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Note: This page contains sample records for the topic "vaisala ceilometer vceil" from the National Library of EnergyBeta (NLEBeta).
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1

ARM - Instrument - vceil  

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govInstrumentsvceil govInstrumentsvceil Documentation VCEIL : Handbook VCEIL : Instrument Mentor Monthly Summary (IMMS) reports VCEIL : Data Quality Assessment (DQA) reports ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Instrument : Vaisala Ceilometer (VCEIL) Beneficiary of Recovery Act funding. Instrument Categories Cloud Properties, Atmospheric Profiling Picture of the Vaisala Ceilometer (Model CL31) Picture of the Vaisala Ceilometer (Model CL31) General Overview The Vaisala Ceilometer (VCEIL) is a self-contained, ground-based, active, remote-sensing device designed to measure cloud-base height, vertical visibility, and potential backscatter signals by aerosols. It detects up to three cloud layers simultaneously. Model CL31 has a maximum vertical range

2

he NCAR and Vaisala collaboration project  

E-Print Network (OSTI)

T he NCAR and Vaisala collaboration project started in 1998 and built on a mutual effort uncertainties at very cold temperatures. The ATD-Vaisala correction procedures compile these sometimes and drop- sondes to support short-term research projects around the world. Researchers often use the ATD

Wang, Junhong

3

Impact of Vaisala Radiosonde Humidity Corrections on ARM IOP...  

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dry bias in Vaisala radiosonde humidity measurements has been noted in comparison to satellite water vapor retrievals (Soden and Lanzante 1996) and Raman lidar measurements...

4

DISCLAIMER  

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DOE/SC-ARM-TR-020 DOE/SC-ARM-TR-020 Vaisala Ceilometer (VCEIL) Handbook VR Morris March 2012 Work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research VR Morris, March 2012, DOE/SC-ARM-TR-020 ii Contents 1.0 General Overview ................................................................................................................................. 1 2.0 Contacts ................................................................................................................................................ 1 2.1 Mentor .......................................................................................................................................... 1 3.0 Deployment Locations and History ...................................................................................................... 1

5

ARM - Datastreams - ceilpblht  

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Datastreamsceilpblht Datastreamsceilpblht Documentation Data Quality Plots Citation DOI: 10.5439/1095593 [ What is this? ] Generate Citation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : CEILPBLHT Boundary-layer height data with VCEIL Active Dates 2011.06.09 - 2014.01.09 Measurement Categories Atmospheric State Originating Instrument Vaisala Ceilometer (VCEIL) Measurements Only measurements considered scientifically relevant are shown below by default. Show all measurements Measurement Units Variable Altitude above mean sea level m alt Base time in Epoch seconds since 1970-1-1 0:00:00 0:00 base_time Planetary boundary layer height First boundary layer height candidate meters bl_height_1 ( time )

6

ARM - Measurement - Cloud base height  

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base height base height ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud base height For a given cloud or cloud layer, the lowest level of the atmosphere where cloud properties are detectable. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments BLC : Belfort Laser Ceilometer MPL : Micropulse Lidar MWRP : Microwave Radiometer Profiler RL : Raman Lidar VCEIL : Vaisala Ceilometer External Instruments NOAASURF : NOAA Surface Meteorology Data, collected by NWS and NCDC

7

ARM - Measurement - Planetary boundary layer height  

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govMeasurementsPlanetary boundary layer height govMeasurementsPlanetary boundary layer height ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Planetary boundary layer height Top of the planetary boundary layer; also known as depth or height of the mixing layer. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments VCEIL : Vaisala Ceilometer External Instruments NCEPGFS : National Centers for Environment Prediction Global Forecast System Field Campaign Instruments

8

In Situ Validation of a Correction for Time-Lag and Bias Errors in Vaisala RS80-H Radiosonde Humidity Measurements  

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In Situ Validation of a Correction for Time-Lag and In Situ Validation of a Correction for Time-Lag and Bias Errors in Vaisala RS80-H Radiosonde Humidity Measurements L. M. Miloshevich National Center for Atmospheric Research Boulder, Colorado H. Vömel and S. J. Oltmans National Oceanic and Atmospheric Administration Boulder, Colorado A. Paukkunen Vaisala Oy Helsinki, Finland Introduction Radiosonde relative humidity (RH) measurements are fundamentally important to Atmospheric Radiation Measurement (ARM) Program goals because they are used in a wide variety of both operational and research applications, including initialization of numerical models and evaluation of model results, validation of remote-sensor water vapor retrievals, construction of water vapor climatologies and studies of climate trends, parameterization of cloud processes, and as input to

9

WBI Ceilometer/MLH andWBI Ceilometer/MLH and CO2 Time Series  

E-Print Network (OSTI)

99 m 420 460 mole/mole 99 m 379 m 340 380 CO2um Time where tower levels 1&2 become well mixed Time/mole 99 m 379 m 340 380 CO2um Time where tower levels 1&2 become well mixed Time where tower levels 1 379 m 340 380 CO2um Time where tower levels 1&2 become well mixed Time where tower levels 1-3 become

Stanier, Charlie

10

Climate zones for maritime clouds  

SciTech Connect

In this paper we use a commercially available lidar ceilometer to investigate how the basic structure of marine boundary-layer clouds varies for four different marine climate regimes. We obtained most of the data used in this analysis from ship-based ceilometer measurements recorded during several different atmospheric and oceanographic field programs conducted in the Atlantic and Pacific oceans. For comparison, we show the results obtained at a mid-latitude continental location and at an ice camp on the Arctic ice shelf. For each analyzed case, we use an extended time series to generate meaningful cloud base and cloud fraction statistics. The Vaisala CT 12K ceilometer uses a GaAs diode laser to produce short (150 ns), high-intensity pulses of infrared radiation (904 nm wavelength). The return signals from a large number of consecutive pulses are coherently summed to boost the signal-to-noise ratio. Each resulting 30-s profile of backscattered power (15-m resolution) is analyzed to detect cloud layers using a specified cloud detection limit. In addition to measurements of cloud base, the ceilometer can also provide information on cloud fraction using a time series of the {open_quotes}cloud{close_quotes} or {open_quotes} no cloud{close_quotes} status reported in the 30-s data.

White, A.B.; Ruffieux, D. [Univ. of Colorado, Boulder, CO (United States); [National Oceanic and Atmospheric Administration, Boulder, CO (United States); Fairall, C.W. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)

1995-04-01T23:59:59.000Z

11

Dry Bias in Vaisala RS90 Radiosonde Humidity Profiles over Antarctica PENNY M. ROWE  

E-Print Network (OSTI)

measurements made by radio- sondes. Some radiosonde humidity sensors experience a dry bias caused by solar were launched in clear skies at solar zenith angles (SZAs) near 83° and 62°. As part of this field) for SZAs near 83°; they are 20% 6% and 24% 5% for SZAs near 62°. Assuming solar heating is minimal at SZAs

Walden, Von P.

12

ARM - Data Announcements Article  

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of a new datastream available to the ARM and broader scientific community thanks to an evaluation conducted to compare the PBL height measurement from the ceilometer against the...

13

Posters Climate Zones for Maritime Clouds A. B. White and D....  

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marine climate regimes. We obtained most of the data used in this analysis from ship-based ceilometer measurements recorded during several different atmospheric and...

14

ARM - Data Announcements Article  

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6, 2015 Data Announcements New and Improved Ceilometer Datastream Available Bookmark and Share First cloud base height data are shown above at the various heights at which cloud...

15

miller-er-99.PDF  

NLE Websites -- All DOE Office Websites (Extended Search)

Correction for Dry Bias in Vaisala Radiosonde RH Data Correction for Dry Bias in Vaisala Radiosonde RH Data E. R. Miller, J. Wang, and H. L. Cole National Center for Atmospheric Research Atmospheric Technology Division Boulder, Colorado Abstract Extensive data analysis of sounding data from the Tropical Ocean Global Atmosphere-Coupled Ocean Atmosphere Response Experiment (TOGA-COARE) and other research projects coupled with supporting evidence from other sources have lead to the conclusion that there is a dry bias in Vaisala radiosonde relative humidity (RH) measurements. This dry bias occurs in both the A-type and H-type radiosonde RH sensors. Convinced of the problem, Vaisala engineers conducted extensive chamber tests on Vaisala sondes of varying age. Vaisala determined that the dry bias was due to contamination

16

1  

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Center for Atmospheric Research Boulder, Colorado A. Paukkunen Vaisala Oy Helsinki, Finland Introduction The goal of this study is to improve the accuracy of relative humidity...

17

1  

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Instrument Measurement Manufacturer Sampling Rate (interval) Accuracy HeightRange Thermometer Temperature Vaisala 1 min. avgs. (1 sec) 0.41C 2 m RH Sensor Relative humidity...

18

www.pmel.noaa.gov/OCS September 2012 NOAA Pacific Marine Environmental Laboratory  

E-Print Network (OSTI)

. Background The Vaisala WXT520 is a combination weather instrument, with sensors that the wind speed sensors of some Vaisala WXT520 combination weather sensors were was going to fix the problem in new instruments. A new sensor received in 2012

19

1  

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Vaisala RS-80H Radiosonde Vaisala RS-80H Radiosonde Dry-Bias Correction Redux B. M. Lesht Environmental Research Division Argonne National Laboratory Argonne, Illinois S. J. Richardson Department of Meteorology Pennsylvania State University University Park, Pennsylvania Introduction In previous studies (e.g., Lesht 1997, 1998, 1999; Lesht and Richardson 2001; Richardson et al. 2000) we examined the effects of dry bias in Vaisala RS-80H radiosonde humidity measurements on Atmospheric Radiation Measurement (ARM) data. Some of this analysis was done by using a preliminary version of a humidity correction algorithm that was developed by Vaisala in conjunction with their colleagues at the National Center for Atmospheric Research (NCAR). Because Vaisala insisted that the information included in the algorithm be proprietary, we were required to execute a

20

Total lightning characteristics of ordinary convection  

E-Print Network (OSTI)

processes involved in the electrical development of thunderstorms. Nine of the thunderstorm cases examined occurred within range of Vaisala Inc.'s Dallas-Fort Worth (DFW) Lightning Detection and Ranging (LDAR) network and the other thirteen cases occurred...

Motley, Shane Michael

2009-06-02T23:59:59.000Z

Note: This page contains sample records for the topic "vaisala ceilometer vceil" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Microsoft Word - westwater_er.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

infrared error that is especially noticeable at night when compared with Vaisala type sensors (Schmidlin et al. 1986). The error of the rod is keyed to the background radiative...

22

Water Vapor Experiment Concludes  

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(Holger Voemel, NOAA and University of Colorado). November 2003 2 first North American launch of the new Vaisala RS92 radiosonde on November 5, 2003. NASA also deployed a...

23

Research Highlight  

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Improved Daytime Precipitable Water Vapor from Vaisala Radiosonde Humidity Improved Daytime Precipitable Water Vapor from Vaisala Radiosonde Humidity Sensors Download a printable PDF Submitter: Cady-Pereira, K. E., Atmospheric and Environmental Research, Inc. Mlawer, E. J., Atmospheric & Environmental Research, Inc. Turner, D. D., National Oceanic and Atmospheric Administration Shephard, M. W., Atmospheric and Environmental Research, Inc. Clough, S. A., Atmospheric and Environmental Research, Inc. Area of Research: Atmospheric Thermodynamics and Vertical Structures Working Group(s): Radiative Processes Journal Reference: Cady-Pereira, K, M Shephard, E Mlawer, D Turner, S Clough, and T Wagner. 2008. "Improved daytime column-integrated precipitable water vapor from Vaisala radiosonde humidity sensors." Journal of Atmospheric and Oceanic Technology doi: 10.1175/2007JTECHA1027.1.

24

Radiosondes Corrected for Inaccuracy in RH Measurements  

DOE Data Explorer (OSTI)

Corrections for inaccuracy in Vaisala radiosonde RH measurements have been applied to ARM SGP radiosonde soundings. The magnitude of the corrections can vary considerably between soundings. The radiosonde measurement accuracy, and therefore the correction magnitude, is a function of atmospheric conditions, mainly T, RH, and dRH/dt (humidity gradient). The corrections are also very sensitive to the RH sensor type, and there are 3 Vaisala sensor types represented in this dataset (RS80-H, RS90, and RS92). Depending on the sensor type and the radiosonde production date, one or more of the following three corrections were applied to the RH data: Temperature-Dependence correction (TD), Contamination-Dry Bias correction (C), Time Lag correction (TL). The estimated absolute accuracy of NIGHTTIME corrected and uncorrected Vaisala RH measurements, as determined by comparison to simultaneous reference-quality measurements from Holger Voemel's (CU/CIRES) cryogenic frostpoint hygrometer (CFH), is given by Miloshevich et al. (2006).

Miloshevich, Larry

25

Southern Great Plains Newsletter  

SciTech Connect

This months issue contains the following articles: (1) Scientists convene at SGP site for complex convective cloud experiment; (2) VORTEX2 spins down; (3) Sunphotometer supports SPARTICUS (a Sun and Aureole Measurement imaging sunphotometer) campaign and satellite validation studies; and (4) Ceilometer represents first deployment of new ground-based instruments from Recovery Act.

