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著者人数: 20名, 形態: 図版あり, Number of authors: 20, Physical characteristics: Original contains illustrations, 資料番号: PA1710058000

著者人数: 17名, 形態: カラー図版あり, Number of authors: 17, Physical characteristics: Original contains color illustrations, 資料番号: PA1710059000

Wind is fundamental in many atmospheric phenomena. Global wind profile observation is important to improve numerical weather prediction (NWP) and various meteorological studies. Wind profile observations are measured mainly by radiosonde networks. Most of the weather stations are on land, while weather stations on oceans and remote land areas are sparsely distributed. The current global wind observing systems do not satisfy the globally homogeneous wind profile observation. A space-based Doppler wind lidar is one of the candidates for future global wind profile observations. In the paper, we present results from feasibility study of space-based Doppler Wind Lidar.

We observed ozone (O3) in the vertical region between 250 and 0.0005 hPa (~ 12–96 km) using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. The new 4 K superconducting heterodyne receiver technology of SMILES allowed us to obtain a one order of magnitude better signal-to-noise ratio for the O3 line observation compared to past spaceborne microwave instruments. The non-sun-synchronous orbit of the ISS allowed us to observe O3 at various local times. We assessed the quality of the vertical profiles of O3 in the 100–0.001 hPa (~ 16–90 km) region for the SMILES NICT Level 2 product version 2.1.5. The evaluation is based on four components: error analysis; internal comparisons of observations targeting three different instrumental setups for the same O3 625.371 GHz transition; internal comparisons of two different retrieval algorithms; and external comparisons for various local times with ozonesonde, satellite and balloon observations (ENVISAT/MIPAS, SCISAT/ACE-FTS, Odin/OSIRIS, Odin/SMR, Aura/MLS, TELIS). SMILES O3 data have an estimated absolute accuracy of better than 0.3 ppmv (3%) with a vertical resolution of 3–4 km over the 60 to 8 hPa range. The random error for a single measurement is better than the estimated systematic error, being less than 1, 2, and 7%, in the 40–1, 80–0.1, and 100–0.004 hPa pressure regions, respectively. SMILES O3 abundance was 10–20% lower than all other satellite measurements at 8–0.1 hPa due to an error arising from uncertainties of the tangent point information and the gain calibration for the intensity of the spectrum. SMILES O3 from observation frequency Band-B had better accuracy than that from Band-A. A two month period is required to accumulate measurements covering 24 h in local time of O3 profile. However such a dataset can also contain variation due to dynamical, seasonal, and latitudinal effects.

Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking, in particular at altitudes above 30 km. We report observations of winds between 8 and 0.01 hPa (~35–80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35–60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30° S to 55° N and with a single profile precision of 7–9 m s–1 between 8 and 0.6 hPa and better than 20 m s–1 at altitudes above. The vertical resolution is 5–7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1–0.05 hPa, an absolute value of the mean difference < 2 m s–1 is found between SMILES profiles retrieved from different spectroscopic lines and instrumental settings. Good agreement (absolute value of the mean difference of ~2 m s–1) is also found with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis in most of the stratosphere except for the zonal winds over the equator (difference > 5 m s−1). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (> 20 m s–1), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50–55° N during sudden stratospheric warmings. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of ~20 m s–1). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds, but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models.

