SPIE Asia-Pacific Remote Sensing最新文献

{"title":"Observation of ionospheric disturbances for earthquakes (M>4) occurred during June 2013 to July 2014 in Indonesia using wavelets","authors":"R. Revathi, S. Lakshminarayana, S. Koteswara Rao, K. Ramesh, K. Uday Kiran","doi":"10.1117/12.2227301","DOIUrl":"https://doi.org/10.1117/12.2227301","url":null,"abstract":"Seismo-ionospheric perturbations are extensively studied for large earthquakes occurred over various parts of the world. Specific signatures of these natural events are observed in the Total electron content (TEC) data prior to their occurrence. Analysis of these natural disasters occurring at a specific location will help in their accurate detection and prediction. In this paper the Java region of Indonesia comprising of a belt of volcanic mountains, where a considerable number of events to analyze their characteristics in the ionosphere are considered for study. This region of Indonesia has an International Global Navigation Satellite System Station at Bakosturnal, Indonesia. Vertical total electron content data on the earthquake day is analyzed for 13 events occurred during June 2013 to July 2014.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114499357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of the space based remote sensing for NWP","authors":"S. Indira Rani, D. Srinivas, J. George","doi":"10.1117/12.2223595","DOIUrl":"https://doi.org/10.1117/12.2223595","url":null,"abstract":"Space based remote sensing provides continuous and contiguous information about the state of the Earth-atmosphere system which is crucial to Numerical Weather Prediction (NWP). Since 1960, after the successful launch of the first weather satellite TIROS-1, a range of weather satellites carrying different sensors to monitor atmospheric parameters used in NWP have not only improved the weather forecasting but also enhanced our understanding of the physical and dynamical processes in the atmosphere. Satellite based earth observing system provides data in different spatial and temporal resolutions from the geostationary and low-earth orbits. This review briefly describes general introduction to both active and passive satellite remote sensing, various satellite sensors used for NWP applications in the past an d in the present and observational data requirements for future NWP models. The presentation also includes the importance of re-calibration of satellite observations of the past, especially the data from Indian satellites (INSAT series) which can be used in the atmospheric reanalysis in the future.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122795667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of MODIS/CERES downwelling shortwave and longwave radiation over global tropical oceans","authors":"V. T., H. Rahaman, M. Ravichandran, S. Ramakrishna","doi":"10.1117/12.2228041","DOIUrl":"https://doi.org/10.1117/12.2228041","url":null,"abstract":"In the present work, we have evaluated the satellite estimated daily downwelling shortwave (QI) and Longwave (QA) radiation from Moderate Resolution Imaging Spectrometer (MODIS) /Clouds and the Earth's Radiant Energy System (CM) with moored buoy observations of Global Tropical Moored Buoy Array (GTMBA) during 2001-2009. The global observed mean of QI and QA in GTMBA (CM) are 228 (233) W/m2 and 410 (405) W/m2 respectively. The mean QI shows a positive bias (~3- 7 W/m2) whereas QA underestimates with a mean negative bias of ~3-6 W/m2 in the tropical Pacific, Atlantic and Indian Ocean. CM underestimates the buoy observed variability in both QI and QA in all the tropical oceans. The correlation coefficient (CC) values in QI (Qa) are 0.79(0.88) 0.79(0.84) and 0.81(0.94) over the Pacific, Atlantic and Indian ocean respectively. The Root Mean Square Error (RMSE) values in QI ranged between 35-43 W/m2 with lowest values in the Atlantic Ocean and highest in the Indian Ocean. The RMSE values in QA are less as compared to QI and it is ~9 W/m2 in all the tropical ocean. The spatial distributions of QI and QA shows seasonality with lower and higher values coinciding with the Inter Tropical Convergence Zone(ITCZ) locations in the QI and QA.