KlimaCampus Kolloquium: Vertical air motion and tropical precipitation: New perspectives on an old problem
The most abundant precipitation on the Earth occurs over the tropical oceans in the so-called Inter-tropical Convergence Zone (ITCZ), a band of moist air extending near the equator from east to west. While it is intuitive that a moist atmosphere favors rich rainfall, the mechanism of tropical moist convection is not as simplistic as it may seem. A counterintuitive example is that heavy precipitation in the tropical east Pacific is found from time to time to develop at the edge of ITCZ in direct contact with a dry subtropical air rather than in the middle of ITCZ protected by its own moist airmass. The talk will begin with addressing this puzzle and offer an explanation with focus on the thermodynamic action of vertical air motion: a modest, shallow updraft at the ITCZ edge tends to grow stronger on its own while an intense, deep ascent at the ITCZ center is destined to decay. Further observations suggest that such contrasting behaviors depending on the depth of ascent may be integrated into a theory shedding new light on understanding the driving mechanism of tropical precipitation over its lifecycle.
Datum
26.06.2025
Uhrzeit
15:15 h
Ort
- Bundesstr. 53, room 022/023
- Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg