Large Scale Surface Radiation Budget from Satellite Observation

During the current reporting period, the focus of our work was on preparing and testing an improved version of our Surface Radiation Budget algorithm for processing the ISCCP D1 data routinely at the SRB Satellite Data Analysis Center (SDAC) at NASA Langley Research Center. The major issues addressed are related to gap filling and to testing whether observations made from ERBE could be used to improve current procedures of converting narrowband observations, as available from ISCCP, into broadband observations at the TOA. The criteria for selecting the optimal version are to be based on results of intercomparison with ground truth

Diurnal Temperature Range Over the United States: A Satellite View

Diurnal temperature range (DTR) is an important climate change index. Information on this parameter comes primarily from sparse and unevenly distributed observations of shelter air temperature. In this study, five years of GOES- 8 based estimates of land surface temperature (LST) over the United States are used to evaluate DTR at high spatial resolution. The spatial and temporal patterns that emerged show a high degree of consistency with independent satellite estimates of the Normalized Difference Vegetation Index (NDVI). Specifically, the arid regions in the western and central U.S. have larger DTRs than the eastern United States or the northwest coast. When stratified by four major surface types, the western U. S. DTRs over these surface types are larger than over the eastern part. It is also observed that urban areas have the lowest DTRs especially over the polluted eastern U. S. The similarity of the DTR spatial and temporal patterns and variations of the independent satellite based vegetation index are encouraging and suggest that satellite based estimates of DTR carry a strong signal on surface conditions which are responsive to climate change

Relationship between downwelling surface shortwave radiative fluxes and sea surface temperature over the tropical Pacific: AMIP II models versus satellite estimates

Incident shortwave radiation at the Earth's surface is the driving force of the climate system. Understanding the relationship between this forcing and the sea surface temperature, in particular, over the tropical Pacific Ocean is a topic of great interest because of possible climatic implications. The objective of this study is to investigate the relationship between downwelling shortwave radiative fluxes and sea surface temperature by using available data on radiative fluxes. We assess first the shortwave radiation from three General Circulation Models that participated in the second phase of the Atmospheric Model Intercomparison Project (AMIP II) against estimates of such fluxes from satellites. The shortwave radiation estimated from the satellite is based on observations from the International Satellite Cloud Climatology Project D1 data and the University of Maryland Shortwave Radiation Budget model (UMD/SRB). Model and satellite estimates of surface radiative fluxes are found to be in best agreement in the central equatorial Pacific, according to mean climatology and spatial correlations. We apply a Canonical Correlation Analysis to determine the interrelated areas where shortwave fluxes and sea surface temperature are most sensitive to climate forcing. Model simulations and satellite estimates of shortwave fluxes both capture well the interannual signal of El Niño-like variability. The tendency for an increase in shortwave radiation from the UMD/SRB model is not captured by the AMIP II models

WCRP surface radiation budget shortwave data product description, version 1.1

Shortwave radiative fluxes which reach the Earth's surface are key elements that influence both atmospheric and oceanic circulation. The World Climate Research Program has established the Surface Radiation Budget climatology project with the ultimate goal of determining the various components of the surface radiation budget from satellite data on a global scale. This report describes the first global product that is being produced and archived as part of that effort. The interested user can obtain the monthly global data sets free of charge using e-mail procedures

Dark London: Dimensions and characteristics of dark tourism supply in the UK capital

This paper will investigate the characteristics of the supply of dark tourism in London, UK through an examination of the identified main dark sites in London, UK. Our methodology is based on web analysis of the presence of marketed and non-marketed dark tourist sites in London, their web visitation, the level of their commercialisation and the characteristics which place them in the various scales as categorised in current literature, notably Stone (2006). We identified that London offers a much more entertainment focussed tourism experience rather than accurate historical and authentic sites which utilised major aspects of dark tourism for purposes such as commemoration or remembrance. The authors found this surprising given London’s long and often dark history

Satellite Estimates of Surface Radiative Fluxes for the Extended San Pedro Basin: Sensitivity to Aerosols