The photophysics of the regioregular (RR) poly(3-alkylthiophene) (P3AT) films is investigated by cw-photoinduced absorption (PIA) measurements based on bleaching signals. The photoexcitation intensity dependence of the cw-PIA signals demonstrates that both photogenerated localized and delocalized polarons obey a bimolecular recombination process under cw photoexcitation. It is demonstrated that the lineshape of cw-PIA bleaching spectra for the P3AT films varies with the length of the alkyl substituents of P3AT. The bleaching spectra reveal a trend that the electron-phonon couplings of final exciton migration sites become strong with increasing the interlamella distance in the P3AT film. This indicates that interlamella couplings affect the electron-phonon couplings of the migration sites locating at two-dimensional lamellas. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The relationship between local meteorological fields and the behaviour of airborne Asian dust that arrived in the Tokyo metropolitan area on 1 April 2007 with the passage of a synoptic-scale cold front has been investigated through Doppler lidar observations, experiments using a regional atmospheric numerical model, and analyses of surface and upper-air meteorological observations. Results of the Doppler lidar observations showed that the Asian dust passed above the metropolitan area with strong south-westerly winds with speeds of 15–26 m s−1. Meteorological fields reproduced by the numerical experiments showed the development of a surface-based stable layer in the metropolitan area caused by nocturnal radiational cooling near the ground surface and south-westerly warm air advection at upper levels. The blocking effect of the mountainous region located to the west of the metropolitan area induced an area of stagnant air inside the metropolitan area and promoted the stable layer development. Although strong downdrafts prevailed in the upper air, the airborne Asian dust did not spread to the ground when the stable layer was formed. These results strongly indicate that the developed stable layer prevented strong downdrafts from spreading to the ground, acting as an obstacle to the transport of the Asian dust particles from the upper air towards the ground. This is considered to be one of the main causes of the low appearance frequency of Asian dust phenomena near the ground in the Tokyo metropolitan area and eastern Japan.

The impact of a foehn phenomenon on the generation of abnormally high surface air temperatures in the Tokyo metropolitan area was investigated through Observing Systems Simulation Experiments (OSSEs) by the use of the variational data assimilation system equipped on Weather Research and Forecasting model (WRF-VAR). First, an abnormally hot weather event on August 16, 2007 was simulated using the JMA’s operational meso-scale analysis data to produce “simulated observations”. Then, the vertical profiles of the simulated observations over several sites were assimilated into an initial field. Results of OSSEs demonstrated that northwesterly winds and high-temperature air associated with the foehn strongly affect the generation of the abnormally high surface air temperatures. Also, the results indicated that southerly sea breezes prevent the impact of the foehn from spreading to the southern part of the metropolitan area.

The front of a sea breeze originating from Sagami Bay passed over Tokyo between 1300 LST and 1400 LST on August 10, 2006. Field observations of wind distributions over Tokyo by the use of a ground-based coherent Doppler lidar developed at the National Institute of Information and Communications Technology showed that a sharp multi-layered structure of vertical wind fields was gradually formed after the sea-breeze front passed the observation site. Numerical simulations using the Weather Research and Forecasting (WRF) model demonstrated that the multi-layered wind structure consisted of 1) the sea breeze at an altitude below 0.8 km above mean sea level (AMSL), 2) a layer of weak winds at an altitude of 0.8-1 km AMSL, 3) a return flow of the sea breeze, and 4) a northerly synoptic wind at an altitude above 3 km AMSL. This is the first direct observation of the formation of sharp multi-layered wind structure over Tokyo associated with sea-breeze circulation.

