Comparing climate change indices between a northern (arid) and a southern (humid) basin in Mexico during the last decades

Abstract

Abstract. It is a matter of current study to determine potential climate changes in different parts of the world, especially in regions like a basin which has the potential to affect socioeconomic and environmental issues in a defined area. This study provides a comparison between several climate change indices trends of two very different basins in Mexico, one located in the northern arid region (the Conchos River basin) and the other in the southern humid area (the Usumacinta River basin). First, quality control, homogenization, and completion of the missing data were applied before calculating the climate change indices and their respective trends for the combined period 1961–1994. A clear warming signal was found for the two basins in addition to an increment in the DTR, in agreement with other studies in Mexico. Also, the Conchos River basin was found to be more humid and the Usumacinta River basin drier, in accordance to a supposed seesaw behavior indicated in previous analysis.

Analysis of Anomalies and Trends of Climate Change Indices in the State of Zacatecas, Mexico

“…Nation-wide research such as the study by [39] reports on a trend of increased number of summer days, increased extreme maximum temperature, and lower extreme minimum temperature. Similar studies focused on Zacatecas and other Mexican states confirm the increase in maximum temperature; however, the same result is not true with respect to minimum temperature, since an increasing trend in minimum temperature has also been found in parts of Chihuahua, Veracruz, Chiapas, and Zacatecas [35][36][37][38]60,61]. Trends are therefore observed to vary depending on geographical location, time of the year, and type of temperature (maximum or minimum) [63]; these results are not unlike other findings from studies throughout the globe and are evidence that local and regional trends can be representative of planetary climate [59].…”

“…Concerning precipitation, the results obtained in the present study were highly related to other investigations [67,69,71] in which precipitation patterns were found to be largely due to oscillations such as PDO and ENSO. Different regions in the center and north of the country present positive precipitation trends, but their statistical significance is very low, and studies such as [38,39] and [72] show that certain areas in northern Mexico have become more humid over the past decades. On the other hand, in states such as Chiapas and Veracruz, located in the country's south, research [34][35][36][37] has reported decreasing precipitation trends, with values of zero in some cases.…”

“…However, precipitation-related trends are unclear, and there are significant differences from one country to another, which indicates that global changes in this climate variable are not homogeneous throughout the world, but vary from one place to another; therefore, subnational and local studies need to be conducted in order to detect and better understand the changes taking place at a small scale, not only concerning precipitation extremes, but also temperature extremes. In the specific case of Mexico, the indices created by the ETCCDI have been used at the local level to detect possible changes in climate in a number of watersheds, states, or cities [34][35][36][37][38][39]; results are generally consistent when analyzing adjacent places or areas with similar climatic conditions, but they can differ for remote watersheds or regions with different climatic conditions. For example, in a study carried out in the state of Veracruz [34], located on the Gulf of Mexico (in the country's southeast), results showed evidence of warmer conditions in recent years (increased frequency of hot days and decreased frequency of cool days), and precipitation was found to occur over shorter periods.…”

“…However, these results differ from those obtained for the Conchos river basin, located in the north of the country, in the state of Chihuahua, where results clearly indicate a significant increase in the duration of dry periods over the past years. [38]. Hence the importance of carrying out local studies on extreme climate trends.…”

Analysis of Anomalies and Trends of Climate Change Indices in Zacatecas, Mexico

“…However, precipitation-related trends are unclear, and there are significant differences from one country to another, which indicates that global changes in this climate variable are not homogeneous throughout the world, but vary from one place to another [34,35]; therefore, subnational and local studies need to be conducted in order to detect and better understand the changes taking place at a small scale, not only concerning precipitation extremes, but also temperature extremes. In the specific case of Mexico, the indices created by the ETCCDI have been used at the local level to detect possible changes in climate in a number of watersheds, states, or cities [36][37][38][39][40][41]; results are generally consistent when analyzing adjacent places or areas with similar climatic conditions, but they can differ for remote watersheds or regions with different climatic conditions. For example, in a study carried out in the state of Veracruz [36], located on the Gulf of Mexico (in the country's southeast), results showed evidence of warmer conditions in recent years (increased frequency of hot days and decreased frequency of cool days), and precipitation was found to occur over shorter periods.…”