Berk A., G. P. Anderson, P. K. Acharya, and E. P. Shettle, 2011: MODTRAN\textregistered 5.2.2 User-檚 Manual. Spectral Sciences, INC., Burlington, MA, 69 pp. |
Blackwell W. J., F. W. Chen, 2009: Introduction to multilayer perceptron neural networks. Neural Networks in Atmospheric Remote Sensing, Massachusetts Institute of Technology, 73- 96.10.1080/01431169721870067472c760e0c0d41e3a07f3aaffac5adhttp%3A%2F%2Fwww.tandfonline.com%2Fdoi%2Fpdf%2F10.1080%2F014311697218700http://www.tandfonline.com/doi/pdf/10.1080/014311697218700ABSTRACT Over the past decade there have been considerable increases in both the quantity of remotely sensed data available and the use of neural networks. These increases have largely taken place in parallel, and it is only recently that several researchers have begun to apply neural networks to remotely sensed data. This paper introduces this special issue which is concerned specifically with the use of neural networks in remote sensing. The feed-forward back-propagation multi-layer perceptron (MLP) is the type of neural network most commonly encountered in remote sensing and is used in many of the papers in this special issue. The basic structure of the MLP algorithm is described in some detail while some other types of neural network are mentioned. The most common applications of neural networks in remote sensing are considered, particularly those concerned with the classification of land and clouds, and recent developments in these areas are described. Finally, the application of neural networks to multi-source data and fuzzy classification are considered. |
Botes D., J. R. Mecikalski, and G. J. Jedlovec, 2012: Atmospheric Infrared Sounder (AIRS) sounding evaluation and analysis of the pre-convective environment. J. Geophys. Res., 117(D9), doi: 10.1029/2011JD016996.10.1029/2011JD0169969dd31fca601e04335441d70faac82b2chttp%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2011JD016996%2Fpdfhttp://onlinelibrary.wiley.com/doi/10.1029/2011JD016996/pdf[1] The Atmospheric Infrared Sounder (AIRS) is a hyperspectral instrument onboard the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS) Aqua satellite. This study investigates the performance of AIRS soundings in characterizing the stability in the pre-convective environment of the southeastern United States. AIRS soundings are collocated with radiosonde observations within 卤1 degree and 2 h of the Aqua overpass. For each case, the AIRS sounding with maximum PBest quality indicator (signifying the pressure level above which the sounding is of best quality) is chosen for analysis. Rapid Update Cycle soundings from 1800 UTC analyses are used to evaluate the results from AIRS. Precipitable water and stability indices including convective available potential energy, convective inhibition, Lifted Index, K-Index, and Total Totals are derived from all soundings. Results indicate that AIRS underestimates instability due to a dry bias at the surface and roughly 900 hPa. A simple method is presented for reconstructing a RAOB-like inversion (in terms of magnitude and altitude) within AIRS soundings, hence developing more representative RAOB-like soundings that can benefit the operational forecaster. |
Craven J. P., R. E. Jewell, and H. E. Brooks, 2002: Comparison between observed convective cloud-base heights and lifting condensation level for two different lifted parcels. Wea. Forecasting, 17, 885- 890. |
EUMETSAT, 2013: ATBD for the MSG GII/TOZ product. EUM/ MET/DOC/11/0247,32 pp. |
Gardner M. W., S. R. Dorling, 1998: Artificial neural networks (the multilayer perceptron): A review of applications in the atmospheric sciences. Atmos. Environ., 32, 2627- 2636.10.1016/S1352-2310(97)00447-0ed69df7e-c2e9-44cd-92e3-663cee2120a9d28230ad05f45455c650b806a5796e42http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F263416087_Artificial_neural_network_%28Multilayer_Perceptron%29A_review_of_applications_in_atmospheric_sciencesrefpaperuri:(72690f7281eb718f0276a81000ee067f)http://www.researchgate.net/publication/263416087_Artificial_neural_network_(Multilayer_Perceptron)A_review_of_applications_in_atmospheric_sciencesABSTRACT Artificial neural networks are appearing as useful alternatives to traditional statistical modelling techniques in many scientific disciplines. This paper presents a general introduction and discussion of recent applications of the multilayer perceptron, one type of artificial neural network, in the atmospheric sciences. |