J. Prell

2010-09-01T23:59:59.000Z

26

Cassandra Wheeler Univ. of Colorado Department of Atmospheric and Oceanic Sciences (ATOC)  

E-Print Network (OSTI)

on the energy budget NOAA's Contribution: Remotely observe cloud layers and environmental conditions Svalbard, Norway 85 °N 0 °E Greenland Location: 87°N Duration: 1 Aug ­15 Sept 2008 Platform : Swedish Icebreaker Oden #12;Ka-Band Radar S-Band Radar Wind Profiler Scanning Radiometer Lidar Ceilometer 2-Channel

27

1  

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Improved Water Vapor Measurements Improved Water Vapor Measurements from ARM Radiosondes L. Miloshevich and A. J. Heymsfield National Center for Atmospheric Research Boulder, Colorado A. Paukkunen Vaisala Oy Helsinki, Finland Introduction Accurate radiosonde measurements of water vapor in the mid and upper troposphere are important for such applications as evaluating remote-sensor water vapor retrievals, initializing numerical models, and improving parameterizations of radiative and cloud processes. Measurements of relative humidity (RH) from Vaisala radiosondes are subject to several measurement errors, most of which increase in magnitude with decreasing temperature (Miloshevich et al. 2000). Several of these measurement errors have already been corrected in part of the Atmospheric Radiation Measurement (ARM) Program dataset

28

Total lightning observations of severe convection over North Texas  

E-Print Network (OSTI)

potential. Total lightning data were obtained from Vaisala Inc.s Dallas/Fort Worth (D/FW) Lightning Detection and Ranging (LDAR) network. Radar data from two Weather Surveillance Radar 1988 Doppler (WSR-88D) sites were used for position data...

McKinney, Christopher Michael

2009-05-15T23:59:59.000Z

29

Professional Paper 13 Climatological Atlas  

E-Print Network (OSTI)

NOAA Professional Paper 13 Climatological Atlas of the World Ocean Rockvilie, Ud. December 1982 U .l #12;ERRATA SHEET for: "Climatological Atlas of the World Ocean" NOAA Professional Paper No. 13 1. .. .. .. 3) Throughout the atlas the quantity Brunt-Vaisala frequency i s specified as having units of cycles

30

Van der Meulen and Brandsma Februari 2007 Thermometer Screen Intercomparison in De Bilt (the  

E-Print Network (OSTI)

conditions during a 6- year field experiment in De Bilt (the Netherlands). The comparison comprised two versions of an aspi- rated Young screen, 4 naturally ventilated round-shaped multi-plate screens (KNMI, Vaisala, Young, Socrima), a slightly aspirated version of the KNMI screen, a synthetic Stevenson screen

Haak, Hein

31

INTERNATIONAL JOURNAL OF CLIMATOLOGY Int. J. Climatol. (in press)  

E-Print Network (OSTI)

field experiment in De Bilt (the Netherlands). The comparison comprised two versions of an aspirated Young screen, four naturally ventilated round shaped multi-plate screens (KNMI, Vaisala, Young, Socrima conditions. The response time of the screens is studied by making a daily comparison of the time stamps

Brandsma, Theo

32

Advanced Lidars for ARM: What Would We Get?  

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CMWG Breakout Session CMWG Breakout Session 2009 ARM Science Team Meeting Advanced Lidars for ARM: What Would We Get? Dave Turner, Ed Eloranta University of Wisconsin - Madison CMWG Breakout Session 2009 ARM Science Team Meeting What is an "Advanced Lidar?" (1) * Ceilometer - Max range ~7km, unpolarized, uncalibrated * Micropulse lidar (MPL) - Sensitive to clouds & aerosols throughout troposphere - Small telescope, rep rate is 1.5 kHz, microjoules of power - Loses sensitivity to cirrus in upper trop during the day - Polarization sensitive - Uncalibrated * Backscatter signals measured by both the MPL and the Ceilometer are convolutions of molecular and particle scattering events - Unable to determine particle extinction without significant assumptions - Main use by ARM has been to determine layer boundaries

33

ARM - Facility News Article  

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Improved Radiosonde Sensor Ready for Launch Improved Radiosonde Sensor Ready for Launch Bookmark and Share At the end of a string tied to the weather balloon, a small sensor package, called a radiosonde, contains the "brains" for measuring atmospheric temperature, pressure and humidity. At the end of a string tied to the weather balloon, a small sensor package, called a radiosonde, contains the "brains" for measuring atmospheric temperature, pressure and humidity. As part of the Balloon Borne Sounding System, radiosondes launched at the the ARM Climate Research Facility sites are supplied by Vaisala, one of the market leaders of this technology. Vaisala began phasing out production of the RS90 radiosondes at the end of calendar year 2004 in favor of their new RS92 model. The new version has an improved global positioning system

34

ARM - PI Product - Radiosondes Corrected for Inaccuracy in RH Measurements  

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ProductsRadiosondes Corrected for Inaccuracy in RH ProductsRadiosondes Corrected for Inaccuracy in RH Measurements Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Radiosondes Corrected for Inaccuracy in RH Measurements 2000.01.01 - 2005.12.31 Site(s) SGP General Description Corrections for inaccuracy in Vaisala radiosonde RH measurements have been applied to ARM SGP radiosonde soundings. The magnitude of the corrections can vary considerably between soundings. The radiosonde measurement accuracy, and therefore the correction magnitude, is a function of atmospheric conditions, mainly T, RH, and dRH/dt (humidity gradient). The corrections are also very sensitive to the RH sensor type, and there are 3 Vaisala sensor types represented in this dataset (RS80-H, RS90, and RS92).

35

ARM - Publications: Science Team Meeting Documents  

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Radiosonde Intercomparison During the Fall 2000 Water Vapor IOP Radiosonde Intercomparison During the Fall 2000 Water Vapor IOP Lesht, B.M. (a) and Richardson, S.J. (b), Argonne National Laboratory (a), University of Oklahoma (b) Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting We conducted 160 dual-radiosonde soundings during the fall 2000 Water Vapor Intensive Operations Period (WVIOP). The soundings were done every three hours at the SGP/CART site central facility from 1430 on 18 September 2000 through 1130 on 8 October 2000. The dual soundings included Vaisala RH-80H radiosondes from four different calibration lots as well as Vaisala RS-90 radiosondes. The radisondes were distributed during the experiment so as to conduct pairwise comparisons between RS-80s, RS-90s and RS-80s/RS-90s. Prior to the WVIOP we tested the calibration of these types of radiosondes

36

The Houston Lightning Mapping Array: Network Installation and Preliminary Analysis  

E-Print Network (OSTI)

in August of the same year. Two additional sensors were added to the network in January 2007, bringing the Houston LDAR-II network to a full set of twelve stations. These sensors were purchased from Vaisala, Inc. who developed a commercial version... functionally similar to the Lightning Mapping Array sensors developed at New Mexico Institute of Mining and Technology. The Houston LDAR-II network remained operational until March 2012 when the network was decommissioned and subsequently replaced...

