Proceedings Volume 7859

Remote Sensing of the Atmosphere and Clouds III

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Proceedings Volume 7859

Remote Sensing of the Atmosphere and Clouds III

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Volume Details

Date Published: 6 December 2010
Contents: 6 Sessions, 14 Papers, 0 Presentations
Conference: SPIE Asia-Pacific Remote Sensing 2010
Volume Number: 7859

Table of Contents

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Table of Contents

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  • Front Matter: Volume 7859
  • Atmospheric Sounding and Trace Gas Species Remote Sensing
  • Cloud and Aerosol Remote Sensing Including Profiling Techniques I
  • Cloud and Aerosol Remote Sensing Including Profiling Techniques II
  • Validation Field Campaign: In situ Data Analysis
  • Poster Session
Front Matter: Volume 7859
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Front Matter: Volume 7859
This PDF file contains the front matter associated with SPIE Proceedings Volume 7859, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.
Atmospheric Sounding and Trace Gas Species Remote Sensing
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Assessment of the calibration performance of Meteosat-8/9 and MTSAT-1R visible channels using cloud targets (Withdrawal Notice)
This paper was presented at the SPIE conference indicated above and has been withdrawn from publication at the request of the authors.
Comparison of IASI temperature and moisture retrievals with radiosonde measurements and numerical model outputs over East Asia
Eun-Han Kwon, Byung-Ju Sohn, Ahyoung Lim, et al.
Temperature and moisture profiles retrieved from Infrared Atmospheric Sounding Interferometer (IASI) were evaluated by using radiosonde observations and model forecasts over East Asia. We used the level 2 products provided by National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) for IASI retrievals. Numerical model outputs from Regional Data Assimilation and Prediction System (RDAPS), Korea Weather Research and Forecasting (KWRF), and UK Met Office model (UM) were also matched with the satellite and radiosonde profiles for examining the model performances, in comparison with satellite data. The statistics of temperature and water vapor profiles were calculated by using the collocated radiosonde measurements as a reference. Both of temperature and moisture retrievals from satellite showed degraded performances over land and in dry conditions. Moist bias of the lower-troposphere is significant in dry condition especially over land, whereas dry bias of the mid-troposphere is significant in moist condition both over land and ocean. Based on the validation results, we discuss which factors can contribute to the improvement of the retrieval results over East Asia.
Cloud and Aerosol Remote Sensing Including Profiling Techniques I
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Cloud sciences using satellite remote sensing, cloud growth model, and radiative transfer
In recent years, it has been revealed that the cloud microphysical properties such as cloud particle radii obtained from satellite remote sensing were of apparent values. A combined use of passive and active sensor has gradually revealed about what we observed using passive imager thorough the vertical information of clouds obtained from active sensors. For understanding the process of cloud growth in nature, model that simulates cloud droplet growth is also needed. Observation results obtained from the satellite remote sensing are used for validating model such as cloud resolving model and spectral-bin microphysics cloud model. Vice-versa, models are used for understanding the process that are hidden in satellite-remote sensing results. We are aiming consistent understanding of clouds with observation and modeling. In this paper, we will introduce a preliminary result of multi-sensor view of warm water clouds and we will review our research strategy of cloud sciences, using satellite remote sensing, the cloud growth model, and the radiative transfer.
Carbonaceous aerosols over Siberia and Indonesia with GOSAT/CAI
Itaru Sano, Mizuki Tanabe, Takamasa Kamei, et al.
Carbonaceous aerosols absorb the visible light, and hence play an important role for climate study. This work intends to develop an algorithm for extracting the optical properties of biomass burning aerosols based on the cloud aerosol imager (CAI) on board greenhouse gases observing satellite (GOSAT). Our algorithm is mainly based on the radiative transfer calculations in the atmosphere involving various kinds of aerosols. This algorithm has been examined for several forest fire events as Siberia in Russia and Kalimantan Island in Indonesia in 2009. As results, aerosol optical thickness (AOT) and single scattering albedo (SSA) at a wavelength 0.55 μm are retrieved. It is of interest to note that AOT takes the values larger than ~2 over Siberia plume, and ~5 or more over the plume in Kalimantan of Indonesia, and the values of SSA are low such as ~0.8 to ~0.9 over core region of the plume. In addition, the AOT results are partially validated by MODIS level-2 products (MYD04).
Cloud and Aerosol Remote Sensing Including Profiling Techniques II
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Improved Goddard profiling (GPROF) database over the Korean Peninsula and its impact on TRMM TMI rainfall
