Project Details
Projekt
Ash Iron Mobiliztion in Volcanic Eruption Plumes
Applicant
Dr. Gholamali Hoshyaripour
Subject Area
Mineralogy, Petrology and Geochemistry
Geophysics
Atmospheric Science
Geophysics
Atmospheric Science
Term
from 2015 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 268937711
Recent studies strongly suggest that volcanic ash fertilizes the surface ocean by releasing soluble iron. However, knowing the fact that ash iron near the volcanic vent is mostly insoluble, the volcanic and atmospheric processes that allow formation of soluble iron species in the ash are poorly understood so far. This study investigates the volcanic plume controls on ash iron solubility. I combine volcanic eruption column modeling with high, mid and low temperature chemical reactions in eruption plumes in order to better constrain volcanic ash iron mobilization taking into account the interaction of different species in a solid-liquid-gas system. First, I use ATHAM to solve the plume dynamics and microphysics. Second, I develop a chemistry and thermodynamics code which gets the environmental conditions (in-plume temperature, pressure, humidity etc) from the ATHAM outputs and simulates the gas-ash/aerosol interactions with special focus on iron chemistry. This model is based on a series of coupled mass balance equations for different species in the eruption column. Terms in these equations are parameterized based on physicochemical interactions of gas, liquid and solid species. Some of the major processes considered in this study are: gas scavenging by ash, liquid water and ice, dissolution of the ash in the liquid phase and ice, iron aqueous chemistry and photochemistry. A series of lab experiments on ash are also considered to evaluate the modeling results against real ash samples and observation. Finally, I propose the favorable volcanic setting and in-plume processes for ash iron mobilization.
DFG Programme
Research Grants
International Connection
Belgium, United Kingdom