The Aeolian Dust Experiment on Climate Impact (ADEC) was initiated in April 2000 as a joint five-year Japan–China project. The goal was to understand the impact of aeolian dust on climate via radiative forcing (RF). Field experiments and numerical simulations were conducted from the source regions in northwestern China to the downwind region in Japan in order to understand wind erosion processes temporal and spatial distribution of dust during their long-range transportation chemical, physical, and optical properties of dust and the direct effect of radiative forcing due to dust. For this, three intensive observation periods (IOP) were conducted from April 2002 to April 2004. The in situ and network observation results are summarized as follows: (1) In situ observations of the wind erosion process revealed that the vertical profile of moving sand has a clear size dependency with height and saltation flux and that threshold wind velocity is dependent on soil moisture. Results also demonstrated that saltation flux is strongly dependent on the parent soil size distribution of the desert surface. (2) Both lidar observations and model simulations revealed a multiple dust layer in East Asia. A numerical simulation of a chemical transport model, CFORS, illustrated the elevated dust layer from the Taklimakan Desert and the lower dust layer from the Gobi Desert. The global-scale dust model, MASINGAR, also simulated the dust layer in the middle to upper free troposphere in East Asia, which originated from North Africa and the Middle East during a dust storm in March 2003. Raman lidar observations at Tsukuba, Japan, found the ice cloud associated with the dust layer at an altitude of 6 to 9 km. Analysis from lidar and the radio-sonde observation suggested that the Asian dust acted as ice nuclei at the ice-saturated region. These results suggest the importance of dust's climate impact via the indirect effect of radiative forcing due to the activation of dust into ice nuclei. (3) Studies on the aerosol concentration indicated that size distributions of aerosols in downwind regions have bimodal peaks. One peak was in the submicron range and the other in the supermicron range. The main soluble components of the supermicron peak were Na+, Ca2+, NO3−, and Cl−. In the downwind region in Japan, the dust, sea salt, and a mixture of the two were found to be dominant in coarse particles in the mixed boundary layer. (4) Observation of the optical properties of dust by sky-radiometer, particle shoot absorption photometer (PSAP), and Nephelometer indicated that unpolluted dust at source region has a weaker absorption than originally believed. A sensitivity experiment of direct RF by dust indicated that single scattering albedo is the most important of the optical properties of dust and that the sensitivity of instantaneous RF in the shortwave region at the top of the atmosphere to the refractive index strongly depends on surface albedo. A global scale dust model, MASINGAR, was used for evaluation of direct RF due to dust. The results indicated the global mean RF at the top and the bottom of the atmosphere were − 0.46 and − 2.13 W m− 2 with cloud and were almost half of the RF with cloud-free condition.

High-resolution simulations on the vertical transport of dust in a fair-weather condition over desert regions are performed with a cloud-resolving modeling approach. Basic processes relevant to the dust transport are examined by focusing on the role of boundary-layer and cloud convection. Although the model settings are simplified, the simulation well reproduces the diurnal variability of fair-weather convective boundary layer and cloud development observed over a Chinese desert. Dry convective motion within the boundary layer and moist convection above the boundary layer play a significant role in regulating the vertical mixing and transport of dust in the atmosphere, and in enhancing the surface winds and thus the dust emission by the downward transport of high momentum in upper levels. The present modeling framework is useful in understanding the small-scale effects on the vertical dust transport associated with boundary-layer convection and cloud convection in a fair-weather environment.

We analyzed the time series data of dust vertical profiles, observed using polarization elastic lidar, from April 8 t h -21 s t , 2002, during the first intensive observation period of the Aeolian Dust Experiment on Climateimpact (ADEC), in Shapotou, Ninxia Province in China. We conducted the analysis with consideration to the upper atmospheric soundings and surface weather data. The results are summarized as follows. 1) A well-mixed dust layer dominated in the boundary layer sampled from around 11 a.m. until around 1 or 2 a.m. local time (Beijing time). Under well-mixed conditions, the mixed layers grew well with dry convections in the boundary layer, especially during the day and in the early evening. 2) Dry convections developed deeper during synoptic low-pressure conditions because of the systematic upward motions prevalent in the low-pressure systems. Vertical wind shear affected growth of the mixed layer as well, that is, weak vertical wind shear condition was favorable for the growth of the mixed layer. The deepest mixed layer was observed on April 13 t h at a thickness of about 6-km above ground, when the pressure was the lowest, the vertical wind shear was very weak, and the atmosphere was dry. The aspect ratios (horizontal/vertical scale ratios) of the convections decreased under low-pressure and weak-shear conditions. On the other hand, the aspect ratios of the convections increased dramatically under high-pressure and strong-shear conditions, because convection growth was suppressed by systematic down-drafts of the high-pressure system and by strong vertical wind shears.