Based on the comparison of TMI measurements and the AWS rain rates, characteristics of rain systems over the Korean Peninsula during summer were examined. It was found that the TMI brightness temperatures (TBs) at high frequency (85 GHz) are generally higher than those in GPROF database for the same rain rate. With these characteristics kept in mind, cloud resolving model simulations were performed by modifying intercept values in the Marshall-Palmer size distribution relationship. The intercept values of graupel and snow were assumed to twice the default value (snow: 1.0 × 108 m-4, Graupel: 4.0 × 106 m-4). Microwave brightness temperatures at passive microwave radiometer frequencies and vertical reflectivity at precipitation radar frequency are calculated by repeated application of the one-dimensional version of Eddington's approximation1. The hydrometeor profiles were selected by comparing with TRMM PR reflectivities. By adding those selected profiles to the convective profiles of GPROF database, we modified database for the rain retrieval over the Korean Peninsula. Rainfall retrievals by using the new database show that quality is significantly improved, indicating the need of algorithm locally more suitable.
Validation Field Campaign: In situ Data Analysis
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Relationship between aerosol characteristics and altitude based on multi-measurements and model simulations
Makiko Nakata, Tsubasa Ohshima, Toshiyuki Fujito, et al.
The suspending particulate matter (PM2.5) is a typical indicator of small particles in the atmosphere. Accordingly in order to monitor the air quality, sampling of PM2.5 has been widely undertaken over the world, especially in the urban cities. On the other hand, it is known that the sun photometry provides us with the aerosol information, e.g. aerosol optical thickness (AOT), aerosol size information and so on. Simultaneous measurements of PM2.5 and the AOT have been performed at a NASA/AERONET (Aerosol Robotics Network) site in urban city of Higashi-Osaka in Japan since March 2004, and successfully provided a linear correlation between PM2.5 and AOT in separately considering with several cases, e.g. usual, anthropogenic aerosols, dust aerosols and so on. This fact suggests that the vertical distribution also should be taken into account separately for each aerosol type. In this work, vertical profiles of atmospheric aerosols are considered based on combination use of photometric data with AERONET, LIDAR (Light Detection and Ranging) measurements and model simulations.
A study of impact of Asian dusts and their transport pathways to Hong Kong using multiple AERONET data, trajectory, and in-situ measurements
Man Sing Wong, Janet Elizabeth Nichol, Kwon Ho Lee
Hong Kong, a commercial and financial city located in south-east China has suffered serious air pollution for the last decade due largely to rapid urban and industrial expansion of the cities of mainland China. However, the potential sources and pathways of aerosols transported to Hong Kong have not been well researched due to the lack of air quality monitoring stations in southern China. Here, an integrated method combining the AErosol RObotic NETwork (AERONET) data, trajectory and Potential Source Contribution Function (PSCF) modeling is used to identify the potential transport pathways and contribution of sources from four characteristic aerosol types. Four characteristic aerosol types were defined using a total of 730 AERONET data measurements between 2005 and 2008. They are coastal urban, polluted urban, dust (likely to be long distance desert dust), and heavy pollution. Results show that the sources of polluted urban and heavy pollution are associated with industrial emissions in southern China, whereas coastal urban aerosols have been affected both from natural marine aerosol and emissions. The PSCF map of dust shows a wide range of pathways followed by east- and south-eastwards trajectories from northwest China to Hong Kong. Although the contribution from dust sources is small compared to the anthropogenic aerosols, a serious recent dust outbreak has been observed in Hong Kong with an elevation of the Air Pollution Index to 500, compared with 50-100 on normal days. Therefore, the combined use of clustered AERONET data, trajectory and the PSCF models can help to resolve the longstanding issue about source regions and characteristics of pollutants carried to Hong Kong.
Poster Session
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The automatic storm recognition, the track, and the early warning use the FY-2 satellite data
Yuling Liu, Sen Li, Jianwen Liu, et al.
Based on the data from FY-2 meteorological satellite, this study investigates the potential of the satellite deep convection index and infrared multi-spectrum brightness temperature in identifying thunderstorm systems. To track the thunderstorm, we adopt the area overlap algorithm improved through the optical flow method. Based on these algorithms and continuous automatic tracking results, we seek to predict the location of thunderstorms by using linear extrapolation. It is proved that the combined usage of those algorithms is effective for thunderstorm identification, tracking and early-warning.
Detection properties of dust and sandstorms by using AVI of MODIS data
The detection properties of dust and sandstorms (DSS) by using AVI are examined. The aerosol vapor index (AVI) is defined as AVI=T12-T11, where T12 and T11 are the brightness temperatures respectively at 12μm and 11μm wave lengths. MODIS data of Terra/Aqua satellites from China to Japan in April 2006 are used. The AVI vs. T11 scatter charts in narrow regions are made. The narrow region means the region which is smaller than about 100km × 100km. Gu et al. (2003) gave a BTD vs. T11 chart which was based on the radiative transfer calculation in the case of the existence of DSS layer between the ground and the satellite, where BTD=-AVI. The AVI vs. T11 scatter charts are compared with the true-color images, the T11 images, the AVI images and the result by Gu et al. The results are as follows: (1) The larger the AVI value is, the larger the optical thickness of DSS is, in the case of narrow region on land and sea with DSS that does not include cloud. The AVI value decreases, in the case of narrow region with DSS that includes cloud. (2) When the DSS is consecutive on land and sea, the AVI value on the land near the boundary of land and sea is about 0.2-2.3K higher than that on the sea, because of the radiative characteristics of land and sea. The AVI value of a pixel (1km2) on the boundary of land and sea is changed by the ratio of land area and sea area.
