Science.gov

Sample records for 20th-century climate simulations

  1. Evaluation of CMIP5 20th century climate simulations for the Pacific Northwest USA

    NASA Astrophysics Data System (ADS)

    Rupp, David E.; Abatzoglou, John T.; Hegewisch, Katherine C.; Mote, Philip W.

    2013-10-01

    temperature and precipitation data from 41 global climate models (GCMs) of the Coupled Model Intercomparison Project Phase 5 (CMIP5) were compared to observations for the 20th century, with a focus on the United States Pacific Northwest (PNW) and surrounding region. A suite of statistics, or metrics, was calculated, that included correlation and variance of mean seasonal spatial patterns, amplitude of seasonal cycle, diurnal temperature range, annual- to decadal-scale variance, long-term persistence, and regional teleconnections to El Niño Southern Oscillation (ENSO). Performance, or credibility, was assessed based on the GCMs' abilities to reproduce the observed metrics. GCMs were ranked in their credibility using two methods. The first simply treated all metrics equally. The second method considered two properties of the metrics: (1) redundancy of information (dependence) among metrics, and (2) confidence in the reliability of an individual metric for accurately ranking models. Confidence was related to how robust the estimate of the metric was to ensemble size, given that for most of the models only a small number of ensemble members (i.e., realizations of the 20th century) were available. A cursory comparison with 24 CMIP3 models revealed few differences between the two generations of models with respect to the statistics analyzed.

  2. Evaluation of CMIP5 20th century simulations for North American climate

    NASA Astrophysics Data System (ADS)

    Sheffield, J.; Maloney, E. D.; Mariotti, A.; Kinter, J. L.

    2012-12-01

    The Coupled Model Inter-comparison Project phase 5 (CMIP5) provides an unprecedented set of model results for improved understanding of climate processes and feedbacks, anthropogenic impacts and potential future changes. In particular, evaluations of the model historical simulations are crucial for assessing model fidelity and are a necessary prerequisite for instilling confidence in their future projections. This study synthesizes results from the NOAA CMIP5 Task Force on 20th century model evaluations for the climate of North America and related climate processes. We evaluate the models for a range of features at spatial scales from continental to regional and for a variety of time scales from intra-seasonal to multi-decadal variability and teleconnections with North American climate. In general the models capture the main features of North American climate including seasonal precipitation, air temperature and sea surface temperature. The hydrological cycle is also reasonably well simulated for the main characteristics of atmospheric moisture convergence and seasonality of the surface water budget but the latter is subject to the biases in precipitation. The spatial distribution of growing season length and number of frost days are generally well simulated, with biases highest in western regions. The frequency of hydroclimate extreme events is not well represented by the models. The skill of the models in representing climatologies of regional processes, such as the Great Plains low-level jet, the North American monsoon and cool season North Atlantic extra-tropical cyclones, is variable and can often be attributed to model resolution. In terms of climate variability, the multi-model ensemble does reasonably well at reproducing observed variability in several aspects, but does less well at capturing observed teleconnections. For intra-seasonal variability, almost half of the models examined can reproduce observed variability in the eastern Pacific and most models

  3. 20th century simulations of the Mediterranean Sea with focus on the climate variability in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Liu, Feifei; Mikolajewicz, Uwe; Six, Katharina

    2017-04-01

    The interannual variability in the Mediterranean Sea has been studied intensively by various modeling groups. However, those studies are generally restricted to the second half of the 20th and the beginning of the 21st century, where reanalysis data are available as forcing. Recently, the newly generated long-term reanalysis datasets enable the extension of such studies to the entire 20th century. However, the performance of these datasets has not been fully tested. Here the long-term (1901-2010) ERA-20C and NOAA-20CR reanalysis datasets are employed as forcing in a high-resolution regional physical and biogeochemical ocean model (MPIOM-HAMOCC) to simulate the 20th century climate evolution of the Mediterranean Sea. The results are also compared with a third simulation forced by the standard NCEP dataset (1948-2010). The aim is to investigate the differences in climate variability induced by these datasets, taking the Adriatic Sea as an example. The simulated interannual variability of sea surface temperature is rather similar in all three simulations, and is consistent with long-term observational compilations. However, the simulated decadal variability of sea surface salinity and circulation pattern shows remarkable differences between the three simulations. As a consequence, the simulated variability of biogeochemical parameters exhibits quite large discrepancies. For instance, the ERA-20C simulation shows a larger interannual variability of the primary production than the NOAA-20CR simulation. First results of the analysis exploring the underlying mechanisms for these differences will be presented.

  4. A time-series analysis of the 20th century climate simulations produced for the IPCC's Fourth Assessment Report.

    PubMed

    Estrada, Francisco; Perron, Pierre; Gay-García, Carlos; Martínez-López, Benjamín

    2013-01-01

    In this paper evidence of anthropogenic influence over the warming of the 20th century is presented and the debate regarding the time-series properties of global temperatures is addressed in depth. The 20th century global temperature simulations produced for the Intergovernmental Panel on Climate Change's Fourth Assessment Report and a set of the radiative forcing series used to drive them are analyzed using modern econometric techniques. Results show that both temperatures and radiative forcing series share similar time-series properties and a common nonlinear secular movement. This long-term co-movement is characterized by the existence of time-ordered breaks in the slope of their trend functions. The evidence presented in this paper suggests that while natural forcing factors may help explain the warming of the first part of the century, anthropogenic forcing has been its main driver since the 1970's. In terms of Article 2 of the United Nations Framework Convention on Climate Change, significant anthropogenic interference with the climate system has already occurred and the current climate models are capable of accurately simulating the response of the climate system, even if it consists in a rapid or abrupt change, to changes in external forcing factors. This paper presents a new methodological approach for conducting time-series based attribution studies.

  5. An Assessment of IPCC 20th Century Climate Simulations Using the 15-year Sea Level Record from Altimetry

    NASA Astrophysics Data System (ADS)

    Leuliette, E.; Nerem, S.; Jakub, T.

    2006-07-01

    Recen tly, multiple ensemble climate simulations h ave been produced for th e forthco ming Fourth A ssessment Report of the Intergovernmental Panel on Climate Change (IPCC). N early two dozen coupled ocean- atmo sphere models have contr ibuted output for a variety of climate scen arios. One scenar io, the climate of the 20th century exper imen t (20C3 M), produces model output that can be comp ared to th e long record of sea level provided by altimetry . Generally , the output from the 20C3M runs is used to initialize simulations of future climate scenar ios. Hence, v alidation of the 20 C3 M experiment resu lts is crucial to the goals of th e IPCC. We present compar isons of global mean sea level (G MSL) , global mean steric sea level change, and regional patterns of sea lev el chang e from these models to r esults from altimetry, tide gauge measurements, and reconstructions.

  6. CLIMATE CHANGE: The Causes of 20th Century Warming.

    PubMed

    Zwiers, F W; Weaver, A J

    2000-12-15

    Global air surface temperatures increased by about 0.6 degrees C during the 20th century, but as Zwiers and Weaver discuss in their Perspective, the warming was not continuous. Two distinct periods of warming, from 1910 to 1945 and since 1976, were separated by a period of very gradual cooling. The authors highlight the work by Stott et al., who have performed the most comprehensive simulation of 20th century climate to date. The agreement between observed and simulated temperature variations strongly suggests that forcing from anthropogenic activities, moderated by variations in solar and volcanic forcing, has been the main driver of climate change during the past century.

  7. Evaluation of Continental Precipitation in 20th-Century Climate Simulations: The Utility of Multi-Model Statistics

    SciTech Connect

    Phillips, T J; Gleckler, P J

    2005-11-01

    At the request of the Intergovernmental Panel on Climate Change (IPCC), simulations of 20th-century climate have been performed recently with some 20 global coupled ocean-atmosphere models. In view of its central importance for biological and socio-economic systems, model-simulated continental precipitation is evaluated relative to three observational estimates at both global and regional scales. Many models are found to display systematic biases, deviating markedly from the observed spatial variability and amplitude/phase of the seasonal cycle. However, the point-wise ensemble mean of all the models usually shows better statistical agreement with the observations than does any single model. Deficiencies of current models that may be responsible for the simulated precipitation biases as well as possible reasons for the improved estimate afforded by the multi-model ensemble mean are discussed. Implications of these results for water-resource managers also are briefly addressed.

  8. An evaluation of 20th century climate for the Southeastern United States as simulated by Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models

    USGS Publications Warehouse

    David E. Rupp,

    2016-05-05

    The 20th century climate for the Southeastern United States and surrounding areas as simulated by global climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) was evaluated. A suite of statistics that characterize various aspects of the regional climate was calculated from both model simulations and observation-based datasets. CMIP5 global climate models were ranked by their ability to reproduce the observed climate. Differences in the performance of the models between regions of the United States (the Southeastern and Northwestern United States) warrant a regional-scale assessment of CMIP5 models.

  9. A Time-Series Analysis of the 20th Century Climate Simulations Produced for the IPCC’s Fourth Assessment Report

    PubMed Central

    Estrada, Francisco; Perron, Pierre; Gay-García, Carlos; Martínez-López, Benjamín

    2013-01-01

    In this paper evidence of anthropogenic influence over the warming of the 20th century is presented and the debate regarding the time-series properties of global temperatures is addressed in depth. The 20th century global temperature simulations produced for the Intergovernmental Panel on Climate Change’s Fourth Assessment Report and a set of the radiative forcing series used to drive them are analyzed using modern econometric techniques. Results show that both temperatures and radiative forcing series share similar time-series properties and a common nonlinear secular movement. This long-term co-movement is characterized by the existence of time-ordered breaks in the slope of their trend functions. The evidence presented in this paper suggests that while natural forcing factors may help explain the warming of the first part of the century, anthropogenic forcing has been its main driver since the 1970’s. In terms of Article 2 of the United Nations Framework Convention on Climate Change, significant anthropogenic interference with the climate system has already occurred and the current climate models are capable of accurately simulating the response of the climate system, even if it consists in a rapid or abrupt change, to changes in external forcing factors. This paper presents a new methodological approach for conducting time-series based attribution studies. PMID:23555866

  10. Intercomparison of CMIP5 and CMIP3 simulations of the 20th century maximum and minimum temperatures over India and detection of climatic trends

    NASA Astrophysics Data System (ADS)

    Sonali, P.; Kumar, D. Nagesh; Nanjundiah, Ravi S.

    2016-01-01

    Climate change impact assessment has become one of the most important subjects of the research community because of the recent increase in frequency of extreme events and changes in the spatiotemporal patterns of climate. This paper analyses the ability of 46 coupled climate models from Coupled Model Intercomparison Project phases 3 and 5 (CMIP5 and CMIP3). The performance of each climate model was assessed based on its skills in simulating the current seasonal cycles (monthly) of both maximum temperature and minimum temperature (Tmax, Tmin) over India. The performance measures such as coefficient of correlation (Skill_r), root mean square error (Skill_rmse), and the skill in simulating the observed probability density function (Skill_s) are mainly employed for evaluation of the simulated monthly seasonal cycle. A new metric called Skill_All which is an intersection of the above three metrics has been defined for the first time. A notable enhancement of Skill_All for CMIP5 vis-a-vis CMIP3 is observed. Further, three best CMIP5 models each for Tmax and Tmin were selected. The methodology employed in this study for model assessment is implemented for the first time for India, which establishes a robust foundation for the climate impact assessment study. The seasonal trends in Tmax and Tmin were analyzed over all the temperature homogenous regions of India for different time slots during the 20th century. Significant trends in Tmin can be seen during most of the seasons over the entire Indian region during last four decades. This establishes the signature of climate change over most parts of India.

  11. Intercomparison of CMIP5 and CMIP3 simulations of the 20th century maximum and minimum temperatures over India and detection of climatic trends

    NASA Astrophysics Data System (ADS)

    Sonali, P.; Kumar, D. Nagesh; Nanjundiah, Ravi S.

    2017-04-01

    Climate change impact assessment has become one of the most important subjects of the research community because of the recent increase in frequency of extreme events and changes in the spatiotemporal patterns of climate. This paper analyses the ability of 46 coupled climate models from Coupled Model Intercomparison Project phases 3 and 5 (CMIP5 and CMIP3). The performance of each climate model was assessed based on its skills in simulating the current seasonal cycles (monthly) of both maximum temperature and minimum temperature (Tmax, Tmin) over India. The performance measures such as coefficient of correlation ( Skill_r), root mean square error ( Skill_rmse), and the skill in simulating the observed probability density function ( Skill_s) are mainly employed for evaluation of the simulated monthly seasonal cycle. A new metric called Skill_All which is an intersection of the above three metrics has been defined for the first time. A notable enhancement of Skill_All for CMIP5 vis-a-vis CMIP3 is observed. Further, three best CMIP5 models each for Tmax and Tmin were selected. The methodology employed in this study for model assessment is implemented for the first time for India, which establishes a robust foundation for the climate impact assessment study. The seasonal trends in Tmax and Tmin were analyzed over all the temperature homogenous regions of India for different time slots during the 20th century. Significant trends in Tmin can be seen during most of the seasons over the entire Indian region during last four decades. This establishes the signature of climate change over most parts of India.

  12. Observed 20th Century Desert Dust Variability: Impact on Climate and Biogeochemistry

    SciTech Connect

    Mahowald, Natalie; Kloster, Silvia; Engelstaedter, S.; Moore, Jefferson Keith; Mukhopadhyay, S.; McConnell, J. R.; Albani, S.; Doney, Scott C.; Bhattacharya, A.; Curran, M. A. J.; Flanner, Mark G.; Hoffman, Forrest M; Lawrence, David M.; Lindsay, Keith; Mayewski, P. A.; Neff, Jason; Rothenberg, D.; Thomas, E.; Thornton, Peter E; Zender, Charlie S.

    2010-01-01

    Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry. While we know that desert dust is sensitive to perturbations in climate and human land use, previous studies have been unable to determine whether humans were increasing or decreasing desert dust in the global average. Here we present observational estimates of desert dust based on paleodata proxies showing a doubling of desert dust during the 20th century over much, but not all the globe. Large uncertainties remain in estimates of desert dust variability over 20th century due to limited data. Using these observational estimates of desert dust change in combination with ocean, atmosphere and land models, we calculate the net radiative effect of these observed changes (top of atmosphere) over the 20th century to be -0.14 {+-} 0.11 W/m{sup 2} (1990-1999 vs. 1905-1914). The estimated radiative change due to dust is especially strong between the heavily loaded 1980-1989 and the less heavily loaded 1955-1964 time periods (-0.57 {+-} 0.46 W/m{sup 2}), which model simulations suggest may have reduced the rate of temperature increase between these time periods by 0.11 C. Model simulations also indicate strong regional shifts in precipitation and temperature from desert dust changes, causing 6 ppm (12 PgC) reduction in model carbon uptake by the terrestrial biosphere over the 20th century. Desert dust carries iron, an important micronutrient for ocean biogeochemistry that can modulate ocean carbon storage; here we show that dust deposition trends increase ocean productivity by an estimated 6% over the 20th century, drawing down an additional 4 ppm (8 PgC) of carbon dioxide into the oceans. Thus, perturbations to desert dust over the 20th century inferred from observations are potentially important for climate and biogeochemistry, and our understanding

  13. Role of tropospheric ozone increases in 20th-century climate change

    NASA Astrophysics Data System (ADS)

    Shindell, Drew; Faluvegi, Greg; Lacis, Andrew; Hansen, James; Ruedy, Reto; Aguilar, Elliot

    2006-04-01

    Human activities have increased tropospheric ozone, contributing to 20th-century warming. Using the spatial and temporal distribution of precursor emissions, we simulated tropospheric ozone from 1890 to 1990 using the NASA Goddard Institute for Space Studies (GISS) chemistry model. Archived three-dimensional ozone fields were then used in transient GISS climate model simulations. This enables more realistic evaluation of the impact of tropospheric ozone increases than prior simulations using an interpolation between preindustrial and present-day ozone. We find that tropospheric ozone contributed to the greater 20th-century warming in the Northern Hemisphere extratropics compared with the tropics and in the tropics compared with the Southern Hemisphere extratropics. Additionally, ozone increased more rapidly during the latter half of the century than the former, causing more rapid warming during that time. This is especially apparent in the tropics and is consistent with observations, which do not show similar behavior in the extratropics. Other climate forcings do not substantially accelerate warming rates in the tropics relative to other regions. This suggests that accelerated tropospheric ozone increases related to industrialization in the developing world have contributed to the accelerated tropical warming. During boreal summer, tropospheric ozone causes enhanced warming (>0.5°C) over polluted northern continental regions. Finally, the Arctic climate response to tropospheric ozone increases is large during fall, winter, and spring when ozone's lifetime is comparatively long and pollution transported from midlatitudes is abundant. The model indicates that tropospheric ozone could have contributed about 0.3°C annual average and about 0.4°C-0.5°C during winter and spring to the 20th-century Arctic warming. Pollution controls could thus substantially reduce the rapid rate of Arctic warming.

  14. Numerical simulation of global temperature change during the 20th century with the IAP/LASG GOALS model

    NASA Astrophysics Data System (ADS)

    Ma, Xiaoyan; Guo, Yufu; Shi, Guangyu; Yu, Yongqiang

    2004-04-01

    The IAP/LASG GOALS coupled model is used to simulate the climate change during the 20th century using historical greenhouse gases concentrations, the mass mixing ratio of sulfate aerosols simulated by a CTM model, and reconstruction of solar variability spanning the period 1900 to 1997. Four simulations, including a control simulation and three forcing simulations, are conducted. Comparison with the observational record for the period indicates that the three forcing experiments simulate reasonable temporal and spatial distributions of the temperature change. The global warming during the 20th century is caused mainly by increasing greenhouse gas concentration especially since the late 1980s; sulfate aerosols offset a portion of the global warming and the reduction of global temperature is up to about 0.11°C over the century; additionally, the effect of solar variability is not negligible in the simulation of climate change over the 20th century.

  15. Climate and society in 20th century Mexico

    NASA Technical Reports Server (NTRS)

    Liverman, Diana M.

    1991-01-01

    Mexican agriculture has been greatly transformed by the widespread introduction of 'Green Revolution' technologies (irrigation, chemical fertilizers, and improved seeds), through land reform, and by land use policies oriented to export crops and grain production. Drought prone Mexico provides an excellent case to study how technological and social changes alter the impact of drought on food and agricultural system. A goal is to document and understand how relationships between climate and agriculture in Mexico have changed in the last fifty years. The results for several locations will be interpreted in light of the prospects of regional climate change due to global warming. This analysis will be complimented by four case studies of vulnerability to drought which will use local records and interviews to try and show how environmental, technological, and social changes may have altered the impacts of climate on local agricultural systems.

  16. 20th century climate warming and tree-limit rise in the southern Scandes of Sweden.

    PubMed

    Kullman, L

    2001-03-01

    Climate warming by ca. 0.8 degree C between the late-19th and late-20th century, although with some fluctuations, has forced multispecies elevational tree-limit advance by > 100 m for the principal tree species in the Swedish part of the Scandinavian mountain range. Predominantly, these processes imply growth in height of old-established individuals and less frequently upslope migration of new individuals. After a slight retardation during some cooler decades after 1940, a new active phase of tree-limit advance has occurred with a series of exceptionally mild winters and some warm summers during the 1990s. The magnitude of total 20th century tree-limit rise varies with topoclimate and is mainly confined to wind-sheltered and snow-rich segments of the landscape. Thickening of birch tree stands in the "advance belt" has profoundly altered the general character of the subalpine/low alpine landscape and provides a positive feedback loop for further progressive change and resilience to short-term cooling episodes. All upslope tree-limit shifts and associated landscape transformations during the 20th century have occurred without appreciable time lags, which constitutes knowledge fundamental to the generation of realistic models concerning vegetation responses to potential future warming. The new and elevated pine tree-limit may be the highest during the past 4000 14C years. Thus, it is tentatively inferred that the 20th century climate is unusually warm in a late-Holocene perspective.

  17. Fire dynamics during the 20th century simulated by the Community Land Model

    SciTech Connect

    Kloster, Silvia; Mahowald, Natalie; Randerson, Jim; Thornton, Peter E; Hoffman, Forrest M; Levis, Sam; Lawrence, Peter J.; Feddema, Johan J.; Oleson, Keith; Lawrence, David M.

    2011-01-01

    Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in terms of magnitude and spatial extent as well as interannual and seasonal variability. Long-term trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005). We obtained substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997 2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite-based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000 2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we predicted a slight downward trend in global fire emissions caused by reduced fuels as a consequence of wood harvesting and also by increases in fire suppression. The model predicted an upward trend during the last three decades of the 20th century as a result of climate variations and large burning events associated with ENSO-induced drought conditions.

  18. Effects of Irrigation on Global Climate During the 20th Century

    NASA Technical Reports Server (NTRS)

    Puma, M. J.; Cook, B. I.

    2010-01-01

    Various studies have documented the effects of modern ]day irrigation on regional and global climate, but none, to date, have considered the time ]varying impact of steadily increasing irrigation rates on climate during the 20th century. We investigate the impacts of observed irrigation changes over this century with two ensemble simulations using an atmosphere general circulation model. Both ensembles are forced with transient climate forcings and observed sea surface temperatures from 1902 to 2000; one ensemble includes irrigation specified by a time ]varying data set of irrigation water withdrawals. Early in the century, irrigation is primarily localized over southern and eastern Asia, leading to significant cooling in boreal summer (June.August) over these regions. This cooling spreads and intensifies by century fs end, following the rapid expansion of irrigation over North America, Europe, and Asia. Irrigation also leads to boreal winter (December.February) warming over parts of North America and Asia in the latter part of the century, due to enhanced downward longwave fluxes from increased near ]surface humidity. Precipitation increases occur primarily downwind of the major irrigation areas, although precipitation in parts of India decreases due to a weaker summer monsoon. Irrigation begins to significantly reduce temperatures and temperature trends during boreal summer over the Northern Hemisphere midlatitudes and tropics beginning around 1950; significant increases in precipitation occur in these same latitude bands. These trends reveal the varying importance of irrigation ]climate interactions and suggest that future climate studies should account for irrigation, especially in regions with unsustainable irrigation resources.

  19. Effects of Irrigation on Global Climate During the 20th Century

    NASA Technical Reports Server (NTRS)

    Puma, M. J.; Cook, B. I.

    2010-01-01

    Various studies have documented the effects of modern ]day irrigation on regional and global climate, but none, to date, have considered the time ]varying impact of steadily increasing irrigation rates on climate during the 20th century. We investigate the impacts of observed irrigation changes over this century with two ensemble simulations using an atmosphere general circulation model. Both ensembles are forced with transient climate forcings and observed sea surface temperatures from 1902 to 2000; one ensemble includes irrigation specified by a time ]varying data set of irrigation water withdrawals. Early in the century, irrigation is primarily localized over southern and eastern Asia, leading to significant cooling in boreal summer (June.August) over these regions. This cooling spreads and intensifies by century fs end, following the rapid expansion of irrigation over North America, Europe, and Asia. Irrigation also leads to boreal winter (December.February) warming over parts of North America and Asia in the latter part of the century, due to enhanced downward longwave fluxes from increased near ]surface humidity. Precipitation increases occur primarily downwind of the major irrigation areas, although precipitation in parts of India decreases due to a weaker summer monsoon. Irrigation begins to significantly reduce temperatures and temperature trends during boreal summer over the Northern Hemisphere midlatitudes and tropics beginning around 1950; significant increases in precipitation occur in these same latitude bands. These trends reveal the varying importance of irrigation ]climate interactions and suggest that future climate studies should account for irrigation, especially in regions with unsustainable irrigation resources.

  20. Multi-season climate synchronized forest fires throughout the 20th century, Northern Rockies, USA

    Treesearch

    Penelope Morgan; Emily K. Heyerdahl; Carly E. Gibson

    2008-01-01

    We inferred climate drivers of 20th-century years with regionally synchronous forest fires in the U.S. northern Rockies. We derived annual fire extent from an existing fire atlas that includes 5038 fire polygons recorded from 12 070 086 ha, or 71% of the forested land in Idaho and Montana west of the Continental Divide. The 11 regional-fire years, those exceeding the...

  1. Long-term natural variability and 20th century climate change.

    PubMed

    Swanson, Kyle L; Sugihara, George; Tsonis, Anastasios A

    2009-09-22

    Global mean temperature at the Earth's surface responds both to externally imposed forcings, such as those arising from anthropogenic greenhouse gases, as well as to natural modes of variability internal to the climate system. Variability associated with these latter processes, generally referred to as natural long-term climate variability, arises primarily from changes in oceanic circulation. Here we present a technique that objectively identifies the component of inter-decadal global mean surface temperature attributable to natural long-term climate variability. Removal of that hidden variability from the actual observed global mean surface temperature record delineates the externally forced climate signal, which is monotonic, accelerating warming during the 20th century.

  2. The climate velocity of the contiguous United States during the 20th century.

    PubMed

    Dobrowski, Solomon Z; Abatzoglou, John; Swanson, Alan K; Greenberg, Jonathan A; Mynsberge, Alison R; Holden, Zachary A; Schwartz, Michael K

    2013-01-01

    Rapid climate change has the potential to affect economic, social, and biological systems. A concern for species conservation is whether or not the rate of on-going climate change will exceed the rate at which species can adapt or move to suitable environments. Here we assess the climate velocity (both climate displacement rate and direction) for minimum temperature, actual evapotranspiration, and climatic water deficit (deficit) over the contiguous US during the 20th century (1916-2005). Vectors for these variables demonstrate a complex mosaic of patterns that vary spatially and temporally and are dependent on the spatial resolution of input climate data. Velocities for variables that characterize the climatic water balance were similar in magnitude to that derived from temperature, but frequently differed in direction resulting in the divergence of climate vectors through time. Our results strain expectations of poleward and upslope migration over the past century due to warming. Instead, they suggest that a more full understanding of changes in multiple climatic factors, in addition to temperature, may help explain unexpected or conflicting observational evidence of climate-driven species range shifts during the 20th century.

  3. Assessing the 20th century performance of global climate models and application to climate change adaptation planning

    NASA Astrophysics Data System (ADS)

    Geil, Kerrie

    Rapid environmental changes linked to human-induced increases in atmospheric greenhouse gas concentrations have been observed on a global scale over recent decades. Given the relative certainty of continued change across many earth systems, the information output from climate models is an essential resource for adaptation planning. But in the face of many known modeling deficiencies, how confident can we be in model projections of future climate? It stands to reason that a realistic simulation of the present climate is at least a necessary (but likely not sufficient) requirement for a model's ability to realistically simulate the climate of the future. Here, I present the results of three studies that evaluate the 20th century performance of global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). (Abstract shortened by ProQuest.).

  4. Global economic impacts of climate variability and change during the 20th century.

    PubMed

    Estrada, Francisco; Tol, Richard S J; Botzen, Wouter J W

    2017-01-01

    Estimates of the global economic impacts of observed climate change during the 20th century obtained by applying five impact functions of different integrated assessment models (IAMs) are separated into their main natural and anthropogenic components. The estimates of the costs that can be attributed to natural variability factors and to the anthropogenic intervention with the climate system in general tend to show that: 1) during the first half of the century, the amplitude of the impacts associated with natural variability is considerably larger than that produced by anthropogenic factors and the effects of natural variability fluctuated between being negative and positive. These non-monotonic impacts are mostly determined by the low-frequency variability and the persistence of the climate system; 2) IAMs do not agree on the sign (nor on the magnitude) of the impacts of anthropogenic forcing but indicate that they steadily grew over the first part of the century, rapidly accelerated since the mid 1970's, and decelerated during the first decade of the 21st century. This deceleration is accentuated by the existence of interaction effects between natural variability and natural and anthropogenic forcing. The economic impacts of anthropogenic forcing range in the tenths of percentage of the world GDP by the end of the 20th century; 3) the impacts of natural forcing are about one order of magnitude lower than those associated with anthropogenic forcing and are dominated by the solar forcing; 4) the interaction effects between natural and anthropogenic factors can importantly modulate how impacts actually occur, at least for moderate increases in external forcing. Human activities became dominant drivers of the estimated economic impacts at the end of the 20th century, producing larger impacts than those of low-frequency natural variability. Some of the uses and limitations of IAMs are discussed.

  5. Global economic impacts of climate variability and change during the 20th century

    PubMed Central

    Estrada, Francisco; Tol, Richard S. J.; Botzen, Wouter J. W.

    2017-01-01

    Estimates of the global economic impacts of observed climate change during the 20th century obtained by applying five impact functions of different integrated assessment models (IAMs) are separated into their main natural and anthropogenic components. The estimates of the costs that can be attributed to natural variability factors and to the anthropogenic intervention with the climate system in general tend to show that: 1) during the first half of the century, the amplitude of the impacts associated with natural variability is considerably larger than that produced by anthropogenic factors and the effects of natural variability fluctuated between being negative and positive. These non-monotonic impacts are mostly determined by the low-frequency variability and the persistence of the climate system; 2) IAMs do not agree on the sign (nor on the magnitude) of the impacts of anthropogenic forcing but indicate that they steadily grew over the first part of the century, rapidly accelerated since the mid 1970's, and decelerated during the first decade of the 21st century. This deceleration is accentuated by the existence of interaction effects between natural variability and natural and anthropogenic forcing. The economic impacts of anthropogenic forcing range in the tenths of percentage of the world GDP by the end of the 20th century; 3) the impacts of natural forcing are about one order of magnitude lower than those associated with anthropogenic forcing and are dominated by the solar forcing; 4) the interaction effects between natural and anthropogenic factors can importantly modulate how impacts actually occur, at least for moderate increases in external forcing. Human activities became dominant drivers of the estimated economic impacts at the end of the 20th century, producing larger impacts than those of low-frequency natural variability. Some of the uses and limitations of IAMs are discussed. PMID:28212384

  6. Spitsbergen landscape under 20th century climate change: Sørkapp Land.

    PubMed

    Ziaja, Wieslaw

    2004-08-01

    A reaction of the European Arctic landscape to a climate change on the scale of a typical middle-sized region is outlined. A wide scope of the methods was used, first of all field mapping and observations. Glaciers are important in the Sørkapp Land landscape because they cover the majority of its territory and undergo quick recessions as a result of the 20th century warming. Glacial recession influence intensively: relief with Quaternary deposits, waters, animals, vegetation and soils. The most important landscape changes in the 20th century are: uplift of the equilibrium line altitude on glaciers by 100-200 m; large glacial recession in both surface and volume; significant decrease of the land area due to recession of tidewater glaciers; lengthening of the coastline, and especially of glacial cliffs; development of the land water network; start of the plant succession in areas abandoned by glaciers. No isostatic uplift has taken place in Sørkapp Land since the Little Ice Age.

  7. Downscaling 20th century flooding events in complex terrain (Switzerland) using the WRF regional climate model

    NASA Astrophysics Data System (ADS)

    Heikkilä, Ulla; Gómez Navarro, Juan Jose; Franke, Jörg; Brönnimann, Stefan; Cattin, Réne

    2016-04-01

    Switzerland has experienced a number of severe precipitation events during the last few decades, such as during the 14-16 November of 2002 or during the 21-22 August of 2005. Both events, and subsequent extreme floods, caused fatalities and severe financial losses, and have been well studied both in terms of atmospheric conditions leading to extreme precipitation, and their consequences [e.g. Hohenegger et al., 2008, Stucki et al., 2012]. These examples highlight the need to better characterise the frequency and severity of flooding in the Alpine area. In a larger framework we will ultimately produce a high-resolution data set covering the entire 20th century to be used for detailed hydrological studies including all atmospheric parameters relevant for flooding events. In a first step, we downscale the aforementioned two events of 2002 and 2005 to assess the model performance regarding precipitation extremes. The complexity of the topography in the Alpine area demands high resolution datasets. To achieve a sufficient detail in resolution we employ the Weather Research and Forecasting regional climate model (WRF). A set of 4 nested domains is used with a 2-km resolution horizontal resolution over Switzerland. The NCAR 20th century reanalysis (20CR) with a horizontal resolution of 2.5° serves as boundary condition [Compo et al., 2011]. First results of the downscaling the 2002 and 2005 extreme precipitation events show that, compared to station observations provided by the Swiss Meteorological Office MeteoSwiss, the model strongly underestimates the strength of these events. This is mainly due to the coarse resolution of the 20CR data, which underestimates the moisture fluxes during these events. We tested driving WRF with the higher-resolved NCEP reanalysis and found a significant improvement in the amount of precipitation of the 2005 event. In a next step we will downscale the precipitation and wind fields during a 6-year period 2002-2007 to investigate and

  8. Effects of 20th Century Warming and Climate Variability on Flood Risk in the Western U.S.

    NASA Astrophysics Data System (ADS)

    Hamlet, A. F.; Lettenmaier, D. P.

    2006-12-01

    Flood risk in the western U.S., although frequently assumed for design purposes to be static, is in reality a function of non-stationary regional climate and climate variability. During the 20th century, the western U.S. has warmed at a rate of about 1 degree C per century overall, and changes in cool season precipitation variability are also evident after about 1975. Using the Variable Infiltration Capacity (VIC) hydrologic model and a long term driving data set from 1916-2003, we examine the implications of these 20th century changes in climate on natural flooding regimes in the West. We find that changes in flood risk that accompany large scale warming are a complex function of mid-winter temperature regimes, which are related to seasonal changes in antecedent snowpack and contributing basin area during storms that cause flooding. In strongly snowmelt dominant river basins, simulated flood risk in most cases has declined with 20th century warming, because of reductions in peak spring snowpack. For river basins near the freezing level in mid-winter the effects of warming on flood risk vary widely and increases or decreases in flood risks can occur in response to warming depending on the relative importance of changes in effective basin area and antecedent snow conditions that are coincident with storms. Relatively warm basins close to the Pacific Coast tend to show increased flood risk, while somewhat colder inland areas tend to show decreased flood risk overall. Flood risk in rain-dominant basins, although affected by small systematic changes in soil moisture, is largely stationary in response to warming. Changes in cool season precipitation variability (increased variance, autocorrelation, and regional synchronicity) since about 1975 are shown to increase flood risk over much of the western U.S., however it is currently unclear whether these precipitation changes are systematic in nature (e.g. related to warming) or whether this is simply one mode of

  9. Evidence for 20th century climate warming and wetland drying in the North American Prairie Pothole Region

    USGS Publications Warehouse

    Werner, B.A.; Johnson, W. Carter; Guntenspergen, Glenn R.

