Thuillier G.,French National Center for Scientific Research |
DeLand M.,SSAI |
Shapiro A.,PMOD WRC |
Schmutz W.,PMOD WRC |
Melo S.M.L.,Canadian Space Agency
Solar Physics | Year: 2012
We present a new method to reconstruct the solar spectrum irradiance in the Ly α - 400 nm region, and its variability, based on the Mg ii index and neutron-monitor measurements. Measurements of the solar spectral irradiance available in the literature have been made with different instruments at different times and different spectral ranges. However, climate studies require harmonised data sets. This new approach has the advantage of being independent of the absolute calibration and aging of the instruments. First, the Mg ii index is derived using solar spectra from Ly α (121 nm) to 410 nm measured from 1978 to 2010 by several space missions. The variability of the spectra with respect to a chosen reference spectrum as a function of time and wavelength is scaled to the derived Mg ii index. The set of coefficients expressing the spectral variability can be applied to the chosen reference spectrum to reconstruct the solar spectra within a given time frame or Mg ii index values. The accuracy of this method is estimated using two approaches: direct comparison with particular cases where solar spectra are available from independent measurements, and calculating the standard deviation between the measured spectra and their reconstruction. From direct comparisons with measurements we obtain an accuracy of about 1 to 2%, which degrades towards Ly α. In a further step, we extend our solar spectral-irradiance reconstruction back to the Maunder Minimum introducing the relationship between the Mg ii index and the neutron-monitor data. Consistent measurements of the Mg ii index are not available prior to 1978. However, we remark that over the last three solar cycles, the Mg ii index shows strong correlation with the modulation potential determined from the neutron-monitor data. Assuming that this correlation can be applied to the past, we reconstruct the Mg ii index from the modulation potential back to the Maunder Minimum, and obtain the corresponding solar spectral-irradiance reconstruction back to that period. As there is no direct measurement of the spectral irradiance for this period we discuss this methodology in light of the other proposed approaches available in the literature. The use of the cosmogenic-isotope data provides a major advantage: it provides information about solar activity over several thousands years. Using technology of today, we can calibrate the solar irradiance against activity and thus reconstruct it for the times when cosmogenic-isotope data are available. This calibration can be re-assessed at any time, if necessary. © 2012 Springer Science+Business Media B.V.
News Article | December 1, 2016
The Gerontological Society of America (GSA) and Senior Service America, Inc., have named Sarah Szanton, PhD, ANP, FAAN, of the Johns Hopkins University School of Nursing as the 2016 recipient of the Senior Service America Senior Scholar Award for Research Related to Disadvantaged Older Adults. This honor acknowledges presentations at the GSA Annual Scientific Meeting that represent exemplary basic or applied research related to the capabilities, contributions, challenges and concerns of disadvantaged older adults, especially those who are low-income and minority group members. The Senior Scholar Award recipient must have five or more years of professional experience after receiving his/her terminal graduate degree. Szanton was selected for the paper "Food Assistance Reduces Nursing Home Admissions for Maryland's Dually Eligible Older Adults." Her study showed that -- all else equal -- older low-income recipients of Supplemental Nutrition Assistance Program (SNAP) benefits are significantly less likely to enter a nursing home. And if they do, their stay is substantially shorter than those who are not SNAP recipients. The award presentation took place at GSA's 2016 Annual Scientific Meeting, which was held November 16 to 20 in New Orleans, LA. This conference fosters interdisciplinary collaboration among researchers, educators, and practitioners who specialize in the study of aging. Visit http://www. for further details. Szanton is an associate professor at the Johns Hopkins University School of Nursing. She has developed a program of research on the role of the environment and stressors in health disparities in older adults, particularly those trying to "age in place" or stay out of a nursing home. The result is a program called CAPABLE, which combines handyman services with nursing and occupational therapy to improve mobility, reduce disability, and decrease healthcare costs. She is currently examining the program's effectiveness through grants from the National Institutes of Health and the Innovations Office at the Center on Medicaid and Medicare Services. She is also conducting a study, funded by the Robert Wood Johnson Foundation, of whether food and energy assistance improve health outcomes for low-income older adults. A former health policy advocate, Szanton aims her research and publications toward changing policy for older adults and their families. Szanton completed undergraduate work in African-American Studies at Harvard University. She holds a MSN degree from the University of Maryland and a PhD from Johns Hopkins University. She has had funding from the National Institute of Nursing Research and the John A. Hartford Foundation. Szanton also is a GSA fellow, which represents the Society's highest class of membership. The Gerontological Society of America (GSA) is the nation's oldest and largest interdisciplinary organization devoted to research, education, and practice in the field of aging. The principal mission of the Society -- and its 5,500+ members -- is to advance the study of aging and disseminate information among scientists, decision makers, and the general public. GSA's structure also includes a policy institute, the National Academy on an Aging Society, and an educational branch, the Association for Gerontology in Higher Education. Senior Service America, Inc. (SSAI) is committed to making it possible for low-income and other disadvantaged older adults to participate fully in determining their own future and the future of their communities. For more than 40 years, the organization has operated the federal Senior Community Service Employment Program (SCSEP) through a network of local subgrantee organizations. For more information, please visit http://www. .