Cullen, Matthew Ryan

2013-06-25T23:59:59.000Z

37

I  

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BAECC: BAECC: I ni*al S ite L ayout AOS Instrument Field, radars, and containers Instrument F ield a nd C ontainers 6 0 m 9 0 m Met Twr T r e e H e i g h t ~ 2 0 M T r e e H e i g h t ~ 2 0 m Tree Height ~5m T r e e H e i g h t ~ 2 0 m K A Z R B S R W P P D M Rad Tables: mfrsr, TSI skyrad, SPN 10 M Scale M W A C R MWR mounted side by side with 1 m in between scan direction indicated by arrows MWR3C p w r P W R D r o p G P R W P A N T E Q 1 9 0 f t 6 4 f t E Q 2 u n d e r s a c r E Q 1 A N T Snow Fence Measurements a re c lose a pproximates. S ite w as l aid o ut D uring A ug S ite V isit Container P ad D etail AMF2 SACR OPS Van GP Van RWP Van 20' 90' 64' PWR 20' 20' mpl 2d VD MAERI BBSS cart WBRG VCEIL Instrument Field 10" 10' 10" 10" 10" SWACR Antenna EQ1 Van AMFX SACR 20' EQ2 under SACR Instrument F ield 1 1 2 3 2 3 Instrument F ield Looking S outh E ast Looking S outh Looking N orth E ast Looking N orth W---Band a nd K a---Band R adar

38

ovtchinnikov-98.pdf  

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51 51 Cloud Remote Sensing Using ARM Instruments: Observations and Modeling M. Ovtchinnikov and Y. L. Kogan Cooperative Institute for Mesoscale Meteorological Studies Norman, Oklahoma Introduction The constantly expanding Atmospheric Radiation Measure- ment (ARM) instrumental base for observing clouds now consists of about a dozen instruments including ceilometers, lidars, and a cloud radar. The majority of these instruments provides indirect measurements and requires a use of retrieval algorithms to deduce cloud properties needed for developing and testing cloud parameterizations for general circulation models (GCMs). In situ aircraft measurements during intensive observation periods (IOPs) are intended to provide ground truth for testing these retrieval procedures.

39

Frequency ratio method for seismic modeling of Gamma Doradus stars  

E-Print Network (OSTI)

A method for obtaining asteroseismological information of a Gamma Doradus oscillating star showing at least three pulsation frequencies is presented. This method is based on a first-order asymptotic g-mode expression, in agreement with the internal structure of Gamma Doradus stars. The information obtained is twofold: 1) a possible identification of the radial order n and degree l of observed frequencies (assuming that these have the same l), and 2) an estimate of the integral of the buoyancy frequency (Brunt-Vaisala) weighted over the stellar radius along the radiative zone. The accuracy of the method as well as its theoretical consistency are also discussed for a typical Gamma Doradus stellar model. Finally, the frequency ratios method has been tested with observed frequencies of the Gamma Doradus star HD 12901. The number of representative models verifying the complete set of constraints (the location in the HR diagram, the Brunt-Vaisala frequency integral, the observed metallicity and frequencies and a re...

Moya, A; Amado, P J; Martin-Ruiz, S; Garrido, R

2004-01-01T23:59:59.000Z

40

ARM - Publications: Science Team Meeting Documents  

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Boundary Layer Structure and Fair-Weather Cumulus Characteristics at the Boundary Layer Structure and Fair-Weather Cumulus Characteristics at the TWP ARM Site - Comparisons with Other Tropical and Subtropical Sites Albrecht, B. and Kollias, P., University of Miami Thirteenth Atmospheric Radiation Measurement (ARM) Science Team Meeting Fair-weather cumuli are fundamental in regulating the vertical structure of water vapor and entropy in the lowest 2 km of the Earths atmosphere over vast areas of the oceans. Boundary layer structures and cloud characteristics observed at Nauru (ARM TWP) during suppressed convective conditions are compared with those observed at other tropical and subtropical sites. Over three years of data from the mm-wavelength cloud radar and ceilometer observations at the Nauru site are analyzed and a statistical description of the field of fair weather cumulus is inferred.

Note: This page contains sample records for the topic "vaisala ceilometer vceil" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Section 74  

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Comparisons of the Micropulse Lidar and the Belfort Comparisons of the Micropulse Lidar and the Belfort Laser Ceilometer at the Atmospheric Radiation Measurement Southern Great Plains Cloud and Radiation Testbed Site D.D. Turner Pacific Northwest National Laboratory Richland, Washington Introduction The general goal of the Atmospheric Radiation Measurement (ARM) Program is to improve general circulation and related models of the atmosphere for global and regional prediction (DOE 1990). In order to achieve this goal, the ARM Program is collecting a prodigious volume of data at its first Cloud and The time period selected to do the comparisons between the Radiation Testbed (CART) in the Southern Great Plains of the instruments was April 4, 1994, through May 8, 1994. In this United States. Some quantities, such as cloud base height, can

42

Research Highlight  

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Cloud Observations at Niamey During the AMF Deployment Cloud Observations at Niamey During the AMF Deployment Submitter: Kollias, P., McGill University Area of Research: Cloud Distributions/Characterizations Working Group(s): Cloud Properties Journal Reference: Kollias, P. and M. A. Miller, 2007: Cloud and Precipitation Observations at Niamey During the 2006 ARM Mobile Facility Deployment. Submitted to Geophysical Research Letters. Daily observed cloud fraction in Niamey during the AMF deployment. The cloud fraction is derived using measurements from the 94-GHz radar, the MPL, and the ceilometer. The vertical resolution is 260 m, and a 5-day temporal filter is applied to the daily cloud fraction profiles. (a) Monthly-averaged cloud and precipitation fraction. The monthly mean and standard deviation of cirrus cloud top (white line), middle cloud tops

43

Microsoft PowerPoint - ARMST2009.shupeposter.ppt [Compatibility Mode]  

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Spring and Fall Arctic Mixed-Phase Clouds: Spring and Fall Arctic Mixed-Phase Clouds: Perspectives from the surface during ISDAC and MPACE Matthew Shupe a , David Turner b , Ed Eloranta b , Pavlos Kollias c p a CIRES - University of Colorado and NOAA/ESRL, b University of Wisconsin- Madison, c McGill University Summary Cloud Boundaries -Cloud top identified using radar, cloud base identified using high spectral resolution lidar or ceilometer. Phase Classification Uses phase specific signatures from radar lidar microwave radiometer and radiosonde measurements (Shupe GRL 2007) Retrieval Methods Analysis involves 6 weeks of single-layer, stratiform, mixed-phase cloud observations from the NSA site during MPACE (Sept-Nov 2004) and ISDAC (April-May 2008)  Similar structure and processes occur in Arctic stratiform

44

ARM - Field Campaign - Winter Single Column Model IOP  

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govCampaignsWinter Single Column Model IOP govCampaignsWinter Single Column Model IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Winter Single Column Model IOP 1999.01.19 - 1999.02.08 Lead Scientist : David Randall Data Availability Actual data files for a number of past SCM IOPs are available from the ARM Archive under IOPs/UAV. Cloud and Radiation Products Derived from Satellite Data Colorado State's Single Column Modeling Home Page For data sets, see below. Description A second winter SCM IOP was conducted (1/19 - 2/8/99) to provide additional sampling of winter weather conditions. This was the first SCM IOP where AERIs and ceilometers were installed at the boundary facilities to give retrievals of temperature and moisture to supplement the sounding data. A

