Download or read book Daytime Raman Lidar Measurements of Water Vapor During the ARM 1997 Water Vapor Intensive Observation Period written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of the importance of water vapor, the ARM program initiated a series of three intensive operating periods (IOPs) at its CART (Cloud And Radiation Testbed) site. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. These IOPs provided an excellent opportunity to compare measurements from other systems with those made by the CART Raman lidar. This paper addresses primarily the daytime water vapor measurements made by the lidar system during the second of these IOPs.

Download or read book Water Vapor Measurements by Raman Lidar During the ARM 1997 Water Vapor Intensive Observation Period written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water vapor is the most important greenhouse gas in the atmosphere, as it is the most active infrared absorber and emitter of radiation, and it also plays an important role in energy transport and cloud formation. Accurate, high resolution measurements of this variable are critical in order to improve the understanding of these processes and thus their ability to model them. Because of the importance of water vapor, the Department of Energy's Atmospheric Radiation Measurement (ARM) program initiated a series of three intensive operating periods (IOPs) at its Cloud and Radiation Testbed (CART) site in northern Oklahoma. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. The ARM CART site is the home of several different water vapor measurement systems. These systems include a Raman lidar, a microwave radiometer, a radiosonde launch site, and an instrumented tower. During these IOPs, additional instrumentation was brought to the site to augment the normal measurements in the attempt to characterize the CART instruments and to address the need to improve water vapor measurement capabilities. Some of the instruments brought to the CART site include a scanning Raman lidar system from NASA/GSFC, additional microwave radiometers from NOAA/ETL, a chilled mirror that was flown on a tethersonde and kite system, and dewpoint hygrometer instruments flow on the North Dakota Citation. This paper will focus on the Raman lidar intercomparisons from the second IOP.

Download or read book Nineteenth International Laser Radar Conference written by Upendra N. Singh and published by . This book was released on 1998 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication contains extended abstracts of papers presented at the Nineteenth International Laser Radar Conference, held at Annapolis, Maryland, July 6-10, 1998; 260 papers were presented in both oral and poster sessions. The topics of the conference sessions were Aerosol Clouds, Multiple Scattering; Tropospheric Profiling, Stratospheric/Mesospheric Profiling; Wind Profiling; New Lidar Technology and Techniques; Lidar Applications, Including Altimetry and Marine; Space and Future Lidar; and Lidar Commercialization/Eye Safety. This conference reflects the breadth of research activities being conducted in the lidar field. These abstracts address subjects from lidar-based atmospheric investigations, development of new lasers and lidar system technology, and current and future space-based lidar systems.

Download or read book Comparison of Columnar Water Vapor Measurements During the Fall 1997 Arm Intensive Observation Period written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-06 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NASA Technical Reports Server (NTRS) houses half a million publications that are a valuable means of information to researchers, teachers, students, and the general public. These documents are all aerospace related with much scientific and technical information created or funded by NASA. Some types of documents include conference papers, research reports, meeting papers, journal articles and more. This is one of those documents.

Download or read book Springer Handbook of Atmospheric Measurements written by Thomas Foken and published by Springer Nature. This book was released on 2021-11-09 with total page 1761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical handbook provides a clearly structured, concise and comprehensive account of the huge variety of atmospheric and related measurements relevant to meteorologists and for the purpose of weather forecasting and climate research, but also to the practitioner in the wider field of environmental physics and ecology. The Springer Handbook of Atmospheric Measurements is divided into six parts: The first part offers instructive descriptions of the basics of atmospheric measurements and the multitude of their influencing factors, fundamentals of quality control and standardization, as well as equations and tables of atmospheric, water, and soil quantities. The subsequent parts present classical in-situ measurements as well as remote sensing techniques from both ground-based as well as airborn or satellite-based methods. The next part focusses on complex measurements and methods that integrate different techniques to establish more holistic data. Brief discussions of measurements in soils and water, at plants, in urban and rural environments and for renewable energies demonstrate the potential of such applications. The final part provides an overview of atmospheric and ecological networks. Written by distinguished experts from academia and industry, each of the 64 chapters provides in-depth discussions of the available devices with their specifications, aspects of quality control, maintenance as well as their potential for the future. A large number of thoroughly compiled tables of physical quantities, sensors and system characteristics make this handbook a unique, universal and useful reference for the practitioner and absolutely essential for researchers, students, and technicians.

