HR: 12:05h
AN: A52C-07    [Abstracts]
TI: Applications of Spectroscopy to Studying Atmospheric Chemistry
AU: * Simpson, W R
EM: ffwrs@uaf.edu
AF: Geophysical Inst. and Chem. Dept., Univ. Alaska Fairbanks, 900 Yukon Drive, Room 186, Fairbanks, AK 99775, United States
AU: Apodaca, R
EM: randy.apodaca@gmail.com
AF: Geophysical Inst. and Chem. Dept., Univ. Alaska Fairbanks, 900 Yukon Drive, Room 186, Fairbanks, AK 99775, United States
AU: Carlson, D A
EM: fsdac8@uaf.edu
AF: Geophysical Inst. and Chem. Dept., Univ. Alaska Fairbanks, 900 Yukon Drive, Room 186, Fairbanks, AK 99775, United States
AB: Spectroscopic techniques are finding increased applications in studies of atmospheric chemistry because of inherent advantages in the techniques and technological improvements in optical and computer components. There are many advantages of using spectroscopy for study of chemistry. Spectroscopy is absolutely calibrated and thus requires only validation, reducing the need for consumable standards and reducing size and weight. Generally, spectroscopic instruments can be built from inexpensive solid-state components with few or no moving parts, improving long-term reliability. Huge advances in optoelectronic components, such as availability of diode lasers, cheap imaging detectors, light emitting diodes, have widened the breadth of applications and reduced costs. In this presentation, we discuss two recent applications of atmospheric spectroscopy that exploit these advantages. In the first application, our group has used off-axis Cavity Ring-Down Spectroscopy (oaCRDS) to make a small and inexpensive detector for nitrate radicals (NO₃) and dinitrogen pentoxide (N₂O₅), which are atmospherically important nitrogen oxides the dominate reactivity during nighttime. This instrument fits in a small waterproof case that is (98cm x 40cm x 15cm), weighs less than 25kg, and uses an inexpensive diode laser. The instrument was recently incompared to a number of other techniques for measuring these gases and showed excellent performance. In a second application, we have used multiple-axis Differential Optical Absorption Spectroscopy (MAXDOAS) to measure halogen oxides and other UV-absorbing gases at remote locations. This instrument will be a part of an autonomous chemical-measuring buoy that will be deployed on the Arctic Ice. The instrument will make measurements and telemeter the data back via an iridium satellite modem. Our MAXDOAS instrument is very small, inexpensive, and uses only 2 watts of power, allowing long life when operating on batteries. Many features were built into the instrument to ensure long-term reliability without physical access the the instrument.
UR: http://www.uaf.edu/chem/simpson
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting