Repozitorij Univerze v Novi Gorici

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


1 - 2 / 2
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
1.
Ice cloud formation potential by free tropospheric particles from long-range transport over the Northern Atlantic Ocean
Claudio Mazzoleni, Katja Džepina, Kendra Wright, R. Chris Owen, Paulo Fialho, Lynn R. Mazzoleni, Swarup China, Peter A. Alpert, Bo Zhang, Simeon K. Schum, 2017, izvirni znanstveni članek

Opis: Long-range transported free tropospheric particles can play a significant role on heterogeneous ice nucleation. Using optical and electron microscopy we examine the physicochemical characteristics of ice nucleating particles (INPs). Particles were collected on substrates from the free troposphere at the remote Pico Mountain Observatory in the Azores Islands, after long-range transport and aging over the Atlantic Ocean. We investigate four specific events to study the ice formation potential by the collected particles with different ages and transport patterns. We use single-particle analysis, as well as bulk analysis to characterize particle populations. Both analyses show substantial differences in particle composition between samples from the four events; in addition, single-particle microscopy analysis indicates that most particles are coated by organic material. The identified INPs contained mixtures of dust, aged sea salt and soot, and organic material acquired either at the source or during transport. The temperature and relative humidity (RH) at which ice formed, varied only by 5% between samples, despite differences in particle composition, sources, and transport patterns. We hypothesize that this small variation in the onset RH may be due to the coating material on the particles. This study underscores and motivates the need to further investigate how long-range transported and atmospherically aged free tropospheric particles impact ice cloud formation.
Najdeno v: ključnih besedah
Ključne besede: atmospheric aerosols, ice nucleating particles, long-range transport, optical microscopy, electron microscopy, Pico Mountain Observatory
Objavljeno: 11.04.2021; Ogledov: 287; Prenosov: 13
URL Polno besedilo (0,00 KB)
Gradivo ima več datotek! Več...

2.
Morphology and mixing state of aged soot particles at a remote marine free troposphere site
Sumit Kumar, Katja Džepina, Michael P. Dziobak, Paulo Fialho, Judith A. Perlinger, Swarup China, Barbara Scarnato, Robert C. Owen, Bo Zhang, MarianT. Ampadu, 2015, izvirni znanstveni članek

Opis: The radiative properties of soot particles depend on their morphology and mixing state, but their evolution during transport is still elusive. Here we report observations from an electron microscopy analysis of individual particles transported in the free troposphere over long distances to the remote Pico Mountain Observatory in the Azores in the North Atlantic. Approximately 70% of the soot particles were highly compact and of those 26% were thinly coated. Discrete dipole approximation simulations indicate that this compaction results in an increase in soot single scattering albedo by a factor of <= 2.17. The top of the atmosphere direct radiative forcing is typically smaller for highly compact than mass-equivalent lacy soot. The forcing estimated using Mie theory is within 12% of the forcing estimated using the discrete dipole approximation for a high surface albedo, implying that Mie calculations may provide a reasonable approximation for compact soot above remote marine clouds.
Najdeno v: ključnih besedah
Povzetek najdenega: ...and mixing state, but their evolution during transport is still elusive. Here we report observations...
Ključne besede: atmospheric aerosol, soot, long-range transport, free troposphere, single scattering albedo
Objavljeno: 11.04.2021; Ogledov: 317; Prenosov: 0
.pdf Polno besedilo (899,35 KB)

Iskanje izvedeno v 0 sek.
Na vrh