Hilton F., Coauthors, 2012: Hyperspectral earth observation from IASI: Five years of accomplishments. Bull. Amer. Meteor. Soc., 93( 3), 347- 370.10.1175/BAMS-D-11-00027.17d1a1845baffef16ed54a5f1105aecbehttp%3A%2F%2Fwww.researchgate.net%2Fpublication%2F231315606_Hyperspectral_Earth_Observation_from_IASI_Five_Years_of_Accomplishmentshttp://www.researchgate.net/publication/231315606_Hyperspectral_Earth_Observation_from_IASI_Five_Years_of_AccomplishmentsThe Infrared Atmospheric Sounding Interferometer (IASI) forms the main infrared sounding component of the European Organisation for the Exploitation of Meteorological Satellites's (EUMETSAT's) Meteorological Operation (MetOp)-A satellite (Klaes et al. 2007), which was launched in October 2006. This article presents the results of the first 4 yr of the operational IASI mission. The performance of the instrument is shown to be exceptional in terms of calibration and stability. The quality of the data has allowed the rapid use of the observations in operational numerical weather prediction (NWP) and the development of new products for atmospheric chemistry and climate studies, some of which were unexpected before launch. The assimilation of IASI observations in NWP models provides a significant forecast impact; in most cases the impact has been shown to be at least as large as for any previous instrument. In atmospheric chemistry, global distributions of gases, such as ozone and carbon monoxide, can be produced in near-搑eal time, and short-lived species, such as ammonia or methanol, can be mapped, allowing the identification of new sources. The data have also shown the ability to track the location and chemistry of gaseous plumes and particles associated with volcanic eruptions and fires, providing valuable data for air quality monitoring and aircraft safety. IASI also contributes to the establishment of robust long-term data records of several essential climate variables. The suite of products being developed from IASI continues to expand as the data are investigated, and further impacts are expected from increased use of the data in NWP and climate studies in the coming years. The instrument has set a high standard for future operational hyperspectral infrared sounders and has demonstrated that such instruments have a vital role in the global observing system. |
Jin X., J. Li, 2010: Improving moisture profile retrieval from broadband infrared radiances with an optimized first-guess scheme. Remote Sensing Letters ,1(4), 231-238, doi:10.1080/01431161003762322.10.1080/01431161003762322c49a1f2c7a3e8afcd742d7c47d5f9022http%3A%2F%2Fwww.tandfonline.com%2Fdoi%2Fabs%2F10.1080%2F01431161003762322http://www.tandfonline.com/doi/abs/10.1080/01431161003762322Variational retrieval of legacy atmospheric moisture profiles needs to begin with a first guess. An optimized first-guess scheme is developed for moisture profile retrieval from broadband infrared (IR) radiances. In this scheme, the non-exponential response of moisturemixingratio toIRradianceat high temperatures (>273 K) is considered. It is found that the first guess of low-level (below 550 hPa) moisture profiles is substantially improved after the new scheme. The data collected by Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation are used for validation. This scheme provides an important optimization method for the next generation of Geostationary Operational Environmental Satellite (GOES)-R legacy profile retrieval algorithm because the Advanced Baseline Imager (ABI) onboard the GOES-R has very similar configurations to SEVIRI. |
Jin X., J. Li, T. J. Schmit, J. L. Li, M. D. Goldberg, and J. J. Gurka, 2008: Retrieving clear-sky atmospheric parameters from SEVIRI and ABI infrared radiances. J. Geophys. Res., 113,D15310, doi: 10.1029/2008JD010040.10.1029/2008JD01004071a69a2c-105e-4cfc-8604-1e296bf9d421ede66aed5c58fddbe049033b7204ee6ehttp%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2008JD010040%2Fpdfrefpaperuri:(2aa7302f0ff2d34c9c88361fd2f78b86)http://onlinelibrary.wiley.com/doi/10.1029/2008JD010040/pdf[1] The algorithm for the current Geostationary Operational Environmental Satellite (GOES) Sounders is adapted to produce atmospheric temperature and moisture legacy profiles from simulated infrared radiances of the Advanced Baseline Imager (ABI) on board the next generation GOES-R. Since the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board the Meteosat Second Generation (MSG) Meteosat-8/9 has many of the same spectral and spatial features as ABI, it is used as proxy to test the algorithm. Because as imagers, SEVIRI and ABI do not have enough CO 2 absorption spectral bands relative to the current GOES Sounders, the legacy profile algorithm for the current GOES Sounders needs to be modified. Both simulations and analysis with radiance measurements indicate that the single temperature-sensitive infrared band (13.4 m) of SEVIRI cannot provide enough temperature profile information. However, SEVIRI's two H 2 O absorption spectral bands (6.2 and 7.2 m) are able to provide useful information on water vapor content above 700 hPa. Because of their high spatial (approximately 3 km for SEVIRI and 2 km for ABI IR bands) and high temporal (15 min full disk coverage) resolutions, SEVIRI and ABI will provide useful profile products with a quality similar to that from the current GOES Sounder prior to the availability of a hyperspectral IR sounding system in geostationary orbit. |
Kitzmiller D. H., W. E. McGovern, 1989: VAS retrievals as a source of information for convective weather forecasts: An objective assessment and comparison with other sources of upper-air observations. Mon. Wea. Rev., 117, 2095- 2110. |