News Article | December 1, 2016
The Gerontological Society of America (GSA) and Senior Service America, Inc., have named David Burnes, BSc, MSW, PhD, of the University of Toronto as the 2016 recipient of the Senior Service America Junior Scholar Award for Research Related to Disadvantaged Older Adults. This honor acknowledges presentations at the GSA Annual Scientific Meeting that represent exemplary basic or applied research related to the capabilities, contributions, challenges and concerns of disadvantaged older adults, especially those who are low-income and minority group members. The Junior Scholar Award recipient must have less than five years of professional experience after receiving his/her terminal graduate degree. Burnes was selected for the paper "Varying Appraisals of Elder Mistreatment among Victims: Findings from a Population-Based Study." This study was the first to ask a random sample of older victims about the seriousness of the mistreatment they experienced. The findings have strong implications for how to detect and respond to elder mistreatment. The award presentation took place at GSA's 2016 Annual Scientific Meeting, which was held November 16 to 20 in New Orleans, Louisiana. This conference fosters interdisciplinary collaboration among researchers, educators, and practitioners who specialize in the study of the aging process. Visit http://www. for further details. Burnes is an assistant professor at the Factor-Inwentash Faculty of Social Work at the University of Toronto and an affiliate scientist at the Rotman Research Institute, Baycrest. He completed a PhD at the Columbia University School of Social Work, concentrating in advanced practice and gerontology. He teaches and researches primarily in the area of gerontology, specializing on the issue of elder mistreatment in community and long-term care settings. His research focuses on understanding and preventing elder mistreatment, including the development of basic knowledge, problem conceptualization, developing and evaluating evidence-based practices/interventions, and outcome measurement. Current projects include identifying the prevalence and risk factors of elder mistreatment in the community, exploring the process of resident-to-resident aggression in long-term care settings, understanding problem severity, implementing goal attainment scaling to measure the effectiveness of elder mistreatment response programs, and developing new ways to operationalize and measure key elder mistreatment outcomes. Burnes also has prior practice experience in areas of child protection and adult counselling/psychotherapy and is currently involved in community-based initiatives to intervene on cases of elder mistreatment. The Gerontological Society of America (GSA) is the nation's oldest and largest interdisciplinary organization devoted to research, education, and practice in the field of aging. The principal mission of the Society -- and its 5,500+ members -- is to advance the study of aging and disseminate information among scientists, decision makers, and the general public. GSA's structure also includes a policy institute, the National Academy on an Aging Society, and an educational branch, the Association for Gerontology in Higher Education. Senior Service America, Inc. (SSAI) is committed to making it possible for low-income and other disadvantaged older adults to participate fully in determining their own future and the future of their communities. For more than 40 years, the organization has operated the federal Senior Community Service Employment Program (SCSEP) through a network of local subgrantee organizations. For more information, please visit http://www. .
Hall D.K.,NASA |
Comiso J.C.,NASA |
Digirolamo N.E.,SSAI |
Shuman C.A.,University of Maryland Baltimore County |
And 2 more authors.
Journal of Climate | Year: 2012
The authors have developed a climate-quality data record of the clear-sky surface temperature of the Greenland Ice Sheet using the Moderate-Resolution Imaging Spectroradiometer (MODIS) ice-surface temperature (IST) algorithm. Daily and monthly quality-controlled MODIS ISTs of the Greenland Ice Sheet beginning on 1 March 2000 and continuing through 31 December 2010 are presented at 6.25-km spatial resolution on a polar stereographic grid along with metadata to permit detailed accuracy assessment. The ultimate goal is to develop a climate data record (CDR) that starts in 1981 with the Advanced Very High Resolution Radiometer (AVHRR) Polar Pathfinder (APP) dataset and continues with MODIS data from 2000 to the present, and into the Visible Infrared Imager Radiometer Suite (VIIRS) era (the first VIIRS instrument was launched in October 2011). Differences in the APP and MODIS cloud masks have thus far precluded merging the APP and MODIS IST records, though this will be revisited after the APP dataset has been reprocessed with an improved cloud mask. IST of Greenland may be used to study temperature and melt trends and may also be used in data assimilation modeling and to calculate ice sheet mass balance. The MODIS IST climate-quality dataset provides a highly consistent and well-characterized record suitable for merging with earlier and future IST data records for climate studies. The complete MODIS IST daily and monthly data record is available online.
