# Sea level: the three applets Test page for the MATH 310 F26 Case Study 1 applets. The full lecture note is `Teaching/MATH310/MATH310F26/Lecture Notes/MATH310F26(Case Study 1) - Sea level, the trend, the tone, and what's left.md`; it embeds these same three divs. ## 1. The raw spectrum <div class="applet" data-applet="gmsl-spectrum"></div> **Check:** on load the chosen bin is k = 32, f = 1.0085 cycles/yr, amplitude 4.73 mm, 4.6× its neighbours, rank 8. Tick *show the wraparound*: J = 104.7 mm, background at the annual bin 1.04 mm. ## 2. The harmonics <div class="applet" data-applet="gmsl-harmonics"></div> **Check:** 1/yr only → 4.71 mm, peaks in Oct; 2/yr bin 0.91 mm (5.5×); RMS 3.851 mm; a = 0.0778. Add 2/yr → 1.67 mm, first peak in Mar; 2/yr bin 1.4×; RMS 3.665. Add 3/yr → 0.38 mm; RMS 3.655. ## 3. The trend and what's left <div class="applet" data-applet="gmsl-trend"></div> **Check:** annual + semiannual → v(2000) = 2.612 mm/yr, a = 0.0777 mm/yr², v(2024) = 4.48 mm/yr; *none* → a = 0.0760. Extrapolate to 2100 → 650 mm above 2000. Window centre 2023.5, width 2 → 9.21 (deseasoned), 6.96 (raw), v = 4.44.