Accuracy of Weather Data in Long-Term Pavement Performance Program Database

2000 ◽  
Vol 1699 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Chung-Lung Wu ◽  
Gonzalo R. Rada ◽  
Aramis Lopez ◽  
Yingwu Fang
Keyword(s):  
Weather Conditions ◽  
Test Site ◽  
Climatic Conditions ◽  
Weighting Scheme ◽  
Pavement Performance ◽  
Weather Data ◽  
Climatic Data ◽  
National Climatic Data Center ◽  
Weather Stations

To provide accurate climatic data for pavements under the Long-Term Pavement Performance (LTPP) Program, a climatic database was developed in 1992 and subsequently revised and expanded in 1998. In the development of this database, up to five nearby weather stations were selected for each test site. Pertinent weather data for the selected weather stations were obtained from the U.S. National Climatic Data Center and the Canadian Climatic Center. With a 1/ R2 weighting scheme, site-specific climatic data were derived from the nearby weather station data. The derived data were referred to as “virtual”weather data. To evaluate the effect of environmental factors on pavement performance and design, automated weather stations (AWS) were installed at LTPP Specific Pavement Study Projects 1, 2, and 8 to collect on-site weather data. Since the virtual weather data were developed for all LTPP test sites and will be used for future pavement performance studies, it is essential that the derived virtual data be accurate and representative of the actual onsite climatic conditions. The availability of the AWS weather data has provided an opportunity to evaluate whether virtual weather data can be used to represent on-site weather conditions. Daily temperature data and monthly temperature and precipitation data were used in this experiment. On the basis of the comparisons made between the virtual and onsite measured (AWS) data, it appears that climatic data derived from nearby weather stations using the 1/R2 weighting scheme estimate the actual weather data reasonably well and thus can be used to represent on-site weather conditions in pavement research and design.

scholarly journals Simulation of Water Vapor Ingress into PV-Modules under Different Climatic Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Philip Hülsmann ◽  
Markus Heck ◽  
Michael Köhl
Keyword(s):  
Water Vapor ◽  
Water Concentration ◽  
Test Site ◽  
Climatic Conditions ◽  
Data Sets ◽  
Climatic Data ◽  
Material Parameters ◽  
Water Ingress ◽  
Pv Modules

This work deals with the simulation of water vapor ingress into wafer-based PV-modules for long-term exposure under different climatic conditions. Measured material parameters together with climatic data sets from four test sites (tropic, moderate, alpine, and arid) were used to calculate the water concentration inside of the encapsulant between solar cell and glass for a lifetime of 20 years. Two back-sheet materials (PET-based and PA-based) combined with EVA as encapsulant were used in respect to their influence on water ingress. The results show faster water ingress for warmer regions, but the highest concentrations were found for the moderate test site. The water ingress was additionally influenced by the used encapsulant and back-sheet combination. In particular the temperature dependency of the mass transfer, which differs from material to material, was the focus of this investigation.

scholarly journals Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Pederzani ◽  
Vera Aldeias ◽  
Harold L. Dibble ◽  
Paul Goldberg ◽  
Jean-Jacques Hublin ◽  
...  
Keyword(s):  
Human Behavior ◽  
Late Pleistocene ◽  
Tooth Enamel ◽  
Climatic Conditions ◽  
Climatic Data ◽  
Human Scale ◽  
Winter Temperatures ◽  
Archaeological Materials ◽  
Climatic Records

AbstractExploring the role of changing climates in human evolution is currently impeded by a scarcity of climatic information at the same temporal scale as the human behaviors documented in archaeological sites. This is mainly caused by high uncertainties in the chronometric dates used to correlate long-term climatic records with archaeological deposits. One solution is to generate climatic data directly from archaeological materials representing human behavior. Here we use oxygen isotope measurements of Bos/Bison tooth enamel to reconstruct summer and winter temperatures in the Late Pleistocene when Neandertals were using the site of La Ferrassie. Our results indicate that, despite the generally cold conditions of the broader period and despite direct evidence for cold features in certain sediments at the site, Neandertals used the site predominantly when climatic conditions were mild, similar to conditions in modern day France. We suggest that due to millennial scale climate variability, the periods of human activity and their climatic characteristics may not be representative of average conditions inferred from chronological correlations with long-term climatic records. These results highlight the importance of using direct routes, such as the high-resolution archives in tooth enamel from anthropogenically accumulated faunal assemblages, to establish climatic conditions at a human scale.

TROPICAL CYCLONE WINDS AT LANDFALL: The ASOS–C-MAN Wind Exposure Documentation Project

2004 ◽  
Vol 85 (6) ◽  
pp. 845-852 ◽  
Author(s):  
Mark Powell ◽  
David Bowman ◽  
David Gilhousen ◽  
Shirley Murillo ◽  
Nick Carrasco ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Building Design ◽  
Web Pages ◽  
Climatic Data ◽  
National Climatic Data Center ◽  
Wind Exposure ◽  
Wind Measurements ◽  
Weather Stations ◽  
Aerodynamic Roughness ◽  
American Society

Photographs describing the wind exposure at automatic weather stations susceptible to tropical cyclones are now available on Web pages at the National Climatic Data Center and the National Data Buoy Center. Given the exposure for one of eight wind direction sectors, a user may estimate the aerodynamic roughness and correct mean wind measurements to an open-terrain exposure. The open-terrain exposure is consistent with the tropical cyclone advisories and forecasts issued by the National Weather Service, as well as building design wind load standards published by the American Society of Civil Engineers.

Selection of Climatic Design Points for Gas Turbine Power Augmentation

2011 ◽  
Author(s):  
Mustapha Chaker ◽  
Cyrus B. Meher-Homji
Keyword(s):  
Gas Turbine ◽  
Optimal Solution ◽  
Climatic Conditions ◽  
Weather Data ◽  
Climatic Data ◽  
Data Set ◽  
Suggested Approach ◽  
Design Point ◽  
Impact Performance ◽  
Selection Of

There is a widespread interest in the application of gas turbine power augmentation technologies such as evaporative cooling or mechanical chilling in the mechanical drive and power generation markets. Very often, the selection of the design point is based on the use of ASHRAE data or a design point that is in the basis of design for the project. This approach can be detrimental and can result in a non optimal solution. In order to evaluate the benefits of power augmentation, users can use locally collected weather data, or recorded hourly bin data set from databases such as TMY, EWD, and IWS. This paper will cover a suggested approach for the analysis of climatic data for power augmentation applications and show how the selection of the design point can impact performance and economics of the installation. The final selection of the design point depends on the specific application, the revenues generated and installation costs. To the authors’ knowledge, this is the first attempt to treat this topic in a structured analytical manner by comparing available database information with actual climatic conditions.

Relationship Between Pavement Temperature and Weather Data: Wisconsin Field Study to Verify Superpave Algorithm

1998 ◽  
Vol 1609 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Peter J. Bosscher ◽  
Hussain U. Bahia ◽  
Suwitho Thomas ◽  
Jeffrey S. Russell
Keyword(s):  
Standard Deviation ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Test Site ◽  
Temperature Data ◽  
Pavement Design ◽  
Asphalt Binders ◽  
Weather Data ◽  
Air Temperatures ◽  
Pavement Temperature

Six test sections were constructed on US-53 in Trempealeau County by using different performance-graded asphalt binders to validate the Superpave pavement temperature algorithm and the binder specification limits. Field instrumentation was installed in two of the test sections to monitor the thermal behavior of the pavement as affected by weather. The instrumentation was used specifically to monitor the temperature of the test sections as a function of time and depth from the pavement surface. A meteorological station was assembled at the test site to monitor weather conditions, including air temperature. Details of the instrumentation systems used and analysis of the data collected during the first 22 months of the project are presented. The analysis was focused on development of a statistical model for estimation of low and high pavement temperatures from meteorological data. The model was compared to the Superpave recommended model and to the more recent model recommended by the Long-Term Pavement Performance (LTPP) program. The temperature data analysis indicates a strong agreement between the new model and the LTPP model for the estimation of low pavement design temperature. However, the analysis indicates that the LTPP and Superpave models underestimate the high pavement design temperature at air temperatures higher than 30°C. The temperature data analyses also indicate that there are significant differences between the standard deviation of air temperatures and the standard deviation of the pavement temperatures. These differences raise some questions about the accuracy of the reliability estimates used in the current Superpave recommendations.

Field Tests of a PV-Powered Air Monitoring System

2003 ◽  
Vol 125 (2) ◽  
pp. 203-206 ◽  
Author(s):  
L. Sanidad ◽  
Y. Baghzouz ◽  
R. Boehm ◽  
E. Hodge
Keyword(s):  
Field Tests ◽  
Computer Code ◽  
Test Site ◽  
Weather Data ◽  
Nevada Test Site ◽  
Air Sampler ◽  
Long Term Performance ◽  
Solar Resource ◽  
Term Performance

A compact stand-alone PV power system was recently designed and built to run an air sampler for environmental monitoring at the Nevada Test Site. This paper presents an overview of the system design and analysis of some of the recorded daily cycles of various power flows during the summer period. The system long-term performance during both high and low solar resource periods is simulated with the computer code PVFORM using historical weather data.

