کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4443049 1311176 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extinction spectra of mineral dust aerosol components in an environmental aerosol chamber: IR resonance studies
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
پیش نمایش صفحه اول مقاله
Extinction spectra of mineral dust aerosol components in an environmental aerosol chamber: IR resonance studies
چکیده انگلیسی

Mineral dust aerosol plays an important role in determining the physical and chemical equilibrium of the atmosphere. To better understand the impact that mineral dust aerosol may have on climate forcing and on remote sensing, we have initiated a study of the optical properties of important components of mineral dust aerosol including silicate clays (illite, kaolinite, and montmorillonite), quartz, anhydrite, and calcite. The extinction spectra are measured in an environmental simulation chamber over a broad wavelength range, which includes both the IR (650–5000 cm−1) and UV–vis (12,500–40,000 cm−1) spectral regions. In this paper, we focus on the IR region from 800 to 1500 cm−1, where many of these mineral dust constituents have characteristic vibrational resonance features. Experimental spectra are compared with Mie theory simulations based on published mineral optical constants. We find that Mie theory generally does a poor job in fitting the IR resonance peak positions and band profiles for nonspherical aerosols in the accumulation mode size range (D∼0.1–2.5 μm). We explore particle shape effects on the IR resonance line profiles by considering analytic models for extinction of particles with characteristic shapes (i.e. disks, needles, and ellipsoids). Interestingly, Mie theory often appears to give more accurate results for the absorption line profiles of larger particles that fall in the coarse mode size range.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Environment - Volume 42, Issue 8, March 2008, Pages 1752–1761
نویسندگان
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