Pareja-Quispe et al. (2025) Meteorological Droughts in the Peruvian Andes: Characteristics and Relationships with Climate Variability

Identification

• Journal: Earth Systems and Environment
• Year: 2025
• Date: 2025-10-06
• Authors: David Pareja-Quispe, Paulo Rodrigo Zanin, João Maria de Sousa Afonso
• DOI: 10.1007/s41748-025-00831-8

Research Groups

• Universidad Nacional Mayor de San Marcos, Lima, Peru
• National Institute of Meteorology and Geophysics of Angola (INAMET), Luanda, Angola

Short Summary

This study analyzed the characteristics and likely causes of meteorological droughts in the Peruvian Andes over 83 years using SPI and SPEI, revealing that western regions experience more frequent and intense droughts, primarily linked to positive phases of the Atlantic Multidecadal Oscillation (AMO), positive El Niño Southern Oscillation (Niño 4 region), and negative Tropical South Atlantic (TSA) sea surface temperature anomalies.

Objective

• To analyze the frequency, intensity, and likely causes of meteorological droughts in the Peruvian Andes to enhance understanding of these extreme events.

Study Configuration

• Spatial Scale: Peruvian Andes (between 20°S and 4°S latitude, and 79°W and 68°W longitude), delimited by the 1000 meter above sea level contour, and subdivided into six regions: Northwest (NW), Northeast (NE), Central-west (CW), Central-eastern (CE), Southwest (SW), and Southeast (SE). Elevations range from 500 meters to 6768 meters.
• Temporal Scale: 83 years (1940-2022) at 1-month and 12-month time-scales for drought indices, with drought intensity and frequency analyzed for 10-year periods (the last period covering 13 years).

Methodology and Data

• Models used: Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI).
• Data sources:
  • Precipitation and potential evapotranspiration: ERA5 reanalysis data (0.25° spatial resolution, monthly time scale).
  • Validation data: In situ data from meteorological stations of the National Service of Meteorology and Hydrology (SENAMHI) of Peru, PISCOp gridded precipitation product.
  • Topographical data: Global 30 Arc-Second Elevation (GTOPO30) dataset.
  • Political boundaries of Peru: GEO GPS PERU.
  • Amazon Basin delimitation: Venticinque et al. (2016).
  • Climate variability indexes (multidecadal: Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO)): NOAA Physical Sciences Laboratory (PSL).
  • Climate variability indexes (interannual: Niño 1+2, Niño 3, Niño 4, Tropical North Atlantic (TNA), Tropical South Atlantic (TSA)): Computed using Sea Surface Temperature (SST) data from Extended Reconstruction Sea Surface Temperature Version 5 (ERSSTv5).
  • Statistical analysis: Non-parametric Spearman-r correlation, bicaudal Student’s t-test (significance at 0.05).

Main Results

• ERA5 reanalysis data effectively captures dry and wet periods in the Peruvian Andes (median Spearman's correlation of 0.80 with in situ data), despite a tendency to overestimate absolute precipitation (median bias of 82.68 mm·month⁻¹).
• The Peruvian Andes exhibits a distinct seasonal precipitation pattern, with peak rainfall from December to April and the driest conditions from June to August. Eastern regions generally receive more precipitation, except for the northern Andes where western regions are wetter from January to April.
• Droughts were more frequent and intense during the 1940-1970 period, particularly in the Northwest, Central-west, and Southwest regions, and showed an increase after the 1990s until 2010.
• The western side of the Peruvian Andes experiences more frequent and intense droughts than the eastern side. For example, during 1940-1949, drought intensity (SPI-1) exceeded 1.7 across almost all of the Peruvian Andes, reaching up to 2 in Central-west and Northwest regions.
• Drought frequencies reached up to 45 occurrences (37.5%) in the Northwest, Central-west, Northeast, and Southwest regions during the 1940s-1950s. The 1970s and 1980s recorded the lowest drought frequencies, ranging from 3 to 21 occurrences (2.5% to 17.5%).
• At the multidecadal scale, positive phases of the Atlantic Multidecadal Oscillation (AMO) are a likely cause of most droughts, showing predominant negative significant correlations with both SPI and SPEI across all six regions. This influence is more pronounced in southern regions during autumn and central/northern regions during winter.
• At the interannual scale, positive phases of the El Niño Southern Oscillation (ENSO) in the Niño 4 region (predominant negative significant correlation) and negative Sea Surface Temperature Anomalies (SSTA) in the Tropical South Atlantic (TSA) (predominant positive significant correlation) are identified as likely causes of droughts in the eastern and western Peruvian Andes, respectively.
• The impact of TSA on droughts is strongest during the austral summer season, followed by autumn and spring, mainly affecting Central-west and Southwest regions. The impact of Niño 4 is strongest during the austral winter season, followed by autumn, extending negative signals to Central-west and Northwest regions.

Contributions

• Provides a comprehensive, long-term (83 years) spatiotemporal analysis of meteorological droughts in the Peruvian Andes using the advanced ERA5 reanalysis data, validated with in situ observations.
• Divides the Peruvian Andes into six distinct sub-regions, allowing for a more detailed assessment of regional drought characteristics and drivers.
• Identifies the significant influence of Atlantic Ocean Sea Surface Temperature Anomalies (AMO at multidecadal scale and TSA at interannual scale) as key drivers of droughts in the Peruvian Andes, complementing previous findings on ENSO.
• Highlights the differential impacts of climate variability on the eastern and western sides of the Peruvian Andes, offering insights for targeted drought mitigation strategies.

Funding

• Universidad Nacional Mayor de San Marcos - RR N° 006081-2023
• Project number B23131471

Citation

@article{ParejaQuispe2025Meteorological,
  author = {Pareja-Quispe, David and Zanin, Paulo Rodrigo and Afonso, João Maria de Sousa},
  title = {Meteorological Droughts in the Peruvian Andes: Characteristics and Relationships with Climate Variability},
  journal = {Earth Systems and Environment},
  year = {2025},
  doi = {10.1007/s41748-025-00831-8},
  url = {https://doi.org/10.1007/s41748-025-00831-8}
}