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125472643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lidar studies on climate sensitivity characteristics of tropical cirrus clouds","authors":"G. S. Motty, G. S. Jayeshlal, M. Satyanarayana, V. P. Mahadevan Pillai","doi":"10.1117/12.2223301","DOIUrl":"https://doi.org/10.1117/12.2223301","url":null,"abstract":"The cirrus clouds play an important role in the Earth’s radiation budget due to their high frequency of occurrence, non-spherical ice crystal formations, and variability in the scattering/absorption characteristics. Mostly, the tropical cirrus clouds are considered as greenhouse modulators. Thus the parameterization of tropical cirrus clouds in terms of the micro- physical properties and the corresponding radiative effects are highly important for the climate studies. For characterizing the radiative properties of cirrus clouds, which depend on the size, shape and number of the ice crystals, the knowledge of extinction coefficient (σ) and optical depth (τ) are necessary. The σ provides information needed for understanding the influence of the scatterers on the radiative budget whereas the τ gives an indication on the composition and thickness of the cloud. Extensive research on the tropical cirrus clouds has been carried out by using a ground based and satellite based lidar systems. In this work, the characteristics of tropical cirrus cloud derived by using the data from the ground based lidar system over the tropical site Gadanki [13.5°N, 79.2°E], India during 2010 are presented. Some of the results are compared with those obtained by us from satellite based CALIOP lidar observations of the CALIPSO mission. It is observed that there is a strong dependence of the some of the physical properties such as occurrence height, cloud temperature and the geometrical thickness on the microphysical parameters in terms of extinction coefficient and optical depth. The correlation of both the σ and τ with temperature is also observed.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132450913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Source apportionment of absorbing aerosols in the central Indo-Gangetic Plain","authors":"Aditya Vaishya, Prayagraj Singh, S. Rastogi, S. Babu","doi":"10.1117/12.2223580","DOIUrl":"https://doi.org/10.1117/12.2223580","url":null,"abstract":"Atmospheric aerosols in the Indo-Gangetic Plain (IGP) depicts high spatial and temporal heterogeneity in their radiative properties. Despite the fact that significant advancement in terms of characterizing aerosols radiative and physiochemical properties in the IGP have been made, information regarding the organic content towards total absorbing aerosol budget is lacking. In the present study we have analyzed two years of aerosol spectral light absorption measurements from the central-IGP, Gorakhpur (26.75°N, 83.38°E, 85m amsl), in order to study their seasonal behavior and to quantify their magnitude in terms of absorbing aerosols loading and source speciation. Remote sensing data in the form of 'Cloud corrected Fire Count' from MODIS Terra and 'Absorption Aerosol Index' from OMI satellites platform have been used to identify absorbing aerosol source regions. Spectral absorption analysis reveals a four-fold enhancement in absorption in the winter (W) and the post-monsoon (PoM) seasons at UV wavelengths as compared to 880 nm on account of increased biomass aerosol contribution to total absorbing aerosol load. Despite having higher fire events and absorption aerosol index, both indicating high biomass burning activities, in the pre-monsoon (PM) season, aerosols from the biomass sources contribute ~ 27% during the W and the PoM seasons as against ~17% in the PM season to the total absorbing aerosol content. This is due to near stagnant wind conditions and shallow height of air masses travelling to the central IGP in the W and the PoM seasons.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126513967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of hydrometeors on the microphysical parameterization in the WRF modelling system over southern peninsular India","authors":"A. R. Ragi, M. Sharan, Z. Haddad","doi":"10.1117/12.2223669","DOIUrl":"https://doi.org/10.1117/12.2223669","url":null,"abstract":"This study examines the influence of Purdue-Lin microphysical parameterization scheme (Lin et al.,1983) on quantitative precipitation for pre-monsoon/monsoon conditions over southern peninsular India in the Weather Research and Forecasting (WRF) model. An ideal microphysical scheme has to describe the formation, growth of cloud droplets and ice crystals and fall out as precipitation. Microphysics schemes can be broadly categorized into two types: bin and bulk particle size distribution (Morrison, 2010). Bulk schemes predict one or more bulk quantities and assume some functional form for the particle size distribution. For better parameterization, proper interpretation of these hydrometeors (Cloud Droplets, Raindrops, Ice Crystals and Aggregates, Rimed Ice Particles, Graupel, Hail) and non-hydrometeors (Aerosols vs. Condensation Nuclei vs. Cloud Condensation Nuclei vs. Ice Nuclei) is very important. The Purdue-Lin scheme is a commonly used microphysics scheme in WRF model utilizing the “bulk” particle size distribution, meaning that a particle size distribution is assumed. The intercept