土星環粒子隨時間變化之表面溫度模擬; Time variations of surface temperatures of saturian ring particles

NCUIR > College of Earth Sciences > Graduate Institute of Space Science > Department of Earth Sciences > Item 987654321/5215

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/5215

Title:	土星環粒子隨時間變化之表面溫度模擬;Time variations of surface temperatures of saturian ring particles
Authors:	張仕忱;Shih-Chen Chang
Contributors:	太空科學研究所
Keywords:	亮度溫度;反照率;熱惰性;土星環;brightness temperature;albedo;saturn's ring;thermal inertia
Date:	2006-06-28
Issue Date:	2009-09-22 09:47:19 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	摘要土星環是一個極薄的盤面且分佈範圍十分廣大，根據以往的觀測，環是由無數個粒子所組成的，大部分是水冰混合物和塵埃的結合，但是，詳細的物理性質，例如：粒子的體積密度、內部結構、尺寸即空間的分佈，都是我們極欲了解的部分。從過去的地面觀測與Pioneer 11、VoyagerⅠ、Ⅱ的資料與影像，得到土星環的溫度變化情況，當粒子進入土星的陰影區時不受太陽光的照射，表面溫度就會迅速的下降，再次接受到太陽的熱源則會被加溫，我們利用此種機制來建立模型，再以數值模擬的方法計算粒子在土星環軌道上運行時的溫度變化情況。其中運用能量方程式來計算表面的溫度變化，而熱傳導方程式計算粒子內部的溫度傳遞，給予不同的參數與假設條件，藉以了解單一粒子的表面與內部的受熱變化情況。根據Ferrari等人建立的Eclipse thermal model考慮了多項實際的影響條件，反映出了不同熱源下的粒子吸收通量，以及在不同熱惰性下陰影區的溫度變化，在我們的模型中也以控制不同的熱惰性來做模擬，和Ferrari等人的模擬作為比較。本篇所建立的為初步的模型，我們用粒子本身的自轉與繞行土星的公轉作為配合的依據，進行各種情況的溫度模擬，由模擬的數據與圖形做進一步的推論，了解溫度的變化趨勢。 Abstract The ring system of Saturn is made up of a large number of icy bodies with sizes ranging from mm to tens of meters . These particles are kept from being collected into a few large objects by the tidal effect of Saturn . The interior and surface structures of individaul ring particles are still unknown . One possibility holds that their surfaces are all covered by a layer or mantle of loosely-bounded dust particles . The Cassini measurements by the remote-sensing instruments such as the optical camera and infrared spectrometer will provide detailed mapping of the spatial variatons of the brightness distribution and temporal changes of the surface temperatures of the rings . We have constructed a numerical model to simulate the temperature variations of the ring particles at different orbital positions as they move around Saturn . The numerical results will provide useful constraints on the physical property of the surface layers of the ring particles in different regions .
Appears in Collections:	[Graduate Institute of Space Science] Department of Earth Sciences

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