45

Section 18  

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Analysis of the Temperature Dependence of Low Cloud Optical Thickness Using ARM Data and the GISS GCM A. D. Del Genio NASA/Goddard Institute for Space Studies New York, New York A. B. Wolf Science Systems and Applications, Inc. New York, New York G. Tselioudis Columbia University New York, New York One of the larger uncertainties in global climate model C The Belfort Laser Ceilometer (BLC) measures cloud base estimates of sensitivity to external perturbations is the height projected climate change of cloud optical thickness. Conventional wisdom suggests that since an adiabatically C The Geostationary Operational Environmental Satellite lifted parcel condenses more water if its temperature is higher, (GOES) infrared satellite brightness temperatures identify its optical thickness should increase with warming. For low

46

ARM - Field Campaign - Observations and Modeling of the Green Ocean Amazon:  

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govCampaignsObservations and Modeling of the Green Ocean Amazon: SKIP govCampaignsObservations and Modeling of the Green Ocean Amazon: SKIP Pre-campaign Measurements Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Observations and Modeling of the Green Ocean Amazon: SKIP Pre-campaign Measurements 2013.03.15 - 2015.12.31 Lead Scientist : Heath Powers For data sets, see below. Description The Self-Kontained Instrument Platform (SKIP) container is being deployed at the T3 GOAmazon site containing a basic set of meteorological and radiometric instrumentation including: SMET, SKYRAD, GRNRAD, and ceilometer (all ARM instruments), an ozone monitor, and a nitric Oxide/nitrogen

47

ARM - Publications: Science Team Meeting Documents  

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Comparison of Boundary Layer Cloud Properties using Surface and GOES Comparison of Boundary Layer Cloud Properties using Surface and GOES Measurements at the ARM SGP Site Dong, X. (a), Minnis, P. (b), Smith, W.L., Jr. (b), and Mace, G.G. (a), University of Utah (a), NASA Langley Research Center (b) Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting Boundary layer cloud microphysical and radiative properties derived from GOES data during March 2000 cloud IOP at ARM SGP site are compared with simultaneous surface-based observations. The cloud-droplet effective radius, optical depth, and top-of-atmoshpere (TOA) albedo are retrieved from a 2-stream radiative transfer model in conjunction with ground-based measurements of cloud radar, laser ceilometer, microwave and solar radiometers. The satellite results are retrieved from GOES visible and

48

ackerman-98.pdf  

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One-Year Cloud Climatology for the One-Year Cloud Climatology for the Southern Great Plains Site T. P. Ackerman, R. T. Marchand, and E. E. Clothiaux Department of Meteorology The Pennsylvania State University University Park, Pennsylvania Introduction The addition of the millimeter wave cloud radar (MMCR) to the suite of instruments at the Southern Great Plains (SGP) site has provided the necessary observations to produce a cloud climatology. Data from the MMCR are currently being combined with data from the Belfort laser ceilometer (BLC) and micropulse lidar (MPL) to determine cloud occurrence and location using algorithms developed by our research group. These basic cloud statistics should prove useful for comparing with both single-column model (SCM) and general circulation model (GCM) predictions of cloud

49

PowerPoint Presentation  

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SIRTA, a French Atmospheric Observatory SIRTA, a French Atmospheric Observatory for Clouds, Aerosols and Water Vapor Institut Pierre Simon Laplace, France H. Chepfer Coordinator : M. Haeffelin (haeffelin@lmd.polytechnique.fr) Contributors : C. Boitel, D. Bouniol, M. Chiriaco, P. Drobinski, J-L. Dusfrene, C. Goukenleuque, M. Grall, A. Hodzic, F. Hourdin, F. Lapouge, A Mathieu, P. Minnis, Y. Morille, C. Naud, V. Noel, B. O'Hirok, J. Pelon, C. Pietras, A. Protat, B. Romand, R. Vautard SIRTA : Atmospheric Remote Sensing 25 km south of Paris Palaiseau (48.7 o N, 2.2 o E) SIRTA Instrumentation LIDAR B-scat Lidar (532, 1064) Clouds, aerosols properties 1999 Ceilometer (KNMI) Cloud, BL Height 2002 IR Doppler Lidar (10.6 mm) 3D Wind 1999

50

ARM - Publications: Science Team Meeting Documents  

NLE Websites -- All DOE Office Websites (Extended Search)

Sizes, Fractional Coverage, and Radar Doppler Moments Profiles of Sizes, Fractional Coverage, and Radar Doppler Moments Profiles of Fair-Weather Cumulus Clouds at the TWP ARM Site Kollias, P., Albrecht B.A., and Dow B.J., University of Miami Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting Fair-weather cumuli are fundamental in regulating the vertical structure of water vapor and entropy in the lowest 2 km of the Earth's atmosphere over vast areas of the oceans. Using data from the mm-wavelength cloud radar, the micro-pulse lidar and ceilometer at the Nauru (TWP-ARM) site, a statistical description of the field of fair weather cumulus is inferred. Frequency diagrams of cloud thickness, fractional coverage, updraft-downdraft magnitudes and cloud reflectivity are calculated. The relationship of the statistical behavior of the cumulus field to the

51

SOAR Data: Data from Shipboard Oceanographic and Atmospheric Radiation (SOAR)1999 through 2001  

DOE Data Explorer (OSTI)

Click on the DATA menu button and then click on a specific ship to find instructions on accessing data from that particular cruise. Instructions will lead you to an FTP site from which data can be downloaded. SOAR data for 1999 through 2001 is reported. SOAR is a global network of research and volunteer ships that carry global change instrumentation. The primary emphasis for SOAR is solar and IR radiation but some ships cary ceilometers, meteorological instruments, and related equipment. All data are collected in a central data collection computer and the flexible data collection software can be adapted to any other user instrumentation. Currently SOAR is installed pas permanent instrumentation on four ships operating in the western Pacific, eastern tropical Pacific, West Indies, and an oceanographic ship that operates around the world. In addition, six other system are used on cruises of opportunity. [Taken from SOAR homepage at http://www.gim.bnl.gov/soar/index.html

52

ARM - Datastreams - sondewrpn  

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Datastreamssondewrpn Datastreamssondewrpn Documentation XDC documentation Data Quality Plots ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : SONDEWRPN Balloon-borne sounding system (BBSS): research winds, Vaisala press., temp, &RH Active Dates 1994.04.20 - 2002.05.27 Measurement Categories Atmospheric State Originating Instrument Balloon-Borne Sounding System (SONDE) Measurements Only measurements considered scientifically relevant are shown below by default. Show all measurements Measurement Units Variable altitude meters above Mean Sea Level alt ( time ) Ascent Rate m/s asc ( time ) Base time in Epoch seconds since 1970-1-1 0:00:00 0:00 base_time Horizontal wind Wind Direction deg deg ( time )