parameter (N0) is, in fact, turns out to be independent of the density. However, in situ observations suggest (Haddad et al., 1996, 1997) that the mass weighted mean diameter is correlated with water content per unit volume (q), leading to the fact that N0 depends on it. Here, in order to analyze the correlation of droplet size distribution with the convection, we have carried out simulations by implementing a consistent methodology to enforce a correlation between N0 and q in the Purdue-Lin microphysics scheme in WRF model. The effect of particles in Indian Summer Monsoon has been examined using frequency distribution of rainfall at surface, daily rainfall over the domain and convective available potential energy and convective inhibition. The simulations are conducted by analyzing the maximum rainfall days in the pre-monsoon/monsoon seasons using Tropical Rainfall Measuring Mission (TRMM) accumulated rainfall data for 24 hours.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116539106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural analysis of tropical cyclone using INSAT-3D observations","authors":"N. Jaiswal, C. Kishtawal","doi":"10.1117/12.2223508","DOIUrl":"https://doi.org/10.1117/12.2223508","url":null,"abstract":"The continuous observations from visible and thermal infrared (TIR) channels of geostationary satellites are highly useful for obtaining the features associated with the shape and dynamics of cloud structures within the tropical cyclones (TCs). As TC develops from an unstructured cloud cluster and intensifies, the cloud structures become more axisymmetric around the centre of the TC. To better understand the structure of TC during different stages of its evolution i.e. from its cyclogenesis to maturity and dissipation, the continuous satellite observations plays a key role. The high spatial and temporal resolution observations from geostationary satellites are very useful in order to analyze the cloud organization during the cyclogenesis. The gradient of the brightness temperatures measures the level of symmetry of each structure, which characterizes the degree of cloud organization of the TC. In the present work, the structural analysis of TC during its life period using the observations from Indian geostationary satellite INSAT-3D has been discussed. The visible and TIR observations from INSAT-3D satellite were used to fix the center position of the cyclone which is an input for the cyclone track and intensity prediction models. This data is also used to estimate the intensity of cyclone in the advanced Dvorak technique (ADT), and in the estimation of radius of maximum winds (Rmax) of TC which is an essential input parameter for the prediction of storm surge associated to the cyclones. The different patterns of cloud structure during the intensification stage, eye-wall formation and dissipation have been discussed. The early identification of these features helps in predicting the rapid intensification of TC which in turn improves the intensity predictions.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128628679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of AIRS and AMSU sounding products in regional numerical weather simulation","authors":"Shen-Cha Hsu, Chian‐Yi Liu, Szu-Chen Kuo","doi":"10.1117/12.2224473","DOIUrl":"https://doi.org/10.1117/12.2224473","url":null,"abstract":"The initial and boundary conditions are critical to the numerical weather prediction (NWP) model. It is known that satellite observations can overcome the limitations of the terrain, especially over the oceans where conventional observations are difficult to obtain. Therefore, the use of satellite data will expect to improve those regions where lack of traditional observation. The Advanced Microwave Sounding Unit (AMSU) and Atmospheric InfraRed Sounder (AIRS) onboard NASA’s EOS Aqua satellite, represent microwave and hyperspectral infrared observations, respectively. Both of them may provide atmospheric temperature and moisture soundings with complementary characteristics. For example, AMSU has the advantage to give cloudy retrievals while AIRS may retain the atmospheric gradient due to its finer high spatial resolution. Both data could estimate atmospheric thermodynamic state with substantial accuracy to improve high impact weather forecast In this study, we adopt the Weather Research and Forecasting (WRF) model and the community Gridpoint Statistical Interpolation (GSI) data assimilation system to evaluate the use of AMSU/AIRS retrievals for severe precipitation at Taiwan. The front, UTC 2016/01/05 22Z, is selected to demonstrate the benefit of using sounding data. The preliminary results shows a positive impact on total precipitable water while the time slope may need further investigation.