Kim D. H., M. H. Ahn, 2014: Introduction of the in-orbit test and its performance for the first meteorological imager of the Communication, Ocean, and Meteorological Satellite. Atmospheric Measurement Techniques, 7, 2471- 2485.10.5194/amt-7-2471-2014f9f41091607bf5acbf8badf38a1aebbchttp%3A%2F%2Fwww.researchgate.net%2Fpublication%2F266322147_Introduction_of_in_orbit_test_and_its_performance_of_the_first_meteorological_imager_of_the_Communication_Ocean_and_Meteorological_Satellitehttp://www.researchgate.net/publication/266322147_Introduction_of_in_orbit_test_and_its_performance_of_the_first_meteorological_imager_of_the_Communication_Ocean_and_Meteorological_SatelliteThe first geostationary Earth observation satellite of Korea - the Communication, Ocean, and Meteorological Satellite (COMS) - was successfully launched on 27 June 2010. After arrival at its operational orbit, the satellite underwent an in-orbit test (IOT) that lasted for about 8 months. During the IOT period, the main payload for the weather application, the meteorological imager, went through successful tests for demonstrating its function and performance, and the test results are introduced here. The radiometric performance of the meteorological imager (MI) is tested by means of signal-to-noise ratio (SNR) for the visible channel, noise-equivalent differential temperature (NEdT) for the infrared channels, and pixel-to-pixel nonuniformity for both the visible and infrared channels. In the case of the visible channel, the SNR of all eight detectors is obtained using the ground-measured parameters with the background signals obtained in orbit. The overall performance shows a value larger than 26 at 5% albedo, exceeding the user requirement of 10 by a significant margin. Also, the relative variability of detector responsivity among the eight visible channels meets the user requirement, showing values within 10% of the user requirement. For the infrared channels, the NEdT of each detector is well within the user requirement and is comparable with or better than the legacy instruments, except for the water vapor channel, which is slightly noisier than the legacy instruments. The variability of detector responsivity of infrared channels is also below the user requirement, within 40% of the requirement, except for the shortwave infrared channel. The improved performance result is partly due to the stable and low detector temperature obtained due to spacecraft design, i.e., by installing a single solar panel on the opposite side of the MI. |
Koenig M., E. de Coning, 2009: The MSG global instability indices product and its use as a nowcasting tool. Wea. Forecasting, 24, 272- 282.10.1175/2008WAF2222141.1b6bd9c3a-95bf-4858-b4e6-43a73351d3596d15d8a9930c2c5d6b87ec571521f0d0http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F240687258_The_MSG_Global_Instability_Indices_Product_and_Its_Use_as_a_Nowcasting_Toolrefpaperuri:(b87e65f3f46f346a0399bf19da1c2d4f)http://www.researchgate.net/publication/240687258_The_MSG_Global_Instability_Indices_Product_and_Its_Use_as_a_Nowcasting_ToolThe European geostationary Meteosat Second Generation (MSG) satellite offers a variety of channels to use for various purposes, including nowcasting of convection. A number of applications have also been developed to make use of these new capabilities for nowcasting, especially for the detection and prediction of severe weather. The MSG infrared channel selection makes it possible to assess the air stability in preconvective, that is, still cloud-free, conditions. Instability indices are traditionally derived from radiosonde profiles. Such indices typically combine measures of the thermal and moisture properties and often only use a small quantity of vertical profile parameters. MSG-based temperature and moisture retrievals are used for the derivation of stability indices, which are a part of the MSG meteorological products derived centrally at the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). Such indices are of an empirical nature, are often only applicable to certain geographic regions, and their thresholds are dependent on seasonal variation, but they can assess the likelihood of convection within the next few hours, thus providing a warning lead of about 6芒鈧-9 h. Numerous test cases and the more quantitative verification process that was initiated by the South African Weather Service show the generally good warning potential of the derived instability fields. The added capability of a nearly continuous monitoring of the instability fields that is guaranteed by MSG's 15-min repeat cycle is most valuable, since it provides nowcasters with new information much more regularly than the twice-a-day soundings at only a limited number of radiosonde stations. The current EUMETSAT instability product is aimed at helping forecasters to focus their attention on a certain region, which can then be monitored more closely with other means, like satellite imagery and radar data, over the next few hours. |