We propose a retrieval method of Asian dust (Yellow sand or Kosa aerosol) columnar amount around source regions using a near ultraviolet radiometry observation from space. The method simultaneously retrieves an optical thickness and mode radius of Kosa aerosol, and then derives its columnar amount. The method was applied to ADEOS-II/GLI data in the spring of 2003 around Taklimakan desert source region, inland China. The retrieved optical thickness and mode radius were about 0.34 and 1.75 µm, respectively, at a validation site. They are comparable to the in situ observations conducted within the framework of ADEC project. The estimated columnar amount around a validation site is about 2.77 g m-2, which seems reasonable under a relatively calm situation. The method should be further validated with a regional model simulation study, and then it is useful to monitor Asian dust around source regions from space in the future.

We present a development and research of the 2-μm coherent lidar with a conductively-cooled laser-diode-pumped single-frequency Q-switched Tm,Ho:YLF pulse laser developed at the NICT.

The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5° N, 79.2° E), India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms.Key words. Atmospheric composition and structure (pressure, density and temperature). Meterology and atmospheric dynamics (climatology)

The campaign of stratospheric aerosol measurement by balloon-borne optical particle counter was conducted four times from April 1997 to March 1999 at Bandung, Indonesia (6.9°S, 107.6°E). Within a few kilometers above the tropopause low aerosol mixing ratios were observed. The layer of relatively small aerosols (size ranges from 0.15 μm to 0.25 μm and from 0.25 μm to 0.4 μm in radius) resided at high altitudes around or above 30 km, while the layer of relatively large aerosols (size range larger than 0.4 μm in radius) resided around 23 km. Peak mixing ratio of the latter layer decreased year by year, suggesting the layer to be originated from the Pinatubo eruption in 1991. The height of the peak mixing ratio of the relatively small particles was relatively low on October 4, 1998, when the stratosphere above 23 km was in the westerly shear phase of the quasi biennial oscillation.

In order to generate a reference signal used in phase locking of quantum cascade lasers (QCLs) operating in the THz range, we adopted a photonic down-conversion technique. Optical two-tone signals are created by a combination of a Mach-Zehnder-modulator-based flat comb generator (MZ-FCG) and a dispersion-flattened dispersion-decreasing fiber (DF-DDF). THz signals generated from the two-tone signal by using a uni-traveling carrier diode (UTC-PD). We have demonstrated generation of 700 GHz signals, and confirmed that the signal has the C/N ratio of greater than 30 dB and the frequency stability of 10-11 at the averaging time of 1 sec.

Stratospheric aerosols originating from the June 1991 explosive eruptions of Mt. Pinatubo has been observed at Fukuoka with a Nd:YAG lidar. Sudden increase of the aerosols in the vicinity just above the tropopause in July 1991 was followed by the appearance of extraordinary strong scattering layer around 21-22 km height. The volcanic aerosols stratified in two distinct layers merged into a broad layer when the background wind field changed from the easterlies to the westerlies and the bulk of the aerosols arrived. After having taken its maximum in the first winter the aerosol burden decreased monotonously. Superposed on the decrease we can read the seasonal variations associated with the seasonal variation in the wind field and the tropopause height also after the second year. Height of the center of gravity of the aerosols relative to the height of tropopause have been approaching gradually to a constant value.

Laser remote sensing technologies are valuable for a variety of scientific requirements. These measurement techniques are involved in several earth science areas, including atmospheric chemistry, aerosols and clouds, wind speed and directions, prediction of pollution, oceanic mixed layer depth, vegetation canopy height (biomass), ice sheet, surface topography, and others. Much of these measurements have been performed from the ground to aircraft over the past decades. To improve knowledge of these science areas with transport models (e.g. AGCM), further advances of vertical profile are required. JAXA collaborated with NICT and RIKEN started a new cross-sectional 3-year program to improve a technology readiness of the critical 1-micron wavelengths from 2011. The efficient frequency conversions such as second and third harmonic generation and optical parametric oscillation/generation are applied. A variety of elements are common issues to lidar instruments, which includes heat rejection using high thermal conductivity materials, laser diode life time and reliability, wavelength control, and suppression of contamination control. And the program has invested in several critical areas including advanced laser transmitter technologies to enable science measurements and improvement of knowledge for space-based laser diode arrays, Pockels cells, advanced nonlinear wavelength conversion technology for space-based LIDIRs. Final goal is aim to realize 15 watt class Q-switched pulse laser over 3-year lifetime.

