Atmospheric water vapor content as indicator of global warming in a Caribbean zone of Colombia

This study shows the importance of the atmospheric water vapor content as an indicator of global warming at local scale in part of the middle and lower basin of the Sinti river (Colombia). The climatic regime of the selected zone is represented by the meteorological stations of Turipand, El Salado, Lorica and La Doctrina. Data series of air temperature Tand relative humidity HR of the mentioned stations, between 1968 and 2011, were selected and tested for quality by rigorous statistical and climatic analysis. Furthermore, atmospheric water vapor density data d(v) were estimated, using mean annual values of T and HR previously calculated for each of the selected 44 years. The interannual trend analysis of the annual means of Tand d: for the four selected stations and the integrated studied zone, demonstrated that even though their climatic variability strongly depends of El Nifio and La Nifia phenomena, the upward trend of both variables remains since 1968. Particularly in the integrated studied zone, an increment in T of 0.75 degrees C (2.7%) or 0.17 degrees C dec' was detected, which coincides with the reported global value by WMO, while d v increased in 1.02 g m(-3)(5.9%) or 0.23 g m(3) dec(-1). It was determinated likewise that 1991-2000 was the warmest decade of the period of time 1968-2011 and not the next one (2001-2010), as it is exposed in diverse studies worldwide. On the contrary of the results obtained from global and regional research, in this study the decadal means do not explain completely the great tropical climatic variability at local level and the effect of the global warming. The statistical analysis ofT and d trends for the periods of time 1968-1974 and 1975-2011 allowed to identify evidences of the possible beginning of the global warming in the studied zone, probably due to the most intensive La Nifia event of the history, registered between 1973 and 1974 (ONI of -2.0). The results obtained in this study about the global warming in the four selected meteorological stations and the integrated studied zone, probably caused by extense and intense human land intervention, confirm that the atmospheric water vapor content d. is the most adequate thermodynamic variable for the description of the behavior of tropical climatic regimes at local level.