Abstract Surface downwelling and upwelling radiative fluxes are important inputs into hydrologic models that evaluate water budgets, and into land surface data assimilation schemes which are driven with radiative fluxes. For large-scale needs, only remote sensing methods can provide such information. The accuracy of the derived fluxes depends on the inference schemes and on the quality of auxiliary input parameters. At present, information on surface short-wave radiative fluxes over the United States is produced in real time by the National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite Data and Information Service (NESDIS) at 0.5 degree resolution, at hourly time intervals, using independently derived auxiliary inputs. Information on aerosol properties and their temporal variability is not available, and at best, is only estimated. During 1997 information on aerosol optical properties was collected at the USDA-Agricultural Research Service Walnut Gulch Experimental Watershed, Arizona, in preparation for future validation efforts in support of new satellite observations (e. g., ADEOS-II). This data set was used to test the sensitivity of a radiation inference scheme to aerosols, in particular, on the determination of clear sky fluxes and the surface albedo. Data from the Arizona Meteorological Network (AZMET) have been utilized to evaluate the satellite estimates for 1997. It was found that the current satellite estimates are within 70 Wm -2 of the ground observations on an hourly time scale and within 24 Wm -2 on a daily time scale. In the latter case this is less than 10% of the mean. Use of actual observations of aerosols, as compared to climatological values, reduces the bias substantially, while less significant changes in the rms were found. Keywords: radiative fluxes, aerosols, remote sensing 2 1. Background Site and history The Semi-Arid Land-Surface-Atmosphere (SALSA) Program seeks to evaluate the consequences of natural and human-induced changes in semi-arid environments (this issue; also see the SALSA home-page at http://www.tucson.ars.ag.gov/salsa/salsahome.html). Information on remote sensing activities in this region is presented in Surface downwelling and upwelling radiative fluxes play an important role as inputs into hydrologic models aimed at evaluating water budgets. Therefore, it is important to determine how well such fluxes can be derived from satellite observations. First estimates of short-wave (SW) surface radiative fluxes (global irradiance) by satellite methods for this region were attempted during the Monsoon '90 experiment Linkage to related activities The Upper San Pedro Basin has been established as the North American semi-arid site for assessing the impacts of climatic variation and for calibrating and validating algorithms and process-based models to be implemented with NASA EOS observations. For example, the basin was selected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument team as a semi-arid validation site as well as a NASA Global Land Cover Test Site. It was also selected as the primary focus site for the EOS interdisciplinary science hydrology team at the University of Arizona and Centre d'Etudes Spatiales de la Biosphere (CESBIO), France. Two Sonora research groups have been involved in research in the USPB: Instituto del Medio Ambiente y Desarrollo Sustentable del Estado de Sonora (IMADES), and Instituto Tecnológico de Sonora (ITSON). Numerous proposals have been funded for research as well as for remotely sensed data acquisition in the basin, which range from ERS-2, SPOT4, ADEOS-II, and for a mesoscale meteorological modeling initiative. Modeling activity focuses on exploring the potential of coupling parameters derived by methods of remote sensing to mesoscale atmospheric models, to aid in diagnosing the spatial distribution of surface fluxes over the entire San Pedro Basin at a 4 x 4 kilometer grid spacing (Toth, 1997). 4 Radiative fluxes used in this study Remotely sensed data The estimated surface SW radiative fluxes (global irradiance) used in this study are produced by NOAA/NESDIS, using the University of Maryland methodology The full archive maintained at the University of Maryland contains additional parameters, that as yet, are not distributed. Specifically, the following types of information are archived: • satellite based information, used to drive the model; • auxiliary data used to drive the model; • Eta model output products relevant for hydrologic modeling; and, • independently derived satellite products. It is planned to expand the number of parameters currently distributed via the World Wide Web to include,e. g., cloud amounts). Validation data Radiative fluxes A comprehensive evaluation of the model was done using data for the entire year of 1996 from several sources (Pinker et al., 2000). Data available from the Surface Radiation Monitoring Network (SURFRAD) (Hicks et al., 1996), the Illinois State Water Survey (Hollinger et al., 1994) and the Arizona Meteorological Network (AZMET) (Brown, 1989) were used. In this study, only AZMET stations, as illustrated in Aerosol observations at Walnut Gulch In December of 1996 a CIMEL sunphotometer was installed at the USDA-ARS Walnut Gulch Experimental Watershed to provide information on aerosol optical depths and other aerosol optical parameters Aerosol sensitivity experiments Issues Satellite inference schemes that use physical models require information on radiances as observed by the satellite sensor in relevant spectral channels, as well as information on the state of the atmosphere and the surface. Such information has been available for some of the needed parameters from numerical weather prediction models (e. g., on water vapor) or from independently derived satellite quantities (e. g., ozone). Typically the