Toró: A Proposed New Term for a Localized Intense Rainfall Phenomenon in Brazil

Concepts de base

This article proposes "toró," a new meteorological term derived from the Tupi-Guarani language, to describe a localized, intense rainfall phenomenon observed in Brazil, characterized by its unique erosive impacts and distinct acoustic signature.

Résumé

This article proposes a new term, "toró," to define a specific type of localized, intense rainfall event observed in Brazil. The term originates from the Tupi-Guarani language, reflecting indigenous knowledge of the phenomenon.

Existing Terminology and Distinctions:

• The article differentiates "toró" from existing terms like "cloudburst" and "rainstorm," arguing that "toró" represents a more intense and localized event.
• It also addresses the confusion surrounding the term "tromba d'água," which is used for both waterspouts and intense rainfall in Brazil.

Characteristics of Toró:

• Intensity: Rainfall exceeding 100 mm within minutes.
• Duration: Extremely short-lived, lasting seconds to minutes.
• Area of Impact: Highly localized, affecting areas smaller than 1 km².
• Erosive Impact: Creates unique, straight, and narrow erosion channels on slopes, termed "tromba-type erosion."
• Acoustic Signature: Described as resembling "too" and "rooo" sounds in the Tupi-Guarani language.

Evidence and Hypothesis:

• The article cites historical accounts, toponyms (place names), and recent events as evidence for the existence of "toró."
• It hypothesizes that "toró" occurs when supercell thunderstorms interact with specific topographical features, intensifying rainfall over small areas.

Research Needs:

• The article acknowledges the need for more empirical data, including measurements of rainfall intensity during "toró" events.
• It suggests using high-resolution satellite imagery and numerical weather models to study the phenomenon further.

Significance:

• Defining "toró" as a distinct meteorological phenomenon can improve communication and understanding of these extreme events.
• It highlights the importance of indigenous knowledge in understanding local weather phenomena.
• Recognizing "toró" can aid in developing better forecasting and disaster preparedness strategies for regions prone to these events.

Stats

Almost 40% of Brazil's current toponymy originates from Guarani.
The maximum absolute temperature recorded during the Russian expedition of 1803/04 on Santa Catarina Island reached only 22°C, approximately 5°C lower than present-day values.
Cloudburst rainfall intensity can range from 25 to 200 mm per hour.
Rainstorms are characterized by moderate precipitation, ranging from 10 to 50 mm per hour.
Toró rainfall intensity can exceed 100 mm in a few minutes.

Citations

"Extraordinary claims require extraordinary evidence." - Carl Sagan
"The term 'toró' has its roots in the Tupi-Guarani language, reflecting the indigenous peoples' profound connection to and understanding of natural events."
"Guarani, an onomatopoeic language, vividly captures the sounds associated with nature, and 'toró' is no exception, mimicking the intense noise of rainfall translated as rainfall like a water jet."

Idées clés tirées de

Description of a New Phenomenon of Atmospheric Hazard

by Reinaldo Haa... à arxiv.org 11-14-2024

https://arxiv.org/pdf/2411.08219.pdf

Questions plus approfondies

How can modern meteorological technology, such as high-frequency radar and weather satellites, be best utilized to capture and analyze the "toró" phenomenon in real-time?

Capturing and analyzing a localized, transient phenomenon like "toró" requires a multi-faceted approach leveraging modern meteorological technology:
1. High-Frequency Radar Network:

Strategic Deployment: Deploy a dense network of high-frequency, dual-polarization Doppler radars in regions prone to "toró" occurrences. This high-density network is crucial due to the localized nature of "toró," ensuring coverage even in remote, mountainous areas.
Rapid Scan Rates: Utilize rapid scan rates (less than 1 minute) to capture the rapid development and evolution of "toró." This high temporal resolution allows for near real-time identification of the characteristic vertical water jet and its associated features.
Vertical Profiling: Employ radar beams with a narrow vertical resolution to accurately profile the vertical structure of precipitation within the "toró." This helps in understanding the intensity and depth of the water column.
2. Geostationary Weather Satellites:

High-Resolution Imaging: Utilize satellites with high-resolution visible and infrared sensors to monitor cloud formations and track the movement of storm systems that could potentially trigger "toró."
Lightning Detection: Integrate data from lightning mapping arrays onboard satellites to identify areas of intense convective activity, a potential precursor to "toró" formation.
Atmospheric Sounding: Leverage satellite-based atmospheric soundings to monitor atmospheric instability and moisture profiles, crucial factors influencing "toró" development.
3. Data Integration and Analysis:

Real-Time Data Fusion: Develop sophisticated data assimilation techniques to integrate real-time data from radar, satellites, and surface weather stations. This provides a comprehensive view of atmospheric conditions leading to "toró."
Automated Detection Algorithms: Develop and implement algorithms that can automatically detect the unique radar and satellite signatures of "toró" in real-time. This allows for timely warnings and alerts.
Numerical Weather Prediction Models: Integrate "toró" observations into high-resolution numerical weather prediction models to improve their ability to forecast these events and their potential impacts.
4. Community-Based Observation Networks:

Citizen Science Initiatives: Engage local communities in reporting "toró" occurrences and their impacts. This can be facilitated through smartphone apps and online platforms, providing valuable ground-truth data.
Traditional Knowledge Integration: Incorporate traditional ecological knowledge, such as the Tupi-Guarani understanding of "toró" indicators, into observation networks to enhance early warning systems.
By effectively integrating these technologies and approaches, we can significantly improve our ability to observe, analyze, and ultimately predict "toró" events, mitigating their potential hazards.

