Microsoft PowerPoint - RS環境情報学 I 掲載用.pptx

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1 2014 年 RS 環境情報学 I Optical remote sensing of atmospheric pollutants 大気汚染物質の光学的リモートセンシング Center for Environmental Remote Sensing (CEReS), Chiba University Hiroaki Kuze, Professor, Dr.Sc. hkuze@faculty.chiba-u.jp 1

2 衛星画像の色の違い (AQUA/MODIS 500 m RGB) 違いの原因 Why these images look different - 1 太陽高度が季節によって違う Solar elevation 2 地表面状態が違う ( 植生や積雪など ) Ground coverage 3 大気中の微粒子であるエアロゾルの量と性質が違う Cloud and aerosol 2

3 放射収支 (radiation budget) と大気の吸収黒体放射 550 nm 10 m 入射 Incoming 5800 K 出射 Outgoing 280 K 平衡状態入射と出射のエネルギーのつり合い窓領域地表面吸収率 % 11 km 3

4 Change of sky color : : : :22 4

$Including refraction, reflection,$

5 Rayleigh scattering and Mie scattering clear sky cloud Rayleigh scattering Mie scattering - Air molecules (N 2, O 2,..) - radius r << 4 - Intensity ( 1 / ) - Scattering due to induced electric dipole moment - Liquid or solid particles (aerosol) - radius r ~ p - Intensity ( 1/ ) - Including refraction, reflection, diffraction, etc. p: Angstrom exponent 5

6 レイリー散乱とミー散乱 (Rayleigh and Mie scattering) 青空 (clear sky) 曇天 (cloudy sky) Rayleigh scattering Mie scattering - 大気分子 (N 2, O 2,..) - 半径 r << 波長 4 - 強度は ( 1/ ) - 光の電場によって誘起された電気双極子モーメントによる散乱 - 液体または固体粒子 ( エアロゾルと総称 ) - 半径 r ~ 波長 p - 強度は ( 1/ ) - 反射屈折回折など複雑な効果を含んだ散乱 p: Angstrom 指数 6

7 Questions Q1 Why colors are different from image to image? Q2 Why distant mountains look blue? Q3 Describe scattering processes in the atmosphere. 7

8 2. Air pollution 大気汚染 8

9 Vertical structure of the atmosphere Stratosphere is formed due to UV absorption of O 3. Molecular composition up to 80 km: N 2 (78 %) O 2 (21 %) H 2 O (0.1 3 %) Ar (0.93 %) CO 2 (0.038 %) 380ppm Ne ( %) CH 4 ( %) 大気の鉛直構造 Thermosphere 熱圏 Mesosphere 中間圏 Stratosphere 成層圏 Troposphere 対流圏 9

10 航空機から見た雲 cirrus 巻雲 cirrocumulus cirrostratus altocumulus 高積雲 altostratus 高層雲 Altitude (km) cumulonimbus 積乱雲 Encyclopedia Britannica

11 Space and time scales of atmospheric trace gases 大気汚染物質の時空間スケール The long-lived species contribute to the ozone hole and greenhouse warming. The moderately long-lived species contribute to regional and urban air pollution and smog. 11

12 Urban smog: PM2.5 Los Angels Alberta, Canada Beijing 12

PM2.5, PM10 and SPM In USA, a new environmental standard of PM2.5 was added in 1997 to the existing standard of PM10. In Japan, the standard for PM10 was established in 1972.

13 PM2.5, PM10 and SPM In USA, a new environmental standard of PM2.5 was added in 1997 to the existing standard of PM10. In Japan, the standard for PM10 was established in The suspended particulate matter (SPM) was defined as particles with diameters less than 10 m. Collection Efficiency Particle Diameter ( m) 13

14 Andersen Sampler (Multi-stage cascade impactor) Aerosol particles accumulate on a filter paper. 14

15 Long-term trend of NO 2 and SPM concentration Ground sampling measurement at around 2000 stations (roadside: 500) ppm NO 2 concentration Environmental standard Roadside General SPM concentration mg/m 3 Roadside General 15

16 SO 2 emission ppm ppm (sampling station measurement) kilo-ton SO 2 in 0.5 o 0.5 o mesh (2000) 16

17 Global distribution of PM2.5 ( g/m 3 ) The global ground-level PM2.5 concentrations are mapped using total column aerosol optical depth (AOD) from the MODIS and MISR satellite instruments and coincident aerosol vertical profiles from the GEOS-Chem global chemical transport model. Global estimates of long-term average (1 January 2001 to 31 December 2006) PM2.5 concentrations at approximately 10 km 10 km resolution indicate a global population-weighted geometric mean PM2.5 concentration of 20 µg/m 3. Donkelaar et al., 17

(11:00, 14:00, and 23:00) observed at 1500 General

18 Asian dust event observed on April 8, 2006 Aqua/MODIS visible band (RGB) SPM distribution on the same day, (11:00, 14:00, and 23:00) observed at 1500 General (non-roadside) Stations. 18

19 3. Solar radiation and Rayleigh scattering 19

20 Atmospheric perspective 大気遠近法 Solar spectrum visible spectrum peaked at around 550 nm (Blackbody Radiation at 5800 K) Molecular Rayleigh scattering enhanced blue color Spectral reflectance of vegetation in the visible range, R max ~ 15% (not very high) Observer 20

分光反射率 Spectral reflectance Oak Spruce カオリナイト

21 分光反射率 Spectral reflectance Oak Spruce カオリナイト (Kaolinite) は陶磁器の材料となる白色の粘土質鉱物オーク (Oak) とトウヒ (Spruce) 植生は可視域では緑 ( 波長 0.55 m 付近 ) の反射を示しその反射率は 10-20% 程度である一方波長 m の近赤外での反射率は 50-90% と非常に大きくなっている図は米国地質調査所のデータベースのデータによる : 21

22 Irradiance and radiance 放射照度と放射輝度 scattered light Incident light beam E [W/m 2 ] irradiance Photon flux J = E / h s -1 m -2 L [W m -2 sr -1 ] radiance 22

23 In the case of plane the angle is measured with the length of the corresponding arc. Since the periphery of a circle with radius r is 2 r, the angle for the total plane can be calculated to be 2 (rad). Solid angle is measured with the area subtended at the surface of a sphere. Since the total area of a sphere with radius r is 4 r 2, the solid angle for total space is calculated to be 4 (sr). 立体角 solid angle ds d r 2 sin d d 23

24 Questions Q1 Why colors are different from image to image? Q2 Why distant mountains look blue? Q3 Describe scattering processes in the atmosphere. Q4 Why the temperature increases in the stratosphere? Q5 Describe species that are important for environmental pollution. Q6 What is the difference between irradiance and radiance? Q7 What s new? New concepts and facts you have learned from today s lecture. 24

スライド 1

スライド 1 評価標準化研究会 2011 年 8 月 12 日衛星データの大気補正と放射伝達 Atmospheric correction and radiation transfer 千葉大学環境リモートセンシング研究センター Center for Environmental Remote Sensing Chiba University 久世宏明 Hiroaki Kuze 環境リモートセンシング研究センター