About

Leila Carvalho is a Professor at the Department of Geography at UC Santa Barbara, located in 6808 Ellison Hall. Her research is situated within an interdisciplinary domain that investigates coupled systems to advance understanding of the Earth’s climate on multiple scales. Her work is primarily focused on Atmospheric & Climate Science, where she explores the complex interactions and feedbacks within the Earth's climate system. Through this interdisciplinary approach, Professor Carvalho contributes to advancing knowledge about climate dynamics and variability, addressing critical questions related to climate processes and their impacts.

Research topics

• Environmental science
• Meteorology
• Climatology
• Geology
• Geography
• Atmospheric sciences
• Political Science
• Social Science
• Computer Science
• Ecology
• Sociology
• Environmental resource management
• Environmental planning
• Business
• Environmental ethics
• Oceanography
• Law
• Engineering

Selected publications

• Potential and limitations of efficient machine-learning wind downscaling for energy-relevant applications in mountainous environments

  2026-03-14

  articleOpen accessCorresponding

  Accurately representing complex spatio-temporal wind fields in mountainous terrain requires high-resolution atmospheric models, but these come with substantial computational cost. Although generally less accurate than physics-based models, machine learning-based wind downscaling offers computationally efficient alternatives for many energy-relevant applications; however, its performance depends on training data and local conditions, limiting its broad applicability.We present an enhanced version of the deep-learning-based near-surface wind downscaling model Devine (Le Toumelin et al., 2023), trained on controlled atmospheric simulations over synthetic topographies covering a wide range of slopes and terrain features. Wind-direction-dependent descriptive features facilitate deployment across different mountainous sites. We evaluate the model using high-resolution atmospheric simulations and ground-based observations in two mountainous regions with contrasting climates and topography, performing a spatio-temporal assessment of its strengths and limitations.The enhanced Devine model reproduces fine-scale wind patterns for terrain-induced flow as used in the training data, demonstrating transferability across mountainous sites. Its rapid generation of high-resolution wind fields enables applications such as wind resource assessment, atlas generation, climate impact studies, and short-term operational forecasts for wind farm operation. Overall, the evaluation shows how the enhanced Devine model can guide energy-related applications, indicating where it performs reliably and where caution is needed due to unrepresented wind regimes such as large-scale pressure-driven flow.LeToumelin, L., Gouttevin, I., Helbig, N., Galiez, C., Roux, M., and Karbou, F. (2023). Emulating the adaptation of wind fields to complex terrain with deep-learning. Artificial Intelligence for the Earth Systems, 2(1):1–39.

  PublisherDOI

• <scp>NSF</scp> NCAR's In Situ Sensing Facility Measurement System During the Sundowner Wind <scp>EXperiment</scp> ( <scp>SWEX</scp> )

  Geoscience Data Journal · 2026-04-01

  articleOpen access

  ABSTRACT NCAR's Earth Observing Laboratory (EOL) In situ Sensing Facility (ISF) deployed all of its instrumentation in the Sundowner Wind EXperiment (SWEX) in April–May 2022 to characterize downslope winds along the southern slopes of the Santa Ynez Mountains in Santa Barbara (SB) County, California. The goal was to understand boundary layer processes and mechanisms that favour sundowners. ISF provided ground‐based surface and remote sensing observations, sounding systems, operations expertise, data quality control and archiving. This paper describes the measurement system employed and important aspects of the data quality control and management process. The ISF observing system can serve as a prototype to build an integrated network of profiling and flux measuring instruments to better understand the complexity and inhomogeneities within the lower troposphere.

  PublisherDOI

• Mountain waves, downslope jets, and boundary layer interactions during the Sundowner Winds Experiment (SWEX) - IOP2

  Atmospheric Research · 2026-03-11

  articleOpen access
  PublisherDOI

• An Overview of the “Vento Norte” Experiment (VNorEx): Observations of Downslope Windstorms over Modest Terrain in Southern Brazil

  Advances in Atmospheric Sciences · 2026-03-13

  articleOpen access
  PublisherOA PDFDOI

• Downslope Windstorms in Coastal Mountains: Observations and Modeling during the Sundowner Wind Experiment (SWEX)