In the last decade the precision of coherent Doppler differential absorption lidar (DIAL) has been greatly improved in near and middle infra-red domains for measuring greenhouse gases such as CO2, CH4 and winds. The National Institute of Information and Communications Technology (NICT, Japan) has developed and is operating a CO2 and wind measuring ground-based coherent DIAL at 2.05 μm (4878 cm-1). The application of this technology from space is now considered. In this analysis we study the use of the NICT DIAL for profiling tropospheric water vapour from space. We present the methodology to select the spectral lines and summarized the results of the selected lines between 4000 and 7000 cm-1. The choice of the frequency offset, the pulse energy and repetition frequency are discussed. Retrieval simulations from the line at 4580 cm-1 (2.18 μm) suitable for the boundary layer and the stronger one at 5621 cm-1 (1.78 μm) for sounding the boundary layer and the middle troposphere, are shown.

We have developing two types of 2micron conductive-cooled lasers for wind and CO 2 measurements. One type of lasers is side pumped Tm,Ho:YLF laser operated at 20-40Hz. The laser rod is cooled down to -80C and laser diodes are operated at normal temperature in a vacuum container. With this type of laser, we have built up a coherent lidar system which is used to measure wind and CO 2 concentration. Ho:YLF laser end-pumped by Tm:fiber laser is another type oscillator which will be operated at high repetition rate of 200-300 Hz in normal temperature. The laser will have an amplifier. These lasers are conductive-cooled, solid-state, eye-safe and suitable for space applications.

We report on broadband comb generation using a combination of a Mach-Zehnder-modulator-based flat comb generator (MZ-FCG) and a dispersion-flattened dispersion-decreasing fiber (DF-DDF), as well as MMW signal generation using the MZ-FCG. For application of quantum cascade lasers operating in the THz range, phase-locking techniques are required to stabilize the frequency and the linewidth. Optical combs are good candidate for a reference source in the phase locking, because of the high stability and accuracy of the comb signals. Generation of a 110 GHz signal by photomixing of two-tone signal extracted from an optical comb signal has been demonstrated as a preliminary experiment.

A Low noise superconducting heterodyne receiver at 3THz is developing for atmospheric or astronomical observations. A NbN HEB(Hot Electron Bolometer) with quasi optical planar (spiral or log-periodic) antenna and a THz-QCL(Quantum Cascade Laser) which is used as a local oscillator are fabricated in our laboratory. The receiver noise temperature in double sideband of ∼2800K which is around 19 times of quantum limit is measured.

Excitons, photocarriers, and bias-induced carriers in regioregular poly(3-alkylthiophene) (P3AT) films were investigated using a variety of spectroscopic techniques, such as continuous-wave- (cw-) and femtosecond (fs-) transient photoinduced absorption (PIA) and device modulation (DM) spectroscopies. Comparison between the cw PIA and DM spectra of the poly(3-hexylthiophene) (P3HT) film reveals that photocarriers generated by cw photoexcitation are dominated by localized polarons, whereas charge injection primarily creates delocalized polarons. The photoexcitation intensity dependence of the cw PIA signals demonstrates that both localized and delocalized photogenerated polarons obey a bimolecular recombination process under cw photoexcitation. The proportion of polarons generated by cw photoexcitation in the P3HT film is estimated to be 1/(1$+$0.137 ${I}^{1/2}$) for $I$ (mW/cm${}^{2}$) by comparison of the spectral intensities between the DM and cw PIA spectra. DM spectroscopy reveals that both localized and delocalized polarons rapidly increase at a rise point of the bias current. The cw PIA bleaching spectra of P3AT films are shown to vary with the length of the alkyl sidechains of P3AT and be almost reproduced using a single Huang-Rhys factor. The Huang-Rhys factors obtained reveal a trend that the electron-phonon couplings of final exciton migration sites become strong with the increase in the interlamella distance in the P3AT film, which indicates that interlamella couplings affect the electron-phonon couplings of the migration sites located at two-dimensional lamellas.

