Wind Direction Intensity and Dominant Wave Period Analysis

Wind Direction, Intensity, and Dominant Wave Period Analysis Keweenaw North Waterway Buoy Bob Shuchman: shuchman@mtu. edu Colin Brooks: colin. brooks@mtu. edu Nate Jessee: nljessee@mtu. edu www. michigantechlakesuperior. org www. mtri. org 1

Analysis of Wind Direction and Speed � The Keweenaw Waterway North buoy gathered data from 7/9/2010 through 10/11/2010. Data is located at www. michigantechlakesuperior. org � A limited selection of records were removed for predeployment recording and sensor errors. � Data presented here represents dates from 7/9/2010 through 10/10/2010. � Two of the parameters collected were wind direction and wind speed. � This data was organized to determine the frequency, duration, and strength of winds moving off shore (from land to water) and on shore (from water to land). 2

General Wind Speed Analysis �For all records spanning from July 9 th through October 10 th 2010, wind speed measurements were recorded every ten minutes. �During this time span, wind speeds were less than 2 m/s for 11. 41% of all records and wind speed was equal to zero for 0. 07% of all records. 3

Analysis of Wind Direction and Speed � On shore and off shore winds are characterized based on the buoy location and the direction of the land. � Wind direction is absolute in that it indicates the direction that wind is moving towards. � On shore events are defined by consecutive recordings of winds with a direction between 45 and 225 degrees where 360/0 is north and 180 degrees as south. 45 225 On Shore Direction 4

Analysis of Wind Direction and Speed �Off shore events are consecutive recordings with a direction greater than 225 and less than 45 degrees where 360/0 is north and 180 degrees is south. Off Shore Direction 45 225 5

Buoy Location 6

Off Shore and On Shore Wind Direction Frequency Histogram: Count of wind direction frequency 9000 8005 7000 6000 Frequency Count of Recordings 8000 5448 5000 4000 Frequency 59. 5% 40. 5% 3000 2000 1000 0 Off Shore On Shore The frequency of wind direction recordings described as either off shore or on shore, a total of 13453 records were taken from July 9 th to October 10 th. 7

Off Shore Wind Event* Duration Statistics Value (Hours) 90 77. 5 80 Wind Speeds For this event 70 60 Max 10. 83 m/s Hours 50 40 Min 5. 31 m/s 30 Ave. 8. 07 m/s 20 10 0 Value (Hours) 2. 68 0. 17 Minimum 8. 35 Maximum Average 0. 33 Median Standard Deviation Description of off shore wind events, described by duration of events in hours. *Events are defined as time periods greater than 10 minutes where wind is consistently moving in the on or off shore direction. 8

Off Shore Wind Speed Statistics Wind Speed Values (m/s) 16. 00 15. 07 14. 00 Wind Speed, m/s 12. 00 10. 00 8. 00 Values (m/s) 6. 00 3. 47 4. 00 3. 05 2. 40 2. 00 0. 00 Minimum Maximum Average Median Standard Deviation Summary of all off shore wind speeds for all off shore events. 9

On Shore Wind Event* Duration Statistics Value (Hours) 6. 00 5. 17 5. 00 Hours 4. 00 Max 5. 92 m/s 3. 00 Values (Hours) Min 4. 32 m/s 2. 00 Ave. 4. 98 m/s 1. 00 0. 17 0. 76 0. 44 0. 17 0. 00 Minimum Maximum Average Median Standard Deviation Description of on shore wind events, described by duration of events in hours. *Events are defined as time periods greater than 10 minutes where wind is consistently moving in the on or off shore direction. 10

On Shore Wind Speed Statistics Wind Speed Values (m/s) 14. 00 12. 56 Wind Speed, m/s 12. 00 10. 00 8. 00 Values (m/s) 6. 00 3. 80 4. 00 3. 38 2. 46 2. 00 0. 00 Minimum Maximum Average Median Standard Deviation Summary of all on shore wind speeds for all on shore events 11

Off Shore and On Shore Event Duration Comparison Event Duration Statistics 90 77. 5 80 70 Hours 60 50 Off Shore Values (Hours) On Shore Values (Hours) 40 30 20 9. 17 10 0 5. 17 0. 17 Minimum Maximum 2. 69 0. 44 Average 0. 33 0. 17 Median 0. 76 Standard Deviation 12