least amount of information in known about aerosols. Therefore, most inference schemes use some type of aerosol climatology. We have followed a two-step approach in the process of inferring surface SW radiative fluxes. Initially, we use an average value of clear sky radiance as derived from about two weeks of clear sky observations. We assume a climatological value of aerosol optical depth 6 Subsequently, we use each clear sky pixel from the beginning of the retrieval time interval (one month segments at a time) and the initially derived surface albedo to subsequently derive an aerosol optical thickness from each clear sky pixel. The corresponding flux at the surface will be selected from a look-up table as the one that is appropriate for all the derived values of input parameters, as well as the inferred aerosol optical depth. This approach was used to produce the surface fluxes presented in Aerosol experiments We have performed an experiment to evaluate the sensitivity of surface SW radiative flux parameters to aerosol information. An off-line version of the GCIP/SRB model was run for the entire year of 1997. All the satellite input parameters, as well as the atmospheric and surface parameters were the same as used by NOAA/NESDIS in the real time runs for 1997 and as archived at the University of Maryland. The only difference was that the climatological aerosol optical depth values used to initialize the retrieval process were replaced by the monthly mean observed values, as presented in Results Surface fluxes In A comparison of hourly mean estimated global irradiance with ground truth as obtained from the control run, is presented in Figures 6 for all sky (a) and clear sky (b) cases independently. In for clear sky). Surface albedo The GCIP/SRB model produces surface downwelling and upwelling SW radiative fluxes (global and reflected radiation), and their ratio is termed "albedo". At instantaneous time scales, the albedo represents the value at the time of the observation. In order to derive a daily value, the downwelling and upwelling fluxes are averaged and their ratio is taken. Since the surface fluxes are computed independently for clear and cloudy pixels, it is possible to produce "clear sky" albedos and all-sky albedos. Preliminary evaluations show that these two values are quite close to each other. In Discussion Radiative fluxes at the earth's surface determine the surface energy budget, and therefore, the rate of evapotranspiration (Dickinson, 1986; Avissar and Verstraete, 1990; Henderson-Sellers, 1993; Sellers et al., 1996; In addition to better aerosol information, there is a need for improved calibration of satellite sensors. It is believed that some degradation of satellite instruments might have occurred. Preliminary estimates of such degradation are as high as 15%. Experiments were performed to evaluate the possible impact of such degradation on the derived surface fluxes Summary Regions classified as semi-arid or arid constitute about one-third of the total global land cover. Often these regions are subjected to soil erosion, wind-storms, and variable aerosol loading. Aerosols are important in altering the radiation that reaches the surface and therefore, they are a source of error in the interpretation of satellite signals. This is particularly true in the visible region of the spectrum. Routine and continuous information on atmospheric aerosol content is lacking. However, such data are becoming available on regional scales under observational initiatives like the Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX) (Russel et al., 1999), AERONET (Holben et al., 1998), SKYNET (Takamura, 1996); and will become available on global scale under new satellite observational programs like MODIS (King et al., 1999), ADEOS and ADEOS-II (http://www.eorc.nasda.go.jp/index.html); and under integrating initiatives like the Global Aerosol Climatology Project (GACP) (Curran et al., 1998; Curran, 1999). Many landscapes in the southwest United States and northern Mexico are being altered from activities such as groundwater mining and overgrazing. Lack of information on aerosols can therefore introduce errors in our ability to estimate from space how much the surface has changed. In the framework of the SALSA Program objectives for long-term monitoring of human-induced change on the hydrological and ecological resources of semi-arid regions, we have conducted an experiment to assess the current uncertainties in aerosol optical depths on such parameters as surface short-wave fluxes and surface albedos. This is important because these parameters influence the modeling of hydrological processes that control the exchange of heat, water vapor and CO2. It was found that using observed aerosol climatology improved radiative flux retrieval from satellite observations and subsequent computation of flux estimates. In addition, it was found that using measured values to initialize the aerosol optical depth in the retrieval of surface global irradiance, the surface albedo increased by about 0.02 on the average. Comparison of satellite estimates of radiative flux were made with data from the Arizona Meteorological Network (AZMET) for 1997 to evaluate the procedures described. It was found that the current satellite estimates are within 70 Wm -2 of the ground observations on an hourly time scale and within 24 Wm -2 on a daily time scale. In the latter case this is less than 10% of the mean. 10 Use of actual observations of aerosols, as compared to climatological values, reduces the bias substantially, while less significant changes in the rms were found. In summary, this study demonstrated that on a local scale, characterizations of aerosols, based even on a limited observational periods is preferred to estimates based on large-scale climatologies