scholarly journals Long-Term Aerosol Climate Data Record Derived from Operational AVHRR Satellite Observations

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
P. K. Chan ◽  
X.-P. Zhao ◽  
A. K. Heidinger
Keyword(s):  
Climate Forcing ◽  
Global Ocean ◽  
Climatic Data ◽  
Climate Data ◽  
Clear Sky ◽  
National Climatic Data Center ◽  
Data Record ◽  
Climate Data Record ◽  
Global Oceans

Aerosol optical thickness (AOT) was retrieved using the Advanced Very High Resolution Radiometer (AVHRR) PATMOS-x Level-2b gridded radiances and the two-channel algorithm of the National Climatic Data Center (NCDC). The primary retrieval product is AOT at 0.63 μm channel. AOT is also retrieved at 0.83 μm or 1.61 μm channel for consistent check. The retrieval was made during day time, under clear sky and snow-free conditions, and over the global oceans. The spatial resolution is 0.1×0.1 degree grid and the temporal resolution is both daily and monthly. The resultant AVHRR AOT climate data record (CDR) spans from August 1981 to December 2009 and provides the longest aerosol CDR currently available from operational satellites. This dataset is useful in studying aerosol climate forcing, monitoring long-term aerosol trends, and evaluating global air pollution and aerosol transport models over the global ocean.

Climate Change, Global Warming, and Agricultural Droughts

2005 ◽  
Author(s):  
Gennady V. Menzhulin ◽  
Sergey P. Savvateyev
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Human Activities ◽  
Fossil Fuels ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Spatial Variations ◽  
Geological Time ◽  
The Earth

The climate of a region is a representation of long-term weather conditions that prevail there. Over the millions of years of the existence of the atmosphere on the earth, the climate has changed all the time; ice ages have come and gone, and this has been the result of natural causes. Recently (on geological time scales) the human population has expanded—from half a billion in 1600, to 1 billion in 1800, to almost 3 billion in 1940, and it now stands at about 6 billion. The climate may well now be influenced not only as before by natural events but also by human activities. For example, we are producing vast amounts of carbon dioxide by burning fossil fuels, and this is causing the temperature of the earth to rise significantly. If we argue that we should control our activities to preserve this planet as a habitable environment for future generations, we need to have some scientific knowledge of the effects of our present activities on climate. In recent years the evidence has been accumulating that on the time scale of decades there is global warming (i.e., the global annual mean surface temperature is increasing). There is also evidence accumulating that part of this increase is a consequence of human activities. The evidence is largely statistical. Within this trend there are bound to be temporal fluctuations and spatial variations. Moreover, in addition to the increase in temperature, it is reasonable to assume that there is, overall, an increase in evaporation of water from the surface of the earth and that there will be a consequent increase in precipitation. But within this overall scenario there are bound to be local variations; some areas may experience more precipitation, but some areas may experience less precipitation. The effect of climate change on the proneness to drought is therefore not uniform but can be expected to vary from place to place. Therefore, whether one is concerned with considering the relation between climate and proneness to drought from the historical evidence or whether one is trying to use models to predict the effect of future climatic conditions, it is necessary to consider the local spatial variations.

Production of Temporally Consistent Gridded Precipitation and Temperature Fields for the Continental United States*

2005 ◽  
Vol 6 (3) ◽  
pp. 330-336 ◽  
Author(s):  
Alan F. Hamlet ◽  
Dennis P. Lettenmaier
Keyword(s):  
United States ◽  
Land Surface ◽  
Snow Water Equivalent ◽  
Temperature Fields ◽  
Climatic Data ◽  
National Climatic Data Center ◽  
Snow Water ◽  
Long Term Trends ◽  
Precipitation And Temperature

Abstract The availability of long-term gridded datasets of precipitation, temperature, and other surface meteorological variables offers the potential for deriving a range of land surface conditions that have not been directly observed. These include, for instance, soil moisture, snow water equivalent, evapotranspiration, runoff, and subsurface moisture transport. However, gridding procedures can themselves introduce artificial trends due to incorporation of stations with different record lengths and locations. Hence, existing gridded datasets are in general not appropriate for estimation of long-term trends. Methods are described here for adjustment of gridded daily precipitation and temperature maxima and minima over the continental United States based on newly available (in electronic form) U.S. Cooperative Observer station data archived at the National Climatic Data Center from the early 1900s on. The intent is to produce gridded meteorological datasets that can be used, in conjunction with hydrologic modeling, for long-term trend analysis of simulated hydrologic variables.

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