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Improvement of the Soil Moisture Diagnostic Equation for Estimating Root-Zone Soil Moisture

Description: Soil moisture information can be used accurately in determining the timing and amount of irrigation applied to plants. Pan and Pan et al. proposed a robust and simple daily diagnostic equation for estimating daily soil moisture. The diagnostic equation evaluates the relationship between the soil moisture loss function and the summation weighted average of precipitation. The loss function uses the sinusoidal wave function which employs day of the year (DOY) to evaluate the seasonal variation in soil moisture loss for a given year. This was incorporated into the daily diagnostic equation to estimate the daily soil moisture for a location. Solar radiation is an energy source that drives the energy and water exchanges between vegetation and the atmosphere (i.e., evapotranspiration), and thus impacts the soil moisture dry-down. In this paper, two parameters (the actual solar radiation and the clear sky solar radiation) are introduced into loss function coefficient to improve the estimation of soil moisture. After the Introduction of the solar radiation data into soil moisture loss function, a slight improvement was observed in the estimated daily soil moisture. Pan observed that generally the correlation coefficient between the estimated and the observed soil moisture is above 0.75 and the root mean square error is below 5.0 (%v/v). The introduction solar radiation data (i.e. clear sky solar radiation and actual solar) improve the correlation coefficient average for all the sites evaluated by 0.03 when the root mean square error is generally below 4.5(%v/v) for the entire root zone.
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Date: May 2018
Creator: Omotere, Olumide Olubunmi
Partner: UNT Libraries

NREL North American Solar Radiation Atlas (Presentation)

Description: This presentation is about NREL's North American Solar Radiation Atlas, which currently includes 48 states (Alaska and Hawaii to be added in the future). It discusses the goals of the Atlas which are to: deliver basic solar performance estimates to general users, deliver a wide variety of additional information to more advanced users, be easy to use, full featured, and extensible.
Date: April 1, 2001
Creator: George, R & Gray-Hann, P.
Partner: UNT Libraries Government Documents Department

Interim Solar Radiation Data Manual: 30-Year Statistics from the National Solar Radiation Data Base

Description: The 30-year (1961-1990) statistics contained in this document have been derived from the National Solar Radiation Data Base (NSRDB) produced by the National Renewable Energy Laboratory (NREL). They outline solar radiation sources, as well as 30-year monthly and annual means of 5 solar radiation elements (three surface and two extraterrestrial) and 12 meteorological elements for 239 locations.
Date: November 1, 1992
Partner: UNT Libraries Government Documents Department

Regularities of Angular Distribution of Near-Horizon Sky Brightness in the Cloudless Atmosphere

Description: The methods of sun-photometry of the atmosphere based, for example, on interpretation of the angular distribution of radiation in the solar almucantar are widely used for retrieval of the aerosol optical characteristics. Preliminary analysis has shown that the near-horizon region also can be interesting for solving some applied problems. As is known, investigations of the structure of the daytime cloudless sky brightness at observation from the ground were carried out principally at zenith angles less than 80{sup o} in visible wavelength range. For further development of the methods it is necessary to obtain more complete data on the distribution of the cloudless sky brightness at great zenith angles of observation and wider wavelength range. The regularities of formation of the sky brightness field in the near-horizon region and just above the horizon line are considered in this paper.
Date: March 18, 2005
Creator: Sakerin, S.M.; Zhuraleva, T.B. & Nasrtdinov, I.M.
Partner: UNT Libraries Government Documents Department

Users manual for SERI QC software assessing the quality of solar radiation data

Description: This manual describes the procedures and software for assessing the quality of solar radiation data. This does not constitute quality control because quality control must take place during the preparations for data collection (selection, calibration, and installation of instruments), during the measurement process, and during the transmission (if any) and recording of the numerical values. Once the data are recorded, only quality assessment can be performed. If quality assessment is performed in real time or soon after the measurement process is completed, it can provide input to control the quality of future measurements. Furthermore, quality assessment can be used for quality control if data judged to be bad are deleted and/or modified. We do not subscribe to these actions because the deletion or modification of data destroys information that might be useful to the user. For example, if an instrument has gone through a gradual failure and all of the data that fail quality assessment criteria are deleted or modified, the user of the data may not be able to detect what was happening and will not question the accuracy of other data collected before the instrument completely failed. Therefore, the SERI QC procedures and software do not delete or modify data. Instead, flags are set to inform the user of any departure of the data from expected values. These flags indicate the magnitude and direction of such departures. For the flags to communicate as much information as possible, this manual attempts to identify and explain the probable causes of various flags. However, we cannot overemphasize the following: Flags only indicate that data do or do not fall within expected ranges. This does not mean that the data that the data are or are not valid.
Date: December 1, 1993
Creator: none,
Partner: UNT Libraries Government Documents Department

ACRF Instrumentation Status: New, Current, and Future - April 2008

Description: The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: May 1, 2008
Creator: Voyles, J. W.
Partner: UNT Libraries Government Documents Department

ARM mobile facility surface meteorology (MET) handbook.

Description: The Atmospheric Radiation Measurement (ARM) Mobile Facility Surface Meteorology station (MET) uses mainly conventional in situ sensors to obtain 1-min statistics of surface wind speed, wind direction, air temperature, relative humidity (RH), barometric pressure, and rainrate. Additional sensors may be added to or removed from the base set of sensors depending upon the deployment location, climate regime, or programmatic needs. In addition, sensor types may change depending upon the climate regime of the deployment. These changes/additions are noted in Section 3.
Date: April 1, 2006
Creator: Ritsche, M. T. & Division, Environmental Science
Partner: UNT Libraries Government Documents Department

Site scientific mission plan for the southern great plains CART site January-June 2000.

Description: The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site was designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This Site Scientific Mission Plan defines the scientific priorities for site activities during the six months beginning on January 1, 2000, and looks forward in less detail to subsequent six-month periods. The primary purpose of this document is to provide scientific guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, and Instrument Team [IT]) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the site program manager, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding. With this issue, many aspects of earlier Site Scientific Mission Plan reports have been moved to ARM sites on the World Wide Web. This report and all previous reports are available on the SGP CART web site.
Date: March 15, 2001
Creator: Peppler, R. A.; Sisterson, D. L. & Lamb, P.
Partner: UNT Libraries Government Documents Department

Kingdom of Saudi Arabia Solar Radiation Atlas

Description: This atlas provides a record of monthly mean solar radiation generated by a Climatological Solar Radiation model, using quasi-climatological inputs of cloud cover, aerosol optical depth, precipitable water vapor, ozone, surface albedo, and atmospheric pressure.
Date: December 16, 1998
Creator: National Renewable Energy Laboratory (U.S.)
Partner: UNT Libraries Government Documents Department

Current Issues in Terrestrial Solar Radiation Instrumentation for Energy, Climate and Space Applications Preprint prepared for New RAD '99

Description: Reductions of uncertainty in terrestrial solar radiation measurements are needed to validate the Earth's radiation balance derived from satellite data. Characterization of solar energy resources for renewable technologies requires greater time and spatial resolution for economical technology deployment. Solar radiation measurement research at the National Renewable Energy Laboratory addresses calibrations, operational characteristics, and corrections for terrestrial solar radiation measurements. We describe progress in measurements of broadband diffuse-sky radiation, and characterization of field instrument thermal offsets and spectral irradiance. The need and prospects for absolute references for diffuse and long-wave terrestrial solar radiation measurements are discussed. Reductions in uncertainty of broadband irradiance measurements from tens of watts per square meter to a few (one to two) watts per square meter are reported, which reduce time and labor to quantify and identify trends in artificial optical radiation sources, terrestrial solar radiation, and the Earth's radiation budget.
Date: October 20, 1999
Creator: Stoffel, T. L.; Reda, I.; Myers, D. R.; Renne, D.; Wilcox, S. W. & Treadwell, J.
Partner: UNT Libraries Government Documents Department

Site scientific mission plan for the southern Great Plain CART site July-December 1997.

