Subregional precipitation climate of the Caribbean and relationships with ENSO and NAO

Abstract

[1] Thirty-five meteorological stations encompassing the Caribbean region (Cuba, Bahamas, Jamaica, Dominican Republic, Puerto Rico, US Virgin Islands, St. Maarten, and Barbados) were analyzed over the time interval 1951-1981 to assess regional precipitation patterns and their relationships with the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO). Application of factor analysis to these series revealed the existence of four geographically distinct precipitation regions, (C1) western Cuba and northwestern Bahamas, (C2) Jamaica, eastern Cuba, and southeastern Bahamas, (C3) Dominican Republic and northwestern Puerto Rico, and (C4) eastern Puerto Rico, US Virgin Islands, St. Maarten, and Barbados. This regionalization is related to different annual cycles and interannual fluctuations of rainfall. The annual cycle is more unimodal and largest in the northwest Caribbean (C1) and becomes increasingly bimodal toward lower latitudes (C4) as expected. Year-to-year variations of precipitation are compared with two well-known climatic indices. The ENSO relationship, represented by Niño 3.4 sea surface temperatures (SST), is positive and stable at all lags, but tends to reverse over the SE Caribbean (C4) in late summer. The NAO influence is weak and seasonally dependent. Early summer rainfall in the northwest Caribbean (C1) increases under El Niño conditions. Clusters 2 and 3 are less influenced by the global predictors and more regional in character.

Exacerbation of the 2013–2016 Pan‐Caribbean Drought by Anthropogenic Warming

“…As compared to previous droughts that also occurred during strong El Niño events (e.g., in 1997–1998), the Pan‐Caribbean drought was considerably more severe (Herrera & Ault, 2017), and it affected regions usually associated with wet conditions during El Niño, such as western Cuba (Jury et al, 2007). …”

“…Because of the relatively coarse horizontal resolution of state‐of‐the‐art gridded observationally based climate products, which varies from 0.5° to 2.5° (~55 to ~280 km, respectively) and thus fails to resolve many of the Lesser Antilles (Dai, 2011; Jury et al, 2007; van der Schrier et al, 2013), we used statistically downscaled observed monthly precipitation and temperature ( T min , T mean , and T max ) data from the Global Precipitation Climatology Centre (Schneider, Becker, Finger, Meyer‐Christoffer, Rudolf, et al, 2015; Schneider, Becker, Finger, Meyer‐Christoffer, & Ziese, 2015) and Berkeley Earth Surface Temperature (Rohde et al, 2013), respectively. The validation of downscaled products and further details of the downscaling and bias‐correction procedures are described in Supporting Information S1 and in Herrera and Ault (2017).…”

Joint modes of climate variability across the inter‐Americas

“…The target data include station rainfall averaged into four Caribbean Antilles Island areas, based on the cluster analysis of Jury et al (2007): (1) western Cuba (annual mean and standard deviation: 103, 53 mm/month), (2) eastern Cuba (82, 40), (3) Dominican Republic and Puerto Rico (92,42), and (4) the Lesser Antilles of the east Caribbean (92,45). The station data were extracted from NCDC/GHCN, and gaps were filled using gridded rainfall estimates from NCEP, based on the CMAP reconstruction technique (Xie and Arkin, 1997;Chen et al, 2002;Yin et al, 2004), available at the website http://iridl.ldeo.columbia.edu/SOURCES/.NOAA/.…”

“…The station data were extracted from NCDC/GHCN, and gaps were filled using gridded rainfall estimates from NCEP, based on the CMAP reconstruction technique (Xie and Arkin, 1997;Chen et al, 2002;Yin et al, 2004), available at the website http://iridl.ldeo.columbia.edu/SOURCES/.NOAA/. In the study by Jury et al (2007), rainfall data were truncated at 1981, but here, we employ a record extending from 1951 to 2005. The rainfall data are divided into early Figure 1 illustrates the percentage of variance explained by the leading principal components for the seasonal (SEAS) and anomaly (ANOM) time-series.…”

“…In the Caribbean Sea and Gulf of Mexico, surface temperatures rise above 28°C from July to October each year, instilling high convective energy and attracting hurricanes Enfield, 2001, 2003;Wang et al, 2006;Wang and Lee, 2007). But along the northern coast of Venezuela and Columbia, there is an axis of strong trade winds that drive ocean upwelling, inhibiting convection across the Antilles Islands particularly in mid-summer (Granger, 1985;Amador, 1998;Magaña et al, 1999;Amador et al, 2000;Jury et al, 2007;Muñoz et al, 2008). The Atlantic and east Pacific intertropical convergence zones (ITCZ) oscillate north-south following the sun and surface heating of North and South America land masses (Horel et al, 1989;Higgins and Shi, 2001;Liebmann and Marengo, 2001;Nogués-Paegle et al, 2002;Vera et al, 2005).…”