Off Shore and On Shore Wind Speed Comparison 16. 00 15. 07 14. 00 12. 56 Wind Speed, m/s 12. 00 10. 00 Off Shore Values (m/s) 8. 00 On Shore Values (m/s) 6. 00 3. 47 4. 00 3. 80 3. 05 3. 38 2. 40 2. 46 2. 00 0. 00 Minimum Maximum Average Median Standard Deviation Represents all wind speed records for all events categorized as on or off shore 13

Major Off Shore Wind Event �Started on September 11 th at 7: 30 p. m. and lasted through September 15 th at 1: 00 a. m. Lasting a total of 77 hours, 30 minutes. �The event had the following characteristics: �Average wind speed: 8. 07 m/s �Minimum wind speed: 5. 31 m/s �Maximum wind speed 10. 83 m/s �The following slide represents the temporal distribution of wind speed. 14

9/11/10 19: 30 9/11/10 21: 00 9/11/10 22: 40 9/12/10 0: 20 9/12/10 2: 00 9/12/10 3: 40 9/12/10 5: 20 9/12/10 7: 00 9/12/10 8: 40 9/12/10 10: 20 9/12/10 12: 00 9/12/10 13: 40 9/12/10 15: 20 9/12/10 17: 10 9/12/10 18: 50 9/12/10 20: 30 9/12/10 22: 10 9/12/10 23: 50 9/13/10 1: 30 9/13/10 3: 10 9/13/10 4: 50 9/13/10 6: 30 9/13/10 8: 10 9/13/10 9: 50 9/13/10 11: 30 9/13/10 13: 10 9/13/10 14: 50 9/13/10 16: 30 9/13/10 18: 10 9/13/10 19: 50 9/13/10 21: 30 9/13/10 23: 10 9/14/10 0: 50 9/14/10 2: 30 9/14/10 4: 10 9/14/10 5: 50 9/14/10 7: 30 9/14/10 9: 10 9/14/10 10: 50 9/14/10 12: 30 9/14/10 14: 10 9/14/10 15: 50 9/14/10 17: 30 9/14/10 19: 10 9/14/10 20: 50 9/14/10 22: 30 9/15/10 0: 10 Wind Speed, m/s Major Off Shore Event, Wind Speed Graph Wind Speed (m/s) 12 10 8 6 Wind Speed (m/s) 4 2 0 15

9/15/2010 4: 00 9/15/2010 0: 30 9/14/2010 21: 00 9/14/2010 17: 30 9/14/2010 14: 00 9/14/2010 10: 30 9/14/2010 7: 00 9/14/2010 3: 30 9/14/2010 0: 00 9/13/2010 20: 30 9/13/2010 17: 00 9/13/2010 13: 30 9/13/2010 10: 00 9/13/2010 6: 30 9/13/2010 3: 00 9/12/2010 23: 30 9/12/2010 20: 00 9/12/2010 16: 20 9/12/2010 12: 50 9/12/2010 9: 20 9/12/2010 5: 50 9/12/2010 2: 20 9/11/2010 22: 50 9/11/2010 19: 30 Wind Direction Major Wind Event Airport and Buoy Data Comparison 350 400 350 250 300 250 200 150 100 50 50 0 0 Wind Direction Degrees (Buoy) * Wind Direction Degrees (Airport) 100 *Wind Directions indicate the actual direction that wind is moving 16

7/10/2010 13: 00 7/12/2010 5: 40 7/14/2010 12: 40 7/16/2010 19: 00 7/19/2010 0: 40 7/21/2010 7: 10 7/23/2010 13: 50 7/25/2010 19: 40 7/28/2010 1: 20 7/30/2010 8: 30 8/1/2010 14: 10 8/3/2010 20: 00 8/6/2010 2: 00 8/8/2010 7: 30 8/10/2010 14: 00 8/12/2010 21: 10 8/15/2010 3: 00 8/17/2010 8: 40 8/19/2010 14: 30 8/21/2010 20: 20 8/24/2010 1: 50 8/26/2010 7: 40 8/28/2010 14: 10 8/30/2010 19: 50 9/2/2010 1: 20 9/3/2010 23: 20 9/5/2010 9: 00 9/7/2010 14: 40 9/9/2010 20: 20 9/12/2010 1: 50 9/14/2010 7: 30 9/16/2010 13: 10 9/18/2010 18: 50 9/21/2010 0: 30 9/23/2010 10: 10 9/25/2010 17: 10 9/28/2010 0: 20 9/30/2010 6: 00 10/2/2010 11: 50 10/4/2010 17: 30 10/6/2010 23: 00 10/9/2010 4: 40 Wind Speed, m/s Wind Speed for Entire Data Series Wind. Speed(m/s) 16 14 12 10 8 6 Wind. Speed(m/s) 4 2 0 Represents all records from July 9 th through October 10 th. 17