Description: The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site is designed to help satisfy the data needs of the Atmospheric Radiation Measurement (ARM) Program Science Team. This document defines the scientific priorities for site activities during the six months beginning on July 1, 1997, and looks forward in lesser detail to subsequent six-month periods. The primary purpose of this Site Scientific Mission Plan is to provide guidance for the development of plans for site operations. It also provides information on current plans to the ARM functional teams (Management Team, Data and Science Integration Team [DSIT], Operations Team, Instrument Team [IT], and Campaign Team) and serves to disseminate the plans more generally within the ARM Program and among the members of the Science Team. This document includes a description of the operational status of the site and the primary site activities envisioned, together with information concerning approved and proposed intensive observation periods (IOPs). The primary users of this document are the site operator, the Site Scientist Team (SST), the Science Team through the ARM Program science director, the ARM Program Experiment Center, and the aforementioned ARM Program functional teams. This plan is a living document that is updated and reissued every six months as the observational facilities are developed, tested, and augmented and as priorities are adjusted in response to developments in scientific planning and understanding.
Date: August 28, 1997
Creator: Lamb, P.J.; Peppler, R.A. & Sisterson, D.L.
Partner: UNT Libraries Government Documents Department

Solar variability observed through changes in solar limb-darkening function and mean diameter. Final report, February 1, 1987--August 31, 1993

Description: The advantages of a dedicated, ground-based observatory over measurements from spacecraft are its relative adaptability, ease of maintenance, and low cost. However, groundbased observations must contend with problems introduced by observing through the Ear-th`s atmosphere and by changes in the long-term stability of the observing instrument. Both of these problems have been addressed at SCLERA and currently pose no limitation of solar diameter measurements at the parts-per-n-tillion level. The atmospheric problems of seeing and differential refraction are managed by separate procedures. For the former, a technique is used for the definition of the edge of a solar limb which exhibits a greatly reduced sensitivity to atmospheric seeing (Hill, Stebbins, and Oleson 1975). For the latter, diameters measured at several solar latitudes are used to yield a solar oblateness and diameter with reduced sensitivity to differential refraction. Differential radius measurements are used to detect changes in the solar limb-darkening function with a reduced sensitivity to differential refraction. The long-term stability of the telescope is monitored with an interferometric technique which is itself stable over long periods of time. Exploration of information contained in the global oscillations of the Sun is the basis of solar seismology programs. Such exploration permits the examination of the internal structure of a star at an unprecedented level of detail and accuracy. Changes in the internal structure of the Sun relevant to changes in energy output can be detected through observing changes in the mode frequency of oscillation. This approach is also used at SCLERA in its study of long-term variability in solar irradiance.
Date: May 31, 1995
Creator: Hill, H.A.
Partner: UNT Libraries Government Documents Department

Multi-Filter Rotating Shadowband Radiometers Mentor Report and Baseline Surface Radiation Network Submission Status

Description: There are currently twenty-four Multi-Filter Rotating Shadowband Radiometers (MFRSR) operating within Atmospheric Radiation Measurement (ARM). Eighteen are located within the Southern Great Plains (SGP) region, there is one at each of the North Slope of Alaska (NSA) and Tropical Western Pacific (TWP) sites, and one is part of the instrumentation of the ARM Mobile Facility. At this time there are four sites, all extended facilities within the SGP, that are equipped for a MFRSR but do not have one due to instrument failure and a lack of spare instruments. In addition to the MFRSRs, there are three other MFRSR derived instruments that ARM operates. They are the Multi-Filter Radiometer (MFR), the Normal Incidence Multi-Filter Radiometer (NIMFR) and the Narrow Field of View (NFOV) radiometer. All are essentially just the head of a MFRSR used in innovative ways. The MFR is mounted on a tower and pointed at the surface. At the SGP Central Facility there is one at ten meters and one at twenty-five meters. The NSA has a MFR at each station, both at the ten meter level. ARM operates three NIMFRs; one is at the SGP Central Facility and one at each of the NSA stations. There are two NFOVs, both at the SGP Central Facility. One is a single channel (870) and the other utilizes two channels (673 and 870).
Date: March 18, 2005
Creator: Hodges, G.
Partner: UNT Libraries Government Documents Department

Atmospheric Radiation Measurement Program facilities newsletter, August 2003.