53

ARM - Field Campaign - Arctic Winter Water Vapor IOP  

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govCampaignsArctic Winter Water Vapor IOP govCampaignsArctic Winter Water Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Arctic Winter Water Vapor IOP 2004.03.09 - 2004.04.09 Lead Scientist : Ed Westwater Data Availability http://www.etl.noaa.gov/programs/2004/wviop/data will contain quicklooks of all of the data. For data sets, see below. Summary During the IOP, the Ground-based Scanning Radiometer of NOAA/ETL, and the ARM MicroWave Radiometer and Microwave Profiler, yielded excellent data over a range of conditions. In all, angular-scanned and calibrated radiometric data from 22.345 to 380 GHz were taken. The Precipitable Water Vapor varied about an order of magnitude from 1 to 10 mm, and surface temperatures varied from about -10 to -40 deg. Celcius. Vaisala RS90

54

ARM - Facility News Article  

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15, 2007 [Facility News] 15, 2007 [Facility News] Radiosonde Temperature Sensor Benefits from Stronger Structure Bookmark and Share The new temperature sensor (front and back shown above) for the RS92 radiosonde sports an integrated fiber-reinforced structure that improves durability while maintaining the needed measurement accuracy and response. The new temperature sensor (front and back shown above) for the RS92 radiosonde sports an integrated fiber-reinforced structure that improves durability while maintaining the needed measurement accuracy and response. Small sensor packages called radiosondes (or "sondes") are used to transmit atmospheric information from weather balloons as they rise through the air. Vaisala, the supplier of sondes used at all the ARM sites, has introduced

55

ARM - Datastreams - sondewnpr  

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Datastreamssondewnpr Datastreamssondewnpr Documentation XDC documentation Data Quality Plots ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : SONDEWNPR Balloon-borne sounding system (BBSS): Vaisala winds, research press., temp, &RH Active Dates 1997.09.18 - 1997.09.26 Measurement Categories Atmospheric State Originating Instrument Balloon-Borne Sounding System (SONDE) Measurements Only measurements considered scientifically relevant are shown below by default. Show all measurements Measurement Units Variable Altitude above mean sea level m alt ( time ) Ascent Rate m/s asc ( time ) Base time in Epoch seconds since 1970-1-1 0:00:00 0:00 base_time Horizontal wind Wind Direction deg deg ( time )

56

Microsoft Word - AMF2 Instruments for BAECC.docx  

NLE Websites -- All DOE Office Websites (Extended Search)

AMF2 AMF2 I nstruments f or B AECC Instrument Mentor Instrument Name Manufacturer Measurement ASSISTII ( like an A eri) Connor F lynn ASSISTII LR---Tech, Inc. Temperature a nd w ater v apor p rofiles CSPHOT Laurie G regory Cimel Sunphotometer CIMEL Electronique Solar i rradiance and sky radiance IRT Vic M orris Infrared Thermometer Heimann Equivalent b lack b ody b rightness t emps MWR---2C Maria C adeddu Microwave Radiometer Radiometrics Column H 20 v apor a nd l iquid MWR---3C Maria C adeddu Microwave Radiometer Radiometrics Column H 20 v apor a nd l iquid TSI Vic Morris/Mike Reynolds Total S ky I mager Yankee Environmental Systems Cloud f raction v alues BBSS Donna Holdridge Balloon B orne Sounding S ystem Vaisala, I nc. Temp, h umidity, p ressure, w ind s peed a nd direction p rofiles

57

Analysis of Selected Radiosonde Data from the ARM/NSA Site  

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Analysis of Selected Radiosonde Data Analysis of Selected Radiosonde Data from the ARM/NSA Site B. Petracca, H. W. Church, and B. D. Zak Sandia National Laboratories Albuquerque, New Mexico R. Storvold and C. Marty Geophysical Institute University of Alaska Fairbanks, Alaska B. M. Lesht Argonne National Laboratories Argonne, Illinois Introduction The purpose of this study was to analyze differences in temperature and relative humidity (RH) profiles obtained from near-simultaneous radiosonde soundings made from different locations at and near the North Slope of Alaska (NSA) Cloud and Radiation Testbed (CART) site. The data for this study come from the Vaisala RS-80H radiosondes flown by Atmospheric Radiation Measurement (ARM) Program during the comparison periods, and from VIZ B2 radiosondes flown by the National Weather Service

58

ARM - Datastreams - sonicwind2d  

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Datastreamssonicwind2d Datastreamssonicwind2d Documentation Data Quality Plots ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : SONICWIND2D Horizontal wind speed and direction from ultrasonic wind sensor (Vaisala WS425), 2m above ground on Barrow MET tower Active Dates 2003.10.31 - 2008.09.16 Measurement Categories Atmospheric State Originating Instrument ultrasonic wind sensor (SONICWIND) Measurements Only measurements considered scientifically relevant are shown below by default. Show all measurements Measurement Units Variable Horizontal wind Wind direction vector mean deg SonicWD_DU_WVT ( time ) Wind direction vector mean standard deviation deg SonicWD_SDU_WVT ( time ) Horizontal wind Wind speed arithmetic mean m/s SonicWS_S_WVT ( time )

59

ARM - Facility News Article  

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Upgrade to Millimeter Wave Cloud Radar Increases Volume of Data Collection Upgrade to Millimeter Wave Cloud Radar Increases Volume of Data Collection Bookmark and Share In mid-April, hardware and software upgrades to the millimeter wave cloud radar (MMCR) at the ARM Climate Research Facility's North Slope of Alaska (NSA) were completed. Hardware upgrades included replacing the OS/2 and Solaris computers with two Windows 2000 computers. One of these computers is for the MMCR radar. It now has a new digital signal processing board that allows much more efficient processing of the radar return signals, resulting in higher temporal resolution. The receiver was also upgraded from a 12 bit to 14 bit analog-to-digital converter. Software on the MMCR radar computer was upgraded to run a modified version of Vaisala's LAP-XM software for controlling and acquiring the radar data. The other computer,

60

ARM - Datastreams - sondewnpn  

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Datastreamssondewnpn Datastreamssondewnpn Documentation XDC documentation Data Quality Plots Citation DOI: 10.5439/1021460 [ What is this? ] Generate Citation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Example sondewnpn Archive Data Plot Example sondewnpn Archive Data Plot Datastream : SONDEWNPN Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, &RH Active Dates 1994.04.12 - 2014.01.10 Measurement Categories Atmospheric State Originating Instrument Balloon-Borne Sounding System (SONDE) Measurements Only measurements considered scientifically relevant are shown below by default. Show all measurements Measurement Units Variable altitude meters above Mean Sea Level alt ( time )

Note: This page contains sample records for the topic "vaisala ceilometer vceil" from the National Library of EnergyBeta (NLEBeta).
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61

