Publications de Imad El Haddad

Temperature, humidity, and ionisation effect of iodine oxoacid nucleation

Andrea Baccarini, Lubna Dada, Houssni Lamkaddam, Imad El Haddad

Iodine oxoacids are recognised for their significant contribution to the formation of new particles in marine and polar atmospheres. Nevertheless, to incorporate the iodine oxoacid nucleation mechanism into global simulations, it is essential to comprehend ...

Royal Soc Chemistry2024

Bulk size-resolved chemical composition and mass concentration of non-refractory submicron aerosols measured in the Swiss container during MOSAiC 2019/2020

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot, Imad El Haddad

This dataset contains the bulk size-resolved chemical composition and mass concentration of non-refractory submicron aerosols (NR-PM1) measured during the MOSAiC expedition from October 2019 to July 2020. These include the mass concentrations of sulfate (S ...

Zenodo2023

Role of sesquiterpenes in biogenic new particle formation

Federico Bianchi, Andrea Baccarini, Lubna Dada, Imad El Haddad

Biogenic vapors form new particles in the atmosphere, affecting global climate. The contributions of monoterpenes and isoprene to new particle formation (NPF) have been extensively studied. However, sesquiterpenes have received little attention despite a p ...

2023

Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere

Andrea Baccarini, Lubna Dada, André Welti, Houssni Lamkaddam, Imad El Haddad, Mihnea Surdu

The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, in marine and polar regions, NH3 is generally low, and H2SO4 is frequently found together with iodine oxoacids [HIOx, i.e., iodic acid ...

American Association for the Advancement of Science2023

Elucidating the present-day chemical composition, seasonality and source regions of climate-relevant aerosols across the Arctic land surface

Julia Schmale, Imad El Haddad

The Arctic is warming two to three times faster than the global average, and the role of aerosols is not well constrained. Aerosol number concentrations can be very low in remote environments, rendering local cloud radiative properties highly sensitive to ...

IOP Publishing Ltd2022

Fragment ion-functional group relationships in organic aerosols using aerosol mass spectrometry and mid-infrared spectroscopy

Satoshi Takahama, Nikunj Dudani, Amir Yazdani, Imad El Haddad

Aerosol mass spectrometry (AMS) and mid-infrared spectroscopy (MIR) are two analytical methods for characterizing the chemical composition of OM. While AMS provides high-temporal-resolution bulk measurements, the extensive fragmentation during the electron ...

2022

Equal abundance of summertime natural and wintertime anthropogenic Arctic organic aerosols

Pragati Rai, Julia Schmale, Houssni Lamkaddam, Imad El Haddad

Aerosols play an important yet uncertain role in modulating the radiation balance of the sensitive Arctic atmosphere. Organic aerosol is one of the most abundant, yet least understood, fractions of the Arctic aerosol mass. Here we use data from eight obser ...

2022

High-frequency gaseous and particulate chemical characterization using extractive electrospray ionization mass spectrometry (Dual-Phase-EESI-TOF)

Andrea Baccarini, Houssni Lamkaddam, Imad El Haddad, Mihnea Surdu

To elucidate the sources and chemical reaction pathways of organic vapors and particulate matter in the ambient atmosphere, real-time detection of both the gas and particle phase is needed. State-of-the-art techniques often suffer from thermal decompositio ...

COPERNICUS GESELLSCHAFT MBH2022

Constraining the response factors of an extractive electrospray ionization mass spectrometer for near-molecular aerosol speciation

Yandong Tong, Julia Schmale, Imad El Haddad

Online characterization of aerosol composition at the near-molecular level is key to understanding chemical reaction mechanisms, kinetics, and sources under various atmospheric conditions. The recently developed extractive electrospray ionization time-of-f ...

2021

Characterization of primary and aged wood burning and coal combustion organic aerosols in an environmental chamber and its implications for atmospheric aerosols

Satoshi Takahama, Nikunj Dudani, Amir Yazdani, Imad El Haddad

Particulate matter (PM) affects visibility, climate, and public health. Organic matter (OM), a uniquely complex portion of PM, can make up more than half of total atmospheric fine PM mass. We investigated the effect of aging on secondary organic aerosol (S ...

European Geosciences Union2021

Large contribution to secondary organic aerosol from isoprene cloud chemistry

Julia Schmale, Daniil Salionov, Sasa Bjelic, Houssni Lamkaddam, Imad El Haddad

Aerosols still present the largest uncertainty in estimating anthropogenic radiative forcing. Cloud processing is potentially important for secondary organic aerosol (SOA) formation, a major aerosol component: however, laboratory experiments fail to mimic ...

2021

Online Aerosol Chemical Characterization by Extractive Electrospray Ionization-Ultrahigh-Resolution Mass Spectrometry (EESI-Orbitrap)

Julia Schmale, Imad El Haddad

Current mass spectrometry techniques for the online measurement of organic aerosol (OA) composition are subjected to either thermal/ionization-induced artifacts or limited mass resolving power, hindering accurate molecular characterization. Here, we combin ...

AMER CHEMICAL SOC2020

Overview: Integrative and Comprehensive Understanding on Polar Environments (iCUPE) – concept and initial results

Jenny Thomas, Julia Schmale, Jakob Boyd Pernov, Imad El Haddad

The role of polar regions is increasing in terms of megatrends such as globalization, new transport routes, demography, and the use of natural resources with consequent effects on regional and transported pollutant concentrations. We set up the ERA-PLANET ...

Copernicus Publications2020