Description: This Monthly newsletter discusses the following topic: New Atmospheric Profiling Instrument Added to SGP CART Suite--A new atmospheric profiling instrument at the SGP CART site is giving researchers an additional useful data stream. The new instrument is a microwave radiometer profiler (MWRP) developed by Radiometrics Corporation.
Date: September 2, 2003
Creator: Holdridge, D.J.
Partner: UNT Libraries Government Documents Department

Parameterization and analysis of 3-D radiative transfer in clouds

Description: This report provides a summary of major accomplishments from the project. The project examines the impact of radiative interactions between neighboring atmospheric columns, for example clouds scattering extra sunlight toward nearby clear areas. While most current cloud models don’t consider these interactions and instead treat sunlight in each atmospheric column separately, the resulting uncertainties have remained unknown. This project has provided the first estimates on the way average solar heating is affected by interactions between nearby columns. These estimates have been obtained by combining several years of cloud observations at three DOE Atmospheric Radiation Measurement (ARM) Climate Research Facility sites (in Alaska, Oklahoma, and Papua New Guinea) with simulations of solar radiation around the observed clouds. The importance of radiative interactions between atmospheric columns was evaluated by contrasting simulations that included the interactions with those that did not. This study provides lower-bound estimates for radiative interactions: It cannot consider interactions in cross-wind direction, because it uses two-dimensional vertical cross-sections through clouds that were observed by instruments looking straight up as clouds drifted aloft. Data from new DOE scanning radars will allow future radiative studies to consider the full three-dimensional nature of radiative processes. The results reveal that two-dimensional radiative interactions increase overall day-and-night average solar heating by about 0.3, 1.2, and 4.1 Watts per meter square at the three sites, respectively. This increase grows further if one considers that most large-domain cloud simulations have resolutions that cannot specify small-scale cloud variability. For example, the increases in solar heating mentioned above roughly double for a fairly typical model resolution of 1 km. The study also examined the factors that shape radiative interactions between atmospheric columns and found that local effects were often much larger than the overall values mentioned above, and were especially large for high sun and near convective clouds ...
Date: March 16, 2012
Creator: Varnai, Tamas
Partner: UNT Libraries Government Documents Department

Progress Report for Annex II--Assessment of Solar Radiation Resources in Saudi Arabia 1993-1997

Description: In 1987, the United States Department of Energy (DOE) and the King Abdulaziz City for Science and Technology (KACST) signed a five-year Agreement for Cooperation in the Field of Renewable Energy Research and Development (R and D), which has been extended to 2000. Tasks include: (1) upgrade solar radiation measurements in Saudi Arabia; (2) assemble a database of concurrent solar radiation, satellite (METEOSAT), and meteorological data; (3) adapt NREL models and other software for Saudi Arabia; (4) develop procedures, algorithms, and software to estimate solar irradiance; and (5) prepare a grid of solar radiation data for preparing maps and atlases and estimating solar radiation resources and solar energy system performances at locations in Saudi Arabia.
Date: August 20, 1999
Creator: Al-Amoudi, Anmed; Alawaji, Saleh H.; Cornwall, Chris; Mahfoodh, Mohammed bin; Marion, Bill; Maxwell, Eugene L. et al.
Partner: UNT Libraries Government Documents Department

Circumsolar radiation data: The Lawrence Berkeley Laboratory reduced data base. Final subcontract report

Description: This report describes the content and format of a circumsolar radiation data base assembled by Lawrence Berkeley Laboratory. This 200-megabyte data base contains detailed intensity profiles of the solar and circumsolar region (out to 3{degrees} from the sun`s center), the total and spectrally divided direct normal radiation data, and the total hemispherical solar radiation in the horizontal plane and the plane facing the sun. Data are available for 11 locations in the United States covering 1976 to 1981. Measurements were made by four automatic scanning instruments called circumsolar telescopes that operated about 16 hours per day. This data base, the Reduced Data Base, was generated from a larger set to provide data in a more manageable form.
Date: December 1, 1991
Creator: Noring, J. E.; Grether, D. F. & Hunt, A. J.
Partner: UNT Libraries Government Documents Department