The severity of wildfires is increasing globally. In this study, we used data from the Global Change Observation Mission-Climate/Second-generation Global Imager (GCOM-C/SGLI) to characterize the biomass burning aerosols that are generated by large-scale wildfires. We used data from the September 2020 wildfires in western North America. The target area had a complex topography, comprising a basin among high mountains along a coastal region. The SGLI was essential for dealing with the complex topographical changes in terrain that we encountered, as it contains 19 polarization channels ranging from near ultraviolet (380 nm and 412 nm) to thermal infrared (red at 674 nm and near-infrared at 869 nm) and has a fine spatial resolution (1 km). The SGLI also proved to be efficient in the radiative transfer simulations of severe wildfires through the mutual use of polarization and radiance. We used a regional numerical model SCALE (Scalable Computing for Advanced Library and Environment) to account for variations in meteorological conditions and/or topography. Ground-based aerosol measurements in the target area were sourced from the National Aeronautics and Space Administration-Aerosol Robotic Network; currently, official satellite products typically do not provide the aerosol properties for very optically thick cases of wildfires. This paper used satellite observations, ground-based observations, and a meteorological model to define an algorithm for retrieving the aerosol properties caused by severe wildfire events.

This study proposed an aerosol characterization process using satellites for severe biomass burning events. In general, these severely hazy cases are labeled as “undecided” or “hazy.” Because atmospheric aerosols are significantly affected by factors such as air quality, global climate change, local environmental risk, and human and biological health, efficient and accurate algorithms for aerosol retrieval are required for global satellite data processing. Our previous classification of aerosol types was based primarily on near-ultraviolet (UV) data, which facilitated subsequent aerosol retrieval. In this study, algorithms for aerosol classification were expanded to events with serious biomass burning aerosols (SBBAs). Once a biomass burning event is identified, the appropriate radiation simulation method can be applied to characterize the SBBAs. The second-generation global imager (SGLI) on board the Japanese mission JAXA/Global Change Observation Mission-Climate contains 19 channels, including red (674 nm) and near-infrared (869 nm) polarization channels with a high resolution of 1 km. Using the large-scale wildfires in Kalimantan, Indonesia in 2019 as an example, the complementarity between the polarization information and the nonpolarized radiance measurements from the SGLI was demonstrated to be effective in radiation simulations for biomass burning aerosol retrieval. The retrieved results were verified using NASA/AERONET ground-based measurements, and then compared against JAXA/SGLI/L2-version-1 products, and JMA/Himawari-8/AHI observations.

It is well known that the heavy soil dust has been transported from the China continent to Japan on westerly winds, especially in spring. The satellite observation is an effective tool for global monitoring of the Asian dust. A new algorithm for detection of Asian dust from space is proposed based on the multispectral satellite data. The derived space-based results are validated with the ground-based measurements and/or model simulations.<BR>The sun/sky photometry has been undertaken at NASA/AERONET stations at Osaka. The suspended particulate matter (SPM) sampling and NIES/LIDAR network equipment have been simultaneously working there. However, it is difficult to relate these ground-based measurements directly to the column space data. Therefore, in order to validate the satellite results with the surface-level data, an aerosol transportation model should be simulated. The measurements are examined with the model simulations.<BR>As a result, the distribution of Asian dust aerosols is retrieved in a comprehensive way in this study.

Using ADEOS-II/GLI aerosol and cloud products, downward and upward solar radiation at the surface and at the top of the atmosphere are estimated to study the Earth radiation budget. There is a good agreement in the main features of the global distribution of radiative fluxes as derived from GLI and from Terra/MODIS, yet, some differences can be noticed and need to be explained. In order to evaluate satellite-retrieved parameters that play a role in the Earth radiation budget, an observational network known as SKYNET has been established in Eastern Asia and it has already been operational during the ADEOS-II/GLI launch. Specifically, observations from the newly developed <I>i-</I>sky radiometer have been used for aerosol and cloud product evaluation. The aerosol products have been found to be in good agreement with observations while the cloud products need further evaluation.

A procedure for aerosol retrieval by combining data provided by POLDER (Polarization and Directionality of the Earth's Reflectances) and GLI (Global Imager) sensors mounted on the ADEOS-2 satellite (Advanced Earth Observing Satellite-2) is proposed. The POLDER sensor provides three channels of unique directional polarization measurements, and the GLI sensor provides high-resolution images over a wide range of wavelengths from near-UV to thermal infrared. It is known that POLDER polarization data are effective for aerosol retrieval over land, and the ratio of reflectances at 0.40 and 0.38μm from GLI can be used to distinguish between nonabsorbing and absorbing aerosols. Our algorithm is tested by detecting the plume from Siberian biomass burning in May 2003. The retrieved aerosol properties are compared with model simulations and ground-based AERONET (Aerosol Robotic Network) data. The results show that our proposed algorithm provides improved data on the aerosol optical thickness.