    2013-01-01

    The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate change may have been sufficient to have a significant impact on wetland cover cycling. Modeled wetlands in the PPR's western Canadian prairies show the most dramatic effects: a recent trend toward shorter hydroperiods and less dynamic vegetation cycles, which already may have reduced the productivity of hundreds of wetland-dependent species.

  10. Evidence for 20th century climate warming and wetland drying in the North American Prairie Pothole Region

    PubMed Central

    Werner, Brett A; Johnson, W Carter; Guntenspergen, Glenn R

    2013-01-01

    The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate change may have been sufficient to have a significant impact on wetland cover cycling. Modeled wetlands in the PPR's western Canadian prairies show the most dramatic effects: a recent trend toward shorter hydroperiods and less dynamic vegetation cycles, which already may have reduced the productivity of hundreds of wetland-dependent species. PMID:24223283

  11. Tuning the climate sensitivity of a global model to match 20th Century warming

    NASA Astrophysics Data System (ADS)

    Mauritsen, T.; Roeckner, E.

    2015-12-01

    A climate models ability to reproduce observed historical warming is sometimes viewed as a measure of quality. Yet, for practical reasons historical warming cannot be considered a purely empirical result of the modelling efforts because the desired result is known in advance and so is a potential target of tuning. Here we explain how the latest edition of the Max Planck Institute for Meteorology Earth System Model (MPI-ESM1.2) atmospheric model (ECHAM6.3) had its climate sensitivity systematically tuned to about 3 K; the MPI model to be used during CMIP6. This was deliberately done in order to improve the match to observed 20th Century warming over the previous model generation (MPI-ESM, ECHAM6.1) which warmed too much and had a sensitivity of 3.5 K. In the process we identified several controls on model cloud feedback that confirm recently proposed hypotheses concerning trade-wind cumulus and high-latitude mixed-phase clouds. We then evaluate the model fidelity with centennial global warming and discuss the relative importance of climate sensitivity, forcing and ocean heat uptake efficiency in determining the response as well as possible systematic biases. The activity of targeting historical warming during model development is polarizing the modeling community with 35 percent of modelers stating that 20th Century warming was rated very important to decisive, whereas 30 percent would not consider it at all. Likewise, opinions diverge as to which measures are legitimate means for improving the model match to observed warming. These results are from a survey conducted in conjunction with the first WCRP Workshop on Model Tuning in fall 2014 answered by 23 modelers. We argue that tuning or constructing models to match observed warming to some extent is practically unavoidable, and as such, in many cases might as well be done explicitly. For modeling groups that have the capability to tune both their aerosol forcing and climate sensitivity there is now a unique

  12. Effect of anthropogenic aerosol forcing on climate change in the North Pacific Ocean during the 20th Century

    NASA Astrophysics Data System (ADS)

    Abe, M.; Watanabe, S.; Kawamiya, M.; Nozawa, T.

    2014-12-01

    Reliable future projection by the climate or Earth system model is crucial for the issue on future climate change. For the reliable future projection, uncertainty of the aerosol effect on the climate change should be reduced, because the uncertainty has been large. Therefore, it is essential to understand the effect of anthropogenic aerosol forcing on climate change in the 20th century. In this study, we have assessed the effect by a comparison between the 20th century historical simulations (20C and piAero) with the aerosol forcing fluctuated realistically over time and fixed in the pre-industrial condition by MIROC-ESM. We focus on the climate change in the North Pacific Ocean (NPO) due to anthropogenic aerosol emitted from China in the late 20th century. In the comparison between the two simulations, there has been little difference in the global mean surface temperature (SAT) from 1851 to 1900. Then the difference appears and reaches to about 0.2 deg. C in 1950's. After 1960, the difference in SAT between the two experiments become large. For SST change in the NPO, small positive trend is found after 1900 in the piAero, but not found in the 20C. Thus, the SST difference in the NPO between the two experiments is significant after 1900. While the positive SST trend in the NPO has been large in the piAero after 1960, SST in the Central NPO shows the negative trend in the 20C. These enlarge SST difference between the two experiments. The negative SST trend in the Central NPO in the 20C is likely to be attributable to an increase of aerosol emission from China. The aerosol increase, which is also found in the NPO, makes solar insolation into the surface decrease mainly through the aerosol indirect effect. This effect decreases SST. Also, the effect is seen in the boreal spring and summer. However, the effect is not found in the piAero. The Pacific Decadal Oscillation (PDO), which is the principal natural variability in the NPO, has been investigated. Linear trend of

  13. Numerical Simulation of the Water Cycle Change Over the 20th Century

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Schubert, Siegfried D.

    2003-01-01

    We have used numerical models to test the impact of the change in Sea Surface Temperatures (SSTs) and carbon dioxide (CO2) concentration on the global circulation, particularly focusing on the hydrologic cycle, namely the global cycling of water and continental recycling of water. We have run four numerical simulations using mean annual SST from the early part of the 20th century (1900-1920) and the later part (1980-2000). In addition, we vary the CO2 concentrations for these periods as well. The duration of the simulations is 15 years, and the spatial resolution is 2 degrees. We use passive tracers to study the geographical sources of water. Surface evaporation from predetermined continental and oceanic regions provides the source of water for each passive tracer. In this way, we compute the percent of precipitation of each region over the globe. This can also be used to estimate precipitation recycling. In addition, we are using the passive tracers to independently compute the global cycling of water (compared to the traditional, Q/P calculation).

  14. Modeling Regional Climate Responses to 17th-20th Century Land Use Change over the Southeastern United States

    NASA Astrophysics Data System (ADS)

    Alder, J. R.; Hostetler, S. W.; Reker, R. R.; Loveland, T. R.; Bernhardt, C. E.; Thompson, R.; Sundquist, E. T.; Willard, D. A.

    2015-12-01

    Regional climate change is the combined response to global and regional radiative forcing, circulation and interactions between the atmosphere and Earth surface. A potentially key component of regional climate change derives from natural and human-caused land use and land-use change (LULC) and related atmosphere-surface feedbacks. In the first step of disentangling and quantifying the effect of LULC over the southeastern United States, we conducted a series of simulations with the RegCM4 regional climate model which includes the Biosphere Atmosphere Transfer Scheme (BATS) surface physics package. Land use and vegetation types determine the specified values of a number of biophysical and physical parameters in BATS such as albedo, roughness length, stomatal resistance, and rooting depth. We ran four simulations in which we specified BATS land use types derived from harmonized reconstructions for 1650, 1850, 1920 and Landsat-based observations for 1992 (Steyaert and Knox, 2008). The simulations were run over a model domain comprising a 20 km × 20 km horizontal grid and 23 atmospheric levels for the period 1990-2000. The boundary conditions for the simulations were derived from the NCAR-NCEP Reanalysis and the NOAA Optimum Interpolated Sea Surface Temperature global data sets. Depending on the time periods considered, the simulations indicate regionally coherent patterns of April-September changes in surface radiation, warming and cooling of up to 2 °C or more, substantial changes in soil moisture and atmospheric humidity associated with conversion of native vegetation to agriculture and agriculture back to forest, draining of wetlands and marshes, and urbanization. Extensive draining of wetlands in the lower Mississippi Valley during the 20th century induced a robust feedback with the atmosphere which suppressed convective summertime precipitation. Our joint analysis of LULC classes and the model simulations suggests a need to be able to disaggregate land use to a

  15. Regional Variability of the 20th century sea level rise from Ocean-Atmosphere Coupled Climate Models

    NASA Astrophysics Data System (ADS)

    Chevrier, Robin; Meyssignac, Benoit; Bourgeois, Elsa; Marzeion, Ben; Cazenave, Anny

    2014-05-01

    Regional Variability of the 20th century sea level rise from Ocean-Atmosphere Coupled Climate Models. R.Chevrier, B. Meyssignac, E. Bourgeois, B. Marzeion and A.Cazenave Over the 20th century, tide gauge records indicate a rise in global mean sea level of 1.7 mm.y-1 (Church and White 2011). This rise is essentially due to the warming of the ocean (which made the ocean water expand and sea level rise by ˜0.6 mm.yr-1) and the melt of mountain glaciers (which added more water to the ocean and made sea level rise by ˜,0.6 mm.yr-1 Gregory et al. 2013). Land water changes and Greenland surface mass balance changes also played a role but of lesser importance ( ˜0.1 mm.yr-1 for the land water storage and ˜0.2 mm.yr-1 for the Greenland mass balance since 1900, Gregory et al. 2013). Each of these different contributors to the 20th century global mean sea level rise had also an impact on the regional sea level changes. This regional signal, which must be added to the global sea level rise to compute the total sea level signal, is essential when we want to assess the impacts of the 20th century sea level rise on coastal areas and low lying islands. In this study we aim to estimate this 20th century regional sea level changes. We use historical runs of the CMIP5 (Coupled Model Intercomparison Project Phase 5) coupled climate models, which cover the period 1850-2006, to estimate the different contributors to the regional sea level changes since 1900. The ocean warming contribution is directly computed from the Temperature and Salinity outputs of the CMIP5 models while the mountain glaciers and the Greenland contributions are computed from offline models using the surface temperature output of CMIP5 models. Concerning the landwater storage contribution, it is actually mainly of anthropogenic origin over the 20th century (Ngoduc et al. 2005, Meyssignac et Cazenave 2012) so it is not modeled in CMIP5 models. Consequently, we use here estimates of the landwater storage

  16. Patterns of Coherent Climate Signals in the Indian Ocean during the 20th Century

    NASA Astrophysics Data System (ADS)

    Tourre, Yves M.; White, Warren B.

    2003-12-01

    QBO, ENSO, and BDO fluctuations are identified in the Indian Ocean from a joint frequency domain analysis of sea surface temperature (SST) and sea level pressure (SLP) conducted over the 20th Century. Within the ENSO band (3- to 7-year period), local fractional variance (LFV) is maximum near 3.4-year period, revealing spatially coherent SST and SLP variability propagating eastward from the Horn of Africa and southwest Indian Ocean respectively, toward the eastern tropical Indian Ocean. Within the QBO band (2.1- to 2.8- year period), LFV is maximum near 2.2-year period revealing spatially coherent SST and SLP variability propagating northward and eastward from Southwestern Ocean, toward the South China Sea. The 3.4-year period ENSO signal diminished in intensity in the 1920s and 1950s, whilst the 2.2-year period QBO signal diminished in the 1910s, 1940s, and 1950s, as observed for the global QBO and ENSO signals [White and Tourre, 2003].

  17. Response of the everglades ridge and slough landscape to climate variability and 20th-century water management

    USGS Publications Warehouse

    Bernhardt, C.E.; Willard, D.A.

    2009-01-01

    The ridge and slough landscape of the Florida Everglades consists of a mosaic of linear sawgrass ridges separated by deeper-water sloughs with tree islands interspersed throughout the landscape. We used pollen assemblages from transects of sediment cores spanning sawgrass ridges, sloughs, and ridge-slough transition zones to determine the timing of ridge and slough formation and to evaluate the response of components of the ridge and slough landscape to climate variability and 20th-century water management. These pollen data indicate that sawgrass ridges and sloughs have been vegetationally distinct from one another since initiation of the Everglades wetland in mid-Holocene time. Although the position and community composition of sloughs have remained relatively stable throughout their history, modern sawgrass ridges formed on sites that originally were occupied by marshes. Ridge formation and maturation were initiated during intervals of drier climate (the Medieval Warm Period and the Little Ice Age) when the mean position of the Intertropical Convergence Zone shifted southward. During these drier intervals, marsh taxa were more common in sloughs, but they quickly receded when precipitation increased. Comparison with regional climate records suggests that slough vegetation is strongly influenced by North Atlantic Oscillation variability, even under 20th-century water management practices. ?? 2009 by the Ecological Society of America.

  18. Response of the Everglades ridge and slough landscape to climate variability and 20th-century water management.

    PubMed

    Bernhardt, Christopher E; Willard, Debra A

    2009-10-01

    The ridge and slough landscape of the Florida Everglades consists of a mosaic of linear sawgrass ridges separated by deeper-water sloughs with tree islands interspersed throughout the landscape. We used pollen assemblages from transects of sediment cores spanning sawgrass ridges, sloughs, and ridge-slough transition zones to determine the timing of ridge and slough formation and to evaluate the response of components of the ridge and slough landscape to climate variability and 20th-century water management. These pollen data indicate that sawgrass ridges and sloughs have been vegetationally distinct from one another since initiation of the Everglades wetland in mid-Holocene time. Although the position and community composition of sloughs have remained relatively stable throughout their history, modern sawgrass ridges formed on sites that originally were occupied by marshes. Ridge formation and maturation were initiated during intervals of drier climate (the Medieval Warm Period and the Little Ice Age) when the mean position of the Intertropical Convergence Zone shifted southward. During these drier intervals, marsh taxa were more common in sloughs, but they quickly receded when precipitation increased. Comparison with regional climate records suggests that slough vegetation is strongly influenced by North Atlantic Oscillation variability, even under 20th-century water management practices.

  19. Patterns of Coherent Low-frequency Climate Variability in the Atlantic basin during the 20th Century

    NASA Astrophysics Data System (ADS)

    Tourre, Y. M.; Paz, S.; Kushnir, Y.; White, W. B.

    2009-09-01

    Using multiple-taper/singular value decomposition method (MTM/SVD) climate variability is diagnosed over the Atlantic Basin during the 20th century. Two low-frequency signals are compared: the Atlantic multi-decadal oscillation (AMO) and the quasi-decadal oscillation (QDO). The AMO is primarily associated with oceanic processes including the thermohaline circulation (THC), whilst the QDO variability reflects faster atmosphere-ocean interactions. They are both correlated with the Atlantic meridional mode (AMM) and the North Atlantic Oscillation. During the second part of the 20th century, the AMO and QDO variability, Sahelian rainfall and hurricanes power dissipation index (PDI), are also significantly correlated. Phase changes in all time-series occurred in the mid- 60s, when the AMO went from positive to negative values, contributing to the last Sahelian drought. Climate change could have further impacts on the AMO after it changed phase in the mid- 90s, enhance levels of hurricane intensity with important environmental and socio-economical consequences.

  20. Climate-change impact on the 20th-century relationship between the Southern Annular Mode and global mean temperature

    PubMed Central

    Wang, Guojian; Cai, Wenju

    2013-01-01

    The positive phase of the El Niño-Southern Oscillation (ENSO) increases global mean temperature, and contributes to a negative phase of the Southern Annular Mode (SAM), the dominant mode of climate variability in the Southern Hemisphere. This interannual relationship of a high global mean temperature associated with a negative SAM, however, is opposite to the relationship between their trends under greenhouse warming. We show that over much of the 20th century this relationship undergoes multidecadal fluctuations depending on the intensity of ENSO. During the period 1925–1955, subdued ENSO activities weakened the relationship. However, a similar weakening has occurred since the late 1970s despite the strong ENSO. We demonstrate that this recent weakening is induced by climate change in the Southern Hemisphere. Our result highlights a rare situation in which climate change signals emerge against an opposing property of interannual variability, underscoring the robustness of the recent climate change. PMID:23784087

  1. Divergent hydrological responses to 20th century climate change in shallow tundra ponds, western Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Wolfe, Brent B.; Light, Erin M.; Macrae, Merrin L.; Hall, Roland I.; Eichel, Kaleigh; Jasechko, Scott; White, Jerry; Fishback, LeeAnn; Edwards, Thomas W. D.

    2011-12-01

    The hydrological fate of shallow tundra lakes and ponds under conditions of continued warming remains uncertain, but has important implications for wildlife habitat and biogeochemical cycling. Observations of unprecedented pond desiccation, in particular, signify catastrophic loss of aquatic habitat in some Arctic locations. Shallow tundra ponds are a ubiquitous feature in the western Hudson Bay Lowlands (HBL), a region that has undergone intense warming over the past ˜50 years. But it remains unknown how hydrological processes in these ponds have responded. Here, we use cellulose-inferred pond water oxygen isotope records from sediment cores, informed by monitoring of modern pond water isotope compositions during the 2009 and 2010 ice-free seasons, to reconstruct hydrological conditions of four shallow tundra ponds in the western HBL over the past three centuries. Following an interval of relative hydrological stability during the early part of the records, results reveal widely differing hydrological responses to 20th century climate change among the study sites, which is largely dependent on hydrological connectivity of the basins within their respective surrounding peatlands. These findings suggest the 20th century has been characterized by an increasingly dynamic landscape that has variably influenced surface water balance - a factor that is likely to play a key role in determining the future water balance of ponds in this region.

  2. Multi-season climate synchronized forest fires throughout the 20th century, northern Rockies, U.S.A.

    PubMed

    Morgan, Penelope; Heyerdahl, Emily K; Gibson, Carly E

    2008-03-01

    We inferred climate drivers of 20th-century years with regionally synchronous forest fires in the U.S. northern Rockies. We derived annual fire extent from an existing fire atlas that includes 5038 fire polygons recorded from 12,070,086 ha, or 71% of the forested land in Idaho and Montana west of the Continental Divide. The 11 regional-fire years, those exceeding the 90th percentile in annual fire extent from 1900 to 2003 (>102,314 ha or approximately 1% of the fire atlas recording area), were concentrated early and late in the century (six from 1900 to 1934 and five from 1988 to 2003). During both periods, regional-fire years were ones when warm springs were followed by warm, dry summers and also when the Pacific Decadal Oscillation (PDO) was positive. Spring snowpack was likely reduced during warm springs and when PDO was positive, resulting in longer fire seasons. Regional-fire years did not vary with El Niño-Southern Oscillation (ENSO) or with climate in antecedent years. The long mid-20th century period lacking regional-fire years (1935-1987) had generally cool springs, generally negative PDO, and a lack of extremely dry summers; also, this was a period of active fire suppression. The climate drivers of regionally synchronous fire that we inferred are congruent with those of previous centuries in this region, suggesting a strong influence of spring and summer climate on fire activity throughout the 20th century despite major land-use change and fire suppression efforts. The relatively cool, moist climate during the mid-century gap in regional-fire years likely contributed to the success of fire suppression during that period. In every regional-fire year, fires burned across a range of vegetation types. Given our results and the projections for warmer springs and continued warm, dry summers, forests of the U.S. northern Rockies are likely to experience synchronous, large fires in the future.

  3. Demographic amplification of climate change experienced by the contiguous United States population during the 20(th) century.

    PubMed

    Samson, Jason; Berteaux, Dominique; McGill, Brian J; Humphries, Murray M

    2012-01-01

    Better understanding of the changing relationship between human populations and climate is a global research priority. The 20(th) century in the contiguous United States offers a particularly well-documented example of human demographic expansion during a period of radical socioeconomic and environmental change. One would expect that as human society has been transformed by technology, we would become increasingly decoupled from climate and more dependent on social infrastructure. Here we use spatially-explicit models to evaluate climatic, socio-economic and biophysical correlates of demographic change in the contiguous United States between 1900 and 2000. Climate-correlated variation in population growth has caused the U.S. population to shift its realized climate niche from cool, seasonal climates to warm, aseasonal climates. As a result, the average annual temperature experienced by U.S. citizens between 1920 and 2000 has increased by more than 1.5°C and the temperature seasonality has decreased by 1.1°C during a century when climate change accounted for only a 0.24°C increase in average annual temperature and a 0.15°C decrease in temperature seasonality. Thus, despite advancing technology, climate-correlated demographics continue to be a major feature of contemporary U.S. society. Unfortunately, these demographic patterns are contributing to a substantial warming of the climate niche during a period of rapid environmental warming, making an already bad situation worse.

  4. Demographic Amplification of Climate Change Experienced by the Contiguous United States Population during the 20th Century

    PubMed Central

    Samson, Jason; Berteaux, Dominique; McGill, Brian J.; Humphries, Murray M.

    2012-01-01

    Better understanding of the changing relationship between human populations and climate is a global research priority. The 20th century in the contiguous United States offers a particularly well-documented example of human demographic expansion during a period of radical socioeconomic and environmental change. One would expect that as human society has been transformed by technology, we would become increasingly decoupled from climate and more dependent on social infrastructure. Here we use spatially-explicit models to evaluate climatic, socio-economic and biophysical correlates of demographic change in the contiguous United States between 1900 and 2000. Climate-correlated variation in population growth has caused the U.S. population to shift its realized climate niche from cool, seasonal climates to warm, aseasonal climates. As a result, the average annual temperature experienced by U.S. citizens between 1920 and 2000 has increased by more than 1.5°C and the temperature seasonality has decreased by 1.1°C during a century when climate change accounted for only a 0.24°C increase in average annual temperature and a 0.15°C decrease in temperature seasonality. Thus, despite advancing technology, climate-correlated demographics continue to be a major feature of contemporary U.S. society. Unfortunately, these demographic patterns are contributing to a substantial warming of the climate niche during a period of rapid environmental warming, making an already bad situation worse. PMID:23115624

  5. The climate velocity of the contiguous United States during the 20th century

    Treesearch

    Solomon Z. Dobrowski; John Abatzoglou; Alan K. Swanson; Jonathan A. Greenberg; Alison R. Mynsberge; Zachary A. Holden; Michael K. Schwartz

    2013-01-01

    Rapid climate change has the potential to affect economic, social, and biological systems. A concern for species conservation is whether or not the rate of on-going climate change will exceed the rate at which species can adapt or move to suitable environments. Here we assess the climate velocity (both climate displacement rate and direction) for minimum temperature,...

  6. An ensemble approach to reconstructing mid-20th century climate using young fossil corals: pitfalls and opportunities

    NASA Astrophysics Data System (ADS)

    Hitt, N. T.; Cobb, K. M.; Sayani, H. R.; Grothe, P. R.; Chen, T.; Cheng, H.; Edwards, R. L.; Lu, Y.; Deocampo, D.; Townsend, K. J.

    2016-02-01

    The tropical Pacific is characterized by a rich spectrum of interannual to decadal-scale climate variability, and has played a key role in shaping the response of global surface temperature to greenhouse forcing, especially evident in the last decade [e.g. Kosaka and Xie, 2013]. However, instrumental records of tropical Pacific temperature and precipitation are sparse prior to the satellite era that began in the late 1970's. Here we investigate the potential of using an "ensemble" of fossil Porites coral samples with U/Th dates that fall in the mid 20th century to constrain temperature and hydrological conditions during this time. By comparing our ensemble of fossil coral d18O and Sr/Ca records to instrumental records of temperature, precipitation, and salinity over the study interval, as well as to long, continuous modern coral d18O and Sr/Ca records, we quantify the uncertainties of the fossil coral "ensemble" approach. Our findings illustrate that the fossil coral "ensemble" approach holds promise for compiling similar reconstructions during periods in the distant past, when direct observations of tropical Pacific climate are extremely scarce. Collectively, our new dataset will provide a useful benchmark for such reconstructions, including much-improved estimates of the uncertainties associated with fossil-coral based reconstructions of mean tropical Pacific climate. References: Kosaka, Yu & Xie, Shang-Ping (2013) Nature 10.1038/nature12534

  7. 20th-century industrial black carbon emissions altered Arctic climate forcing.

