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2-2 Balloon-borne Superconducting Submillimeter-Wave Limb-Emission Sounder for Observations of Middle Atmosphere
| Content Provider | Semantic Scholar |
|---|---|
| Author | Yoshihisa, Irimajiri |
| Copyright Year | 2002 |
| Abstract | We are currently developing a balloonborne superconducting submillimeter-wave limb-emission sounder (BSMILES) for observations to determine the altitude profile of molecules affecting stratospheric ozone depletion. As shown in Fig.1(a), the limb sounding method allows the observation of the limb of the atmosphere in a tangential direction. Therefore, high-sensitivity observation is possible through deep penetration into the atmosphere; in other words, by employing a long distance of integration. The scanning of an observation beam at the elevation angle (altitude) provides high resolution in observation. The sounder receives emission line spectra from ozone and molecules relating to ozone depletion in the stratosphere to determine the quantity of these trace substances. Chlorine monoxide (ClO) is said to play an important role in the depletion of the ozone due to its interaction with chlorofluorocarbons. The intensity of emission lines from this molecule is weak in the millimeter band (200 GHz), while it is relatively strong in the sub-millimeter frequency band (650 GHz). In this band, however, water vapor in the troposphere absorbs these molecules such that it becomes difficult to observe them from the ground (except for locations high in the mountains, at altitudes of thousands of meters). Observation from high altitudes thus requires the use of airplanes, balloons, satellites, or a space station. A manned airplane has advantages in controlling the arrangement of instruments and in repeated single-flight observations, but cannot reach altitudes that are high enough to enable observation of molecules with sufficiently high resolution. Observation from space is advantageous in that it becomes possible to observe a wide range of the earth’s surface, although this method has the disadvantages of enormous costs in terms of development, time, and human resources. It is also necessary to take extensive precautionary measures before each launch. On the other hand, balloon-borne instruments are relatively cheap and can be developed using a small amount of resources in a short time. Moreover, if the balloon-borne instruments are designed to be recyclable, they can be used repeatedly, providing enough data to resolve problems and improve design. Thus, balloons |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://nict.go.jp/publication/shuppan/kihou-journal/journal-vol49no2/2-02.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
