Temperature anomaly in the volcano Popocatepetl area, Mexico

Abstract:

Anomaly changes in the diurnal behavior of the temperature measured in the near-surface soil (30-40 cm) in Tlamacas monitoring site, volcano Popocatepetl area, are presented. Results of statistical analysis show 2 essential changes for the temperature characteristics observed during 2007-2009 and 2013-2014 monitoring periods:

1.) Minimum and maximum of the diurnal temperature have moved approximately to the 14 LT and to midnight, 24 LT, respectively (Fig 1., c). Under the “normal” condition, the absolute minimum of daily temperature is observed during sunrise (about 7 LT) for the atmosphere measurements and with certain time lag (about 9 LT, Fig.1,b) for the measurements in soil (depending on the depth), and absolute temperature maximum is observed in time when Solar radiation is not enough to provide heating of the atmosphere (about 16 LT) or the Earth surface (about 17 LT, Fig.1,b).

Dispersion of the residual temperature (24-hours running trend of the temperature substituted) is 6 times lower for the period of monitoring 2013-2014 (Fig.1, g and h) in comparison with a period 2007-2009 (Fig.1, e and f). In other words, a temperature variation between the maximum and minimum during the day became 6 times lower that it was before.