Investigation of local flow features in Istanbul. Part I: High-resolution sensitivity simulations

Yasemin Ezber; Omer Lutfi Sen; Zafer Boybeyi; Mehmet Karaca

doi:10.1002/joc.4248

Investigation of local flow features in Istanbul. Part I: High-resolution sensitivity simulations

Yasemin Ezber^*, Omer Lutfi Sen, Zafer Boybeyi, Mehmet Karaca

^*Corresponding author for this work

Eurasia Institute of Earth Sciences

George Mason University

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

The three-dimensional non-hydrostatic mesoscale model, OMEGA (Operational Multiscale Environment model with Grid Adaptivity), is utilized to investigate the thermally driven local flows and their interaction with each other over the province of Istanbul, Turkey. Idealized case simulations are conducted in order to describe the contribution of sea-land breezes and urban heat island (UHI) circulation to the local flow over the city. The city of Istanbul is located between two water bodies, Black Sea in the north and Sea of Marmara in the south. A convergence zone is observed at about 1000 LST over the region due to the merge of two sea breezes that develop at both sides and advance towards inland areas. Investigation further indicates that the other geographic features of the city have substantial effects on the local flow. The Bosphorus Strait, which connects Black Sea to Sea of Marmara and divides the city into two parts, channels the flow. Although not significantly high and steep, the topography enhances the flow strength. Besides, urbanized regions in the south, by generating UHI circulation, prevent the inland penetration of the sea breeze that develops in the south. The numerical simulations reveal that the large-scale wind direction controls the inland penetration of the sea breeze. One of the outstanding features of the local flows is that all hypothetical simulations including the Bosphorus indicate a strong fan-like airflow in the immediate south of the strait. The flow is more intense in the northerly prevailing wind case. It is also found that stronger large-scale flows (e.g. 2.5 and 10 m s^-1) do not allow the formation of a sea breeze over the region. A warmer sea surface than land surface (about 2 °C) makes changes in the duration and extension of the land-sea breeze circulation. The duration of a land breeze circulation is long, and the southerly sea breeze is onset close to the south coast under the northeasterly flow conditions.

Original language	English
Pages (from-to)	3812-3833
Number of pages	22
Journal	International Journal of Climatology
Volume	35
Issue number	13
DOIs	https://doi.org/10.1002/joc.4248
Publication status	Published - 15 Nov 2015

Bibliographical note

Publisher Copyright:
© 2015 Royal Meteorological Society.

Keywords

Idealized case simulation
Mesoscale model
Sea-land breeze
Urban heat island circulation

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1002/joc.4248

Cite this

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title = "Investigation of local flow features in Istanbul. Part I: High-resolution sensitivity simulations",

abstract = "The three-dimensional non-hydrostatic mesoscale model, OMEGA (Operational Multiscale Environment model with Grid Adaptivity), is utilized to investigate the thermally driven local flows and their interaction with each other over the province of Istanbul, Turkey. Idealized case simulations are conducted in order to describe the contribution of sea-land breezes and urban heat island (UHI) circulation to the local flow over the city. The city of Istanbul is located between two water bodies, Black Sea in the north and Sea of Marmara in the south. A convergence zone is observed at about 1000 LST over the region due to the merge of two sea breezes that develop at both sides and advance towards inland areas. Investigation further indicates that the other geographic features of the city have substantial effects on the local flow. The Bosphorus Strait, which connects Black Sea to Sea of Marmara and divides the city into two parts, channels the flow. Although not significantly high and steep, the topography enhances the flow strength. Besides, urbanized regions in the south, by generating UHI circulation, prevent the inland penetration of the sea breeze that develops in the south. The numerical simulations reveal that the large-scale wind direction controls the inland penetration of the sea breeze. One of the outstanding features of the local flows is that all hypothetical simulations including the Bosphorus indicate a strong fan-like airflow in the immediate south of the strait. The flow is more intense in the northerly prevailing wind case. It is also found that stronger large-scale flows (e.g. 2.5 and 10 m s-1) do not allow the formation of a sea breeze over the region. A warmer sea surface than land surface (about 2 °C) makes changes in the duration and extension of the land-sea breeze circulation. The duration of a land breeze circulation is long, and the southerly sea breeze is onset close to the south coast under the northeasterly flow conditions.",

keywords = "Idealized case simulation, Mesoscale model, Sea-land breeze, Urban heat island circulation",

author = "Yasemin Ezber and Sen, {Omer Lutfi} and Zafer Boybeyi and Mehmet Karaca",

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year = "2015",

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doi = "10.1002/joc.4248",

language = "English",

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T2 - High-resolution sensitivity simulations

AU - Ezber, Yasemin

AU - Sen, Omer Lutfi

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AU - Karaca, Mehmet

PY - 2015/11/15

Y1 - 2015/11/15

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AB - The three-dimensional non-hydrostatic mesoscale model, OMEGA (Operational Multiscale Environment model with Grid Adaptivity), is utilized to investigate the thermally driven local flows and their interaction with each other over the province of Istanbul, Turkey. Idealized case simulations are conducted in order to describe the contribution of sea-land breezes and urban heat island (UHI) circulation to the local flow over the city. The city of Istanbul is located between two water bodies, Black Sea in the north and Sea of Marmara in the south. A convergence zone is observed at about 1000 LST over the region due to the merge of two sea breezes that develop at both sides and advance towards inland areas. Investigation further indicates that the other geographic features of the city have substantial effects on the local flow. The Bosphorus Strait, which connects Black Sea to Sea of Marmara and divides the city into two parts, channels the flow. Although not significantly high and steep, the topography enhances the flow strength. Besides, urbanized regions in the south, by generating UHI circulation, prevent the inland penetration of the sea breeze that develops in the south. The numerical simulations reveal that the large-scale wind direction controls the inland penetration of the sea breeze. One of the outstanding features of the local flows is that all hypothetical simulations including the Bosphorus indicate a strong fan-like airflow in the immediate south of the strait. The flow is more intense in the northerly prevailing wind case. It is also found that stronger large-scale flows (e.g. 2.5 and 10 m s-1) do not allow the formation of a sea breeze over the region. A warmer sea surface than land surface (about 2 °C) makes changes in the duration and extension of the land-sea breeze circulation. The duration of a land breeze circulation is long, and the southerly sea breeze is onset close to the south coast under the northeasterly flow conditions.

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M3 - Article

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SN - 0899-8418

VL - 35

SP - 3812

EP - 3833

JO - International Journal of Climatology

JF - International Journal of Climatology

IS - 13

ER -

Investigation of local flow features in Istanbul. Part I: High-resolution sensitivity simulations

Abstract

Bibliographical note

Keywords

UN SDGs

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