    PubMed

    McConnell, Joseph R; Edwards, Ross; Kok, Gregory L; Flanner, Mark G; Zender, Charles S; Saltzman, Eric S; Banta, J Ryan; Pasteris, Daniel R; Carter, Megan M; Kahl, Jonathan D W

    2007-09-07

    Black carbon (BC) from biomass and fossil fuel combustion alters chemical and physical properties of the atmosphere and snow albedo, yet little is known about its emission or deposition histories. Measurements of BC, vanillic acid, and non-sea-salt sulfur in ice cores indicate that sources and concentrations of BC in Greenland precipitation varied greatly since 1788 as a result of boreal forest fires and industrial activities. Beginning about 1850, industrial emissions resulted in a sevenfold increase in ice-core BC concentrations, with most change occurring in winter. BC concentrations after about 1951 were lower but increasing. At its maximum from 1906 to 1910, estimated surface climate forcing in early summer from BC in Arctic snow was about 3 watts per square meter, which is eight times the typical preindustrial forcing value.

  8. Impact of fire on global land carbon, water, and energy budgets and climate during the 20th century through changing ecosystems

    NASA Astrophysics Data System (ADS)

    Li, F.; Lawrence, D. M.; Bond-Lamberty, B. P.; Levis, S.

    2016-12-01

    Fire is an integral Earth system process and the primary form of terrestrial ecosystem disturbance on a global scale. Here we provide the first quantitative assessment and understanding on fire's impact on global land carbon, water, and energy budgets and climate through changing ecosystems. This is done by quantifying the difference between 20th century fire-on and fire-off simulations using the Community Earth System Model (CESM1.2). Results show that fire decreases the net carbon gain of global terrestrial ecosystems by 1.0 Pg C/yr averaged across the 20th century, as a result of biomass and peat burning (1.9 Pg C/yr) partly offset by changing gross primary productivity, respiration, and land-use carbon loss (-0.9 Pg C/yr). In addition, fire's effect on global carbon budget intensifies with time. Fire significantly reduces land evapotranspiration (ET) by 600 km3/yr and increases runoff, but has limited impact on precipitation. The impact on ET and runoff is most clearly seen in the tropical savannas, African rainforest, and some boreal and Southern Asian forests mainly due to fire-induced reduction in the vegetation canopy. It also weakens both the significant upward trend in global land ET prior to the 1950s and the downward trend from 1950 to 1985 by 35%. Fire-induced changes in land ecosystems affects global energy budgets by significantly reducing latent heating and surface net radiation. Fire changes surface radiative budget dominantly by raising surface upward longwave radiation and net longwave radiation. It also increases the global land average surface air temperature (Tas) by 0.04°C, and significantly increases wind speed and decreases surface relative humidity. The fire-induced change in wind speed, Tas, and relative humidity implies a positive feedback loop between fire and climate. Moreover, fire-induced changes in land ecosystems contribute 20% of strong global land warming during 1910-1940, which provides a new mechanism for the early 20th

  9. Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming

    USGS Publications Warehouse

    Euskirchen, E.S.; McGuire, A.D.; Chapin, F.S.

    2007-01-01

    The warming associated with changes in snow cover in northern high-latitude terrestrial regions represents an important energy feedback to the climate system. Here, we simulate snow cover-climate feedbacks (i.e. changes in snow cover on atmospheric heating) across the Pan-arctic over two distinct warming periods during the 20th century, 1910-1940 and 1970-2000. We offer evidence that increases in snow cover-climate feedbacks during 1970-2000 were nearly three times larger than during 1910-1940 because the recent snow-cover change occurred in spring, when radiation load is highest, rather than in autumn. Based on linear regression analysis, we also detected a greater sensitivity of snow cover-climate feedbacks to temperature trends during the more recent time period. Pan-arctic vegetation types differed substantially in snow cover-climate feedbacks. Those with a high seasonal contrast in albedo, such as tundra, showed much larger changes in atmospheric heating than did those with a low seasonal contrast in albedo, such as forests, even if the changes in snow-cover duration were similar across the vegetation types. These changes in energy exchange warrant careful consideration in studies of climate change, particularly with respect to associated shifts in vegetation between forests, grasslands, and tundra. ?? 2007 Blackwell Publishing Ltd.

  10. Quantifying the Lack of Consistency between Climate Model Projections and Observations of the Evolution of the Earth's Average Surface Temperature since the Mid-20th Century

    NASA Astrophysics Data System (ADS)

    Michaels, P. J.; Knappenberger, P. C.

    2014-12-01

    Recent climate change literature has been dominated by studies which show that the equilibrium climate sensitivity is better constrained than the latest estimates from the Intergovernmental Panel on Climate Change (IPCC) and the U.S. National Climate Assessment (NCA) and that the best estimate of the climate sensitivity is considerably lower than the climate model ensemble average. From the recent literature, the central estimate of the equilibrium climate sensitivity is ~2°C, while the climate model average is ~3.2°C, or an equilibrium climate sensitivity that is some 40% lower than the model average.To the extent that the recent literature produces a more accurate estimate of the equilibrium climate sensitivity than does the climate model average, it means that the projections of future climate change given by both the IPCC and NCA are, by default, some 40% too large (too rapid) and the associated (and described) impacts are gross overestimates.A quantitative test of climate model performance can be made by comparing the range of model projections against observations of the evolution of the global average surface temperature since the mid-20th century. Here, we perform such a comparison on a collection of 108 model runs comprising the ensemble used in the IPCC's Fifth Assessment Report and find that the observed global average temperature evolution for all trend lengths (with one exception) since 1986 is less than 97.5% of the model distribution, meaning that the observed trends are significantly different from the average trend simulated by climate models. For periods approaching 40 years in length, the observed trend lies outside of (below) the range that includes 95% of all climate model simulations.We conclude that at the global scale, this suite of climate models has failed. Treating them as mathematical hypotheses, which they are, means that it is the duty of scientists to, unfortunately, reject their predictions in lieu of those with a lower climate

  11. Response of the global water availability and use model WaterGAP to different climatic forcings and human impacts within the late 20th century

    NASA Astrophysics Data System (ADS)

    Müller Schmied, Hannes; Eisner, Stephanie; Portmann, Felix T.; Fink, Gabriel; Flörke, Martina; Döll, Petra

    2015-04-01

    Global-scale hydrological modeling faces multiple sources of uncertainty resulting from e.g. input data, model structure and model parameters, and it is of particular interest to investigate the sensitivity of a model to these influences. In the last years, a number of climate forcing data sets were developed for the global modelling community, and variable fields were found to differ significantly between the data-sets in certain regions. On the other side, human activity has a significant impact on the global hydrological cycle, e.g. through the construction of dams and the abstraction of water for irrigation purposes. In a global-scale hydrological modelling approach, human impact can be represented in various ways. It can be neglected (i.e. naturalized conditions without human impacts on river flow are simulated), kept at a constant level (e.g. present day conditions), or it can be simulated time-variant hence mimicking historical development of reservoirs and irrigation demand. Both uncertainties (forcing data, human impact) are influencing the response (i.e. output) of a water model, and it is assumed that the sensitivity of model outputs increases when combining the uncertainties of both input data. In this study we applied the WaterGAP global water availability and use model for 12 simulation setups resulting from four climate forcings (PGMFD v.2 (Princeton), GSWP3 (Global Soil Wetness Project 3), WATCH (WATCH Forcing Data, WFD), WATCH+WFD/ERAInterim) and three settings for human impact (naturalized, constant human impacts, time-varying human impacts). We assess the modeled water balance components for the late 20th century and evaluate the relative response to climate forcing as compared to human impact. Results are presented for selected large river basins as well as for the global scale.

  12. VEMAP phase 2 bioclimatic database. I. Gridded historical (20th century) climate for modeling ecosystem dynamics across the conterminous USA

    Treesearch

    Timothy G.F. Kittel; Nan. A. Rosenbloom; J.A. Royle; C. Daly; W.P. Gibson; H.H. Fisher; P. Thornton; D.N. Yates; S. Aulenbach; C. Kaufman; R. McKeown; Dominque. Bachelet; David S. Schimel

    2004-01-01

    Analysis and simulation of biospheric responses to historical forcing require surface climate data that capture those aspects of climate that control ecological processes, including key spatial gradients and modes of temporal variability. We developed a multivariate, gridded historical climate dataset for the conterminous USA as a common input database for the...

  13. Sensitivity of isoprene emissions from the terrestrial biosphere to 20th century changes in atmospheric CO2 concentration, climate, and land use

    NASA Astrophysics Data System (ADS)

    LathièRe, J.; Hewitt, C. N.; Beerling, D. J.

    2010-03-01

    We describe the development and analysis of a global model based on Model of Emissions of Gases and Aerosols from Nature (MEGAN) (Guenther et al., 2006) for estimating isoprene emissions from terrestrial vegetation. The sensitivity of calculated isoprene emissions to descriptors including leaf age, soil moisture, atmospheric CO2 concentration, and regional variability of emission factors is analyzed. The validity of the results is evaluated by comparison with compilations of published field-based canopy-scale observations. Calculated isoprene emissions reproduce above-canopy flux measurements and the site-to-site variability across a wide range of latitudes, with the model explaining 60% of the variance. Although the model underestimates isoprene emissions, especially in northern latitude localities, this disagreement is significantly corrected when regional variability of emission factors for particular plant functional types is considered (r2 = 0.78). At the global scale, we estimate a terrestrial biosphere isoprene flux of 413 TgC yr-1 using the present-day climate, atmospheric CO2 concentration, and vegetation distribution, and this compares with other published estimates from global modeling studies of 402 to 660 TgC yr-1. The validated model was used to calculate changes in isoprene emissions in response to atmospheric CO2 increase, climate change, and land use change during the 20th century (1901-2002). Changes in all of these factors are found to impact significantly on isoprene emissions over the course of the 20th century. Between 1901 and 2002, we estimate that at the global scale, climate change was responsible for a 7% increase in isoprene emissions, and rising atmospheric CO2 caused a 21% reduction. However, by the end of the 20th century (2002), anthropogenic cropland expansion has the largest impact reducing isoprene emissions by 15%. Overall, these factors combined to cause a 24% decrease in global isoprene emissions during the 20th century. It

  14. Changes in the relationships between climate and silver fir (Abies alba Mill.) growth during the 20th century in the Tuscan Apennine Alps (Middle Italy)

    NASA Astrophysics Data System (ADS)

    D'Aprile, F.; Tapper, N.; Baker, P.; Bartolozzi, L.; Bottacci, A.

    2012-04-01

    In the Tuscan Apennine Alps, recent research has shown that similarity in trends of monthly climate variables (i.e., temperature and rainfall) is non-stationary amongst sites during the 20th century even between sites that differ little in elevation and at a relatively short distance from each other (D'Aprile et al., 2010; D'Aprile et al., 2011). Moreover, the level of correlation between series of monthly climate variables varies irregularly from highly positive to negative over time. We hypothesised that those changing climate conditions, even at the local level, could cause different tree-ring growth responses in silver fir amongst sites. The hypothesis was tested by dendroclimatological analysis, which was applied to study stands in silver fir forests close to the meteorological stations where climate analysis has been made. Results show that the influences of both monthly mean temperature and monthly rainfall on silver fir growth vary greatly during the 20th century in the Tuscan Apennine Alps, and the ways that they change differ with month and amongst sites. Within sites, differences in the relationships between climate variables and silver fir tree-ring growth appear small in spite of different elevation of the study stands. These results contribute a changing point in forest planning and management especially in consideration of the need to adapt forest management and interventions to changing climate conditions and mitigate the impacts on silver fir forests. Moreover, they introduce climate variability as a key parameter in sustainable forest management for biodiversity conservation, socially responsible uses, nature conservation, and survival of the only conifer tree species typical of mountain mixed forest ecosystems in the Apennine Alps.

