Adalberto Tejeda Martínez

Heat waves and heat days in an arid city in the northwest of México: current trends and in climate change scenarios.

The aim of this work is to study heat waves (HWs) in Mexicali, Mexico, because numerous deaths have been reported in this city, caused by heatstroke. This research acquires relevancy because several studies have projected that the health impacts of HWs could increase under various climate change scenarios, especially in countries with low adaptive capacity, as is our case. This paper has three objectives: first, to analyze the observed change in the summer (1 June to 15 September) daily maximum temperature during the period from 1951 to 2006; secondly, to characterize the annual and monthly evolution of frequency, duration and intensity of HWs; and finally, to generate scenarios of heat days (HDs) by means of a statistical downscaling model, in combination with a global climate model (HadCM3), for the 2020s, 2050s, and 2080s. The results show summer maximum temperatures featured warming and cooling periods from 1951 until the mid-1980s and, later, a rising tendency, which prevailed until 2006. The duration and intensity of HWs have increased for all summer months, which is an indicator of the severity of the problem; in fact, there are 2.3 times more HWs now than in the decade of the 1970s. The most appropriate distribution for modeling the occurrence of HDs was the Weibull, with the maximum temperature as co-variable. For the 2020s, 2050s, and 2080s, HDs under a medium-high emissions scenario (A2) could increase relative to 1961–1990, by 2.1, 3.6, and 5.1 times, respectively, whereas under a medium-low emissions scenario (B2), HDs could increase by 2.4, 3.4, and 4.0, for the same projections of time.

On simulation of air temperature curve near the ground in presence of frosts in Valley of Perote (Mexico)

An exponential of the time function was used in order to model the air temperature curve near the ground after frost in the Valley of Perote (Mexico). From January to March 1989 air temperature was recorded with a telethermograph, and data from 22 frosts were used to adjust and evaluate the exponential function.

Efecto de la urbanización en el balance de energía superficial de un bosque de niebla al este de México

Este trabajo es parte del proyecto CONACyT-UV (CB2012-183040) “Interaccion superficie/atmosfera en la zona montanosa central de la vertiente del golfo de Mexico: observaciones y modelacion a alta resolucion”.