  2026-03-13

  articleOpen access1st authorCorresponding

  Coastal Santa Barbara is among the most wildfire-prone communities in Southern California. Downslope, dry, and gusty windstorms frequently occur along the south-facing slopes of the east–west-oriented Santa Ynez Mountains (SYM), which separate the Pacific Ocean from the Santa Ynez Valley. These winds, known as Sundowner Winds, typically peak after sunset and often persist overnight. They represent the most critical fire-weather phenomenon in the region.The Sundowner Winds Experiment (SWEX), conducted from 1 April to 15 May 2022, integrated airborne and ground-based observations to examine interactions between continental and marine atmospheric boundary layers (ABLs), assess mountain waves and hydraulic jumps and their influence on surface winds and dew point, and evaluate forecasting challenges in mesoscale models.This study analyzes two Sundowner events—IOP-2 (April 5–6) and IOP-10 (May 12–13)—affecting the eastern SYM. IOP-2 occurred during a heat wave, with temperatures reaching the 95th percentile, whereas IOP-10 reflected typical spring conditions.During IOP-2, observations revealed sharp elevated inversions near the SYM, with mountain waves propagating across these layers. The free atmosphere was extremely dry, and strong horizontal winds were confined near inversion height. On the lee side, a large-amplitude lee wave evolved into a hydraulic jump, followed by wave breaking and a downslope jet. Despite strong offshore forcing, a shallow sea breeze developed over the eastern foothills, while nighttime marine boundary layer (MBL) intrusion—capped by a strong inversion—played a key role in the Sundowner cycle. Descending wave structures and rotor circulations produced reversed flows and enhanced surface winds. A nocturnal mid-channel eddy over the Santa Barbara Channel further stratified the MBL and decoupled it from the downslope jet. WRF simulations at 1-km resolution underestimated ridgetop and lee slope winds and overestimated coastal winds, with biases linked to misrepresentation of ABL height, inversion strength, and delayed MBL advection.IOP-10 was investigated using ground-based instruments and radiosondes. It featured the second-largest observed mean sea level pressure difference between Santa Barbara and Bakersfield during SWEX. However, winds exceeding 20 m/s occurred on eastern slopes hours before peak pressure differences. LiDAR detected vertical motions near 6 m/s, associated with lifting of the lee-slope jet and weakening of surface winds—evidence of mountain wave activity influencing wind intermittency. Similar to IOP-2, the nocturnal mid-channel eddy contributed to lifting the lee jet and terminating Sundowners near the surface.These findings emphasize the need for accurate representation of inversion structure and height, as well as marine–continental ABL interactions, in mesoscale models. Realistic simulation of complex flow dynamics—such as mountain waves and hydraulic jumps—is essential to improve forecasts of downslope winds in coastal environments. The SWEX campaign provided unique measurements to evaluate these features.

  PublisherDOI

• What Was Homer Honing in the Odyssey?

  Perspectives of Earth and Space Scientists · 2025-01-04

  articleOpen accessSenior author

  Abstract We summarize the data provided in Homer's the Odyssey concerning Odysseus' journey and suggest a completely new view of what was Homer trying to convey to us. We suggest that Homer was honing the idea of synergy between rules (determinism) and chance (randomness), an idea deeply rooted in natural processes as well in mathematics.

  PublisherOA PDFDOI

• Insights on the Spatiotemporal Variability of Downslope Winds in Coastal Santa Barbara: A Case Study from the Sundowner Winds Experiment (SWEX)

  Monthly Weather Review · 2025-09-03 · 1 citations

  article

  Abstract The coastal plain of Santa Barbara County (SBC) is bounded by the cool waters of the Pacific Ocean to the south and the west–east-oriented Santa Ynez Mountains (SYM) to the north. Downslope windstorms with a typical onset after sunset are frequently observed on the lee slopes of the SYM. These northerly winds are known as Sundowner winds or simply Sundowners. The Sundowner Winds Experiment (SWEX), conducted between 1 April and 15 May 2022, aimed to unravel mechanisms responsible for the spatiotemporal variability of these winds. The present study examines data collected from lidar wind profilers, radiosondes, and surface stations during the 12–13 May 2022 intensive observation period (IOP). Gusty winds were observed on both the western and eastern slopes of the SYM. This event was associated with the second-largest observed mean sea level pressure difference between the Santa Barbara and Bakersfield airports during SWEX. However, horizontal wind speeds exceeding 20 m s −1 were recorded on the eastern slopes of the SYM hours before the most pronounced observed pressure differences. Furthermore, lidar measurements in the foothills of the eastern SYM exhibited positive vertical wind speeds of approximately 6 m s −1 . These ascending vertical motions were associated with the lifting of the lee-slope jet and a concurrent weakening of winds near ground level—a clear indication of mountain-wave activity influencing surface winds. While mesoscale numerical simulations with 1-km grid spacing captured the spatial patterns of the winds, their temporal variability was inadequately represented in highly turbulent regions.