  15. VEMAP Phase 2 bioclimatic database. I. Gridded historical (20th century) climate for modeling ecosystem dynamics across the conterminous USA

    USGS Publications Warehouse

    Kittel, T.G.F.; Rosenbloom, N.A.; Royle, J. Andrew; Daly, Christopher; Gibson, W.P.; Fisher, H.H.; Thornton, P.; Yates, D.N.; Aulenbach, S.; Kaufman, C.; McKeown, R.; Bachelet, D.; Schimel, D.S.; Neilson, R.; Lenihan, J.; Drapek, R.; Ojima, D.S.; Parton, W.J.; Melillo, J.M.; Kicklighter, D.W.; Tian, H.; McGuire, A.D.; Sykes, M.T.; Smith, B.; Cowling, S.; Hickler, T.; Prentice, I.C.; Running, S.; Hibbard, K.A.; Post, W.M.; King, A.W.; Smith, T.; Rizzo, B.; Woodward, F.I.

    2004-01-01

    Analysis and simulation of biospheric responses to historical forcing require surface climate data that capture those aspects of climate that control ecological processes, including key spatial gradients and modes of temporal variability. We developed a multivariate, gridded historical climate dataset for the conterminous USA as a common input database for the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP), a biogeochemical and dynamic vegetation model intercomparison. The dataset covers the period 1895-1993 on a 0.5?? latitude/longitude grid. Climate is represented at both monthly and daily timesteps. Variables are: precipitation, mininimum and maximum temperature, total incident solar radiation, daylight-period irradiance, vapor pressure, and daylight-period relative humidity. The dataset was derived from US Historical Climate Network (HCN), cooperative network, and snowpack telemetry (SNOTEL) monthly precipitation and mean minimum and maximum temperature station data. We employed techniques that rely on geostatistical and physical relationships to create the temporally and spatially complete dataset. We developed a local kriging prediction model to infill discontinuous and limited-length station records based on spatial autocorrelation structure of climate anomalies. A spatial interpolation model (PRISM) that accounts for physiographic controls was used to grid the infilled monthly station data. We implemented a stochastic weather generator (modified WGEN) to disaggregate the gridded monthly series to dailies. Radiation and humidity variables were estimated from the dailies using a physically-based empirical surface climate model (MTCLIM3). Derived datasets include a 100 yr model spin-up climate and a historical Palmer Drought Severity Index (PDSI) dataset. The VEMAP dataset exhibits statistically significant trends in temperature, precipitation, solar radiation, vapor pressure, and PDSI for US National Assessment regions. The historical climate and

  16. How probable was the 20th century global warming?

    NASA Astrophysics Data System (ADS)

    Papalexiou, Simon Michael; Markonis, Yannis

    2016-04-01

    The increase of global mean temperature during the 20th century, according to the Intergovernmental Panel on Climate Change (IPCC), is very plausible due to the anthropogenic greenhouse gas emissions. In addition, climate model projections suggest that the global mean temperature will further rise during the 21st century. While the vast majority of scientists have endorsed IPCC's conclusions, not a few individual scientists, have expressed a disagreement regarding the validity of climate model projections. In this study, the answer to a fundamental question is sought. That is, how probable was the global warming of the 20th century considering only recorded and reconstructed global mean temperatures values, and assuming that the global mean temperature is a stationary stochastic process. In order to answer this question, a stationary stochastic model is set that incorporates (a) the observed autocorrelation structure of the global mean temperature, (b) past observations of global mean temperature and (c) global, regional and site-specific reconstructions of global mean temperature changes during the last two millennia. Based on an intense Monte Carlo simulation, the probability of a global mean temperature trend with equal or greater slope than the observed one in the 20th century is presented.

  17. To what extent does climate explain variations in reported malaria cases in early 20th century Uganda?

    PubMed

    Tompkins, Adrian M; Larsen, Laragh; McCreesh, Nicky; Taylor, David

    2016-03-31

    Malaria case statistics were analysed for the period 1926 to 1960 to identify inter-annual variations in malaria cases for the Uganda Protectorate. The analysis shows the mid-to-late 1930s to be a period of increased reported cases. After World War II, malaria cases trend down to a relative minimum in the early 1950s, before increasing rapidly after 1953 to the end of the decade. Data for the Western Province confirm these national trends, which at the time were attributed to a wide range of causes, including land development and management schemes, population mobility, interventions and misdiagnosis. Climate was occasionally proposed as a contributor to enhanced case numbers, and unusual precipitation patterns were held responsible; temperature was rarely, if ever, considered. In this study, a dynamical malaria model was driven with available precipitation and temperature data from the period for five stations located across a range of environments in Uganda. In line with the historical data, the simulations produced relatively enhanced transmission in the 1930s, although there is considerable variability between locations. In all locations, malaria transmission was low in the late 1940s and early 1950s, steeply increasing after 1954. Results indicate that past climate variability explains some of the variations in numbers of reported malaria cases. The impact of multiannual variability in temperature, while only on the order of 0.5°C, was sufficient to drive some of the trends observed in the statistics and thus the role of climate was likely underestimated in the contemporary reports. As the elimination campaigns of the 1960s followed this partly climate-driven increase in malaria, this emphasises the need to account for climate when planning and evaluating intervention strategies.

  18. 20th-Century doubling in dust archived in an Antarctic Peninsula ice core parallels climate change and desertification in South America.

    PubMed

    McConnell, Joseph R; Aristarain, Alberto J; Banta, J Ryan; Edwards, P Ross; Simões, Jefferson C

    2007-04-03

    Crustal dust in the atmosphere impacts Earth's radiative forcing directly by modifying the radiation budget and affecting cloud nucleation and optical properties, and indirectly through ocean fertilization, which alters carbon sequestration. Increased dust in the atmosphere has been linked to decreased global air temperature in past ice core studies of glacial to interglacial transitions. We present a continuous ice core record of aluminum deposition during recent centuries in the northern Antarctic Peninsula, the most rapidly warming region of the Southern Hemisphere; such a record has not been reported previously. This record shows that aluminosilicate dust deposition more than doubled during the 20th century, coincident with the approximately 1 degrees C Southern Hemisphere warming: a pattern in parallel with increasing air temperatures, decreasing relative humidity, and widespread desertification in Patagonia and northern Argentina. These results have far-reaching implications for understanding the forces driving dust generation and impacts of changing dust levels on climate both in the recent past and future.

  19. Diagnosing Influences on Tropical Pacific Corals: From Salinity Budgets to 20th Century Trends

    NASA Astrophysics Data System (ADS)

    Stevenson, S. L.; Cobb, K.; Powell, B.; Merrifield, M. A.

    2013-12-01

    Both modeling and observational studies support the hypothesis that 20th century climate change has affected the Walker circulation, but the exact magnitude of the anthropogenic influence remains uncertain. A major obstacle is the sparsity of tropical Pacific observations during the early part of the 20th century; coral-based paleoclimate records provide a critical source of data with which to constrain estimates of tropical Pacific conditions, but can be difficult to interpret dynamically. Here, a new synthesis of coralline oxygen isotope records (delta-18O) with 20th century instrumental data and model simulations is presented in order to bridge the gap between paleoclimate information and dynamical influences. Walker circulation changes are related to precipitative, advective, and other processes local to reefs on the central Pacific islands of Palmyra and Kiritimati; this is done both using observational data products and a suite of 20th century simulations with the Regional Ocean Modeling System (ROMS). The "dynamical forward models" thus obtained from the budgets of temperature and salinity are then used to derive probabilistic estimates of early-20th century Walker circulation strength. Implications for quantitative Walker circulation reconstructions prior to the 20th century are discussed.

  20. An ensemble approach to reconstructing 20th century climate trends in data-sparse regions of the tropical Pacific using young fossil corals

    NASA Astrophysics Data System (ADS)

    Hitt, N. T.; Cobb, K. M.; Sayani, H. R.; Grothe, P. R.; Atwood, A. R.; O'Connor, G.; Chen, T.; Hagos, M. M.; Deocampo, D.; Edwards, R. L.; Cheng, H.; Lu, Y.; Thompson, D. M.

    2016-12-01

    Sea-surface temperature (SST) variability in the central tropical Pacific drives global-scale responses through atmospheric teleconnections, so the response of this region to anthropogenic forcing has important implications for regional climate responses in many areas. However, quantification of anthropogenic SST trends in the central tropical Pacific is complicated by the fact that instrumental SST observations in this region are extremely limited prior to 1950, with trends of opposite sign observed across the various gridded instrumental datasets (Deser et al., 2010). Researchers have turned to multi-century coral records to reconstruct ocean temperatures through time, but the paucity of such records prohibits the generation of uncertainty estimates. In this study, we use a large collection of U/Th-dated fossil corals that to investigate a new ensemble approach to reconstructing temperature from the Central Pacific over the late 20th century. Here we combine monthly-resolved d18O and Sr/Ca from 8 5-14 year long coral records from Christmas Island (2°N, 157°W) to quantify temperature and hydrological trends in this region from 1930 to present. We compare our fossil coral ensemble reconstruction to a long modern coral core from this site that extends back to 1940, as well as to gridded SST datasets. We also provide the first well-replicated coral d18O and Sr/Ca records across both the 1997/98 and 2015/2016 El Nino events, comparing the strength of these two events in the context of long-term temperature trends observed in our longer reconstruction. We conclude that the fossil coral ensemble approach provides a robust means of reconstructing 20th century climate trends. Deser et al., 2010, GRL, doi: 10.1029/2010GL043321

  1. How do anthropogenic aerosol trends change arctic and global climate in CCSM4 over the 20th century?

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Bitz, C. M.; Doherty, S. J.

    2013-12-01

    Since the Clean Air Act began in 1972, global mean sulfate aerosol concentration has been decreasing rapidly, while black carbon concentration has been increasing continuously. What impacts would these aerosol concentration trends impose on the arctic and global climate? In this study, we use atmospheric aerosol single-forcing simulations of the Community Climate System Model version 4 (CCSM4), which has fully coupled atmosphere, ocean, land and sea ice components. The single forcing experiments were carried out by prescribing the time- and space-evolving concentrations of sulfate and black carbon, respectively. The aerosol concentrations were derived from an earlier version of the atmosphere component model run with interactive chemistry and observational-based estimates of reactive-gas emissions. All other forcings were kept fixed at 1850 levels, including surface deposition of black carbon on snow and sea ice. In an ensemble mean of 9 integrations, sulfate aerosols alone could produce ~0.3 K/Decade warming in surface air temperature over the Eurasian arctic from 1975 to 2005 through direct radiative forcing. The increased atmospheric concentration of black carbon reduces the surface air temperature in the arctic, and produces up to 0.5 K/Decade cooling in the Eurasian arctic. In agreement with previous studies, the Arctic cooling from increased atmospheric black carbon concentration is mainly caused by a reduction in atmospheric northward heat transport.

  2. Role of clouds, aerosols, and aerosol-cloud interaction in 20th century simulations with GISS ModelE2

    NASA Astrophysics Data System (ADS)

    Nazarenko, L.; Rind, D. H.; Bauer, S.; Del Genio, A. D.