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125642234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TRMM observations of latent heat distribution over the Indian summer monsoon region and associated dynamics","authors":"K. Subrahmanyam, K. Kishore Kumar","doi":"10.1117/12.2223905","DOIUrl":"https://doi.org/10.1117/12.2223905","url":null,"abstract":"The latent heat released/absorbed in the Earth’s atmosphere due to phase change of water molecule plays a vital role in various atmospheric processes. It is now well established that the latent heat released in the clouds is the secondary source of energy for driving the atmosphere, the Sun being the primary. In this context, studies on latent heat released in the atmosphere become important to understand the some of the physical processes taking place in the atmosphere. One of the important implications of latent heat release is its role in driving the circulations on various temporal and spatial scales. Realizing the importance of latent heat released in the clouds, a comprehensive study is carried out to understand its role in driving the mesoscale circulation. As Indian summer monsoon (ISM) serves as natural laboratory for studying the clouds and their microphysics, an attempt is made to explore the latent heat distribution over this region using 13 years of Tropical Rainfall Measuring Mission (TRMM) observations. The observed profiles of latent heating over ISM region showed large spatial and temporal variability in the magnitude thus reflecting the presence of organization of convection on mesoscale. The latent profiles in convective and stratiform regions are segregated to study the differences in their interaction with large-scale environment. Various re-analysis dataset were used to examine the role of latent heating distribution on the mesoscale circulation. The significance of the present study lies in establishing the vertical distribution of latent heating and their impact on the background circulation.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"723 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126931993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remote measurement of cloud microphysics and its influence in predicting high impact weather events","authors":"Paul Shukla Bipasha, John Jinya","doi":"10.1117/12.2223373","DOIUrl":"https://doi.org/10.1117/12.2223373","url":null,"abstract":"Understanding the cloud microphysical processes and precise retrieval of parameters governing the same are crucial for weather and climate prediction. Advanced remote sensing sensors and techniques offer an opportunity for monitoring micro-level developments in cloud structure. . Using the observations from a visible and near-infrared lidar onboard CALIPSO satellite (part of A-train) , the spatial variation of cloud structure has been studied over the Tropical monsoon region . It is found that there is large variability in the cloud microphysical parameters manifesting in distinct precipitation regimes. In particular, the severe storms over this region are driven by processes which range from the synoptic to the microphysical scale. Using INSAT-3D data, retrieval of cloud microphysical parameters like effective radius (CER) and optical depth (COD) were carried out for tropical cyclone Phailine. It was observed that there is a general increase of CER in a top–down direction, characterizing the progressively increasing number and size of precipitation hydrometeors while approaching the cloud base. The distribution of CER relative to cloud top temperature for growing convective clouds has been investigated to reveal the evolution of the particles composing the clouds. It is seen that the relatively high concentration of large particles in the downdraft zone is closely related to the precipitation efficiency of the system. Similar study was also carried using MODIS observations for cyclones over Indian Ocean (2010-2013), in which we find that that the mean effective radius is 24 microns with standard deviation 4.56, mean optical depth is 21 with standard deviation 13.98, mean cloud fraction is 0.92 with standard deviation 0.13 and mainly ice phase is dominant. Thus the remote observations of microstructure of convective storms provide very crucial information about the maintenance and potential devastation likely to be associated with it. With the synergistic observations from A-Train , geostationary and futuristic imaging spectroscopic sensors, a multi-dimensional, and multi-scalar exploration of cloud systems is anticipated leading to accurate prediction of high impact weather events.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"14 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116216210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}