Fabrice Lambert
Pontificia Universidad Católica de Chile

14 de abril de 2024, 10:30
Aula 8,CIMA, Pab. II


Mineral dust aerosols scatter and absorb solar and thermal radiation, act as ice and cloud condensation nuclei, darken snowy surfaces after deposition, and play an important role in biogeochemical cycles both on land and in the ocean. Emitted in deserts and semi-arid regions, dust particles are entrained in the atmosphere by surface winds and reach the higher levels of the troposphere through ascending air currents; from there, they can be transported across the globe. Dust particles are removed from the air by both dry (gravitational settling) and wet (washout through precipitation) deposition processes.

Unlike well-mixed greenhouse gases, the climatic effects of dust vary seasonally and regionally and are not well represented by global averages. Paleoclimate model simulations of dust emissions, load, direct radiative effects, and their impacts on the carbon cycle through iron fertilisation are accompanied by significant uncertainty. The large spread in model results can mainly be attributed to differences in the representation of dust emission and deposition mechanisms, differences in boundary conditions (including vegetation), inclusion of glaciogenic (formed by glacier abrasion) dust sources, different aerosol size ranges and optical properties, and assumptions about dustborne iron solubility and bioavailability.

In this talk, we will review the latest advances in paleodust modelling and the primary uncertainties that still hinder paleoclimatic simulations of atmospheric dust, as well as strategies for addressing some of them. We are looking forward to seeing you at the seminar!

Fabrice Lambert es académico del Instituto de Geografía de la Pontificia Universidad Católica de Chile. Doctor en física climática en la Universidad de Berna, Suiza, utiliza herramientas estadísticas avanzadas para investigar la variabilidad climática anual a milenial del hemisferio sur sobre la base de registros de alta resolución provenientes de diversos archivos paleoclimáticos. Sus intereses de investigación incluyen la evolución espacial y temporal de las concentraciones de polvo en la atmósfera durante la última transición glacial-interglacial y las estimaciones de forzamiento radiativo del polvo y fertilización de hierro del océano durante este intervalo de tiempo. Su investigación incluye trabajos de terreno, de laboratorio y de simulaciones con modelos.