Download or read book The Refurbishment and Upgrade of the Atmospheric Radiation Measurement Raman Lidar written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Atmospheric Radiation Measurement Program (ARM) Climate Research Facility (ACRF) Raman lidar (CARL) is an autonomous, turn-key system that profiles water vapor, aerosols, and clouds throughout the diurnal cycle for days without attention (Goldsmith et al. 1998). CARL was first deployed to the Southern Great Plains CRF during the summer of 1996 and participated in the 1996 and 1997 water vapor intensive operational periods (IOPs). Since February 1998, the system has collected over 38,000 hrs of data (equivalent of almost 4.4 years), with an average monthly uptime of 62% during this time period. This unprecedented performance by CARL makes it the premier operational Raman lidar in the world. Unfortunately, CARL began degrading in early 2002. This loss of sensitivity, which affected all observed variables, was very gradual and thus was not identified until the autumn of 2003. Analysis of the data suggested the problem was not associated with the laser or transmit portion of the system, but rather in the detection subsystem, as both the background values and the peak signals showed a marked decreases over this time period. The loss of sensitivity of a factor of 2-4, depending on the channel, resulted in higher random error in the retrieved products, such as the aerosol backscatter coefficient and water vapor mixing ratio. Figure 1 shows the random error at 2 km for aerosol backscatter coefficient (top) and water vapor mixing ratio (middle), in terms of percent of the signal for both average daytime (red) and nighttime (blue) data from 1998 to 2005. The seasonal variation of water vapor is easily seen in the random error in the water vapor mixing ratio data. The loss of sensitivity also affected the maximum range of the usable data, as illustrated by the dramatic decrease in the maximum height seen in the water vapor mixing ratio data (bottom). This degradation, which results in much larger random errors, greatly hinders the analysis of data sets such as the Aerosol IOP (March 2003) and the AIRS Water Vapor Experiment (December 2003). The degradation and its impact on the Aerosol IOP analysis are reported in Ferrare et al. 2005.

Download or read book Encontro Nacional de F sica de Reatores e Termohidr ulica ENFIR 6 written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Atmospheric and Oceanic Technology written by and published by . This book was released on 2004 with total page 1002 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IGARSS 98 written by and published by Institute of Electrical & Electronics Engineers(IEEE). This book was released on 1998 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theme of the GRSS '98 emphasizes the role of remote sensing for managing limited natural resources. It covers topics such as: applications of remote sensing; electromagnetic problems; data processing techniques; geophysical models; and techniques and instrumentation.

Download or read book Analysis and Calibration of CRF Raman Lidar Cloud Liquid Water Measurements written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Atmospheric Radiation Measurement (ARM) Raman lidar (RL), located at the Southern Great Plains (SGP) Climate Research Facility (CRF), is a unique state-of-the-art active remote sensor that is able to measure profiles of water vapor, aerosol, and cloud properties at high temporal and vertical resolution throughout the diurnal cycle. In October 2005, the capability of the RL was extended by the addition of a new detection channel that is sensitive to the Raman scattering of liquid water. This new channel permits the system, in theory, to measure profiles of liquid water content (LWC) by the RL. To our knowledge, the ARM RL is the only operation lidar with this capability. The liquid water Raman backscattering cross-section is a relatively weak and spectrally broad feature, relative to the water vapor Raman backscatter signal. The wide bandpass required to achieve reasonable signal-to-noise in the liquid water channel essentially eliminates the ability to measure LWC profiles during the daytime in the presence of large solar background, and thus all LWC observations are nighttime only. Additionally, the wide bandpass increases the probability that other undesirable signals, such as fluorescence from aerosols, may contaminate the observation. The liquid water Raman cross-section has a small amount of overlap with the water vapor Raman cross-section, and thus there will be a small amount of 'cross-talk' between the two signals, with water vapor contributing a small amount of signal to the LWC observation. And finally, there is significant uncertainty in the actual strength of the liquid water Raman cross-section in the literature. The calibrated LWC profiles, together with the coincident cloud backscatter observations also made by the RL, can be used to derive profiles of cloud droplet effective radius. By combining these profiles of effective radius in the lower portion of the cloud with the aerosol extinction measurements made below the cloud by the RL, the first aerosol indirect effect can be investigated using a single instrument, thereby reducing the uncertainty associated with aligning the different sampling periods and fields of view of multiple instruments. We have applied a "first principles" calibration to the LWC profiles. This approach requires that the relative differences in optical efficiency between the water vapor and liquid water channels be known; this relative difference is easily computed using the efficiency values of the beam splitters and interference filters in the lidar that were provided by the vendors of these components. The first principles approach then transfers the calibration from the water vapor mixing ratio to the LWC using the difference in the optical efficiency and an interpolated value of the liquid water Raman cross section from the literature, and the better established water vapor Raman cross section. After accounting for all known error sources, the vertical integral of LWC was compared against a similar value retrieved from a co-located ground-based infrared radiometer. The RL and infrared radiometer have significantly different fields of view; thus to compare the two sensors the data were averaged to 5 min intervals where only cloudy samples were included in the average of each. While there is fair scatter in the data (r=0.47), there is also a clear indication of a positive correlation between the infrared and the RL values. The value of the slope of the regression is 0.49, which indicates a tendency of the RL measurements to underestimate the total liquid amount with respect to the infrared retrieval. Research continues to investigate the source of the bias, but the most likely candidate is the large uncertainty in the liquid water Raman cross-section as there have been no direct measurements made of this parameter at the lidar's laser wavelength of 355 nm. The calibrated LWC profile was then used together with the cloud backscatter coefficient profile from the RL to derive profiles of cloud droplet effective radius and cloud droplet number density. These profiles of cloud droplet size together with the aerosol extinction observed by the same lidar are used to investigate the aerosol indirect effect in several case studies in August 2006. Russo F. "An investigation of Raman lidar measurements and their application to the study of the aerosol indirect effect", PhD Thesis (2007). Russo F., D.N. Whiteman, D.D. Turner, B.B. Demoz, R.M. Hoff, I. Veselovskii, "Measurements of the Aerosol Indirect Effect using a Raman lidar. Part 1: cloud liquid water measurements", manuscript in preparation. Russo F., D.N. Whiteman, D.D. Turner, B.B. Demoz, R.M. Hoff, I. Veselovskii, "Measurements of the Aerosol Indirect Effect using a Raman lidar. Part 2: the calculation of IE", manuscript in preparation.