Krasnopolsky V. M., 2007: Neural network emulations for complex multidimensional geophysical mappings: Applications of neural network techniques to atmospheric and oceanic satellite retrievals and numerical modeling. Rev. Geophys., 45,RG3009, doi: 10.1029/2006RG000200.10.1029/2006RG000200dd2025617ccc3c612a6faa6c2b9a8ceehttp%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2006RG000200%2Fpdfhttp://onlinelibrary.wiley.com/doi/10.1029/2006RG000200/pdf[1] A group of geophysical applications, which from the mathematical point of view, can be formulated as complex, multidimensional, nonlinear mappings and which in terms of the neural network (NN) technique, utilize a particular type of NN, the multilayer perceptron (MLP), is reviewed in this paper. This type of NN application covers the majority of NN applications developed in geosciences like satellite remote sensing, meteorology, oceanography, numerical weather prediction, and climate studies. The major properties of the mappings and MLP NNs are formulated and discussed. Three particular groups of NN applications are presented in this paper as illustrations: atmospheric and oceanic satellite remote sensing applications, NN emulations of model physics for developing atmospheric and oceanic hybrid numerical models, and NN emulations of the dependencies between model variables for application in data assimilation systems. |
Lee S. J., M. H. Ahn, and Y. Lee, 2013: Application of artificial neural network for direct estimation of atmospheric instability Index (CAPE) from geostationary satellite. Proceedings of Autumn Meeting of KMS, 544-545, Gwang-ju, Korea, Kor. Meteo. Soc. |
Lee S. J., M. H. Ahn, and Y. Lee, 2014a: Application of artificial neural network for the direct estimation of atmospheric instability from a geostationary satellite imager. 10pp, Proceedings of the 19th ITSC, Jeju Island, South Korea. |
Lee Y. -K., Z. L. Li, J. Li, and T. J. Schmit, 2014b: Evaluation of the GOES-R ABI LAP retrieval algorithm using the GOES-13 sounder. J. Atmos. Oceanic Technol.,31, 3-19, doi: 10.1175/JTECH-D-13-00028.1.10.1175/JTECH-D-13-00028.1a85bf888963c7c80e1a427c4dd9cd7adhttp%3A%2F%2Fwww.researchgate.net%2Fpublication%2F274493065_Evaluation_of_the_GOES-R_ABI_LAP_Retrieval_Algorithm_Using_the_GOES-13_Sounderhttp://www.researchgate.net/publication/274493065_Evaluation_of_the_GOES-R_ABI_LAP_Retrieval_Algorithm_Using_the_GOES-13_SounderABSTRACT A physical retrieval algorithm has been developed for deriving the legacy atmospheric profile (LAP) product from infrared radiances of the Advanced Baseline Imager (ABI) on board the next-generation Geostationary Operational Environmental Satellite (GOES-R) series. In this study, the GOES-R ABI LAP retrieval algorithm is applied to the GOES-13 sounder radiance measurements (termed the GOES-13 LAP retrieval algorithm in this study) for its validation as well as for potential transition of the GOES-13 LAP retrieval algorithm for the operational processing of GOES sounder data. The GOES-13 LAP retrievals are compared with five different truth measurements: radiosonde observation (raob) and microwave radiometer-measured total precipitable water (TPW) at the Atmospheric Radiation Measurement Cloud and Radiation Testbed site, conventional raob, TPW measurements from the global positioning system-integrated precipitable water NOAA network, and TPW measurements from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E). The results show that with the GOES-R ABI LAP retrieval algorithm, the GOES-13 sounder provides better water vapor profiles than the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) forecast fields at the levels between 300 and 700 hPa. The root-mean-square error (RMSE) and standard deviation (STD) of the GOES-13 sounder TPW are consistently reduced from those of the GFS forecast no matter which measurements are used as the truth. These substantial improvements indicate that the GOES-R ABI LAP retrieval algorithm is well prepared to provide continuity of quality to some of the current GOES sounder products, and the algorithm can be transferred to process the current GOES sounder measurements for operational product generation. |
Li J., C. -Y. Liu, P. Zhang, and T. J. Schmit, 2012: Applications of full spatial resolution space-based advanced infrared soundings in the preconvection environment. Wea. Forecasting, 27, 515- 524.10.1175/WAF-D-10-05057.1d98866a4-497b-4a50-a188-0b008cc632383605c939c8bf3cc3796c857bfb02fc6chttp%3A%2F%2Fwww.researchgate.net%2Fpublication%2F258724591_Applications_of_Full_Spatial_Resolution_Space-Based_Advanced_Infrared_Soundings_in_the_Preconvection_Environmentrefpaperuri:(1bfedd0ba8665571a7f03e0d948da085)http://www.researchgate.net/publication/258724591_Applications_of_Full_Spatial_Resolution_Space-Based_Advanced_Infrared_Soundings_in_the_Preconvection_EnvironmentAbstract Advanced infrared (IR) sounders such as the Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) provide atmospheric temperature and moisture profiles with high vertical resolution and high accuracy in preconvection environments. The derived atmospheric stability indices such as convective available potential energy (CAPE) and lifted index (LI) from advanced IR soundings can provide critical information 1 ~ 6 h before the development of severe convective storms. Three convective storms are selected for the evaluation of applying AIRS full spatial resolution