Characterization of Future Caribbean Rainfall and Temperature Extremes across Rainfall Zones

Abstract

End-of-century changes in Caribbean climate extremes are derived from the Providing Regional Climate for Impact Studies (PRECIS) regional climate model (RCM) under the A2 and B2 emission scenarios across five rainfall zones. Trends in rainfall, maximum temperature, and minimum temperature extremes from the RCM are validated against meteorological stations over 1979–1989. The model displays greater skill at representing trends in consecutive wet days (CWD) and extreme rainfall (R95P) than consecutive dry days (CDD), wet days (R10), and maximum 5-day precipitation (RX5). Trends in warm nights, cool days, and warm days were generally well reproduced. Projections for 2071–2099 relative to 1961–1989 are obtained from the ECHAM5 driven RCM. Northern and eastern zones are projected to experience more intense rainfall under A2 and B2. There is less consensus across scenarios with respect to changes in the dry and wet spell lengths. However, there is indication that a drying trend may be manifest over zone 5 (Trinidad and northern Guyana). Changes in the extreme temperature indices generally suggest a warmer Caribbean towards the end of century across both scenarios with the strongest changes over zone 4 (eastern Caribbean).

Future Caribbean temperature and rainfall extremes from statistical downscaling

“…Climatology plots of modelled and observed temperature and rainfall extremes were created for six Caribbean zones by averaging the climatology of all stations in the zone (Figure 2). The zones are premised on the work of Jury (2009), Stephenson et al (2014) and McLean et al (2015) and span the north Caribbean (Zone 1) through the southeastern Caribbean (Zone 5) and Belize (Zone 6) (see Figure 2). Spatial plots of the difference between modelled and observed annually averaged extreme rainfall indices are also examined to assess the skill of the model for or within a zone.…”

“…It is useful to note as well that trends in historical temperature (and rainfall) extremes for Caribbean subregions also reflect different responses in magnitude and in some cases direction of the climate change signal. See, for example Stephenson et al (2014) and McLean et al (2015). These provide further justification for exploring the changes spatially and by zones even in relation to temperature.…”

Long‐term trends in precipitation and temperature across the Caribbean

“…The main feature of precipitation over the Caribbean is a well-defined annual cycle. Taylor and Alfaro (2005) and Jury (2009c) showed that for most of the region (Belize and the islands of the Caribbean Sea), this cycle is characterized by maximum precipitation from May to November and a dry period peaking in February-March. Particularly in the northwest of the Caribbean, the wet season tends to be bimodal with peaks in May-June (early season) and August-October (late season).…”

“…The basic climatology of the region has been described in a number of earlier works (e.g. the earlier works of Hastenrath previously mentioned) and more recently by Taylor and Alfaro (2005). Many studies (e.g.…”

“…coverage and coherency) in the context of the discussion of the trends they reflect. Changes in daily precipitation and temperature extremes have been considered by Peterson et al (2002), Stephenson et al (2014), and Mclean et al (2015) and this timescale is not considered here. This study is structured as follows.…”