4.3.2 Atlantic K1 TACs

Diurnal components are generally smaller than semidiurnal constituents in the Atlantic, and TACs are also generally lower magnitude (usually <sup>&</sup>lt;100 mm m<sup>1</sup> )

#### Figure 13.

M2 TAC Atlantic Ocean maps [10]. North American locations are shown in (a), Western Europe and United Kingdom locations are shown in (b), and Eastern Europe locations are shown in (c). Red markers indicate positive TACs and blue markers indicate negative TACs, with magnitudes proportional to marker size, as shown in the legend in (a). Black markers indicate insignificant results. Green-and-yellow background maps show the global tidal solutions overs the satellite era, taken from the TPXO7.2 solution [62, 63], with green and yellow colors giving the tidal amplitudes, and black lines showing tidal phases. Maps were generated using MATLAB version R2011a (www.mathworks.com).

Figure 14.

K1 TAC Atlantic Ocean maps [10]. North America locations are shown in (a), Western Europe and United Kingdom locations are shown in (b), and Eastern Europe locations are shown in (c). Markers and background maps are as described in Figure 13. Maps were generated using MATLAB version R2011a (www.mathworks.com).

#### Figure 15.

δ-HAT Atlantic Ocean maps [10], showing combined variability of eight largest gravitational tides (M2 + S2 N2 + K2 + K1 + O1 + P1 + Q1). North American locations are shown in (a), Western Europe and United Kingdom locations are shown in (b), and Eastern Europe locations are shown in (c). Markers are as described in Figure 13. Maps were generated using MATLAB version R2011a (www.mathworks.com).

and less often significant. However, there are still some regions of interest. The K1 tide (Figure 14a) has TACs that are consistently negative along the North American coast from Florida through maritime Canada. However, the TACs in the Gulf of Mexico are mainly positive, as well as in the Caribbean. K1 has some isolated positive TACs in Europe in the western English Channel, while the eastern Channel has a concentration of negative TACs (Figure 14b). There is a negative TAC at Bakar, Croatia (labeled "BAK" in Figure 14) at the end of the Adriatic Sea, where a large diurnal amplification occurs, and a small positive TAC at the end of the Gulf of Finland, where a diurnal amplification of the otherwise small Baltic tides also occurs (Figure 14c).

### 4.3.3 Atlantic δ-HATs

The calculation of the δ-HATs in the Atlantic use an eight-tide combination instead of the four-tide combination used in the Pacific, as detailed in Devlin et al. [10]. Results in North America (Figure 15a) are generally positive in the eastern Gulf of Mexico, Puerto Rico, and a large magnitude δ-HAT is seen in the Bahamas (+323 mm m<sup>1</sup> ; labeled "BAH" in Figure 15). New York City, New York ("NYC"), Boston, Massachusetts ("BOS"), Bar Harbor, Maine ("BH"), and parts of the Delaware Bay also are strongly positive. Strong negative δ-HATs are found from Florida to Wilmington, North Carolina (413 mm m<sup>1</sup> ; "WIL"), and at St. John at the head of the Bay of Fundy (378 mm m<sup>1</sup> ; "STJ"). In Europe (Figure 15b, c), strong positive δ-HATs are found in the southern North Sea at Cuxhaven, Germany (+219 mm m<sup>1</sup> ; "CUX") and in the Netherlands. Three locations within semienclosed regions of the Irish Sea show the strongest positive δ-HATs; at Avonmouth located at the head of the Severn Estuary (+256 mm m<sup>1</sup> ; "AVON"), and at Heysham ("HEY") and Millport ("MIL"; +385 and +341 mm m<sup>1</sup> , respectively). However, there are mainly negative δ-HATs seen in the rest of the UK, including most of the English Channel.

#### Figure 16.

Tidal anomaly correlations (TACs) of detrended M2 amplitude to detrended MSL in Hong Kong [11], with the marker size showing the relative magnitude according to the legend, in units of mm m<sup>1</sup> . Red/blue markers indicate positive/negative TACs, and black markers indicate TACs which are not significantly different from zero. Maps were generated using MATLAB version R2011a (www.mathworks.com).
