## 2 Study Area
### Climate Setting  
The subtropical South Pacific anticyclone, where the dry air high-pressure belt reaches the continent at south latitude 31\({}^{\circ}\)[44], is the main driver behind the climate of the Dry Andes. It is characterized by arid to semi-arid climates, with low precipitation values, relative humidity, and cloudiness. This results in high solar radiation and terrestrial surfaces with very low percentages of vegetation and humidity. In both Argentina and Chile, year-to-year precipitation varies notably in accordance with the El Nino or ENSO (El Nino Southern Oscillation) phenomenon [45; 46; 47]. This aspect directly affects the region's runoff water [48; 49].  
The topography and coastal position of the Andes mountain range have a strong influence on the general atmospheric circulation, notably differentiating the eastern and western climatic systems [50; 51]. Moist air masses of the Pacific Ocean rise through the Andes orography, which acts as a barrier to moisture transfer [52]. For this reason, the water reserves that supply the surrounding regions are concentrated in the mountain ranges, with precipitations being higher in the western than in the eastern sector. It is worth mentioning that the Argentinian side of the study area has the highest elevations in the American continent, namely Mount Aconcagua (6962 m.a.s.l.) and Cerro Mercedario (6770 m.a.s.l.) (Figure 1). The southern winds predominate on the western flank of the Andes, while on the eastern slope, the winds blow mainly from the north [53]. According to [PERSON] et al. [36] in the Central Andes, the precipitation coming from the humid Pacific masses occurs almost exclusively as snowfall and is mostly concentrated in the austral winter, between the months of May and August. Moreover, the eastern sector is also influenced by wet Atlantic air masses from the southeast [53]. This arid situation is accompanied by intense solar radiation, which in the Dry Andes, has an annual average of 400 w/m\({}^{2}\). [PERSON] [54] discusses the influence of solar radiation on the processes of fusion and on the soil temperature in the area. The special climate conditions of the area make the DInSAR technique a suitable tool for the target study of this work.  
Recent climatic records show a trend of rising temperatures in the Central Andes. Between 1979 and 2006, the average temperature of the air has risen between 0.2 \({}^{\circ}\)C and 0.4 \({}^{\circ}\)C per decade [55]. [PERSON] and [PERSON] [56] indicate that this warming is related to the decrease in the snowfalls that supply the Central Andes basins. This situation is more evident with the retreat and mass loss of glaciers in the basins of both Chile and Argentina since the beginning of the twentieth century [57; 35].  
The precipitation in the Dry Andes (27\({}^{\circ}\) and 33\({}^{\circ}\) lat. south and 3000-4000 m.a.s.l.) varies between 200 mm/year in the northern sector and 700-800 mm/year in the south. Precipitation increases during El Nino periods and decreases during La Nina. Meanwhile, the 0 \({}^{\circ}\)C isotherm of the MAAT increases in height from 3700 m.a.s.l. in the south up to 4300 m.a.s.l. in the north [58].  
As a first approximation order, MAAT can be used to delimit mountainous regions and altitudinal belts with the occurrence of permafrost. MAAT below \(-3\)\({}^{\circ}\)C indicates areas with a significant amount of permafrost, while only a few occurrences of permafrost exist around \(-1\)\({}^{\circ}\)C [59].