Crow W.T.,U.S. Department of Agriculture |
Van Den Berg M.J.,Ghent University |
Huffman G.J.,SSAI |
Huffman G.J.,NASA |
Pellarin T.,Grenoble Institute of Technology
Water Resources Research | Year: 2011
Recently, Crow et al. (2009) developed an algorithm for enhancing satellite-based land rainfall products via the assimilation of remotely sensed surface soil moisture retrievals into a water balance model. As a follow-up, this paper describes the benefits of modifying their approach to incorporate more complex data assimilation and land surface modeling methodologies. Specific modifications improving rainfall estimates are assembled into the Soil Moisture Analysis Rainfall Tool (SMART), and the resulting algorithm is applied outside the contiguous United States for the first time, with an emphasis on West African sites instrumented as part of the African Monsoon Multidisciplinary Analysis experiment. Results demonstrate that the SMART algorithm is superior to the Crow et al. baseline approach and is capable of broadly improving coarse-scale rainfall accumulations measurements with low risk of degradation. Comparisons with existing multisensor, satellite-based precipitation data products suggest that the introduction of soil moisture information from the Advanced Microwave Scanning Radiometer via SMART provides as much coarse-scale (3 day, 1) rainfall accumulation information as thermal infrared satellite observations and more information than monthly rain gauge observations in poorly instrumented regions. Copyright 2011 by the American Geophysical Union.
Kashlinsky A.,SSAI |
Kashlinsky A.,NASA |
Arendt R.G.,NASA |
Arendt R.G.,University of Maryland, Baltimore |
And 4 more authors.
Astrophysical Journal | Year: 2012
We extend previous measurements of cosmic infrared background (CIB) fluctuations to ≲ 1° using new data from the Spitzer Extended Deep Survey. Two fields with depths of ≃ 12 hrpixel-1 over three epochs are analyzed at 3.6 and 4.5 μm. Maps of the fields were assembled using a self-calibration method uniquely suitable for probing faint diffuse backgrounds. Resolved sources were removed from the maps to a magnitude limit of magAB ≃ 25, as indicated by the level of the remaining shot noise. The maps were then Fourier transformed and their power spectra were evaluated. Instrumental noise was estimated from the time-differenced data, and subtracting this isolates the spatial fluctuations of the actual sky. The power spectra of the source-subtracted fields remain identical (within the observational uncertainties) for the three epochs indicating that zodiacal light contributes negligibly to the fluctuations. Comparing to 8 μm power spectra shows that Galactic cirrus cannot account for the fluctuations. The signal appears isotropically distributed on the sky as required for an extragalactic origin. The CIB fluctuations continue to diverge to >10 times those of known galaxy populations on angular scales out to ≲ 1°. The low shot-noise levels remaining in the diffuse maps indicate that the large-scale fluctuations arise from the spatial clustering of faint sources well below the confusion noise. The spatial spectrum of these fluctuations is in reasonable agreement with an origin in populations clustered according to the standard cosmological model (ΛCDM) at epochs coinciding with the first stars era. © 2012. The American Astronomical Society. All rights reserved.
Loeb N.G.,NASA |
Journal of Climate | Year: 2010
To provide a lower bound for the uncertainty inmeasurement-based clear-and all-sky direct aerosol radiative forcing (DARF), a radiative perturbation analysis is performed for the ideal case in which the perturbations in global mean aerosol properties are given by published values of systematic uncertainty in Aerosol Robotic Network (AERONET) aerosol measurements. DARF calculations for base-state climatological cloud and aerosol properties over ocean and land are performed, and then repeated after perturbing individual aerosol optical properties (aerosol optical depth, single-scattering albedo, asymmetry parameter, scale height, and anthropogenic fraction) from their base values, keeping all other parameters fixed. The total DARF uncertainty from all aerosol parameters combined is 0.5-1.0 W m -2, a factor of 2-4 greater than the value cited in the Intergovernmental Panel on Climate Change's (IPCC's) Fourth Assessment Report. Most of the total DARF uncertainty in this analysis is associatedwith single-scattering albedo uncertainty. Owing to the greater sensitivity to single-scattering albedo in cloudy columns, DARF uncertainty in all-sky conditions is greater than in clear-sky conditions, even though the global mean clear-sky DARF is more than twice as large as the all-sky DARF. © 2010 American Meteorological Society.
