Potential Influence of the Atlantic Multidecadal Oscillation in the Recent Climate of a Small Basin in Central Mexico

Martín José Montero-Martínez,Mercedes Andrade-Velázquez,Oscar Pita-Díaz

doi:10.3390/atmos13020339

Abstract

One of the main current challenges is detecting changes in the climate at the regional level. The present study tried to address this issue by looking for some influence of large-scale climate oscillations on the climate of a small and complex topography basin in Central Mexico. We collected temperature and precipitation data from 44 climate stations within an area of up to 20 km around the Apatlaco River sub-basin (~30 km south of Mexico City) during the period 1950–2013. Posteriorly, quality analysis and homogenization of the climate databases were performed by using the Climatol algorithm. We analyzed the trend of five ETCCDI climate indices through several statistical tests. Finally, we calculated simple Pearson correlations of those indices with four climate oscillation indices that have affected Mexico’s climate in the recent past. The results revealed that the Atlantic Multidecadal Oscillation had a clear influence on four of the five indices analyzed in the study area. The summer days and the extreme maximum and minimum temperatures accounted for a small increase in the temperature of the middle east (urban) basin compared to the middle west (rural), which could be a manifestation of the heat island effect or the difference in soil type (and therefore albedo) of the two zones. As expected, the midsummer drought effect predominated in most of the sub-basin, with only the uppermost part showing monsoon-type precipitation during a typical year.

Highlights

In search of a better comprehension of global climate variability, research interests have extended from global warming to internal climate variability [1]
The sea surface temperature changes related to the dominant internal climate variability are the El Niño–Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO), which run at 2–7-year, decadal, and multidecadal (65–80-year) time scales, respectively [2–4]
Higher values were noted in the northern part of the middle east zone, which was the urbanized zone and where a potential effect related to the heat island caused higher rainfall in that area

Summary

Introduction

In search of a better comprehension of global climate variability, research interests have extended from global warming to internal climate variability [1]. Internal climate variability comprises various timescales, such as the interannual, decadal, and multidecadal. The sea surface temperature changes related to the dominant internal climate variability are the El Niño–Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO), which run at 2–7-year, decadal, and multidecadal (65–80-year) time scales, respectively [2–4]. The decadal to multidecadal internal climate variability is critical for understanding the timing and magnitude of changes in the global mean surface temperature [5,6], regional climate [4,7,8], and climate extremes [9]. Climate variability in central Mexico is driven primarily by the PDO/ENSO and the AMO/NAO signals [27]. [21] stated that the AMO probably lost much of its influence in Central Mexico at the beginning of the 20th century, and since the PDO has driven the major changes in the climate. The difficulty in detecting the AMO could be due to the influence of the PDO/ENSO, which complicates the pattern of climate changes related to the AMO [30,31]

Objectives

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Results

Conclusion