  PublisherDOI

• Spectral unmixing of a multi-decadal Landsat time sequence to reconstruct herbaceous fractional cover dynamics in wildfire-prone Mediterranean-type ecosystems

  International Journal of Remote Sensing · 2025-05-13

  article
  PublisherDOI

• Gravity waves induced by a downslope windstorm in modest terrain: a case study

  Quarterly Journal of the Royal Meteorological Society · 2025-05-12 · 1 citations

  article

  Abstract This study examines a typical episode of a downslope windstorm known as “Vento Norte” (VNOR; “North Wind” in Portuguese) in the state of Rio Grande do Sul, Brazil. The temporal and spatial evolution of the VNOR episode is analyzed by means of sonic anemometer data collected at 10 vertical levels on a 30 m tower, two automated weather stations located at contrasting topographies, and radiosonde data launched twice daily. The primary focus is on the nighttime period that precedes the onset of the VNOR at the surface. The wind and potential temperature profiles showed that this episode was accompanied by a northerly nocturnal low‐level jet peaking at near the terrain slope. A stable boundary layer (SBL) characterized by easterly light winds developed at low elevations in the orographic depression. The Scorer parameter indicated an atmospheric profile favorable to the development of low‐level wave trapping around 500 m. A micrometeorological analysis revealed intense and persistent wave activity near ground level preceding the onset of the VNOR. Wavelet spectral analyses suggested the presence of gravity waves with 5 min time‐scales during this period. These oscillations, initially detected at the tower's high elevations, became more persistent and propagated to the bottom of the SBL as the night advanced. The wave‐like structures were associated with intermittent bursts of turbulence influencing the exchange processes at the surface layer and impacting the SBL flow patterns. This study highlights the dynamics of the VNOR and their multiscale interactions, providing insights into the understanding of the main flow characteristics in such conditions.

  PublisherDOI

• Investigating the spatial structure of winds in complex terrain using a mobile wind lidar

  2025-03-15

  preprintOpen accessSenior authorCorresponding

  In the lee of the Santa Ynez Mountains north of Santa Barbara, CA, late afternoon-to-early morning episodes of offshore, northerly gusty downslope surface winds are frequently observed. These downslope winds are locally known as Sundowners. Sundowners are spatially non-uniform and can be accompanied by rapid increases in temperature and decreases in relative humidity with significant impact on fire behavior. Our understanding of the spatial and temporal variability of Sundowners and the underlying mesoscale mechanisms is limited. To address this knowledge gap, the NSF-funded Sundowner Wind Experiment (SWEX) was conducted in Spring 2022. &amp;#160;In this presentation, we focus on observations made by the surface-based mobile observing platform UWOW (University of Virginia Wind Observatory on Wheels), a trailer-mounted lidar system to measure spatial and temporal variations of lower tropospheric winds. &amp;#160;UWOW uses a HALO photonics StreamLine XR Doppler lidar, a GPS, and an inertial navigation system placed in a custom trailer to measure boundary layer winds while traveling on the road. UWOW can measure wind profiles from approximately 100 to 3000 m above ground with 30 m vertical spacing. During SWEX, UWOW travelled about 7000 km on roads around the Santa Ynez Mountains to document the spatial wind and aerosol variability during Sundowner Wind days and during undisturbed days. Data examples and comparisons with 1-km numerical simulations using the Weather Research and Forecasting (WRF) model will be discussed.&amp;#160;

  PublisherDOI

Recent grants

• Climate Variability and Impacts on Regional Surface Runoff in High Asia Mountains

  NSF · $564k · 2011–2017

• RAPID: Decadal Variability of the American Monsoons--An Assessment of CMIP5 Simulation

  NSF · $30k · 2011–2013

• Collaborative Research: Sundowner Winds EXperiment (SWEX) in Santa Barbara, California

  NSF · $1.2M · 2020–2026

• PREEVENTS Track 2: Understanding Extreme Fire Weather Hazards and Improving Resilience in Coastal Santa Barbara, California

  NSF · $1.5M · 2017–2023

Frequent coauthors

• Charles Jones

  University of California, Santa Barbara

  103 shared

• Brant Liebmann

  University of Colorado Boulder

  36 shared

• D. B. Nash

  University of California, San Diego

  13 shared

• George N. Kiladis

  National Oceanic and Atmospheric Administration

  13 shared

• Gert‐Jan Duine

  University of California, Santa Barbara

  12 shared

• Forest Cannon

  University of California, San Diego

  12 shared

• Dave Allured

  11 shared

• Qinghua Ding

  University of California, Santa Barbara

  10 shared

Labs

• Leila Carvalho's LabPI

  Not provided

Education

• Ph.D., Atmospheric Sciences (meteorology)

  University of Sao Paulo

• M.S., Atmospheric Sciences (meteorology)

  University of Sao Paulo

• B.S., Atmospheric Sciences (meteorology)

  University of Sao Paulo