ワクセイタイキニオケルタジュウオヨビジュンジサンラン

京都大学0048新制・課程博士理学博士甲第1446号理博第321号新制||理||189(附属図書館)3927UT51-49-B9京都大学大学院理学研究科宇宙物理学専攻(主査)教授 川口 市郎, 教授 清水 彊, 教授 宮本 正太郎学位規則第5条第1項該当Kyoto UniversityDA

Global distribution of atmospheric water vapor

This paper presents a procedure on how to derive the atmospheric water vapor content from ADEOS/POLDER data. A POLDER sensor, mounted on the Earth observation satellite ADEOS in 1996, is a unique sensor which can gather multi-(up to 14) directional polarization measurements of one target. Two channels of POLDER data in the near infrared wavelengths are examined in this study. The first channel is in the water vapor absorption band of 0.910 μm and the second is in the gas absorption-free band of 0.865 μm. In practice, a ratio of each reflectance for these two channels is used to estimate the total column water vapor content. This algorithm will be referred to as the two-channel ratio method. The measured water vapor content from the POLDER data is in close agreement with the ground measurements undertaken at several NASA/AERONET stations. Global distribution of water vapor content presents the typical characteristics of spatial and temporal changes over the whole period of the ADEOS satellite\u27s deployment. The water vapor content has high values over the tropical zone and decreases with latitude. Furthermore, the Indian monsoon is clearly demonstrated in the water vapor map. It should be noted that the water vapor content retrieved from the POLDER data has been validated with AERONET measurements. The global map of water vapor is mutually compared with that of aerosol properties, which are derived from the POLDER polarization data. In addition to the comparison of water vapor content with aerosol loading, it has been found that the WA (water vapor-aerosol) index, i.e. the product of the water vapor content, aerosol optical thickness and Angstrom exponent, is a good indicator to classify the regional characteristics of the atmosphere-surface system. For example, high and low values in the WA index represent a bio-active area and a desert-dust area, respectively.本文データの一部は、CiNiiから複製したものである

Satellite derived aerosol information over East Asia in spring of 2003

Japanese observing satellite, called ADEOS-2 (Advanced Earth Observing Satellite-2), carried POLDER-2 (Polarization and Directionality of Earth Reflectances) and operated from April to the end of October in 2003. This work shows the aerosol information, over East Asia region from April to June derived from POLDER-2 data. Our retrieval algorithm for aerosols is based on the light scattering behavior of the atmospheric particles in the visible and near infrared wavelengths. It is shown that very thick aerosol layer has covered over East Asia during the period. The retrieved results are validated with ground based sun photometry.本文データの一部は、CiNiiから複製したものである

Algorithms for Aerosol Correction Based on a Combination of OCTS and POLDER

[Abstract]A better atmospheric correction for space-based data given by the second generation of ocean color sensors, e.g. ADEOS/OCTS and POLDER, is the main aim of this work. The new sensors possess high radiometric sensitivity and multi-channels in the visible and near-infrared wavelengths. This paper focuses on retrieval algorithms for atmospheric aerosols using both radiance and polarization data. It is shown first that a heterogeneous aerosol model following the Maxwell-Garnett mixing rule with small water-soluble inclusions in an oceanic matrix is available to interpret both the OCTS and POLDER data in the near infrared wavelength. Then an atmospheric correction process, which is based on the radiative transfer process in an atmosphere-ocean model involving the retrieved aerosol models, is applied to the ocean color data in the visible spectrum. Finally our procedure provides the phytoplankton pigment concentration near the sea surface defined as an expected map of the normalized difference phytoplankton index (NDPI). We would like to emphasize that the aerosol retrieval is improved by a combination of radiance and polarization data. In addition, it is of interest to mention that both of the NDPI maps obtained from OCTS and POLDER show the seasonal flow pattern of the currents over the North Pacific Ocean near Japan on April 26 in 1997