Information on dust emission and its transportation in non-dust storm days is quite scarce. In this study, a laser Ceilomter was used to monitor the dust vertical profile for a whole year and the meteorological observation and sounding data were obtained for mixing layer analysis. The results indicate that the dust are prone to accumulate near ground at night and early morning, while begin to attenuate and weaken after sunrise. The diurnal change for summer half year is rather greater than that for winter half year. It can be concluded that dust transport is still possible through middle troposphere in clear days forced by convection strength, which results in the dust vacancy near ground in the afternoon. As the dusts transported through middle troposphere may have finer particles than dust storm, its environmental and climatic impacts cannot be ignored.

Dust profiles have been observed by a laser Ceilometer (MEISEI CT25K) at Shapatou, China which is located at the edge of the Tengger Desert. The observation was conducted throughout one year of 2004 successfully and showed the behaviors of the atmospheric dust profile from near the surface to about the 1000-m height. The results of the observation were compared with several other meteorological data, such as surface, radio sonde and sky radiometer measurements. In particular, the dust profiles observed on calm and fair weather days were analyzed and compared with other meteorological data. The dust profile at the calm and fare weather day in the desert area is mainly influenced by thermal convection due to strong surface heating in the warm season. The dust amount lower than the 500-m height decreases in the daytime and recovers in the nighttime. The data of the sky radiometer shows that the total amount of the dust at the same calm and fair-weather days is almost constant during the daytime. The observational evidence was explained in the paper.

[1] A series of high-resolution simulations explicitly resolving diurnally varying convective motion is performed for investigating the dynamical processes of dust emission and transport induced by boundary layer and cumulus convection under fair-weather conditions in a midlatitude desert area. The simulation set examines the sensitivity of the dust dynamics to vertical wind shear, upper level wind speed, and moist convection. The simulated results qualitatively capture the diurnal variation of the dust layer observed by lidar in a desert area in northern China. Dry convection plays a primary role in vertically mixing dust within the boundary layer. If cumulus convection also comes into play, mass concentration of dust increases not only within the boundary layer but also in the free troposphere. A coupled effect of dry and moist convection is important because convection is more enhanced with the coupled effect than without moist processes and in addition transports upper level higher momentum down to the surface, intensifying surface winds and hence dust emission. A wind speed exceeding the threshold for surface dust emission is necessary at the upper levels of the daytime boundary layer for the surface wind enhancement. Although the amount of dust lifted is much smaller during a single diurnal cycle of fair weather than is associated with a single case of synoptic disturbances, the total amount of dust emission due to fair-weather processes may not be neglected in a longer timescale. This suggests that a proper parameterization for dry and moist convection in fair weather needs to be employed in large-scale simulations.

For the study of stratospheric aerosol over the Tropics, balloon-borne OPC measurements have been made six times from April 1997 to March 2000 at Bandung, Indonesia (6.9?S, 107.6?E) where Lidar measurements have also been made since early 1997. Correlative measurements of Lidar and OPC were conducted on March 25,1998 and August 23, 1999. Results of the latter measurement were compared in this paper. The profile of back scattering ratio measured by Lidar almost represents a vertical distribution of small particles having radii smaller than O.4?m. We calculated back scattering coefficients from the results of OPC measurement. The calculated and measured back scattering coefficients were not consistent completely but not so unreasonable.

Tropospheric aerosols effects on climate in directly through various cloud formation, the lidar has been used to study the composition of many particles mixing in the atmosphere including to study the aerosol and cloud. Currently, it has many types of lidar systems depending on the purpose of measurements. In this report, the ground-based lidar system was established at King Mongkut's Institute of Technology Ladkrabang (KMITL), THAILAND to study and measure the aerosol in boundary layer and cirrus clouds in the tropopause region. The aerosol measurement is in the form of scattering ratio whereas the signal depolarization has been applied to identify layers of cirrus clouds. The lidar system consists of laser source (Nd:YAG) with second harmonic wavelength, 28 cm Schmidt-Cassegrain telescope, photomultiplier tube (PMT) and data acquisition system.