16 7/9/2010 13: 00 7/11/2010 10: 10 7/13/2010 7: 30 7/15/2010 6: 50 7/17/2010 4: 00 7/19/2010 1: 20 7/20/2010 23: 20 7/22/2010 20: 40 7/24/2010 19: 10 7/26/2010 16: 30 7/28/2010 15: 20 7/30/2010 12: 40 8/1/2010 10: 00 8/3/2010 7: 30 8/5/2010 5: 10 8/7/2010 2: 20 8/8/2010 23: 30 8/10/2010 21: 40 8/12/2010 20: 30 8/14/2010 18: 00 8/16/2010 15: 20 8/18/2010 12: 30 8/20/2010 10: 20 8/22/2010 7: 30 8/24/2010 4: 40 8/26/2010 2: 10 8/28/2010 0: 20 8/29/2010 21: 30 8/31/2010 18: 50 9/2/2010 16: 10 9/3/2010 23: 20 9/5/2010 7: 00 9/7/2010 4: 20 9/9/2010 1: 30 9/10/2010 22: 50 9/12/2010 20: 10 9/14/2010 17: 20 9/16/2010 14: 40 9/18/2010 12: 00 9/20/2010 9: 20 9/22/2010 10: 00 9/24/2010 9: 10 9/26/2010 6: 30 9/28/2010 5: 20 9/30/2010 2: 30 10/2/2010 0: 00 10/3/2010 21: 30 10/5/2010 18: 40 10/7/2010 15: 50 10/9/2010 13: 10 Wind Speed, m/s Major Off Shore Wind Event Within Entire Time Line Wind Speed (m/s) Major offshore wind event 14 12 10 8 6 4 2 0 Represents all records from July 9 th through October 10 th and highlights the major off shore event 18

Dominant Wave Period Analysis �High Frequency (HF) Radar is sensitive to dominant wave period length. �Wave periods of small length, less than 2 seconds for example, may be unnoticed by HF Radar. �An analysis was performed to determine how frequently the dominant wave period dropped below a specific value. Each event was also characterized by the length of time the wave period value was below the threshold. 19

General Dominant Wave Period Analysis �For all records spanning from July 9 th to October 10 th, dominant wave period measurements were recorded every ten minutes. �The dominant wave period had a value of zero second for 0. 01% of all records. �Also, dominant wave period value was less than 2 seconds for 15. 98% of all records and greater than 5 seconds for 16. 03% of all records between July 9 th and October 10 th. 20

Frequency and Duration of Wave Periods less than 2 seconds. Count and Duration of Wave Period Events less than 2 Seconds 250 200 Frequency Count of Events 217 142 150 100 Frequency 50 6 6 11 3 1 2 1 1 0 0 0 0 0 1 0 0 Duration of Wave periods less than 2 seconds le ss th an 10 m i 10 nut m es in ut e 1 h s o 2 ur ho u 3 h rs ou 4 rs ho u 5 h rs ou 6 rs ho u 7 h rs ou 8 rs ho u 9 rs ho 10 urs ho 11 urs ho 12 urs ho 13 urs ho 14 urs ho 15 urs ho 16 urs ho 17 urs ho 18 urs ho 19 urs ho 20 urs ho 21 urs ho 22 urs ho 23 urs ho ur s 1 d ay 0 23 18 This graph represents 15. 98 % of all records from July 9 th through October 10 th. 21

Frequency and Duration of Wave Periods less than 1. 5 Seconds Count and Duration of Wave Period Events less than 1. 5 Seconds 160 147 140 100 Frequency Count of Events 120 80 67 Frequency 60 40 21 20 10 6 1 0 0 3 hours 4 hours 5 hours 6 hours 7 hours 0 less than 10 10 minutes 30 minutes 1 hour 2 hours Duration of Wave Periods less than 1. 5 Seconds This graph represents 3. 95 % of all records from July 9 th through October 10 th. 22

Frequency and Duration of Wave Periods equal to zero seconds Count and Duration of Wave Period Events less than 1. 1 Seconds 2. 5 2 Frequency Count of Events 2 1. 5 Frequency 1 0. 5 0 0 less than ten minutes 0 10 minutes 20 minutes Duration of Wave Periods of Zero Seconds 0 greater than 20 minutes This graph represents 0. 01 % of all records from July 9 th through October 10 th. 23