soundings and the derived products on providing warning information in the preconvection environments. In the first case, the AIRS full spatial resolution soundings revealed local extremely high atmospheric instability 3 h ahead of the convection on the leading edge of a frontal system, while the second case demonstrates that the extremely high atmospheric instability is associated with the local development of severe thunderstorm in the following hours. The third case is a local severe storm that occurred on 7-8 August 2010 in Zhou Qu, China, which caused more than 1400 deaths and left another 300 or more people missing. The AIRS full spatial resolution LI product shows the atmospheric instability 3.5 h before the storm genesis. The CAPE and LI from AIRS full spatial resolution and operational AIRS/AMSU soundings along with Geostationary Operational Environmental Satellite (GOES) Sounder derived product image (DPI) products were analyzed and compared. Case studies show that full spatial resolution AIRS retrievals provide more useful warning information in the preconvection environments for determining favorable locations for convective initiation (CI) than do the coarser spatial resolution operational soundings and lower spectral resolution GOES Sounder retrievals. |
Li Z. L., J. Li, J. W. P. Menzel, T. J. Schmit, J. P. Nelson III, J. Daniels, and S. A. Ackerman, 2008: GOES sounding improvement and applications to severe storm nowcasting. Geophys. Res. Lett., 35,L03806, doi: 10.1029/2007GL032797.10.1029/2007GL0327979bec177b29006bd198403af69eb10396http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2007GL032797%2Ffullhttp://onlinelibrary.wiley.com/doi/10.1029/2007GL032797/full[1] An improved clear-sky physical retrieval algorithm for atmospheric temperature and moisture is applied to the Geostationary Operational Environmental Satellite-12 (GOES-12) Sounder. A comparison with the microwave radiometer (MWR) measured total precipitable water (TPW) at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site from June 2003 to May 2005 shows that the TPW retrievals are improved by 0.4 mm over the legacy GOES Sounder TPW product. The Lifted Index (LI) derived product imagery (DPI) from the improved soundings better depicts the pre-convective environment surrounding a tornadic supercell at Eagle Pass, Texas on 24 April 2007. Another severe storm case from 13 April 2006 demonstrates that the improved physical algorithm successfully detects low-level moisture. Both cases show the new retrievals along with the derived products will help the forecasters with short-term severe storm nowcasting. |
Liu H., C. Wu, J. Li, and Q. Chengli, 2014: Deriving atmospheric instability indices directly from Geostationary Interferometric Infrared Sounder (GIIRS) radiances. poster presentation in the 19th ITSC, Jeju Island, South Korea. |
Ma X. L., T. J. Schmit, and W. L. Smith, 1999: A nonlinear physical retrieval algorithm-its application to the GOES-8/9 sounder. J. Appl. Meteor., 38, 501- 513.10.1175/1520-0450(1999)038<0501:ANPRAI>2.0.CO;2712d4ce2-d99c-4806-8716-3aa8de73186b6a5d5cb4e0983766db17c63e9608fa60http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F252954623_A_Nonlinear_Physical_Retrieval_Algorithm--Its_Application_to_the_GOES89_Sounderrefpaperuri:(6fba49d314dc3999f93e66a2bae7af3a)http://www.researchgate.net/publication/252954623_A_Nonlinear_Physical_Retrieval_Algorithm--Its_Application_to_the_GOES89_SounderAbstract A nonlinear physical retrieval algorithm is developed and applied to the GOES-8/9 sounder radiance observations. The algorithm utilizes Newtonian iteration in which the maximum probability solution for temperature and water vapor profiles is achieved through the inverse solution of the nonlinear radiative transfer equation. The nonlinear physical retrieval algorithm has been tested for one year. It has also been implemented operationally by the National Oceanic and Atmospheric Administration National Environmental Satellite, Data and Information Service during February 1997. Results show that the GOES retrievals of temperature and moisture obtained with the nonlinear algorithm more closely agree with collocated radiosondes than the National Centers for Environmental Prediction (NCEP) forecast temperature and moisture profile used as the initial profile for the solution. The root-mean-square error of the total water vapor from the solution first guess, which is the NCEP 12-h forecast (referred to as the -渂ackground-), is reduced approximately 20% over the conventional data-rich North American region with the largest changes being achieved in areas of sparse radiosonde data coverage. |