Could the "toró" phenomenon be a localized manifestation of a more common meteorological event, and if so, what factors contribute to its unique characteristics in specific geographic locations?

Yes, the "toró" phenomenon, with its intense, localized downbursts of rain, could be a geographically specific manifestation of more common meteorological events like microbursts or cloudbursts, amplified by unique topographical and atmospheric conditions.
Here's a breakdown of potential contributing factors:
1. Orographic Lift and Enhancement:

Steep Terrain: As suggested in the context, areas with steep slopes, gorges, and riffs, like those found in Southern Brazil and the Himalayas, can experience enhanced orographic lift. This occurs when air masses are forced upwards by the terrain, leading to rapid cooling, condensation, and intense precipitation.
Lee-Side Convergence: The presence of mountains can create complex wind patterns. As air descends on the leeward side (opposite the windward side where the initial uplift occurs), it can converge and accelerate, further intensifying downdrafts and localized precipitation.
2. Atmospheric Instability and Moisture:

Convective Available Potential Energy (CAPE): High CAPE values indicate significant atmospheric instability, a key ingredient for strong updrafts and heavy rainfall. Tropical and subtropical regions, like Brazil, often experience high CAPE, making them susceptible to intense convective events.
Precipitable Water Content: High levels of atmospheric moisture provide the fuel for heavy rainfall. Coastal areas, especially those influenced by warm ocean currents, tend to have higher precipitable water content, increasing the potential for intense downpours.
3. Microburst Dynamics:

Descending Rain Shafts: Microbursts are powerful downdrafts within thunderstorms that hit the ground and spread horizontally with intense force. The "toró" phenomenon could be a result of these downdrafts channeling through narrow valleys or gorges, concentrating their energy and leading to extreme rainfall over a small area.
Evaporation and Cooling: As rain falls through drier air below the cloud base, it can evaporate, cooling the air and further accelerating the downdraft. This process, known as evaporative cooling, can intensify microbursts and contribute to the sudden, powerful nature of "toró."
4. Localized Variations in Topography and Land Cover:

Small-Scale Terrain Features: Even subtle variations in topography within a larger mountainous region can influence airflow and precipitation patterns, leading to highly localized "toró" occurrences.
Deforestation and Land Use Change: Alterations in land cover, particularly deforestation, can modify local wind patterns and rainfall distribution, potentially exacerbating the intensity and frequency of "toró" in certain areas.
In essence, while "toró" shares characteristics with more common meteorological events, its unique intensity and highly localized nature likely arise from a complex interplay of orographic enhancement, atmospheric instability, microburst dynamics, and localized variations in topography and land cover. Further research, particularly high-resolution modeling studies that incorporate these factors, is crucial to fully understand and predict these events.

Considering the increasing frequency and intensity of extreme weather events globally, how can traditional ecological knowledge, like the Tupi-Guarani understanding of "toró," be integrated with modern science to improve climate change adaptation and disaster risk reduction strategies?

Integrating Traditional Ecological Knowledge (TEK), such as the Tupi-Guarani understanding of "toró," with modern science is crucial for developing effective climate change adaptation and disaster risk reduction strategies, especially in the face of increasingly frequent and intense extreme weather events. Here's how this integration can be achieved:
1. Bridging Knowledge Systems:

Collaborative Research: Foster partnerships between scientists and indigenous communities, recognizing TEK holders as experts in their local environments. This involves co-designing research projects, ensuring respectful knowledge exchange, and prioritizing community benefits.
Interdisciplinary Approaches: Encourage collaboration between meteorologists, climatologists, anthropologists, linguists, and TEK holders to develop a holistic understanding of "toró" and similar phenomena. This includes studying traditional indicators, forecasting methods, and coping mechanisms.
2. Enhancing Observation and Early Warning Systems:

Incorporating Traditional Indicators: Integrate indigenous knowledge of environmental cues, such as animal behavior, plant responses, or cloud formations, that may precede "toró" events. This can complement modern meteorological data and improve early warning systems, particularly in data-sparse regions.
Community-Based Monitoring: Empower local communities to monitor and report environmental changes related to "toró" and other extreme weather events. This can involve training community members in data collection, utilizing mobile technology for real-time reporting, and establishing communication channels with local authorities.
3. Strengthening Disaster Risk Reduction and Adaptation Strategies:

Learning from Traditional Practices: Document and analyze traditional coping mechanisms used by indigenous communities to mitigate the impacts of "toró," such as land management techniques, water harvesting methods, or resilient housing structures. These practices can inform modern disaster risk reduction strategies.
Developing Culturally Appropriate Solutions: Ensure that adaptation and risk reduction measures are culturally sensitive and consider the specific needs and priorities of indigenous communities. This includes respecting land rights, incorporating traditional values, and ensuring equitable access to resources and information.
4. Preserving and Revitalizing TEK:

Supporting Language and Cultural Transmission: Promote the preservation and revitalization of indigenous languages and cultural practices, which are essential for transmitting TEK across generations. This can involve language immersion programs, cultural centers, and community-led initiatives.
Documenting and Archiving TEK: Establish systematic methods for documenting and archiving TEK related to "toró" and other climate-related phenomena. This ensures that valuable knowledge is preserved for future generations and can be accessed by researchers and policymakers.
By integrating the Tupi-Guarani understanding of "toró" and other forms of TEK with modern science, we can develop more effective, equitable, and culturally appropriate strategies for adapting to climate change and reducing the risks posed by extreme weather events. This approach recognizes the value of diverse knowledge systems and fosters collaboration between indigenous communities and scientists for the benefit of all.