New Mexico Geological Society Annual Spring Meeting — Abstracts

Climate changes can affect mean annual air temperature, which in turn can be reflected in ground surface temperature change. Below several meters depth, heat transfer in the vadose zones of the southwestern United States is likely dominated by conduction. Therefore, in the Albuquerque Basin, vadose zones of about 100 m and deeper should afford a unique opportunity to examine surface temperature changes over the past several centuries. Increased surface temperatures should be defined by concave upward temperature-depth profiles. In 1996 and 1997 temperatures were measured in the vadose zone at seven sites near the southwest corner of Kirtland Air Force Base. These data were taken with a conventional sensor having a relatively long time constant in air. Although some of the data suggest possible surface warming over the past few decades, the data are quite variable in character even though the measurement sites are within a few kilometers. Recent measurements in 2003 at three additional sites in the Albuquerque Basin, one site within a few kilometers of the Kirtland Air Force Base sites, have been made with a new sensor having a relatively fast time response in air. Interestingly, the recent data at these three sites show little if any surface temperature change. More subsurface temperatures are needed to consider possible surface temperature change and climate change in the Albuquerque Basin. Variations in precipitation, evaporation, and vegetation shading should be considered in terms of their potential effects on surface temperature. At present the influence of these factors on surface temperature cannot be ruled out. Therefore, the thermal effect of recent climate change may be partially masked in the deserts of the southwestern United States.