Atmospheric Radiation Measurement Climate Research Facility | Argonne  

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Atmospheric Radiation Measurement Climate Research Facility Atmospheric Radiation Measurement Climate Research Facility Argonne scientists study climate change 1 of 22 Argonne scientists study climate change The U.S. Department of Energy's Office of Science provided $60 million in ARRA funding for climate research to the Atmospheric Radiation Measurement (ARM) Climate Research Facility, a DOE national user facility that has been operating climate observing sites around the world for nearly two decades. These sites help scientists study clouds and their influence on the sun's radiant energy, which heats our planet. Above is one of the purchases: the Vaisala Present Weather Detector. It optically measures visibility, present weather, precipitation intensity, and precipitation type. It provides a measure of current weather conditions by combining measurements from three

62

Thunderhead Radiation Measurements and Radiative Flux Analysis in Support of STORMVEX  

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Thunderhead Radiation Thunderhead Radiation Measurements and Radiative Flux Analysis in Support of STORMVEX Chuck Long Jay Mace Intent * Provide downwelling broadband radiation measurements at Thunderhead * Physically small footprint portable system * Designed to provide inputs necessary for Radiative Flux Analysis Basic RFA System COPS Hornisgrinde Deployment 1200m elevation System Components * Eppley ventilated PSP * Eppley ventilated PIR * Delta-T SPN-1 * Vaisala HMP-50 T/RH probe * Campbell CR23X datalogger SPN-1 Radiometer * Uses 7 thermopile detectors and a patented shading pattern * Measures Total and Diffuse SW with no moving parts * Includes internal heaters Relative accuracy StDev = 13.6 Winter Mountain Deployment Frost/Snow Mitigation * NSA Heated Ventilator Evaluation IOP - Testing various configurations and

63

The Frequency Ratio Method for the seismic modelling of gamma Doradus stars. II The role of rotation  

E-Print Network (OSTI)

The effect of rotation on the Frequency Ratio Method (Moya et al. 2005) is examined. Its applicability to observed frequencies of rotating gamma Doradus stars is discussed taking into account the following aspects: the use of a perturbative approach to compute adiabatic oscillation frequencies; the effect of rotation on the observational Brunt-Vaisala integral determination and finally, the problem of disentangling multiplet-like structures from frequency patterns due to the period spacing expected for high-order gravity modes in asymptotic regime. This analysis reveals that the FRM produces reliable results for objects with rotational velocities up to 70 kms/s, for which the FRM intrinsic error increases one order of magnitude with respect to the typical FRM errors given in Moya et al. (2005). Our computations suggest that, given the spherical degree "l" identification, the FRM may be discriminating for m = 0 modes, in the sense that the method avoids any misinterpretation induced by the presence of rotation...

Surez, J C; Martin-Ruiz, S; Amado, P J; Garrido, A G R

2005-01-01T23:59:59.000Z

64

Research Highlight  

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Comparisons Between Radiosondes and Remote Sensors During the 2004 NSA Comparisons Between Radiosondes and Remote Sensors During the 2004 NSA Arctic Winter Radiometric Experiment Submitter: Westwater, E. R., University of Colorado Area of Research: Atmospheric Thermodynamics and Vertical Structures Working Group(s): Radiative Processes Journal Reference: Mattioli, V, ER Westwater, D Cimini, JS Liljegren, BM Lesht, SI Gutman, and FJ Schmidlin. 2007. "Analysis of radiosonde and ground-based remotely sensed PWV data from the 2004 North Slope of Alaska Arctic Winter Radiometric Experiment." Journal of Atmospheric and Oceanic Technology 243: 415-431. Description of radiosondes launched during the 2004 NSA Arctic Winter Radiometric Experiment. Dual-radiosonde launch of the Vaisala RS90 and Chilled Mirror radiosondes is pictured here.

65

A 25-month database of stratus cloud properties generated from ground-based measurements at the Atmospheric Radiation Measurement Southern Great Plains Site  

SciTech Connect

A 25-month database of the macrophysical, microphysical, and radiative properties of isolated and overcast low-level stratus clouds has been generated using a newly developed parameterization and surface measurements from the Atmospheric Radiation Measurement central facility in Oklahoma. The database (5-min resolution) includes two parts: measurements and retrievals. The former consist of cloud base and top heights, layer-mean temperature, cloud liquid water path, and solar transmission ratio measured by a ground-based lidar/ceilometer and radar pair, radiosondes, a microwave radiometer, and a standard Eppley precision spectral pyranometer, respectively. The retrievals include the cloud-droplet effective radius and number concentration and broadband shortwave optical depth and cloud and top-of-atmosphere albedos. Stratus without any overlying mid or high-level clouds occurred most frequently during winter and least often during summer. Mean cloud-layer altitudes and geometric thicknesses were higher and greater, respectively, in summer than in winter. Both quantities are positively correlated with the cloud-layer mean temperature. Mean cloud-droplet effective radii range from 8.1 {mu}m in winter to 9.7 {mu}m during summer, while cloud-droplet number concentrations during winter are nearly twice those in summer. Since cloud liquid water paths are almost the same in both seasons, cloud optical depth is higher during the winter, leading to greater cloud albedos and lower cloud transmittances. (c) 2000 American Geophysical Union.

Dong, Xiquan [Meteorology Department, University of Utah, Salt Lake City (United States)] [Meteorology Department, University of Utah, Salt Lake City (United States); Minnis, Patrick [NASA Langley Research Center, Hampton, Virginia (United States)] [NASA Langley Research Center, Hampton, Virginia (United States); Ackerman, Thomas P. [Pacific Northwest National Laboratory, DOE, Richland, Washington (United States)] [Pacific Northwest National Laboratory, DOE, Richland, Washington (United States); Clothiaux, Eugene E. [Department of Meteorology, Pennsylvania State University, University Park (United States)] [Department of Meteorology, Pennsylvania State University, University Park (United States); Mace, Gerald G. [Meteorology Department, University of Utah, Salt Lake City (United States)] [Meteorology Department, University of Utah, Salt Lake City (United States); Long, Charles N. [Department of Meteorology, Pennsylvania State University, University Park (United States)] [Department of Meteorology, Pennsylvania State University, University Park (United States); Liljegren, James C. [Ames Laboratory, DOE, Ames, Iowa (United States)] [Ames Laboratory, DOE, Ames, Iowa (United States)

2000-02-27T23:59:59.000Z

66

Estimation of CO2 effluxes from suburban forest floor and grass using a process-based model  

Science Journals Connector (OSTI)

