| Autor: |
Santos, V., Durán‐Quesada, A. M., Sánchez‐Murillo, R., Gastmans, D. |
| Předmět: |
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| Zdroj: |
Geophysical Research Letters; 8/16/2024, Vol. 51 Issue 15, p1-11, 11p |
| Abstrakt: |
Understanding the key drivers controlling rainfall stable isotope variations in inland tropical regions remains a global challenge. We present novel high‐frequency isotope data (5–30 min intervals) to disentangle the evolution of six stratiform rainfall events (N = 112) during the passage of convective systems in inland Brazil (September 2019–June 2020). These systems produced stratiform rainfall of variable cloud features. Depleted stratiform events (δ18Oinitial ≤ −4.2‰ and δ18Omean ≤ −6.1‰) were characterized by cooler cloud‐top temperatures (≤−38°C), larger areas (≥48 km2), higher liquid‐ice ratios (≥3.1), and higher melting layer heights (≥3.8 km), compared to enriched stratiform events (δ18Oinitial ≥ −3.8‰ and δ18Omean ≥ −5.1‰). Cloud vertical structure variability was reflected in a wide range of δ18O temporal patterns and abrupt shifts in d‐excess. Our findings provide a new perspective to the ongoing debate about isotopic variability and the partitioning of rainfall types across the tropics. Plain Language Summary: Stable water isotopes were used to analyze the formation of stratiform rainfall in the inland tropics of Brazil. The growth of this type of precipitation is associated with continuous condensation‐deposition processes. High‐resolution isotopic variations were analyzed using meteorological information, including satellite products and vertical micro rain radar observations. Our results showed that for stratiform rainfall, clouds with higher temperatures are related to more heavy isotopes, while less heavy isotopes are more frequent for stratiform rainfall coming from colder clouds. Our findings provide a detailed framework to improve isotope enabled models skills to represent the isotopic composition for different cloud types based on observations. Key Points: Weather systems and cloud development modulate rainfall isotope depletionsCloud top temperature, rain area, and water content (liquid‐ice ratio) are key parameters to decipher tropical rainfall isotope variationsIsotopic variations during intra‐evens are controlled by cloud phases, rainfall vertical structure, and the height of the melting layer [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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