeze ◽  
Dominant Factor ◽  
Land Breeze ◽  
Moist Convection ◽  
Diurnal Variability

Abstract. This study examines the diurnal variation in precipitation over Hainan Island in the South China Sea using gauge observations from 1951 to 2012 and Climate Prediction Center MORPHing technique (CMORPH) satellite estimates from 2006 to 2015, as well as numerical simulations. The simulations are the first to use climatological mean initial and lateral boundary conditions to study the dynamic and thermodynamic processes (and the impacts of land–sea breeze circulations) that control the rainfall distribution and climatology. Precipitation is most significant from April to October and exhibits a strong diurnal cycle resulting from land–sea breeze circulations. More than 60 % of the total annual precipitation over the island is attributable to the diurnal cycle with a significant monthly variability. The CMORPH and gauge datasets agree well, except that the CMORPH data underestimate precipitation and have a 1 h peak delay. The diurnal cycle of the rainfall and the related land–sea breeze circulations during May and June were well captured by convection-permitting numerical simulations with the Weather Research and Forecasting (WRF) model, which were initiated from a 10-year average ERA-Interim reanalysis. The simulations have a slight overestimation of rainfall amounts and a 1 h delay in peak rainfall time. The diurnal cycle of precipitation is driven by the occurrence of moist convection around noontime owing to low-level convergence associated with the sea-breeze circulations. The precipitation intensifies rapidly thereafter and peaks in the afternoon with the collisions of sea-breeze fronts from different sides of the island. Cold pools of the convective storms contribute to the inland propagation of the sea breeze. Generally, precipitation dissipates quickly in the evening due to the cooling and stabilization of the lower troposphere and decrease of boundary layer moisture. Interestingly, the rather high island orography is not a dominant factor in the diurnal variation in precipitation over the island.

scholarly journals Transport of Pollutants by the Sea Breeze in São Paulo under the South Atlantic High

2018 ◽  
pp. 148-161 ◽  
Author(s):  
Júlio Barboza Chiquetto ◽  
Flávia Noronha Dutra Ribeiro ◽  
Débora Souza Alvim ◽  
Rita Yuri Ynoue ◽  
Josiane Da Silva ◽  
...  
Keyword(s):  
Sea Breeze ◽  
Early Morning ◽  
Sao Paulo ◽  
South Atlantic ◽  
Metropolitan Region ◽  
Land Breeze ◽  
São Paulo ◽  
Breeze Circulation ◽  
The South ◽  
Prefrontal Region

The land-sea breeze circulation is important for the Metropolitan Region of São Paulo (MRSP), influencing predominant wind direction during the night and day, and so, the transport of pollution in the local scale. In the summer of 2014, there were 43 exceedances of the state air quality by ozone, when the South Atlantic Subtropical High strengthened over southeast Brazil. We aimed to study how the land-sea breeze circulation influenced the transport of the pollutants CO, NO, NO2 and O3 in the study area using the WRF/Chem model in the period 28/01-01/02/2014. Two scenarios were considered: CTRL – vehicular emissions based on current emission inventories and SENS – removing 75% of emissions in the MRSP. Results were analysed through maps with the spatial distribution of pollutants in the domain and showed the importance of the land-sea breeze circulation for the transport of pollution. Analysis of the divergence field proved useful for identifying the sea breeze front. Higher O3 concentrations were simulated in the prefrontal convergence line, due to stagnation and accumulation of pollutants brought by the passage of the sea breeze over polluted areas, resulting in the transport of ozone and other pollutants to distant areas northwest during the afternoon and evening. There was also transport of pollutants to the south in the early morning caused by the land breeze. Upward air motion due to the convergence in the prefrontal region caused vertical transport of ozone during the afternoon.

Sign in / Sign up

Export Citation Format

Share Document