Abstract Carbon dioxide is an important greenhouse gas, and its atmospheric concentration has been predicted to increase in the future. The objective of this study was to quantify the soil CO2 efflux in a suburban area including mixed deciduous forest and grass by numerically modeling the CO2 transport through the soil profile. Three stations per land-cover (forest and grass) were selected at the Cub Hill site (MD, USA), where the US Forest Service operates an urban flux tower. Six VAISALA CO2 sensors (Vaisala Inc., Finland) per monitoring station were horizontally installed at 6 different depths (soil surface, 0.02, 0.05, 0.10, 0.20, and 0.30m from the soil surface) in the mid of May, 2011. Temperature and volumetric soil moisture measurements were taken using thermistors and EC-5 sensors (Decagon devices, Pullman, WA, USA) that were installed at the same depths as the CO2 sensors except for the soil surface. These data were recorded every 10min. To evaluate the numerical model (SOILCO2), CO2 efflux using the standard chamber method was measured once a week. The CO2 effluxes from the standard chamber method ranged from 3.32נ10?9 to 7.28נ10?8m3m?2s?1 and 6.79נ10?9 to 1.45נ10?7m3m?2s?1 for forest and grass, respectively. The CO2 effluxes from bare soil at the grass site varied with the range of 3.63נ10?8 to 9.37נ10?8m3m?2s?1. The pulse effect (a rapid increase of CO2 concentrations right after rainfall events) in grass, where changes in soil moisture were larger than in the forest, was more apparent than in the forest. Diurnal patterns similar to those of temperature were observed from CO2 profiles in soils. The SOILCO2 model estimated the soil CO2 effluxes with coefficients of correlation of 0.64 and 0.76 at forest and grass, respectively, and root mean square error (RMSE) of 1.58נ10?8 and 2.06נ10?8m3m?2s?1 for forest and grass, respectively. This study suggests that the SOILCO2 model can provide a better understanding of the contribution of the soil ecosystem to the carbon cycle in suburban environments including mixed deciduous forest and grass.

J.A. Chun; K. Szlavecz; M. Bernard; D. Ferrer; J. Hom; N. Saliendra

2014-01-01T23:59:59.000Z

67

The dynamics of the radiative envelope of rapidly rotating stars. I. A spherical Boussinesq model  

E-Print Network (OSTI)

Context: The observations of rapidly rotating stars are increasingly detailed and precise thanks to interferometry and asteroseismology; two-dimensional models taking into account the hydrodynamics of these stars are very much needed. Aims: A model for studying the dynamics of baroclinic stellar envelope is presented. Methods: This models treats the stellar fluid at the Boussinesq approximation and assumes that it is contained in a rigid spherical domain. The temperature field along with the rotation of the system generate the baroclinic flow. Results: We manage to give an analytical solution to the asymptotic problem at small Ekman and Prandtl numbers. We show that, provided the Brunt-Vaisala frequency profile is smooth enough, differential rotation of a stably stratified envelope takes the form a fast rotating pole and a slow equator while it is the opposite in a convective envelope. We also show that at low Prandtl numbers and without $\\mu$-barriers, the jump in viscosity at the core-envelope boundary generates a shear layer staying along the tangential cylinder of the core. Its role in mixing processes is discussed. Conclusions: Such a model provides an interesting tool for investigating the fluid dynamics of rotating stars in particular for the study of the various instabilities affecting baroclinic flows or, even more, of a dynamo effect.

Michel Rieutord

2006-02-02T23:59:59.000Z

68

Stability and Turbulence in the Atmospheric Boundary Layer: A Comparison of Remote Sensing and Tower Observations  

SciTech Connect

When monitoring winds and atmospheric stability for wind energy applications, remote sensing instruments present some advantages to in-situ instrumentation such as larger vertical extent, in some cases easy installation and maintenance, measurements of vertical humidity profiles throughout the boundary layer, and no restrictions on prevailing wind directions. In this study, we compare remote sensing devices, Windcube lidar and microwave radiometer, to meteorological in-situ tower measurements to demonstrate the accuracy of these measurements and to assess the utility of the remote sensing instruments in overcoming tower limitations. We compare temperature and wind observations, as well as calculations of Brunt-Vaisala frequency and Richardson numbers for the instrument deployment period in May-June 2011 at the U.S. Department of Energy National Renewable Energy Laboratory's National Wind Technology Center near Boulder, Colorado. The study reveals that a lidar and radiometer measure wind and temperature with the same accuracy as tower instruments, while also providing advantages for monitoring stability and turbulence. We demonstrate that the atmospheric stability is determined more accurately when the liquid-water mixing ratio derived from the vertical humidity profile is considered under moist-adiabatic conditions.

Friedrich, K.; Lundquist, J. K.; Aitken, M.; Kalina, E. A.; Marshall, R. F.

2012-01-01T23:59:59.000Z

69

AMIE (ARM MJO Investigation Experiment): Observations of the Madden-Julian Oscillation for Modeling Studies Science Plan  

SciTech Connect

Deep convection in the tropics plays an important role in driving global circulations and the transport of energy from the tropics to the mid-latitudes. Understanding the mechanisms that control tropical convection is a key to improving climate modeling simulations of the global energy balance. One of the dominant sources of tropical convective variability is the Madden-Julian Oscillation (MJO), which has a period of approximately 3060 days. There is no agreed-upon explanation for the underlying physics that maintain the MJO. Many climate models do not show well-defined MJO signals, and those that do have problems accurately simulating the amplitude, propagation speed, and/or seasonality of the MJO signal. Therefore, the MJO is a very important modeling target for the ARM modeling community geared specifically toward improving climate models. The ARM MJO Investigation Experiment (AMIE) period coincides with a large international MJO initiation field campaign called CINDY2011 (Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011) that will take place in and around the Indian Ocean from October 2011 to January 2012. AMIE, in conjunction with CINDY2011 efforts, will provide an unprecedented data set that will allow investigation of the evolution of convection within the framework of the MJO. AMIE observations will also complement the long-term MJO statistics produced using ARM Manus data and will allow testing of several of the current hypotheses related to the MJO phenomenon. Taking advantage of the expected deployment of a C-POL scanning precipitation radar and an ECOR surface flux tower at the ARM Manus site, we propose to increase the number of sonde launches to eight per day starting in about mid-October of the field experiment year, which is climatologically a period of generally suppressed conditions at Manus and just prior to the climatologically strongest MJO period. The field experiment will last until the end of the MJO season (typically March), affording the documentation of conditions before, during, and after the peak MJO season. The increased frequency of sonde launches throughout the experimental period will provide better diurnal understanding of the thermodynamic profiles, and thus a better representation within the variational analysis data set. Finally, a small surface radiation and ceilometer system will be deployed at the PNG Lombrum Naval Base about 6 km away from the ARM Manus site in order to provide some documentation of scale variability with respect to the representativeness of the ARM measurements.

Long, C; Del Genio, A; Gustafson, W; Houze, R; Jakob, C; Jensen, M; Klein, S; Leung, L Ruby; Liu, X; Luke, E; May, P; McFarlane, S; Minnis, P; Schumacher, C; Vogelmann, A; Wang, Y; Wu, X; Xie, S

2010-03-22T23:59:59.000Z