In order to analyze the urban atmospheric particles in Asia, we have undertaken simultaneous measurements of aerosols and suspended particulate matter (SPM) at a NASA/AERONET station at Kinki University Campus, Higashi-Osaka, since March in 2004. The relationship between concentration of suspended particulate matter (PM) and column aerosol optical thickness (AOT) is examined. It is found that a strong linear correlation exists between PM and AOT, and better correlation is obtained for the aerosols with the same origin, such as anthropogenic aerosols and dusts, rather than overall. The derived regression lines between PM<SUB>2.5</SUB> and AOT highlight the possibility that the PM<SUB>2.5</SUB> concentration can be estimated from the AOT, and vice versa. As a result, a distribution map of PM<SUB>2.5</SUB> has been obtained by using AOT values derived from Terra/MODIS data observed in April 2006 over East Asia.

The GOSAT satellite has been designed for retrieving the carbon dioxide amount in the atmosphere by a Fourier transform spectro-radiometer (TANSO-FTS). It is, however, known that FTS-observed radiances in the near-infrared spectral region are heavily contaminated by a solar radiation component scattered by atmospheric aerosols, which is known as "path radiance". In order to correct the path radiance, a multispectral visible-near infrared imager (TANSO-CAI) will be on board the GOSAT satellite to acquire the aerosol and cloud information that is indispensable for correcting the atmospheric path radiance to improve the carbon dioxide remote sensing by FTS. In this article, we study aerosol retrieval algorithms and cloud screening algorithms using the four channel radiances of CAI. We also present the methodology for vicarious calibration and validation for the CAI remote sensing, intercomparison of CAI-retrieved aerosol products with those from other satellite-borne sensors, and the data fusion strategy of satellite-measured and model-simulated aerosol properties.

The particle samples over Higashiosaka were collected by personal air sampler during asian-dust storms in April of 2005 and 2006. The size and elemental composition of individual perticles were investigated by scanning electron microprobe equipped energy-dispersive X-ray analyzer. From the results of individual particle analysis of Asian dust storm particles, Si-rich particles occupied 76.0% in 2.5-10.0μm diameter particles and 93.0% in <2.5μm diameter particles in April of 2005. In April 2006, Si-rich particles occupied 97.0% in 2.5-10.0μm diameter particles and 99.7% in <2.5μm diameter particles. Anthropogenic sulfur contaminated particles without sea salt were occupied by 2.2% in 2.5-10.0μm diameter particles and 3.6% in <2.5μm diameter particles in April 2005, and those were occupied by 0.4% in 2.5-10.0μm diameter particles and 2.9% in less than 2.5μm diameter particles in April 2006. From these results we confirmed that the degree of adsorption of anthropogenic sulfur oxides on to Asian dust storm particles during transport process from China to Japan was small in 2005 and 2006 over Higashiosaka.

To monitor urban atmospheric particles, we have undertaken simultaneous measurements of aerosols and suspended particulate matter (SPM) at Kinki University Campus, Higashi-Osaka, Japan, since 2004. The largest dust event recorded during our long-term observations was detected during the spring of 2006.We also examined the relationship between PM2.5 concentrations and aerosol properties obtained from radiometry using a multi-spectral photometer located at a NASA/AERONET station. We found a linear correlation between aerosol optical thickness and PM2.5 concentrations for both ordinary days and days with dust events.

