## 3 Results
### Sea Level Characteristics for Jamaica  
Figure 2a shows that southern Jamaica is located in a region with annual increasing sea level trend of approximately 3.1 mm/year for the 27-year period from 1993 to 2019. The Kingston altimetry data had a linear slope value of +3.2 mm/year (Figure 2b). When the estimate was adjusted for GIA of 0.6 mm/year, instrumental drift of 0.1 mm/year, and after accounting for uncertainties [60], the final rate of rise was estimated as 3.3 \(\pm\) 0.4 mm/year. This is slightly higher than the global mean SLR estimate of 3.1 \(\pm\) 0.3 mm/year from 1993 to 2018 [18], but lower than the 3.7 \(\pm\) 0.5 mm/year reported in the Sixth Assessment Report of the IPCC for 2006 to 2018 [12].  
Figure 2: _Cont._Both the calculated Kingston trend and the regional values shown in Figure 2a are higher than that determined by previous studies utilising altimetry. For example,  
Figure 2: (**a**) Sea level trend in the Caribbean basin (mm/year). (**b**) Sea level anomalies 1993–2019 (mm). (**c**) Annual cycle of sea level anomalies, for Kingston, Jamaica. Anomalies with respect to 1993–2019 baseline. (**d**) Seasonal variation with respect to the annual cycle mean (mm). (**e**) Seasonal sea level variability (annual cycle amplitude, cm).  
[PERSON] et al. (2012) [17] determined the basin average sea level rise from altimetry to be ~1.7 \(\pm\) 0.6 mm/year over the period 1993-2009 and up to 2 mm/year around the Greater Antilles islands of Jamaica and Cayman. [PERSON] and [PERSON] (2013) [23] also estimated the basin average to be ~1.7 mm/year using altimetry data spanning 1993-2010. This suggests an acceleration of sea level rise in the Caribbean including for the seas near Jamaica, driven by changes post-2010. This is also visually evident in Figure 2b. The value of re-examining some of the previous analyses with the extended timeseries is also clear.  
Seasonally, southern Jamaican sea levels reach an annual maximum in July-August (Figure 2c). Ref. [21] also identified a summer peak for the wider Caribbean basin using altimetry data from 1993 to 2010. Figure 2c supports the findings of [61] with respect to seasonal variation but for a longer 27-years altimetry timeseries. The annual cycle is attributed to the steric response of the Caribbean Sea to heat fluxes at the surface as it warms and cools throughout the year [20,21]. The July-August peak also coincides with the summer intensification of the CLIJ and the northward movement of the Intertropical Convergence Zone (ITCZ). The ITCZ moves southwards in the winter, when sea level anomalies are negative, and northwards in the summer, when sea level anomalies are positive [20]. The summer sea level peak also falls within the north tropical Atlantic hurricane season (June-November), which peaks in August-September [67].  
With respect to an annual mean, the climatology of Jamaican sea level is characterized by largest negative anomalies for the three-month season March through May (Figure 2d). There is a positive summer season phase (June through August) when sea levels are higher by 7 cm or more than at the start of the year. The mean annual amplitude in the annual cycle around Jamaica (and for much of the eastern island chain) is ~10 cm (Figure 2e). Highest amplitudes in the main Caribbean basin occur south of Jamaica and coincide with the CLLJ region.