[Procak]_601_lab 8

Name: ¥odherine rocall GEOL1551 — Waves and Tides Readings: Textbook chapter on waves and tides Objective: The objective of this exercise is to familiarize you with processes that control wave and tidal cnergy. Understanding process is critical for making forecasts of conditions that occurred in the past, present or future. Throughout this exercise you will: 1. Demonstrate basic data literacy in graph interpretation by identifying values of meteorological and oceanographic variables (with appropriate units) at specified times and describe their change over time 2. dentify trends in wind speed in a time series and establish the relationship between the two variables. o 3. Identify specific values of wind speed and maximum wave height in a time series and establish the relationship between the two variables. 4. Identify specific values of wave period and wave height and use these to calculate wavelength and wave speed. 5. Identify Spring and Neap tides on tidal charts and relate to astronomical positions of Earth, Sun and Moon. 6. Identify amphidromic points on a tidal range chart and interpret information in that chart. Part 1 - Waves Understanding wave energy is of great significance due to its impacts on shipping, on coastal processes including sediment transport, erosion and biological systems, and for production of electricity. To begin, read the information on this webpage and complete the “Quick Checks”: https://datalab.marine.rutgers.edu/ooi-lab-exercises/lab-6-ocean-waves-linking-the-marine-atmosphere-and-the- ocean-surface/ Then click “Lab 6.1 at the bottom to begin the lab and answer the questions below: Use the first graph 1. What is the maximum and minimum barometric pressure during this week? o) imom " 1096, 4L Mip pom, 4(1;5 L(? 2. What is the day and time when the maximum and minimum occur? May imom’ Q01§ ol Jo} 1400 NS '}o\g; o\ /oYy 1§ 60 3. What is the barometric pressure on Janwary 4, 2513 at 1800? Loy Y 4. Describe the changes to barometric pressure between January 1 and the end of January 4. T\\(, c\r\cnstJ ore Vel V“i“if"‘v\ dorns Tan V¥ ¥ Tan “{*

Use the lower graph to answer these questions: A< ing $peed inwreased | the bacmdoic Pregore decreascd 7. Recall that winds are generated by air movin barometric pressure had drop would be weaker or stronger? g from high pressure to low pressure. If the ped more on January 4th (e.g., to 945 mbar), do you think the winds The Wind would be teake Click “Next Lab 6.2” to continue Use the upper graph to answer these questions: 8. Calculate the total decrease in barometric pressure between January 4, 2018 0000 (midnight) and January 4, 2018, 1800 (6pm). _ 1oy s 1026.94 53 10. Find the first time the wind speed exceeded 12 m/s and then the time when it dropped below 12m/s e — again. Calculate the total time the wind speed was above 12 m/s. Remember Yyou can hover over the wind speed data with your cursor to record the wind speed and time. 201 /01 foy Ol 10D Exteeyey ‘ Qlot o- > (}Ol y/ol/.o’} O}'.,Q’b Aeopoes A \Ood’\/ the lower graph to answer these questions: 1. Identify the maximum wind speed and maximum wave height during the week. Mor g\ oy Max wove - €4k

19. The waves measured during this time period classify as deep-water waves meaning fhc waves do not “feel’ the bottom because the water depth is more than twice the wavelength. Using the following equation, calculate the wavelength (L) for the waves on January 5, 2018 at 0000 (the time period of largest wave height): L= 1.56*T2. T is wave period in seconds. SHOW WORK L=l @ L |.s(°(4,7m) AR 20. Based on your answer above, calculate how fast these waves are traveling at this location. [Remember, speed = L/T or wavelength/wave period] UG, 7¢ _L‘Q 15, 47 21. Explain how the speed of a wave changes with the wavelength. The Spec does nok Clpese Limitations on wave height: Recall that deep water wave speed (c) is controlled by the wave period (T). Because speed equals distance (wavelength: L) over time (c = L/T), one can also relate wavelength to wave period for deep-water waves as you did in #14 above: L =1.56*T2. Using this information and recalling that waves become unstable and break when height exceeds 1/7 the wavelength (H/L=1/7), calculate the maximum wave height that corresponds with the wave periods (T) shown below. You will need to solve for wavelength FIRST, then for Hmax. Round your answer to the nearest whole number. 22. T=6s, Hmax= SG mS(e.l(o 23, T=9 Hmax=_\O% g k0% 24, T=125, Hmax= 075 m 94.by

25. A typical wavelength of a tsunami may be 100 km. Given that, are tsunami deep-water waves, intermediate waves, or shallow-water waves? Shallow. Weie- Waves Part 2: Tides We’re going to look at predicted tide heights at two locations — One in NC, and one where I used to live in VA! 26. Locate the following tidal stations and produce a one-month tidal record for October 2021 (Plot Daily) for each. How? Click the link, edit the dates at bottom left, click “Plot Daily”. **On each plot, label the sections corresponding to Spring and Neap tides, save and upload with this assignment.** 8656483 Beaufort, NC: https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=8656483 8638017 James River, VA: https://tidesandcurrents.noaa.gov/noaatidepredictions.htm|?id=8638017 27. What is the maximum range between high and low tide at each station? Which location has a greater tidal range? NC (onse. U4Y E\' hsh . oW . 0.0\ i bkt 216 VA e 30t v Dosh In the upper left of the website, click “Products” then scroll down to “Astronomical Data”. Look at a plot of the lunar phases during the same month as the tide data and use it to answer questions 23 & 24. 28. Compare your tide charts to the phases of the moon for the month. How do the moon phases affect iy : . the tides? Be specific. Lhen . moon 10 ok & Qll 0- hews Moen the Fdes o 23 i Wighay whlv low il o lev the. porma\ 29, Perigee and apogee configurations are also noted on the Astronomical Data chart. When do these occur for this month? How do these configurations affect the tides? |8 Oche- 8™ iy Persee & pkber ' (¢ agesce during Peciser A hida & hishedhon usel s Apesec b Fact oge o ey hon drerie