JAMSTECみらい研究航海で得られた西部太平洋赤道上空エアロゾルについて。

黄砂や煙霧とともに微生物群(バイオエアロゾル)が，アジア大陸から日本へ越境輸送され，日本各地へと拡散沈着するため，その環境・健康影響に学術的関心が集まる。申請者らは，東アジア(日中韓蒙)において，黄砂を捕集する高高度調査(気球, ヘリコプター, 山岳積雪を使用)を実施し，日本へと越境輸送された微生物の種組成とその健康影響が，日本海沿岸と太平洋沿岸で大別できる可能性を突き止めた。しかし，観測地点は日本海側に偏り，太平洋側への国内移送や沈着程度を講じる観測が不十分であった。本申請では，日本本土(日本海ー太平洋)の観測地を拡充し，「越境微生物の国内での拡散・沈着過程」を理解すると伴に，そ影響を評価する。 黄砂飛来時に日本海側（能登）と太平洋側（関西，関東）の上空500ー2500ｍにおいてヘリコプター観測を行い，高高度の大気粒子を捕集した。また，黄砂・煙霧発生が頻発する春から初夏(4月-6月)にかけて，金沢，鳥取，香川，東京，長野，大阪の観測地において，建物屋上(高さ10m)で長期的に観測した。大気試料のゲノムDNA（環境ゲノム）に含まれる細菌・カビの分類指標遺伝子（16SとITS）核酸塩基配列を解読した。遺伝子解析ソフト(Qiime2)で微生物群集構造を解析したところ，黄砂と煙霧によって細菌は越境しやすく，本国内において真菌と混合する傾向が見られた。感染症（非結核抗酸症）の原因微生物も検出され，潜在的に長距離拡散される可能性も見出した。また分離した真菌株からもカビ毒が検出された。これより，黄砂煙霧とともに国内を拡散する有害種(キーストーン種)の候補に目処が立ちつつある。 こうした研究成果は，環境系の有名学術誌に多数掲載され，書籍「大気微生物の世界」にまとめられた。また，一般からの注目も熱く，大気観測全般を纏めたガリレオXやNHKスペシャルなどの取材を受けた。

本研究課題「エアロゾル輸送における山岳地形効果の解明」実施のため下記のプロジェクトを実施中である．特に2021年度の内容に関して報告を行う． ■日米共同観測「DRAGON J-ALPS」に基づく計測実験（2021年度）：米国NASAとの打合せで2021年3～5月の春季において再実験を行った．2020年度内に機器のメンテナンス，再設置，必要な機器の交換を済ませた．2021年度も引き続きコロナウイルスの影響を受けたが概ね機器が順調に稼働し，無事集中実験期間が終了できた．国立・国定公園内に設置した一部の機器は期限となる6月に撤去を行ったが，その他の大部分は10月～12月まで稼働を続けることができた．回収した機器は米国内にて2022年度6月頃には再校正が終了し，データが確定予定である． ■衛星計測：2021年度も引き続きGCOM-C衛星SGLIデータ，Himawari-8衛星AHIデータを用いて，特に黄砂イベントを中心に解析を行った． ■領域モデル：2020年度末に実施した集中観測の初期解析をSCALE-Chemによるモデルシミュレーションを用いて実施し米国AGUが発刊する国際オンライン論文誌（Natata et al., Effects of Mountains on Aerosols Determined by AERONET/DRAGON/J-ALPS Measurements and Regional Model Simulations, Earth and Space Science, doi:10.1029/2021EA001972）に掲載された．

This study aimed at performance of efficient system for aerosol retrieval based on the satellite data utilized together with ground-based measurements, radiative transfer algorithms, and the numerical model simulations. Summary of this work is as follows: Improved description of aerosol models, and validation it by using Terra/MODIS and ADEOS-2/GLI. 2. Development of radiative transfer system for polarization or non-polarization field. 3. An absorbing aerosol index (AAI) has been proposed defined as the ratio of the satellite-observed radiance at a wavelength of 412 nm to that at 380 nm in order to detect the absorbing particles. 4. Application for air pollution, PM analysis and an impact on the environment and climate change. 5. Validation system for satellite observations based on NASA/AERONET data. 6. The obtained results in this study are available for JAXA/GCOM-C/SGLI and other future missions.

This work intends to develop a procedure to estimate PM2.5 concentration over mega city in Japan. The procedure is composed of two parts as: 1. Aerosol retrieval from satellite reflectance measurements. 2. Conversion into PM2.5 concentration from retrieved aerosol optical thickness (AOT). The comparison of retrieved AOT from GOSAT/CAI with NASA/AERONET AOT measurements is performed in Osaka region. As results, a root mean square error value of AOT (RMSE-AOT) is around 0.09 in all retrieved wavelengths and the RMSE-AOT at a wavelength of 670 nm over Osaka region is around 0.07. Finally, satellite retrieved PM2.5 concentration also coincides with in situ PM2.5 measurements, RMSE-PM2.5 is around 6 ug/m3.