Download or read book Raman Lidar Measurements During the International Hzo Project 1 written by D. N. Whiteman and published by BiblioGov. This book was released on 2013-08 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The amount of water vapor in the atmosphere helps to determine the likelihood that severe storms may develop. The concentration of water vapor, though, is highly variable in space and time. And yet small changes in water vapor concentration over a short period of time or over a short spatial distance can determine whether a storm may or may not develop. Therefore, in order to improve the ability to forecast severe weather such as thunderstorms it is important to measure water vapor in the atmosphere with high spatial and temporal resolution. One of the most attractive research tools for measuring water vapor in the atmosphere with high spatial and temporal resolution is a Raman lidar. A Raman lidar consists of a laser transmitter, a telescope receiver and optics and electronics for processing opticand electronic signals. A laser pulse is emitted into the atmosphere and it interacts with molecules in the atmosphere causing them to become excited and to emit, through the Raman process, photons of different wavelength than emitted by the laser. The molecule that emitted these emitted. This is the way that a Raman lidar identifies water vapor molecules in the atmosphere. can be identified based on the wavelength of the photons One of the great challenges in Raman lidar measurements has been to make useful daytime measurements of the water vapor profile under bright daytime conditions. In this first of two papers, we describe the instrumentation and analysis of the first documented Raman lidar that is able to measure water vapor in the daytime with sufficient quality to permit the study of developing storm systems.

Download or read book Raman lidar measurements of water vapor and aerosol clouds during the FIRE SPECTRE field campaign written by and published by . This book was released on 1992 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the Atmospheric Radiation Measurement ARM Science Team Meeting written by and published by . This book was released on 1998 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Water Vapor Within the Planetary Boundary Layer Based on the ARM Raman Lidar Observation at the SGP Site written by Kyoko Taniguchi and published by . This book was released on 2007 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IGARSS 2000 written by Tammy I. Stein and published by IEEE Standards Office. This book was released on 2000 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Daytime Raman Lidar Profiling of Atmospheric Water Vapor written by and published by . This book was released on 1994 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed measurements of the distribution of water vapor in the atmosphere are needed for a variety of scientific inquiries, including global climate change and related issues in radiative processes (water vapor is the major greenhouse gas in the atmosphere), and studies of a variety of atmospheric processes such as cloud formation and atmospheric circulation. The Raman lidar is a leading candidate for an instrument capable of the detailed, time- and space-resolved measurements required by these and other studies.

Download or read book Arr t s et remontrances du parlement de Bordeaux au roi sur ce qui a suivi la r clamation de cette compagnie contre les lettres patentes accord es en 1752 au bureau des finances 21 juillet 1756 written by and published by . This book was released on 1756 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: