Changes in precipitation and temperature extremes in Central America and northern South America, 1961–2003

Abstract

[1] In November 2004, a regional climate change workshop was held in Guatemala with the goal of analyzing how climate extremes had changed in the region. Scientists from Central America and northern South America brought long-term daily temperature and precipitation time series from meteorological stations in their countries to the workshop. After undergoing careful quality control procedures and a homogeneity assessment, the data were used to calculate a suite of climate change indices over the period. Analysis of these indices reveals a general warming trend in the region. The occurrence of extreme warm maximum and minimum temperatures has increased while extremely cold temperature events have decreased. Precipitation indices, despite the large and expected spatial variability, indicate that although no significant increases in the total amount are found, rainfall events are intensifying and the contribution of wet and very wet days are enlarging. Temperature and precipitation indices were correlated with northern and equatorial Atlantic and Pacific Ocean sea surface temperatures. However, those indices having the largest significant trends (percentage of warm days, precipitation intensity, and contribution from very wet days) have low correlations to El Niño-Southern Oscillation. Additionally, precipitation indices show a higher correlation with tropical Atlantic sea surface temperatures.

Observed (1970–1999) climate variability in Central America using a high-resolution meteorological dataset with implication to climate change studies

“…This detection has been linked to (hydro)climatic processes in mid-latitudes that are sensitive to temperature, such as Tavg, snow accumulations and timing of streamflow in snow-controlled basins Pierce et al 2008;Hidalgo et al 2009). Overall, observed changes in P in mid-latitude regions show fewer locations with significant trends than the changes in temperature (Aguilar et al 2005;Alexander et al 2006). Therefore, in a region like Central America where the P trends are small, the P anomalies associated with natural climatic causes are the largest contribution to the variability.…”

“…Second, even if the trends in annual P are small, the distribution of rainfall at shorter time-scales could still cause significant changes in hydrological variables that would require special adaptation measures. Some studies have suggested that the frequencies of extreme (high and low) P events are increasing (Aguilar et al 2005;IPCC 2007). …”

Changes in daily climate extremes in the eastern and central Tibetan Plateau during 1961–2005

“…Both for precipitation and temperature, data plots are available for visual inspections to reveal more outliers as well as a variety of problems that cause changes in the seasonal cycle or variance of the data. Also, histograms of the data are created which reveal problems that show up when looking at the data set as a whole [Aguilar et al, 2005;New et al, 2006]. Figure 3 is an example of the plots used to quality control precipitation data.…”

“…Figure 3 is an example of the plots used to quality control precipitation data. It explains the data density in two different ways: a histogram (bars) and a Kernel-filtered (line) which is a nonparametric approach to density fitting [Aguilar et al, 2005]. Both show that precipitation data in the station is fine.…”

“…Zhang et al, 2005], Central America and northern South American [Aguilar et al, 2005], and central and south Asia [Klein Tank et al, 2006]. Global changes in daily climate extremes have been analyzed [Alexander et al, 2006;Frich et al, 2002].…”