複合センサ(ADEOS-II/GLI及びPOLDER)データを用いた大気粒子特性の導出を行った.GLIによる近紫外,可視波長データを利用し,炭素性エアロゾル識別を実施,エアロゾル種別を考慮した上で偏光情報により光学的厚さなどのエアロゾル特性を導出した.また,エアロゾル輸送モデルによる計算結果を併用したデータ解析も試みた.以上の結果,エアロゾル種の違いによる導出精度悪化を低減することができた.

(1)NASA/AERONET放射計等による大気エアロゾル地上観測、(2)SPMのサンプリング計測と化学分析、(3)エアロゾル放射特性とSPM値の関係解析、(4)地上と衛星データの併合によるエアロゾルマップの導出等に関し、継続的に研究実績を挙げている. (5)2008年5月にNIESライダーネットワーク機器を設置し、(6)エアロゾルの発生から拡散までの解明、(7)総合的なデータ解析手法の実装、(8)モデルシミュレーションと実データの融合を実現した.

For evaluation of indirect effects of aerosol particles on climate, field experiments, named with Magic Monkey Project (MMP), were carried out in Artificial Cloud Experimental System (ACES) established in an abandoned vertical shaft with 430m depth in Kamaishi Mining Co. in Iwate pref., Japan. The experiments evaluating the influence of the number concentration of (NH4)2SO4/NaC1 aerosol particles on the properties of resulting cloud droplets were performed in November every year from 2002 to 2005. At the top of ACES there were two fans which made updraft inside ACES at the maximum 1.4[m/sec]. In the ACES any favorable altitude for measurement are accessible by ladders settled from the bottom to the top. Cloud droplets were visible around 30m above the bottom. Aerosol particles of ammonium sulfate and sodium chloride were generated at the bottom of ACES by atomizers into the air. According to the results obtained in the preliminary experiments intense measurements were carried out between the bottom and the altitude of 100m from there. Cloud droplets were sampled by impactors at several altitudes. Inside ACES the temperature is very stable around 13.0 degree Celsius at the bottom. Temperature profiles in the ACES showed that temperature lapse rates were small around 30-50m above the bottom of ACES where cloud generation started. When aerosol particles, such as ammonium sulfate and sodium chloride, were generated at the bottom, the number concentration of cloud droplets increased and their diameter decreased keeping the amount of liquid water contents almost constant. Among the parameters influenced to change the climate, the indirect effect of aerosol is the one with largest uncertainty. Although the results obtained here are envisioned to be used in a general circulation model (GCM), we can not use those result directly. The procedure to modify the obtained results for GCM model was also considered.

衛星データを用いて,全地球規模での大気エアロゾル特性導出システムを開発した.本システムの特徴は偏光の取り扱いが可能という点である.衛星搭載偏光センサデータ解析が可能である.実際に,フランスCNESが運用するPOLDERセンサデータを利用しエアロゾル推定を全球規模で行った.解析実施期間はADEOS/POLDERが稼働した,1996年11月〜1997年6月,及びADEOS-2/POLDER-2が稼働した2003年3月〜2003年10月である.同期間のPOLDER-1/-2全レベル1データ(約6TB)を入手,解析を行い,全球におけるエアロゾル光学特性(波長0.55μmにおける光学的厚さ,オングストローム指数)を導出した.衛星データからの導出プロダクトは全地球規模で展開されたAERONET地上観測値と比較検証を行った.検証結果よりRMS誤差で0.1の精度で光学的厚さが導出されている.本導出結果より,特に中央アフリカ,インド北部,中国大陸において定常的に人為起源によるエアロゾル(焼畑燃焼,工業由来による小粒子)が大量に排出されていることが確認された. 和歌山県白浜,長崎県福江島,大阪府東大阪の3カ所にて放射計を設置し地上からのエアロゾル観測を実施した.特に白浜及び大阪は米国NASAが管轄するAERONETデータとして準リアルタイムに取得データがWebで公開されている.また福江のデータはSKYNETのデータとして,千葉大学のWebにて公開されている.本研究で取得する放射計データは,NASA/GSFC,及び,ハワイ島マウナロア山,マウイ島ハレアカラ山にて絶対検定を実施しており,その精度を0.01以下の誤差となっている.

The obtained results during this search period from 2001 to 2004 are as follows ; 1.Aerosol retrieval using satellite data The global distribution of aerosols are obtained by using polarization data together with radiance data derived from ADEOS/POLDER in 1997 and 2003. The basic idea of our aerosol retrieval is that the scattering behavior of aerosols plays a sufficient role in the polarization field of the Earth atmosphere-surface system in the near infrared wavelengths. It is shown that the aerosol loading increases from 1997 to 2003, and aerosol events, which means anomaly lots of aerosol loading, are shown in north-west Africa and east Asia. 2.Ground based photo-polarimetry of aerosols To characterize urban aerosols, sun/sky photometry and polarimetry with PSR-1000 (Opto Research) have been performed over Higashi-Osaka since 1996. Multi-spectral photometer CE-318-2 (Cimel Electronique) was subsequently set up for an AERONET site in 2002. Another AERONET instrument (CE-318-1) has been operating at Shirahama since 2000 as a part of NASA/AERONET. The radiometers at both Osaka and Shirahama were calibrated using a standard AERONET procedure. The new SPM-613D instrument makes it possible to determine the relationship between aerosol properties and the particulate mass

The purpose of this study is to develop the method for the early recovery of the biodiversity in the oligotropical coastal area. It is of importance in the recovery of the biodiversity to make kelp forest grow in the concerned area. In order for it, sufficient nutrient is required as well as the proper seedbed. Hence, in this study, granulated fertilizer, which contains nutrient, such as nitrogen, phosphorus and iron, is coated by the special polymer, and then, is mixed into the porous concrete in order to provide seedbed and nutrient simultaneously. The physical and chemical properties of porous concrete with granulated fertilizer are discussed. Then brief note is appended to describe the method to select the place of implantation and to control the implantation with the aid of the artificial satellite to measure the chlorophyll concentration on sea surface. Research results from 2001 to 2005 are as follows. 1)Manufacturing method and rheological properties of binder and also segregation of fresh porous concrete (POC.) 2)Physical and chemical properties of porous concrete (POG)., and clarified the durability of freezing and thawing, washout test by water and abrasion by grain in sea 3)Properties of POC mixed with fertilizer and converter slag in seawater. 4)Seaweed adhesion onto POC mixed fertilizer and converter slag. 5)Water purification performance of POC. 6)Properties and seaweed adhesion of POC using the recycled material. 7)Chlorophyll concentration of sea surface and consistency of data measured from satellite observation.

本年の研究実績は次のとおりである. ○地上・洋上からの大気エアロゾル観測 大気エアロゾル観測をサンフォトメターや偏光放射計を用いて測定した.本年の重点的な観測は4月から5月にかけて行われたAPEXとACE-ASIAである.APEXは主として奄美大島笠利町を中心に行われ偏光放射計を用いた観測を行った.また,同時期に能登半島柳田村で自動型放射計をACE-ASIA国際エアロゾル同定キャンペーンの一部として臨時設置,運用した.大阪,和歌山県白浜においては定常的に運用していており,観測結果はhttp://aeronot.gsfc.nasa.govにて随時更新されている. 2000年10月〜現在 白浜 AERONETサイトとして大気観測(定常運用) 2001年4月 奄美大島 APEX-E2キャンペーン一部 2001年4月〜5月 能登半島 ACE-ASIAキャンペーン一部 2001年8月 モンゴル 千葉大との共同観測 2001年8月〜12月 Cimel偏光放射計のキャリブレーション(NASA/GSFCにて) 2001年11月〜12月 赤道太平洋洋上 海洋科学技術センター観測船「みらい」による大気観測 2001年12月〜2月 東大阪AERONETサイトとして大気観測(定常運用) 2002年3月 偏光放射計PSR-1000並びに全自動偏光放射計(Prede)のキャリブレーション(米マウナロア山)とエアロゾル高度分布観測 通年 東大阪 近畿大学キャンパス屋上にて大気偏光観測 ○衛星データを用いた大気エアロゾル導出 ADEOS/POLDERデータを基に,エアロゾル特性導出精度向上のための地表面からの偏光情報が違う,砂漠域,森林域,海域に分割し,また標高情報を加味したエアロゾル情報を全地球規模で導出した.また,地表面偏光を直接測定するための計測器作成準備を行った.

本年度の実績は,次の2つに大別できる. 1) 地上からの大気エアロゾル観測. 2) 衛星データに基づく大気エアロゾル特性全球分布作成とその季節変化調査. 1)の地上観測は,陸(近畿大学上空)を中心とし,偏光及び光学的厚さの測定を行った.また,解析時に必要となる観測時における気象データに関しても,同時収集を行なった. 2) 1)の解析システムを応用し,宇宙開発事業団より打ち上げられた,みどり(ADEOS)衛星搭載の偏光センサー(POLDER)データ処理用のシステムを作成した.センサー稼働期間の1996年11月から1997年6月のうち,季節変化の見込まれる1996年11月,1997年1月,4月の全観測データについて解析を行なった.解析結果を用い,各月における大気エアロゾル指標である光学的厚さ(Optical Thickness of Aerosols)とオングストローム指数(Ångstrom Exponent)の全球分布図を作成した.その結果,場所,季節による大気エアロゾル指標に大きな違いが見られた.具体的には,冬季の11,1月においては,アフリカ西岸から大西洋にかけて,サハラ砂漠起源のエアロゾルの吹き出しを導出できた.また、4月のアジア地域においても,ゴビ砂漠,タクラマカン砂漠起源である黄砂粒子によるエアロゾル粒子の飛来が明瞭に導出できた.これらは,他研究者が他センサーデータを用いて行なった解析結果とも一致し,精度良い広域エアロゾル特性分布図を作成できた.これらは気候変動モデルにおける地球大気放射収支計算,特に温暖化シミュレーションの精度向上のための基礎データとしても利用可能である.

本研究は地球環境システムに大きな影響を及ぼす大気-海洋間の放射輸送過程のモデリングとシミュレーションを理論・観測両面から実現しようとするものである. 具体的には,大気放射輸送の鍵を握る大気エアロゾルの光学特性導出アルゴリズムを提案し,ADEOS/OCTS,POLDERの近赤外波長データを用いたエアロゾル・リトリ-バルに成果を挙げている.特に,通常用いられてきた散乱光強度だけではなく,新たに偏光度をも併用して,精度の向上を図った.今年度は特に,地球大気モデルの精密化を目指し,上記大気エアロゾルモデルの検証に加え,大気の垂直構造の影響・地上物体や海陸境界域における周辺効果の見積もり・海および海面モデルの再構築を考慮した. 総合的な放射輸送システムを構築するには,種々のデータセットが必要である.大気エアロゾルモデルを含む地球大気,海洋(陸)などに関するデータセット,多重散乱計算結果のデータベース,更に,開発アルゴリズム検証のための実験及びテストデータも必要となる.これらのデータは併せて,地球大気基礎データベースとして有用なものになる.データ及び計算機システムは,当研究室にて稼働中である.シミュレーションに際し,汎用性・更新性の高い柔軟な構造を持つソフトウエアの開発に留意した.

We intend to develop efficient algorithms for aerosol retrieval. Our algorithm is based on an idea that aerosol characteristics can be estimated in terms of the scattering behavior. Polarization feature strongly depends on the aerosol characteristics, e.g.refractive index, size, or shape of aerosols. An efficient algorithm for aerosol retrieval is developed by considering simulations in the polarization field. Thus it is our purpose to continue our photopolarimetric measurements of aerosols and simultaneously simulate polarization field. The ground truth including research vessel observations have been undertaken for these four years. Certainly new satellite data by both of ADEOS/OCTS and POLDER are available to compile the global-scale aerosol distribution. The following products have been compiled ;

本研究では,大気エアロゾルの光学特性(化学組成,密度,大きさ等)の時空間変化からその起源や分布を調べた.エアロゾル光学特性の導出にあたり,放射強度と合わせて,偏光度を利用した.偏光度データの取得には,下記のスケジュールで多波長偏光放射計(PSR1000)を用いて検証実験を実施した. ●平成8年5月〜平成9年2月 近畿大学(東大阪市) ●平成8年5月〜平成9年1月 気象庁気象研究所(つくば市)にて気象研,金沢工大と共同観測 ●平成8年7月,平成9年3月 神戸商船大学深江丸にて四国・九州沖にて洋上観測 これらの取得データを基に,光散乱シミュレーション値と比較照合から最適なエアロゾルモデルの導出を行った.得られた結果を次に記す. 1)つくば市上空,東大阪市上空の陸域のエアロゾルに関しては,有機物溶存型エアロゾル(Water Solubleタイプ)と,都市型エアロゾルとしての煤(Sootタイプ)などが混合している.また,エアロゾル粒径半径と分布は,変化が激しい. 2)大阪湾など,瀬戸内海上空では海塩粒子(Oceanicタイプ)と共に,陸域起源の有機物溶存型が混合している. 3)太平洋上では,ほぼ海塩粒子に限られ,エアロゾル粒径分布変化はほとんど無かった. 本研究と通じて,人的な影響だけでなく大陸と海洋の影響を受けた日本近海の大気エアロゾルの地域的な分布状況や,粒径変化が分かった.