The impact of sound field systems on learning and attention in elementary school classrooms

Purpose: An evaluation of the installation and use of sound field systems (SFS) was carried out to investigate their impact on teaching and learning in elementary school classrooms. Methods: The evaluation included acoustic surveys of classrooms, questionnaire surveys of students and teachers and experimental testing of students with and without the use of SFS. Students ’ perceptions of classroom environments and objective data evaluating change in performance on cognitive and academic assessments with amplification over a six month period are reported. Results: Teachers were positive about the use of SFS in improving children’s listening and attention to verbal instructions. Over time students in amplified classrooms did not differ from those in nonamplified classrooms in their reports of listening conditions, nor did their performance differ in measures of numeracy, reading or spelling. Use of SFS in the classrooms resulted in significantly larger gains in performance in the number of correct items on the nonverbal measure of speed of processing and the measure of listening comprehension. Analysis controlling for classroom acoustics indicated that students ’ listening comprehension score

GCIP water and energy budget synthesis (WEBS)

As part of the World Climate Research Program\u27s (WCRPs) Global Energy and Water-Cycle Experiment (GEWEX) Continental-scale International Project (GCIP), a preliminary water and energy budget synthesis (WEBS) was developed for the period 1996–1999 from the “best available” observations and models. Besides this summary paper, a companion CD-ROM with more extensive discussion, figures, tables, and raw data is available to the interested researcher from the GEWEX project office, the GAPP project office, or the first author. An updated online version of the CD-ROM is also available at http://ecpc.ucsd.edu/gcip/webs.htm/. Observations cannot adequately characterize or “close” budgets since too many fundamental processes are missing. Models that properly represent the many complicated atmospheric and near-surface interactions are also required. This preliminary synthesis therefore included a representative global general circulation model, regional climate model, and a macroscale hydrologic model as well as a global reanalysis and a regional analysis. By the qualitative agreement among the models and available observations, it did appear that we now qualitatively understand water and energy budgets of the Mississippi River Basin. However, there is still much quantitative uncertainty. In that regard, there did appear to be a clear advantage to using a regional analysis over a global analysis or a regional simulation over a global simulation to describe the Mississippi River Basin water and energy budgets. There also appeared to be some advantage to using a macroscale hydrologic model for at least the surface water budgets

Conceptualizing cultures of violence and cultural change

The historiography of violence has undergone a distinct cultural turn as attention has shifted from examining violence as a clearly defined (and countable) social problem to analysing its historically defined 'social meaning'. Nevertheless, the precise nature of the relationship between 'violence' and 'culture' is still being established. How are 'cultures of violence' formed? What impact do they have on violent behaviour? How do they change? This essay examines some of the conceptual aspects of the relationship between culture and violence. It brings together empirical research into nineteenth-century England with recent research results from other European contexts to examine three aspects of the relationship between culture and violence. These are organised under the labels 'seeing violence', 'identifying the violent' and 'changing violence'. Within a particular society, narratives regarding particular kinds of behaviour shape cultural attitudes. The notion 'violence' is thus defined in relation to physically aggressive acts as well as by being connected to other kinds of attitudes and contexts. As a result, the boundaries between physical aggression which is legitimate and that which is illegitimate (and thus 'violence') are set. Once 'violence' is defined, particular cultures form ideas about who is responsible for it: reactions to violence become associated with social arrangements such as class and gender as well as to attitudes toward the self. Finally, cultures of violence make efforts to tame or eradicate illegitimate forms of physical aggression. This process is not only connected to the development of new forms of power (e.g., new policing or punishment strategies) but also to less tangible cultural influences which aim at changing the behaviour defined as violence (in particular among the social groups identified as violent). Even if successful, this three-tiered process of seeing violence, identifying the violent and changing violence continues anew, emphasising the ways that cultures of violence develop through a continuous process of reevaluation and reinvention