The calibration of Microtops II sun photometers over ocean
Aerosol plays important on the climate and environment. Aerosol parameter, such as optical thickness, is usually measured by the 5-channel hand-held MICROTOPS II sun photometer and the calibration coefficients of instruments measurements play a vital role in determining the accuracy of the aerosol optical thickness. However, long time usage and some clean operation of the MICROTOPS II sun photometer maybe make the sensitivity decline or lead some system excursion. It needs to update calibration constants annually to obtain some precise aerosol optical thickness. It is fussy that the general method use Langley-plot technique in clear and stable atmosphere condition or standard lamp in laboratory. According to marine atmosphere status and measurement conditions, the measurement under relative stable atmosphere condition on Dec 6, 7 2008 is selected as calibration experiment. By analyzing the aerosol optical thickness measured by the instrument with factory calibration constants, it is certain that the variety of atmosphere is stable or the variety of atmosphere optical thickness is slowly linear decreasing or increasing by the reorganization of measurements. The three continuous measurements are set as a group. Using similar Langley plot method with those groups, a new method to calibrating the 5-channel MICROTOPS II sun photometer which is named as SIO maritime measurement calibration method is presented. The calibration coefficients at five wavelengths is obtained by the new method and compared with the factory calibration and Langley plot method. It shows that the proposed calibration way can be conduct handily in the common atmospheric environment and maritime observation. It can provide good aerosol optical thickness at each measurement using this way.
Monitoring middle-atmospheric water vapor over Seoul by using a 22 GHz ground-based radiometer SWARA
Soohyun Ka, Evelyn de Wachter, Niklaus Kaempfer, et al.
Water vapor is the strongest natural greenhouse gas in the atmosphere. It is most abundant in the troposphere at low altitudes, due to evaporation at the ocean surface, with maximum values of around 6 g/kg. The amount of water vapor reaches a minimum at tropopause level and increases again in the middle atmosphere through oxidation of methane and vertical transport. Water vapor has both positive and negative effects on global warming, and we need to study how it works on climate change by monitoring water vapor concentration in the middle atmosphere. In this paper, we focus on the 22 GHz ground-based radiometer called SWARA (Seoul Water vapor Radiometer) which has been operated at Sookmyung women's university in Seoul, Korea since Oct. 2006. It is a joint project of the University of Bern, Switzerland, and the Sookmyung Women's University of Seoul, South Korea. The SWARA receives 22.235 GHz emitted from water vapor spontaneously and converts down to 1.5 GHz with +/- 0.5 GHz band width in 61 kHz resolution. To represent 22.235 GHz water vapor spectrum precisely, we need some calibration methods because the signal shows very weak intensity in ~0.1 K on the ground. For SWARA, we have used the balancing and the tipping curve methods for a calibration. To retrieve the water vapor profile, we have applied ARTS and Qpack software. In this paper, we will present the calibration methods and water vapor variation over Seoul for the last 4 years.
Climate affected by dust aerosol over arid region of Makkah, Saudi Arabia
Aerosols play an important role in the global climate balance, and therefore they could be important in climate change. Natural variations of aerosols, especially due to dust storm are recognized as a significant climate forcing, that is, a factor that alters the Earth's radiation balance and thus tends to cause a global temperature change. Aerosol optical depth, τ(λ) is the most comprehensive variable to characterize aerosol due to atmospheric pollution. The aerosol optical properties in Makkah observed during dust period (March-May) from 2006 to 2009 had been presented in this study. Aerosol optical depths at all wavelengths showed a sharp increase during major dust outbreak in spring when compared with the average for the season. For example at Makkah, aerosol optical depths increase from the spring average value of 0.43±0.02 at 550 nm to values >0.70 during major dust event days in 2006. These tend to increasingly of temperature during this period as results of absorbing aerosol effect. In this paper, we used AOD data from Terra MODIS to evaluate the trend of dust aerosol events in Makkah throughout 4 years dataset with supported data of subtype of aerosol and air temperature from CALIPSO and MERRA respectively. The higher values of AOD are corresponding to the low visibility due to presents of high concentration of dust.
Multiple light scattering calculations for aerosol retrieval
Sonoyo Mukai, Takuma Yokomae, Makiko Nakata, et al.
In this work we focus on aerosol retrieval in the heavy events such as dust storm and biomass burning plume. It is natural to consider that incident solar light multiply interacts with the atmospheric aerosols due to dense radiation field in the aerosol event, that is to say the optical thickness of Earth atmosphere increases too much to do sun/sky photometry from surface-level. However the space-based observations are available for monitoring the atmospheric aerosols even in the heavy aerosol events. Here retrieval algorithms from space for such aerosol events are proposed. In practice, appropriate index for detection of dust storm or biomass burning plume, diagnostic method of core part of the aerosol event, and simulation code of radiative transfer for semi-infinite atmosphere model are newly developed. In this work, the space- or surface-based measurements, multiple scattering calculations and model simulations are synthesized together for aerosol retrieval.