Variation of stratospheric aerosol affects atmospheric minor constituents and climate through changes in the radiation field as well as by dynamic and chemical processes. In order to estimate the impact quantitatively, it is very important to observe stratospheric aerosol vertical distribution and their lime variation To obtain stratospheric aerosol especially in equatorial region a lidar was installed in Bandung (6.9° S; 107.7° E) Indonesia under collaboration between National Institute of Aeronautic and Space (LAPAN), Communication Research Laboratory of Japan and Meteorological Research Institute of Japan. The Lidar transmitter system employ fundamental (1064 nm), second harmonic (532 nm) and third harmonic (355 am) wavelengths ofNd: YAG laser are transmitted. The second harmonic backscatter light and its N2 ranian backscatter light (607 am) are collected by a 28 cm and a 35 cm diameter telescope. In 35 cm telescope system, upper troposphere and stratosphere are observed by photon counting. 532 am light component polarized parallel and perpendicular to the laser light are separately observed to get information about shape of aerosol. Bandung is located at around 750 m above mean sea level and it is surrounded by mountains, therefore clouds are easily formed especially between 10 and 17 km height. Stratospheric aerosol over Bandung are spreaded between 18 and 35 km in altitude and form more than 1 sub layer, below 30 km and upper 30 km. The maximum aerosol concentration is obtained around 22.5 km height. To understand the seasonal variation of stratospheric aerosol we integrated the backscattering coefficients for altitude range 18-35 km and it was obtained that the stratospheric aerosol concentration in 1997 was higher than in 1999. The integrated backscattering coefficient in June was higher than in August. But seems the seasonal variation of integrated backscattering coefficient in Bandung does not so clear determined yet.

We are developing a new remote-operational lidar system, with multimedia technology. This system reduces the necessity to go to the remote place. The system is located in Rikubetsu (43.3N, 143.5E), in north portion of Japan, which is a famous place for a fair weather all the year round. We use SHG of Nd:YAG laser and receive P, S components of Mie back scatter with photon counter. All necessary controling of instruments such as the roof of the housing, tilt mirror, laser, photon counters, oscilloscope, and so on, are done by personal computers. Operator uses a web browser from a remote site to operate the lidar system, with monitoring the weather and the total state of the system. There is another workstation which runs a newly developed desktop video conference system. With these system, several persons can simultaneously observe and watch the data, discuss with each other. We can now observe the aerosols more frequently than ever. This will let us to get precise information about the aerosols in north regions of Japan.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The observation of atmosphere dust in China's desert show that there is a continuous dust layer always existed in lower atmosphere under the height of 5 km. The dust concentration in the layer is changed with altitude and season. According to the Lidar data analysis the backscattering ratio value changes in the range of 2.5-5.5 in clear weather. The higher value ofthe ratio can be extended to the height about the height of3.5 km. The dust concentration is reduced sharply over 3.5 km. In the range of 15-20 km height, an aerosol layer is often observed in Shapotou region. The maximum backscattering ratio usually appears in 1 5- 1 8 km. The value is approximately 1.2.

