Spatial and temporal patterns, trends and teleconnection of cumulative rainfall deficits across Central America

Abstract

Central America is a region vulnerable to hydrometeorological threats. Recently, the impacts of droughts caused higher economic losses in comparison to, for example, floods and landslides. This study focuses on the spatio‐temporal behaviour of cumulative rainfall deficits across Central America attempting to provide an historical context to the most recent drought episodes. We developed a long‐term (1950–2014), monthly rainfall data set that merged large‐scale interpolated products with a station observation network to spatially and temporally evaluate the 12‐month Standardized Precipitation Index (SPI12) across the region. We found that El Niño cannot always be associated with drier conditions and that severe droughts are likely to spatially develop from localized phenomena to cover the entire region beyond the Central American drought corridor (CADC). Furthermore, there is not always a clear separation into the Pacific and Caribbean domain in terms of drought behaviour, but generally El Niño episodes can be associated with drier conditions on the Pacific slope and wetter conditions in the Caribbean. We could also show that trends in the SPI series are spatially variable and that more localized significant positive and negative trends exist throughout Central America. For example, central pacific Nicaragua was identified as a hot spot for significant drying conditions related to El Niño. We aim at developing this effort into a near‐real time and publicly available drought monitor in the near future to increase resilience and adaption efforts in the region.

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“…Guevera-Murua et al (2018) reported a similar influence of the ENSO in Guatemala, cold phases were related to wet periods and warm phases were related to dry periods. Figure 7 showed that the relationship between the ENSO and the SPI-12 was inverse for the basin, however it also showed that there could be some others events involved in this relationship (Muñoz-Jiménez et al, 2019). This behaviour could be associated to the seasonal ENSO-PDO relation and to its influence on the Mexican climate;…”

“…Climate change will not affect everyone to the same degree; developing countries and the most vulnerable social groups will be the most affected (Mateos et al, 2016). In the Mesoamerican and Caribbean regions, challenges in this regard are growing Muñoz-Jiménez et al, 2019).…”

“…El cambio climático no afectará a todos en la misma medida; los países en desarrollo y los grupos sociales más vulnerables serán los más afectados (Mateos et al, 2016). En las regiones de Mesoamérica y del Caribe, van creciendo los retos en lo que a esto respecta Muñoz-Jiménez et al, 2019).…”

Tracer hydrology of the data‐scarce and heterogeneous Central American Isthmus

“…Nonequilibrium processes under an unsaturated condition below the cloud base, enhance the net transfer of water molecules from the falling drops to the surrounding air (Crawford, Hollins, Meredith, & Hughes, 2017;Graf, Wernli, & Sodemann, 2018;Kong & Pang, 2016;Salamalikis, Argiriou, & Dotsika, 2016), resulting in enriched surface rainfall. The latter process is a potential common feature within the CADC, whereby recent warm ENSO-induced droughts decreased rainfall amounts and intensities as well as promoting more intense warming and unsaturated atmosphere conditions during rainfall events (Jimenez et al, 2018;Muñoz-Jiménez et al, 2019).…”

Tracing Water Sources and Fluxes in a Dynamic Tropical Environment: From Observations to Modeling

“…In Central Costa Rica, our high-resolution rainfall isotope data are unique in the sense that they comprise ENSO's neutral, warm (very strong and weak), and cold (moderate) phases. In general, warm ENSO events result in a large rainfall deficit across the Pacific slope of Central America and a surplus over the Caribbean slope (Sánchez-Murillo et al, 2017b;Muñoz-Jiménez et al, 2019). Variations in rainfall distribution patterns are a response of ENSO driven anomalous ITCZ migrations (Adam et al, 2016) and moisture transport modulation (Durán-Quesada et al, 2017).…”