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Grandes y rápidos cambios de velocidad inducidos por el derretimiento en la zona de ablación de la capa de hielo de
R S W van de Wal1, W Boot, M R van den Broeke
1Institute for Marine and Atmospheric research Utrecht, Utrecht University, Netherlands. r.s.w.vandewal@uu.nl
Science (New York, N.Y.)
|July 5, 2008
Resumen
La velocidad del hielo de Groenlandia aumenta dramáticamente con el agua de deshielo, pero el flujo general de hielo permanece estable debido a los ajustes del sistema. Esta retroalimentación estacional puede limitar los impactos a largo plazo del calentamiento climático en la capa de hielo.
Área de la Ciencia:
- Glaciología glaciología.
- Ciencias del clima Ciencias del clima Ciencias del clima
- Observación de la Tierra Observación de la Tierra
Sus antecedentes:
- La respuesta de la capa de hielo de Groenlandia al cambio climático es un área crítica de investigación.
- Comprender la dinámica del hielo, particularmente los cambios de velocidad, es clave para predecir el aumento del nivel del mar.
Objetivo del estudio:
- Para investigar las fluctuaciones rápidas de la velocidad del hielo en la zona de ablación de la capa de hielo de Groenlandia.
- Para cuantificar la relación entre la producción de agua de deshielo y la velocidad del hielo.
- Evaluar las implicaciones a largo plazo de estas dinámicas para la estabilidad de la capa de hielo.
Principales métodos:
- Se utilizaron las observaciones continuas del Sistema de Posicionamiento Global (GPS).
- El análisis se centró en la zona de ablación occidental de la capa de hielo de Groenlandia.
- Los datos cubrían períodos a corto plazo (días) y a largo plazo (17 años).
Principales resultados:
- La velocidad del hielo aumentó en un factor de 4 en cuestión de días en respuesta al aumento del agua de deshielo.
- Esta respuesta rápida es significativamente más fuerte y más rápida de lo documentado anteriormente.
- A pesar de las fluctuaciones a corto plazo, las velocidades anuales del hielo mostraron una ligera disminución en 17 años, lo que indica ajustes en el sistema.
- Se identificó un mecanismo de retroalimentación positiva estacional entre la tasa de fusión y la velocidad del hielo.
Conclusiones:
- El sistema hidráulico englacial se ajusta constantemente a la entrada variable de agua de deshielo, manteniendo un flujo de hielo relativamente estable.
- El mecanismo de retroalimentación identificado es principalmente estacional y puede tener una influencia limitada en la respuesta de la capa de hielo al calentamiento climático a largo plazo.
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