High‐Elevation Monsoon Precipitation Processes in the Central Andes of Peru

Chavez, Steven; Silva, Yamina; Barros, Ana P.

doi:10.1029/2020jd032947

Cited by 11 publications

(8 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Topographical influences on the distribution of precipitation are also well known over tropical/subtropical regions (Chavez and Takahashi 2017;Ashfaq 2020). Over South America, the Andes play an important role in maintaining the South American Low-Level Jet (SALLJ) on their east, which is an important mechanism for transporting warm and moist air from the tropics to the subtropics (Vera et al 2006;Doss-Gollin et al 2018;Montini et al 2019;Kumar et al 2020;Chavez et al 2020).…”

Section: Reference Period (1994-2015) Comparisonsmentioning

confidence: 99%

Assessment of CMIP6 Performance and Projected Temperature and Precipitation Changes Over South America

et al. 2021

View full text Add to dashboard Cite

We evaluate the performance of a large ensemble of Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) over South America for a recent past reference period and examine their projections of twenty-first century precipitation and temperature changes. The future changes are computed for two time slices (2040–2059 and 2080–2099) relative to the reference period (1995–2014) under four Shared Socioeconomic Pathways (SSPs, SSP1–2.6, SSP2–4.5, SSP3–7.0 and SSP5–8.5). The CMIP6 GCMs successfully capture the main climate characteristics across South America. However, they exhibit varying skill in the spatiotemporal distribution of precipitation and temperature at the sub-regional scale, particularly over high latitudes and altitudes. Future precipitation exhibits a decrease over the east of the northern Andes in tropical South America and the southern Andes in Chile and Amazonia, and an increase over southeastern South America and the northern Andes—a result generally consistent with earlier CMIP (3 and 5) projections. However, most of these changes remain within the range of variability of the reference period. In contrast, temperature increases are robust in terms of magnitude even under the SSP1–2.6. Future changes mostly progress monotonically from the weakest to the strongest forcing scenario, and from the mid-century to late-century projection period. There is an increase in the seasonality of the intra-annual precipitation distribution, as the wetter part of the year contributes relatively more to the annual total. Furthermore, an increasingly heavy-tailed precipitation distribution and a rightward shifted temperature distribution provide strong indications of a more intense hydrological cycle as greenhouse gas emissions increase. The relative distance of an individual GCM from the ensemble mean does not substantially vary across different scenarios. We found no clear systematic linkage between model spread about the mean in the reference period and the magnitude of simulated sub-regional climate change in the future period. Overall, these results could be useful for regional climate change impact assessments across South America.

show abstract

Section: Reference Period (1994-2015) Comparisonsmentioning

confidence: 99%

Assessment of CMIP6 Performance and Projected Temperature and Precipitation Changes Over South America

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In the context of our study at 4709 m ASL, where nearly 50% of the precipitation is solid, the proximity to the melting layer provides a unique opportunity to observe and analyze the transition of precipitation types. The melting layer, typically located between 4500 and 5000 m ASL in the Andes [25,26], is the region where falling snow begins to melt and transition into rain. This transition zone is of particular interest for meteorological studies and climate models, as the type of precipitation (solid or liquid) can have significant impacts on surface processes, energy balance, and hydrological cycles.…”

Section: Discussionmentioning

confidence: 99%

Rethinking Water Sustainability: Precipitation Changes in the Peruvian Andes in the Face of Climate Change

Peña,

Valdivia,

Yarleque

et al. 2023

Preprint

View full text Add to dashboard Cite

In high-altitude regions, such as the Peruvian Andes, understanding the transformation of precipitation types under climate change is critical to the sustainability of water resources and the survival of glaciers. Conventional wisdom has primarily focused on the snow-rain dichotomy, often overlooking the potential importance of graupel and hail. In this study, we offer a fresh perspective on this issue, investigating the distribution and types of precipitation on a tropical glacier in the Central Andes. We utilized data from an optical-laser disdrometer and compact weather station installed at 4709 m ASL, combined with future climate scenarios from the CMIP6 project, to model potential future changes in precipitation, including the often-ignored hydrometeor forms of graupel and hail. Our findings highlight that increasing temperatures could lead to significant reductions in solid-phase precipitation, including graupel and hail, with implications for the mass balance of Andean glaciers. For instance, a 2°C rise might result in less than 10\% of precipitation as solid, transforming the hydrological processes of the region. The two future climate scenarios from the CMIP6 project, SSP2-4.5 and SSP5-8.5, offer a broad perspective on potential climate outcomes that could impact precipitation patterns in the Andes. Our study underscores the need to revisit and expand our understanding of high-altitude precipitation in the face of climate change, paving the way for improved water resource management strategies and sustainable glacier preservation efforts in these fragile ecosystems.

show abstract

“…In the eastern slopes of the Andes in the Western Amazon, previous studies using Continental aerosol reported severe underestimation of precipitation rates at hot spots of orographic precipitation (Espinoza et al, 2015;Chavez and Takahashi, 2017;Eghdami and Barros, 2019;Chavez et al, 2020). Furthermore, aerosol-cloud-radiation feedbacks modify the land-surface energy budget and establish gradients in surface temperature and surface fluxes can either enhance or suppress updrafts.…”

Section: Data Availability Statementmentioning

confidence: 98%

Aerosol indirect effects on orographic clouds and precipitation

Chavez

Barros

2023

Front. Earth Sci.

View full text Add to dashboard Cite

The sensitivity of warm orographic cloud development to aerosol indirect effects was investigated through aerosol-aware Weather Research and Forecast model simulations contrasting aerosol-cloud-precipitation interactions using the default (generic) aerosol and regional aerosol measurements from the Integrated Precipitation and Hydrology Experiment in the Southern Appalachian Mountains for three rainfall events: 1) enhanced local convection; 2) a frontal system, and 3) a tropical system. Using the regional aerosol activation spectrum yields higher number of drops than using the default, smaller cloud droplets and delayed rainfall onset under weak synoptic forcing conditions. Evaluation against aircraft measurements in isolated convective clouds reveals that while the model microphysics falls short of reproducing the vertical structure of nonprecipitating clouds, the liquid water content, and the concentration of cloud droplets near cloud base are in keeping with observations. The simulated cloud vertical structure shows the regional signature of orographic enhancement over the mountains vis-a-vis the adjacent plains. In the inner region, valley-ridge circulations organize the spatial patterns of cloudiness under weak synoptic forcing. The formation of early afternoon low-level clouds over the ridges in the summertime reflects the aerosol indirect effect. By contrast, for large-scale systems with strong and sustained moisture convergence at low levels (frontal and tropical systems), mechanically forced rainfall efficiency is enhanced, there is no delay in the onset of precipitation, and the aerosol indirect effect is negligible. This study shows that the impact of aerosol-cloud-precipitation interactions on the spatial variability of orographic rainfall is conditional on weather regime.

show abstract

High‐Elevation Monsoon Precipitation Processes in the Central Andes of Peru

Cited by 11 publications

References 78 publications

Assessment of CMIP6 Performance and Projected Temperature and Precipitation Changes Over South America

Assessment of CMIP6 Performance and Projected Temperature and Precipitation Changes Over South America

Rethinking Water Sustainability: Precipitation Changes in the Peruvian Andes in the Face of Climate Change

Aerosol indirect effects on orographic clouds and precipitation

Contact Info

Product

Resources

About