Martinez M. A., M. Velazquez, M. Manso, and I. Mas, 2007: Application of LPW and SAI SAFNWC/MSG satellite products in pre-convective environments. Atmospheric Research, 83, 366- 379.10.1016/j.atmosres.2005.10.0222fdc0d15-4e27-446a-b39c-cff629bebf773218f45418634224f668397adba075dbhttp%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS0169809506001347refpaperuri:(e40c30320ab4c5ea21e8fdea6a035544)http://www.sciencedirect.com/science/article/pii/S0169809506001347ABSTRACT The Spinning Enhanced Visible and Infrared Imagery (SEVIRI) instrument, on board the Meteosat Second Generation (MSG), is a radiometer with eight infrared (IR) spectral bands. Seven of these channels are used to retrieve Layer Precipitable Water (LPW) and Stability Analysis Imagery (SAI). Both products are the PGE07 and the PGE08 of SAFNWC (Satellite Application Facility on support to Nowcasting and Very Short-Range Forecasting). The authors at Instituto Nacional de Meteorología (INM) have developed the LPW and SAI algorithms, in the SAFNWC framework. Both products are retrieved using statistical retrieval based on neural networks. The main advantage of these algorithms versus physical retrieval algorithms is the independence from the Numerical Weather Prediction (NWP) models. The LPW provides information on the water vapor contained in a vertical column of unit cross-section area in three layers in the troposphere (low, middle and high) and in the total layer in cloud free areas. The SAI provides estimations of the atmospheric instability in cloud free areas, in particular the Lifted Index (LI).The stability and precipitable water obtained with both products are routinely generated every 15 min at a satellite horizontal resolution of 3 km in NADIR. A significant advantage of these MSG products, compared to traditional measurements such as radiosondes, is their ability to measure high resolution temporal and spatial variations of atmospheric stability and moisture in pre-convective environments. The main disadvantage is that they do not have the vertical resolution of radiosonde. The MSG moisture and stability time trend fields are especially useful during the period preceding the outbreak of convection due to the high resolution. Once the outbreak of convection occurs, the products calculated in the clear air pixels surrounding the convective system will allow to foresee the evolution of the convection. |
Menzel W. P., F. C. Holt, T. J. Schmit, R. M. Aune, A. J. Schreiner, G. S. Wade, and D. G. Gray, 1998: Application of GOES-8/9 soundings to weather forecasting and nowcasting. Bull. Amer. Meteor. Soc., 79( 10), 2059- 2077.10.1175/1520-0477(1998)0792.0.CO;22d7924a18ee1af33c05901c9a94e7b64http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249615689_Application_of_GOES89_Soundings_to_Weather_Forecasting_and_Nowcastinghttp://www.researchgate.net/publication/249615689_Application_of_GOES89_Soundings_to_Weather_Forecasting_and_NowcastingCompares an updated set of geostationary sounders which were used to measure atmospheric radiances in 18 infrared spectral bands since 1994, to those available from the generation of Geostationary Operational Environmental Satellites (GOES). Examination of the anticipated movements from the GOES-8/9 sounders; Effectiveness of sounding projects over North America using the GOES-8/9 sounders. |
Oolman L., 2014: Upper Air Data Soundings. University of Wyoming, College of Engineering, Department of Atmospheric Science . [Available online at http://weather.uwyo.edu/],accessed in July 2014.10.1109/MCSE.2012.71bd6daf7998bce17094ca6fbd439ef824http%3A%2F%2Fetc.usf.edu%2Fclipart%2F44700%2F44764%2F44764_uni_wy.htmhttp://etc.usf.edu/clipart/44700/44764/44764_uni_wy.htmWe met with Provost Al Karnig a month ago and expressed concern about how the review process works. We do not think it works well. Administrators should be hired to carry out the policy of the board of trustees. It appears that the faculty and staff of the University have |
Romero R., M. Gay, and C. A. Dowsell III, 2007: European climatology of severe convective storm environmental parameters: a test for significant tornado events. Atmospheric Research, 83, 389- 404.10.1016/j.atmosres.2005.06.011ec1dd2abe1b5a0e21b5a131d9eb66dd6http%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS0169809506001360http://www.sciencedirect.com/science/article/pii/S0169809506001360ABSTRACT A climatology of various parameters associated with severe convective storms has been constructed for Europe. This involves using the reanalysis data base from ERA-40 for the period 1971-2000 and calculating monthly means, variability range and extremes occurrence of fields such as convective available potential energy, convective inhibition energy, mid-tropospheric lapse rate, low-tropospheric moisture content and storm relative helicity for different layers. This process is a first step towards development of a synthetic climatology of European severe weather, and is publicly available at the web site http://ecss.uib.es. Preliminary results derived from these products were presented during the ECSS 2004 conference. This paper is devoted to a more detailed presentation and discussion of the main results. It is hypothesized that preferred areas for severe thunderstorms occurrence in Europe would extend along a zonal belt over the south-central regions, where high helicity associated with the extratropical storm tracks and thermodynamically-favourable profiles established over the southern Atlantic and Mediterranean Sea would most likely be concatenated.Further, this effort has been complemented with a collection of existing reports of significant (at least F2) tornadoes in Europe during the period 1971-2003. We present this data set in this paper and it also can be found at the website http://ecss.uib.es. Thus, the tornado collection can be used to test the appropriateness of the parameters selected for the synthetic climatology. In particular, it is found that the convective available potential energy, low-tropospheric moisture content and environmental shear, when related to the monthly climatology, are reasonably good descriptors of the tornadic environments. |
