Vertical profiles of urban wind speed, wind direction and turbulence measured by LiDAR on campus of University College Cork, Ireland

Vertical Profiles of Urban wind speed, wind direction and turbulence measured by LiDAR on campus of University College Cork, Ireland

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README version 1.3, 21/07/2022

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Contact info:

Paul Leahy, University College Cork

paul.leahy@ucc.ie | +353 21 4902017

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Contents

1. Measurement location and time period

2. What is measured (brief description)

3. Instrumentation

4. CSV file detailed descriptions

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1. Measurement location and time period:

North roof of Kane Building, University College Cork (UCC), Ireland.

Lat 51 d 53 m 34 s N.

Long 8 d 29 m 39 s W.

Roof is c. 39 m above sea level, and c. 26 m above ground level (ground level reference point is the car park West of the UCC Kane Building).

The measurements were taken over a time period of several months in the years 2013 / 2014.

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2. What is measured (brief description):

* LiDAR Wind speed (horizontal and vertical), wind direction, turbulence intensity at 5  altitudes; reference point (0 m) for these altitudes is the top of the LiDAR instrument c. 1.2 m above roof level.

* Air temperature, atmospheric pressure, relative humidity.

* Wind speed and direction from an ultrasonic anemometer mounted on top of the instrument (c. 1.2 m above roof level).

* 10-minute average values (2 files) and high-resolution (c. 23 sec) data (1 file) are provided.

See 'CSV file detailed description' below for detailed information.

* Diagnostic information.

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2.1 Surrounding terrain:

Surrounding area is urban/suburban. The aspect is northerly.

To the West: 2-5 storey buildings, open spaces, suburban.

To the South: 2-3 storey buildings, open spaces, trees, river.

To the East: 2-3 storey buildings, open spaces.

To the North: A higher section of the Kane Building roof (47 m asl), 1-3 storey buildings, suburban.

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3. Instrumentation:

ZephIR 175 continuous wave wind profiling LiDAR with integrated sonic anemometer, temperature, humidity, air temperature pressure sensors and GPS.

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4. CSV files detailed description:

4.1 Data on 10-minute averages:

Filename 05092013-03122013_10min_res.csv contains:

10 minute averaged data from 05/09/2013 to 03/12/2013.

Measurement altitudes: 148 m, 90 m, 69 m, 44 m, 19m above instrument level.

 

Filename 03122013-07082014_10min_res.csv contains:

10 minute averaged data from:  03/12/2013 to 07/08/2014.

Measurement altitudes:  148 m, 90 m,  50 m, 35 m,  15 m above instrument level.

Note: from 19/06/2014 onwards, LiDAR data missing (MET data continues).

 

The first two rows contain header information.

Row 1 contains location information (GPS record)) and the measurement altitudes for wind speeds.

Sample GPS record: N51535775W8296590 = 51 d 53.5775 m North; 8 d 29.6590 m West.

Row 2 contains the data column headers including units.

 

Wind speeds at each altitude are recorded:

No of Packets (= number of scan units averaged over) []

Wind direction (mean) [deg]

Horizontal wind speed (mean) & standard deviation [m/s]

Vertical wind speed (mean) & standard deviation [m/s]

Horizontal variance [m^2/s^2]                      

Horizontal min [m/s]                              

Horizontal max [m/s]                             

TI (turbulence intensity) []

 

Other meteorological data:

Air temperature [^oC]

Pressure [mbar]

Rel. Humidity [%]

Rain indicator  [unitless] Higher values indicate more rain during the averaging interval.

Wind Speed [m/s] (column 'MET Wind Speed' measured at the top of the instrument by the ultrasonic anemometer)

Wind direction [deg] (column 'MET Direction' measured at the top of the instrument by the ultrasonic anemometer).

 

Other housekeeping and diagnostic data:

Instrument tilt [deg]

Instrument bearing [deg]

GPS data [degrees N, degrees W]

Battery voltage [V] 

Optics, electronics and battery temperature [^oC]

 

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4.2 Data with high time resolution (~23 s):

 

Filename 05092013-11112013_23s_res.csv contains:

High resolution data from 05/09/2013 to 11/11/2013

Measurement altitudes: 148 m, 90 m, 69 m, 44 m, 19m.

 

Note on time resolution:

The time resolution of processed wind measurements is c. 3 seconds per wind level, and around 8 seconds to reset to the first level. A full wind profile measurement at 5 altitudes therefore takes around (5 x 3) + 8 = 23 s to complete.

The raw scanning resolution of the instrument is higher than this, as each wind measurement is an average of several values.

 

Row 1 contains location information (lat, long) and the vertical measurement levels for wind speeds.

Row 2 contains the data column headers including units.

 

Wind speeds at each altitude are recorded:

No of Packets (= scan units averaged over) []

Wind direction (mean) [deg]

Horizontal wind speed (mean) & standard deviation [m/s]

Vertical wind speed (mean) & standard deviation [m/s]

Horizontal variance [m^2/s^2]    not defined as measurement interval is too short.

Horizontal min [m/s]                    not defined as measurement interval is too short.                            

Horizontal max [m/s]                    not defined as measurement interval is too short.                             

TI (turbulence intensity) []           not defined as measurement interval is too short.

 

Other meteorological data:

Air temperature [^oC]

Pressure [mbar]

Rel. Humidity [%]

Rain indicator  [unitless] Higher values indicate more rain during the scanning interval.

Wind Speed [m/s] (column 'MET Wind Speed' measured at the top of the instrument by the ultrasonic anemometer)

Wind direction [deg] (column 'MET Direction' measured at the top of the instrument by the ultrasonic anemometer.

 

Other housekeeping and diagnostic data:

Instrument tilt [deg]

Instrument bearing [deg]

GPS data [degrees N, degrees W]

Battery voltage [V] 

Optics, electronics and battery temperature [^oC]

 

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4.3 Quality control indicators:

 

9998                    atmospheric conditions which adversely affect LiDAR wind speed measurements e.g. fog

9999                    high quality wind speed measurement not possible e.g. very low wind speed or obscuration of optical path

Status Flag         'Green' => good

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