Teng H.,U.S. National Center for Atmospheric Research |
Branstator G.,U.S. National Center for Atmospheric Research |
Wang H.,SSAI |
Meehl G.A.,U.S. National Center for Atmospheric Research |
Washington W.M.,U.S. National Center for Atmospheric Research
Nature Geoscience | Year: 2013
Heat waves are thought to result from subseasonal atmospheric variability. Atmospheric phenomena driven by tropical convection, such as the Asian monsoon, have been considered potential sources of predictability on subseasonal timescales. Mid-latitude atmospheric dynamics have been considered too chaotic to allow significant prediction skill of lead times beyond the typical 10-day range of weather forecasts. Here we use a 12,000-year integration of an atmospheric general circulation model to identify a pattern of subseasonal atmospheric variability that can help improve forecast skill for heat waves in the United States. We find that heat waves tend to be preceded by 15-20 days by a pattern of anomalous atmospheric planetary waves with a wavenumber of 5. This circulation pattern can arise as a result of internal atmospheric dynamics and is not necessarily linked to tropical heating. We conclude that some mid-latitude circulation anomalies that increase the probability of heat waves are predictable beyond the typical weather forecast range. © 2013 Macmillan Publishers Limited.
Rutan D.A.,NASA |
Kato S.,SSAI |
Doelling D.R.,SSAI |
Rose F.G.,NASA |
And 3 more authors.
Journal of Atmospheric and Oceanic Technology | Year: 2015
The Clouds and the Earth's Radiant Energy System Synoptic (SYN1deg), edition 3, product provides climate-quality global 3-hourly 1° × 1° gridded top of atmosphere, in-atmosphere, and surface radiant fluxes. The in-atmosphere surface fluxes are computed hourly using a radiative transfer code based upon inputs from Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS), 3-hourly geostationary (GEO) data, and meteorological assimilation data from the Goddard Earth Observing System. The GEO visible and infrared imager calibration is tied to MODIS to ensure uniform MODIS-like cloud properties across all satellite cloud datasets. Computed surface radiant fluxes are compared to surface observations at 85 globally distributed land (37) and ocean buoy (48) sites as well as several other publicly available global surface radiant flux data products. Computed monthly mean downward fluxes from SYN1deg have a bias (standard deviation) of 3.0Wm-2 (5.7%) for shortwave and -4.0Wm-2 (2.9%) for longwave compared to surface observations. The standard deviation between surface downward shortwave flux calculations and observations at the 3-hourly time scale is reduced when the diurnal cycle of cloud changes is explicitly accounted for. The improvement is smaller for surface downward longwave flux owing to an additional sensitivity to boundary layer temperature/humidity, which has a weaker diurnal cycle compared to clouds. © 2015 American Meteorological Society.
Hall D.K.,NASA |
Foster J.L.,NASA |
DiGirolamo N.E.,SSAI |
Geomorphology | Year: 2012
Earlier onset of springtime weather, including earlier snowmelt, has been documented in the western United States over at least the last 50years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for the management of streamflow. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work, such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud-gap-filled (CGF) map products and 30years of discharge and meteorological station data are studied. Streamflow data from streams in WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period as a whole. The extent of snow-cover (percent of basin covered) derived from the lowest elevation zone (2500-3000m) of the WRR, using MODIS CGF snow-cover maps, is strongly correlated with maximum monthly discharge on 30 April, where Spearman's Rank correlation, rs,=0.89 for the decade of the 2000s. We also investigated stream power for Bull Lake Creek above Bull Lake; and found a trend (significant at the 90% confidence level) toward reduced stream power from 1970 to 2009. Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature measured during the 40-year study period, possibly contributing to a reduction in snow cover. In addition, the strong relationship between percent of basin that was snow covered, and maximum monthly streamflow indicates that MODIS snow-cover maps are useful for predicting streamflow, and can be used to improve management of water resources in the drought-prone western United States. © 2011.