Schmit T. J., J. Li, J. L. Li, W. F. Feltz, J. J. Gurka, M. D. Goldberg, and K. J. Schrab, 2008: The GOES-R advanced baseline imager and the continuation of current sounder products. Journal of Applied Meteorology and Climatology,47, 2696-2711, doi: 10.1175/2008JAMC1858.1.10.1175/2008JAMC1858.122eb93e1bf2b562d707359a4be805d42http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F238428465_The_GOES-R_Advanced_Baseline_Imager_and_the_Continuation_of_Current_Sounder_Productshttp://www.researchgate.net/publication/238428465_The_GOES-R_Advanced_Baseline_Imager_and_the_Continuation_of_Current_Sounder_ProductsAbstract The first of the next-generation series of Geostationary Operational Environmental Satellites (GOES-R) is scheduled for launch in the 2015 time frame. One of the primary instruments on GOES-R, the Advanced Baseline Imager (ABI), will offer more spectral bands, higher spatial resolution, and faster imaging than does the current GOES Imager. Measurements from the ABI will be used for a wide range of qualitative and quantitative weather, land, ocean, cryosphere, environmental, and climate applications. However, the first and, likely, the second of the new series of GOES will not carry an infrared sounder dedicated to acquiring high-vertical-resolution atmospheric temperature and humidity profiles that are key to mesoscale and regional severe-weather forecasting. The ABI will provide some continuity of the current sounder products to bridge the gap until the advent of the GOES advanced infrared sounder. Both theoretical analysis and retrieval simulations show that data from the ABI can be combined with temperature and moisture information from forecast models to produce derived products that will be adequate substitutes for the legacy products from the current GOES sounders. Products generated from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) measurements also demonstrate the utility of those legacy products for nowcasting applications. However, because of very coarse vertical resolution and limited accuracy in the legacy sounding products, placing a hyperspectral-resolution infrared sounder with high temporal resolution on future GOES is an essential step toward realizing substantial improvements in mesoscale and severe-weather forecasting required by the user communities. |
Seemann S. W., J. Li, W. P. Menzel, and L. E. Gumley, 2003: Operational retrieval of atmospheric temperature, moisture, and ozone from MODIS infrared radiances. J. Appl. Meteor., 42, 1072- 1091.10.1117/12.4666860ae777e6-12ba-41d3-be16-f7ed5e73871d025d3731fe69135e53ba908d5fa6d477http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F228942078_Operational_Retrieval_of_Atmospheric_Temperature_Moisture_and_Ozone_from_MODIS_Infrared_Radiancesrefpaperuri:(6eb821970c67af751e14dabfadc4cba1)http://www.researchgate.net/publication/228942078_Operational_Retrieval_of_Atmospheric_Temperature_Moisture_and_Ozone_from_MODIS_Infrared_RadiancesThe algorithm for retrieving atmospheric temperature, moisture, and total column ozone using the Moderate Resolution Imaging Spectroradiometer (MODIS) longwave infrared radiances is presented. The operational MODIS algorithm performs clear sky retrievals globally over land and ocean for both day and night. The algorithm is based on a regression and has an option to follow the statistical retrieval with a nonlinear physical retrieval. The regression coefficients are determined from an extension of the NOAA-88 data set containing more than 8400 global radiosonde measurements of atmospheric temperature, moisture and ozone profiles. Evaluation of atmospheric products is performed by a comparison with data from ground-based instrumentation, geostationary infrared sounders, and polar orbiting microwave sounders. MODIS moisture products are in general agreement with the gradients and distributions from the other satellites, while MODIS depicts more detailed structure with its improved spatial resolution. |
