How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

Abstract

When looking at an agricultural landscape from above, one sees a patchwork of fields, whereas tall trees and alleys between the fields only cover a small fraction of the area. However, the trees can be prominent when observing the landscape from ground level. This view and emphasis on agricultural fields is mirrored in the way the agricultural landscape is treated in meteorological models; since the land surface is accounted for by assigning characteristic parameters to dominant land use classes from satellite imagery, the small scale tree features of the landscape are ignored. The overall aim of this study is to quantify the effect of solitary trees on the wind field and offer an estimate of how the presence of scattered trees would affect the surface roughness for a larger scale model. We present high-detail laser scans of solitary trees and discuss how they can successfully be transferred into parameterizations of the landscape in coarser resolution models. We also present wake measurements caused by solitary trees observed with both long-range and short range wind scanners, which spatially resolve the wind field. In previous work (Dellwik et al. 2019), the high resolution scans of tree geometry were used in high-resolution computational fluid dynamics (CFD) models, where the tree is parameterized as a distributed drag force. A novelty used in this study was that the total force on the tree had been experimentally assessed using strain gauges, which allowed for a much more certain assessment of the tree parameterization in the CFD model. By using the simulated wind fields from the CFD model and the total observed force on the tree in combination with basic micro-meteorological relationships, the effect of a solitary tree can be quantified in terms of changes to surface roughness.
Original languageEnglish
Publication date2019
Number of pages1
Publication statusPublished - 2019
EventEMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology - Lyngby, Copenhagen, Denmark
Duration: 9 Sep 201913 Sep 2019
https://www.ems2019.eu/

Conference

ConferenceEMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology
LocationLyngby
CountryDenmark
CityCopenhagen
Period09/09/201913/09/2019
Internet address

Cite this

Dellwik, E., Angelou, N., Mann, J., van der Laan, P., Burak Altun, S., & Simon, E. (2019). How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment. Abstract from EMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology, Copenhagen, Denmark.
Dellwik, Ebba ; Angelou, Nikolas ; Mann, Jakob ; van der Laan, Paul ; Burak Altun, Safak ; Simon, Elliot. / How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment. Abstract from EMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology, Copenhagen, Denmark.1 p.
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title = "How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment",
abstract = "When looking at an agricultural landscape from above, one sees a patchwork of fields, whereas tall trees and alleys between the fields only cover a small fraction of the area. However, the trees can be prominent when observing the landscape from ground level. This view and emphasis on agricultural fields is mirrored in the way the agricultural landscape is treated in meteorological models; since the land surface is accounted for by assigning characteristic parameters to dominant land use classes from satellite imagery, the small scale tree features of the landscape are ignored. The overall aim of this study is to quantify the effect of solitary trees on the wind field and offer an estimate of how the presence of scattered trees would affect the surface roughness for a larger scale model. We present high-detail laser scans of solitary trees and discuss how they can successfully be transferred into parameterizations of the landscape in coarser resolution models. We also present wake measurements caused by solitary trees observed with both long-range and short range wind scanners, which spatially resolve the wind field. In previous work (Dellwik et al. 2019), the high resolution scans of tree geometry were used in high-resolution computational fluid dynamics (CFD) models, where the tree is parameterized as a distributed drag force. A novelty used in this study was that the total force on the tree had been experimentally assessed using strain gauges, which allowed for a much more certain assessment of the tree parameterization in the CFD model. By using the simulated wind fields from the CFD model and the total observed force on the tree in combination with basic micro-meteorological relationships, the effect of a solitary tree can be quantified in terms of changes to surface roughness.",
author = "Ebba Dellwik and Nikolas Angelou and Jakob Mann and {van der Laan}, Paul and {Burak Altun}, Safak and Elliot Simon",
year = "2019",
language = "English",
note = "EMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology ; Conference date: 09-09-2019 Through 13-09-2019",
url = "https://www.ems2019.eu/",

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Dellwik, E, Angelou, N, Mann, J, van der Laan, P, Burak Altun, S & Simon, E 2019, 'How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment', EMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology, Copenhagen, Denmark, 09/09/2019 - 13/09/2019.

How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment. / Dellwik, Ebba; Angelou, Nikolas; Mann, Jakob; van der Laan, Paul; Burak Altun, Safak ; Simon, Elliot.

2019. Abstract from EMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology, Copenhagen, Denmark.

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

TY - ABST

T1 - How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment

AU - Dellwik, Ebba

AU - Angelou, Nikolas

AU - Mann, Jakob

AU - van der Laan, Paul

AU - Burak Altun, Safak

AU - Simon, Elliot

PY - 2019

Y1 - 2019

N2 - When looking at an agricultural landscape from above, one sees a patchwork of fields, whereas tall trees and alleys between the fields only cover a small fraction of the area. However, the trees can be prominent when observing the landscape from ground level. This view and emphasis on agricultural fields is mirrored in the way the agricultural landscape is treated in meteorological models; since the land surface is accounted for by assigning characteristic parameters to dominant land use classes from satellite imagery, the small scale tree features of the landscape are ignored. The overall aim of this study is to quantify the effect of solitary trees on the wind field and offer an estimate of how the presence of scattered trees would affect the surface roughness for a larger scale model. We present high-detail laser scans of solitary trees and discuss how they can successfully be transferred into parameterizations of the landscape in coarser resolution models. We also present wake measurements caused by solitary trees observed with both long-range and short range wind scanners, which spatially resolve the wind field. In previous work (Dellwik et al. 2019), the high resolution scans of tree geometry were used in high-resolution computational fluid dynamics (CFD) models, where the tree is parameterized as a distributed drag force. A novelty used in this study was that the total force on the tree had been experimentally assessed using strain gauges, which allowed for a much more certain assessment of the tree parameterization in the CFD model. By using the simulated wind fields from the CFD model and the total observed force on the tree in combination with basic micro-meteorological relationships, the effect of a solitary tree can be quantified in terms of changes to surface roughness.

AB - When looking at an agricultural landscape from above, one sees a patchwork of fields, whereas tall trees and alleys between the fields only cover a small fraction of the area. However, the trees can be prominent when observing the landscape from ground level. This view and emphasis on agricultural fields is mirrored in the way the agricultural landscape is treated in meteorological models; since the land surface is accounted for by assigning characteristic parameters to dominant land use classes from satellite imagery, the small scale tree features of the landscape are ignored. The overall aim of this study is to quantify the effect of solitary trees on the wind field and offer an estimate of how the presence of scattered trees would affect the surface roughness for a larger scale model. We present high-detail laser scans of solitary trees and discuss how they can successfully be transferred into parameterizations of the landscape in coarser resolution models. We also present wake measurements caused by solitary trees observed with both long-range and short range wind scanners, which spatially resolve the wind field. In previous work (Dellwik et al. 2019), the high resolution scans of tree geometry were used in high-resolution computational fluid dynamics (CFD) models, where the tree is parameterized as a distributed drag force. A novelty used in this study was that the total force on the tree had been experimentally assessed using strain gauges, which allowed for a much more certain assessment of the tree parameterization in the CFD model. By using the simulated wind fields from the CFD model and the total observed force on the tree in combination with basic micro-meteorological relationships, the effect of a solitary tree can be quantified in terms of changes to surface roughness.

M3 - Conference abstract for conference

ER -

Dellwik E, Angelou N, Mann J, van der Laan P, Burak Altun S, Simon E. How does a single tree affect the roughness of a landscape: Results from a Single Tree Experiment. 2019. Abstract from EMS Annual meeting 2019: European Conference for Applied Meteorology and Climatology, Copenhagen, Denmark.