Lidar and Optical Particle Counter (OPC) measurements were performed in the Canadian Arctic and in the Indonesian Tropical region. The observations yielded very interesting and important results about the features of the latitudinal difference in the stratospheric aerosols. Besides the latitudinal difference, the aerosol distributions and their time variation showed unique characteristics in each of the regions. In Arctic winter, the aerosol concentration varies frequently day-to-day. In the Tropical region, the aerosol distribution and the vertical transport is, probably, controlled by the variation of the circulation pattern in the lower stratosphere related to the QBO in the tropical stratosphere. Based on the results of the simultaneous measurements by lidar and OPCs, we estimated surface area density, volume density, S-parameter (extinction to backscatter ratio), backscatter to surface area conversion factor, and backscatter to volume conversion factor of the stratospheric aerosols at 20km-altitude in the Arctic and Tropical regions.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Height profiles of temperatures and winds of the middle atmosphere between 30km to 60km are observable only by Rayleigh lidar and Rayleigh Doppler lidar except for rocket sounding which is expensive and not suitable for continuous measurements. We developed a Rayleigh lidar system and it is now working well for temperature observations of the Arctic middle atmosphere at Poker Flat Research Range near Fairbanks, Alaska (65.1N, 147.5W). A comparison of lidar data and balloon sonde data showed good agreement in overlapped altitudes. A Rayleigh Doppler lidar for wind measurements of the middle atmosphere is under the phase of development. The expected accuracy in measurements of horizontal winds up to an altitude of 60km is smaller than 6m/s in 2hours observation. The system will be also operated at Poker Flat. The combination of these lidars and radars installed at Poker Flat give us chances of simultaneous observations of the structure and dynamics of the atmosphere in broad range of altitudes. Here, we give descriptions of the Rayleigh lidar and the Rayleigh Doppler lidar for the observations of the Arctic middle atmosphere at Poker Flat.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We installed a lidar system for observations of the stratospheric aerosols at Bandung, Indonesia on November 1996. The system employed the second harmonic wavelength (532nm) of Nd:YAG laser. We can measure scattering ratio and depolarization of 532nm, and Raman scattering of N 2 (607nm). The system works well and the stratospheric aerosols were detected between 18km and about 35km. Cirrus clouds are always observed between 10km and tropopause and area around tropopause is clear except for cloud-like structures. Integrated backscattering coefficient (IBC) of the stratospheric aerosols in 1997 is about 6x10 -5 sr -1 level and smaller than the value observed in mid-latitude, corresponding to the higher tropopause in the equatorial region. Variation of IBC at Bandung seems to be small. It is yet not clear whether current aerosol load is background level or not. We need more long period observations to discuss about seasonal, QBO, and long term variation of aerosol load.

PSCs play important roles not only in global climate change through its own effects on radiation budget of the earth but also in ozone depletion through heterogeneous chemical processes which occur on the surfaces of the PSCs. The mechanisms of the processes, however, have never clarified enough because of scarcity of data especially in arctic stratosphere. Japanese lidar group started operating Japan Arctic Lidar Network in arctic region in 1993, and plenty of lidar data have been obtained so far. The PSC lidar at Eureka station (80° N, 86° W) in Canadian arctic forms a link in the chain of the network. Adding to the lidar observation, we started to perform balloonborne observation of the PSCs in the last winter. In this presentation, the results of the balloonborne and lidar observation of PSCs are shown.

Ultrafast photoexcitation dynamics of the bodipy-anthracene-radical triad of the photoexcited quartet state and its control compounds were investigated by fs-laser spectroscopy. The fs-spectroscopy successfully unveiled complicated dynamical processes consisting of electron-transfer, energy-transfer, and charge separated ion-pair generation. Based on the results, a pathway leading to the high-spin state generation is discussed.

Bleaching probe spectroscopy performed for regioregular poly(3-hexylthiophene) diodes reveals that coexistent morphological phases determine the conducting and optical properties of conjugated polymer films. Photoinduced absorption measurements demonstrate that exciton migration occurs from lamella aggregates to morphological sites consisting of quasiuncoupled chains and that the latter sites determine steady-state photophysical properties. Spectroscopy synchronized with diode operation reveals that the morphological locations of injected carriers in polymer diodes vary with the applied bias.

Ground-based UV DIAL lidar observations of the springtime Antarctic ozone were numerically simulated with realistic ozone and aerosol profiles, using an excimer Raman ozone lidar system whose performance is the same as that at Kyushu University. Computed results show that the ozone profiles can be measured when polar stratospheric clouds (PSC) do not exist. When PSC do exist, the profile may also be observed up to the bottom of the stratosphere. However, in this condition simultaneous co-observation with other observation methods is desirable, since the lidar-observed ozone profile is sensitive to the PSC optical properties.