Seidel D. J., B. Sun, M. Pettey, and A. Reale, 2011: Global radiosonde balloon drift statistics. J. Geophys. Res. , 116,D07102, doi:10.1029/2010JD014891.10.1029/2010JD014891709efe04cfad2b51a68ef8d540578254http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2010JD014891%2Fpdfhttp://onlinelibrary.wiley.com/doi/10.1029/2010JD014891/pdf[1] The drift of radiosonde balloons during their ascent has generally been considered a negligible factor in applications involving radiosonde observations. However, several applications envisioned for observations from the Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) require estimates of balloon drift. This study presents a comprehensive global climatology of radiosonde balloon drift distance and ascent time, based on 2 years of data from 419 stations, with particular attention to GRUAN stations. Typical drift distances are a few kilometers in the lower troposphere, 655 km in the midtroposphere, 6520 km in the upper troposphere, and 6550 km in the lower stratosphere, although there is considerable variability due to variability in climatological winds. Drift distances tend to increase with height above the surface, be larger in midlatitudes than in the tropics, be larger in winter than in summer, and vary with wind (and consequent balloon drift) direction. Most estimates of elapsed time from balloon launch to various pressure levels, due to vertical balloon rise, have median values ranging from about 5 min at 850 hPa to about 1.7 h at 10 hPa, with ranges of about 20% of median values. Observed elapsed times exceed those estimated using assumed 5 or 6 m/s rise rates. |
Setv谩k, M., J. M眉ller, 2013: 2.5-minute rapid scan experiments with the MSG satellites. 7th European Conference on Severe Storms, Helsinki, Finland, 3-7June 2013. |
Taravat A., S. Proud, S. Peronaci, F. de Frate, and N. Oppelt, 2015: Multilayer perceptron neural networks model for meteosat second generation SEVIRI daytime cloud masking. Remote Sensing, 7, 1529- 1539.10.3390/rs702015291bb87f74125741a172ef52ffe5154b8dhttp%3A%2F%2Fwww.researchgate.net%2Fpublication%2F273280497_Multilayer_Perceptron_Neural_Networks_Model_for_Meteosat_Second_Generation_SEVIRI_Daytime_Cloud_Maskinghttp://www.researchgate.net/publication/273280497_Multilayer_Perceptron_Neural_Networks_Model_for_Meteosat_Second_Generation_SEVIRI_Daytime_Cloud_MaskingA multilayer perceptron neural network cloud mask for Meteosat Second Generation SEVIRI (Spinning Enhanced Visible and Infrared Imager) images is introduced and evaluated. The model is trained for cloud detection on MSG SEVIRI daytime data. It consists of a multi-layer perceptron with one hidden sigmoid layer, trained with the error back-propagation algorithm. The model is fed by six bands of MSG data (0.6, 0.8, 1.6, 3.9, 6.2 and 10.8 渭m) with 10 hidden nodes. The multiple-layer perceptrons lead to a cloud detection accuracy of 88.96%, when trained to map two predefined values that classify cloud and clear sky. The network was further evaluated using sixty MSG images taken at different dates. The network detected not only bright thick clouds but also thin or less bright clouds. The analysis demonstrated the feasibility of using machine learning models of cloud detection in MSG SEVIRI imagery. |
Zhang G. J., 2002: Convective quasi-equilibrium in midlatitude continental environment and its effect on convective parameterization. J. Geophys. Res.,107, ACL 12-1-ACL 12-16, doi: 10.1029/2001JD001005.10.1029/2001JD00100526bee36d9d609af286f08e421e18cea1http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2001JD001005%2Fpdfhttp://onlinelibrary.wiley.com/doi/10.1029/2001JD001005/pdf[1] The quasi-equilibrium assumption proposed by Arakawa and Schubert assumes that convection is controlled by the large-scale forcing in a statistical sense, in such a way that the stabilization of the atmosphere by convection is in quasi-equilibrium with the destabilization by the large-scale forcing. The assumption was developed largely based on observations in the tropical maritime environment and has not been evaluated in midlatitudes. This study examines the quasi-equilibrium assumption in midlatitude continental convection environment using summertime observations from the Southern Great Plains of the United States. Two complementary approaches are taken for this purpose. The first one compares the net time rate of change of convective available potential energy to that due to the large-scale forcing. The second one examines the contributions to the net change of CAPE from the boundary layer air and the free tropospheric air above. Results from both the approaches indicate that the quasi-equilibrium assumption is not well suited for midlatitude continental convection. It is shown that the net change of CAPE is comparable to and largely comes from that due to thermodynamic changes of the boundary layer air, while the contribution from the free troposphere above the boundary layer is negligible. The analysis also shows that the role of convective inhibition to suppress convection is the most pronounced when the large-scale forcing in the free troposphere is weak. On the basis of these and other observations, a modification to the quasi-equilibrium assumption is proposed. It assumes that convective and large-scale processes in the free troposphere above the boundary layer are in balance, so that contribution from the free troposphere to changes in CAPE is negligible. This assumption is then tested using the single column model of the NCAR CCM3 by modifying the closure in the CCM3 convection scheme. Such a modification significantly improves the single column model simulation. The applicability of this new quasi-equilibrium assumption to tropical convection environment is also discussed. |