    2015-12-01

    Simulations of aerosols, clouds and their interaction contribute to the major source of uncertainty in predicting the changing Earth's energy and in estimating future climate. Anthropogenic contribution of aerosols affects the properties of clouds through aerosol indirect effects. Three different versions of NASA GISS global climate model are presented for simulation of the twentieth century climate change. All versions have fully interactive tracers of aerosols and chemistry in both the troposphere and stratosphere. All chemical species are simulated prognostically consistent with atmospheric physics in the model and the emissions of short-lived precursors [Shindell et al., 2006]. One version does not include the aerosol indirect effect on clouds. The other two versions include a parameterization of the interactive first indirect aerosol effect on clouds following Menon et al. [2010]. One of these two models has the Multiconfiguration Aerosol Tracker of Mixing state (MATRIX) that permits detailed treatment of aerosol mixing state, size, and aerosol-cloud activation. The main purpose of this study is evaluation of aerosol-clouds interactions and feedbacks, as well as cloud and aerosol radiative forcings, for the twentieth century climate under different assumptions and parameterizations for aerosol, clouds and their interactions in the climate models. The change of global surface air temperature based on linear trend ranges from +0.8°C to +1.2°C between 1850 and 2012. Water cloud optical thickness increases with increasing temperature in all versions with the largest increase in models with interactive indirect effect of aerosols on clouds, which leads to the total (shortwave and longwave) cloud radiative cooling trend at the top of the atmosphere. Menon, S., D. Koch, G. Beig, S. Sahu, J. Fasullo, and D. Orlikowski (2010), Black carbon aerosols and the third polar ice cap, Atmos. Chem. Phys., 10,4559-4571, doi:10.5194/acp-10-4559-2010. Shindell, D., G. Faluvegi

  3. The climate of Carpathian Region in the 20th century based on the original and modified Holdridge life zone system

    NASA Astrophysics Data System (ADS)

    Szelepcsényi, Zoltán; Breuer, Hajnalka; Sümegi, Pál

    2014-09-01

    The Holdridge life zone system has already been used a number of times for analysing the effects of climate change on vegetation. But a criticism against the method was formulated that it cannot interpret the ecotones (e.g. forest steppe). Thus, in this paper transitional life zones were also determined in the model. Then, both the original and modified life zone systems were applied for the climatic fields of database CRU TS 1.2. Life zone maps were defined in the Carpathian Region (43.5-50.5° N, 15.5-28° E) for each of five 20-year periods between 1901 and 2000. We estimated correctness of the result maps with another vegetation map using Cohen's Kappa statistic. Finally, temporal changes in horizontal and vertical distribution of life zones were investigated. The coverage of boreal region decreased with 59.46% during the last century, while the warm temperate region became almost two and a half larger (257.36%). The mean centres of those life zones, which were not related to mountains, shifted northward during the investigation period. In case of the most abundant life zone types, the average distribution elevation increased. Using the modified model, the potential distribution of forest steppe could be also identified.

  4. Reproduction of 20th century inter- to multi-decadel surface temperature variablilty in radiatively forced coupled climate models

    USDA-ARS?s Scientific Manuscript database

    Coupled Model Intercomparison Project 3 simulations of surface temperature were evaluated over the period 1902-1999 to assess their ability to reproduce historical temperature variability at 211 global locations. Model performance was evaluated using the running Mann Whitney-Z method, a technique th...

  5. Role of Clouds, Aerosols, and Aerosol-Cloud Interaction in 20th Century Simulations with GISS ModelE2

    NASA Technical Reports Server (NTRS)

    Nazarenko, Larissa; Rind, David; Bauer, Susanne; Del Genio, Anthony

    2015-01-01

    The key uncertainties in the climate sensitivity to the increasing greenhouse gases lie in the behavior and impact of short-lived species, such as tropospheric aerosols and ozone, and secondly, in the response and impact of the ocean circulation.

  6. Multi-Scale Influences of Climate, Spatial Pattern, and Positive Feedback on 20th Century Tree Establishment at Upper Treeline in the Rocky Mountains, USA

    NASA Astrophysics Data System (ADS)

    Elliott, G. P.

    2009-12-01

    The influences of 20th century climate, spatial pattern of tree establishment, and positive feedback were assessed to gain a more holistic understanding of how broad scale abiotic and local scale biotic components interact to govern upper treeline ecotonal dynamics along a latitudinal gradient (ca. 35°N-45°N) in the Rocky Mountains. Study sites (n = 22) were in the Bighorn, Medicine Bow, Front Range, and Sangre de Cristo mountain ranges. Dendroecological techniques were used for a broad scale analysis of climate at treeline. Five-year age-structure classes were compared with identical five-year bins of 20th century climate data using Spearman’s rank correlation and regime shift analysis. Local scale biotic interactions capable of ameliorating broad scale climate inputs through positive feedback were examined by using Ripley’s K to determine the spatial patterns of tree establishment above timberline. Significant correlations (p < 0.01) between tree establishment and climate were confined to the Front Range, where a positive correlation exists with summer (June-Aug) and cool season (Nov-Apr) temperature range (Tmax-Tmin). Additionally, trees in the Front Range are almost exclusively situated in a random spatial pattern above timberline (4/5 sites). Random spatial patterns imply that positive feedback is of minimal importance and that trees are more closely aligned with broad scale changes in abiotic conditions. This tight coupling between climate and treeline vegetation in the Front Range helps explain synchronous ecological (tree establishment) and climate regime shifts (temperature) during the early 1950s. Similar to the Front Range, a majority of trees at upper treeline in the Bighorn Mountains are in a random spatial pattern, but their existence appears to be dependent on shelter availability in the lee of boulders. This contingency helps explain the lag time between a regime shift to more favorable temperatures and subsequent peaks in tree establishment

  7. 20th-Century doubling in dust archived in an Antarctic Peninsula ice core parallels climate change and desertification in South America

    PubMed Central

    McConnell, Joseph R.; Aristarain, Alberto J.; Banta, J. Ryan; Edwards, P. Ross; Simões, Jefferson C.

    2007-01-01

    Crustal dust in the atmosphere impacts Earth's radiative forcing directly by modifying the radiation budget and affecting cloud nucleation and optical properties, and indirectly through ocean fertilization, which alters carbon sequestration. Increased dust in the atmosphere has been linked to decreased global air temperature in past ice core studies of glacial to interglacial transitions. We present a continuous ice core record of aluminum deposition during recent centuries in the northern Antarctic Peninsula, the most rapidly warming region of the Southern Hemisphere; such a record has not been reported previously. This record shows that aluminosilicate dust deposition more than doubled during the 20th century, coincident with the ≈1°C Southern Hemisphere warming: a pattern in parallel with increasing air temperatures, decreasing relative humidity, and widespread desertification in Patagonia and northern Argentina. These results have far-reaching implications for understanding the forces driving dust generation and impacts of changing dust levels on climate both in the recent past and future. PMID:17389397

  8. Role of Clouds, Aerosols, and Aerosol-Cloud Interaction in 20th Century Simulations with GISS ModelE2

    NASA Technical Reports Server (NTRS)

    Nazarenko, Larissa; Rind, David; Bauer, Susanne; Del Genio, Anthony

    2015-01-01

    We use the new version of NASA Goddard Institute for Space Studies (GISS) climate model, modelE2 with 2º by 2.5º horizontal resolution and 40 vertical layers, with the model top at 0.1 hPa [Schmidt et al., 2014]. We use two different treatments of the atmospheric composition and aerosol indirect effect: (1) TCAD(I) version has fully interactive Tracers of Aerosols and Chemistry in both the troposphere and stratosphere. This model predicts total aerosol number and mass concentrations [Shindell et al., 2013]; (2) TCAM is the aerosol microphysics and chemistry model based on the quadrature methods of moments [Bauer et al., 2008]. Both TCADI and TCAM models include the first indirect effect of aerosols on clouds [Menon et al., 2010]; the TCAD model includes only the direct aerosol effect. We consider the results of the TCAD, TCADI and TCAM models coupled to "Russell ocean model" [Russell et al., 1995], E2-R. We examine the climate response for the "historical period" that include the natural and anthropogenic forcings for 1850 to 2012. The effect of clouds, their feedbacks, as well as the aerosol-cloud interactions are assessed for the transient climate change.

  9. Climate and polar motion during the GRACE observing period: 2002-2015: Implications for decadal scale oscillations during the 20th Century

    NASA Astrophysics Data System (ADS)

    Ivins, Erik; Adhikari, Surendra; Larour, Eric

    2016-04-01

    The motion of the Earth's pole in space has been observed with great accuracy for the last 115 years. The angular variations of the pole position away from its mean are a well explained at annual and 434-day periods. Variations at annual periods are caused by changes in the mass and angular momentum forced by all Earth surface changes that have near seasonality. The 434-day period is explained as a resonance between the cumulative driving forces having periods near the Chandler wobble free eigenmode of the Earth and is well understood theoretically. The Earth also has a longer-term drift that is explained primarily as a response to the ice age changes in the moments of inertial of the Earth. However, there has been a long-standing search for the origins of pole variations that have a period near 10 years. Using GRACE space gravimetry we show that ice mass losses from Greenland and Antarctica, and when combined with changes in continental hydrology, explain almost all the main features of interannual time scale polar wander. The discovery has broad interdisciplinary implications, as we show that decadal scale pole variations are directly linked to global changes continental water. The energy sources for these pole position changes are, therefore, likely to be associated with decadal scale ocean and atmospheric oscillations that also drive 20th Century on-land wet-dry oscillations at decadal-scale across the globe. Variability in pole position, therefore, offers a tool for assessing past stability of our climate, and for the future, now faced with an increased intensity in the water cycle and more vulnerable to ice sheet instability.

  10. Temporal variability of total cloud cover at a Mediterranean megacity in the 20th century: Evidence from visual observations and climate models

    NASA Astrophysics Data System (ADS)

    Founda, Dimitra; Giannakopoulos, Christos; Pierros, Fragiskos

    2013-04-01

    Cloud cover is one of the major factors that determine the radiation budget and the climate system of the Earth. Moreover, the response of clouds has always been an important source of uncertainty in global climate models. Visual surface observations of clouds have been conducted at the National Observatory of Athens (NOA) since the mid 19th century. The historical archive of cloud reports at NOA since 1860 has been digitized and updated, spanning now a period of one and a half century. Mean monthly values of total cloud cover were derived by averaging subdaily observations of cloud cover (3 observations/day). Changes in observational practice (e.g. from 1/10 to 1/8 units) were considered, however, subjective measures of cloud cover from trained observers introduces some kind of uncertainty in the time series. Data before 1884 were considered unreliable, so the analysis was restricted to the series from 1884 to 2012. The time series of total cloud cover at NOA is validated and correlated with historical time series of other (physically related) variables such as the total sunshine duration as well as DTR (Diurnal Temperature Range) which are independently measured. Trend analysis was performed on the mean annual and seasonal series of total cloud cover from 1884-2012. The mean annual values show a marked temporal variability with sub periods of decreasing and increasing tendencies, however, the overall linear trend is positive and statistically significant (p <0.001) amounting to +2% per decade and implying a total increase of almost 25% for the whole analysed period. These results are in agreement qualitatively with the trends reported in other studies worldwide, especially concerning the period before the mid 20th century. On a seasonal basis, spring and summer series present outstanding positive long term trends, while in winter and autumn total cloud cover reveals also positive but less pronounced long term trends Additionally, an evaluation of cloud cover and

  11. Historical flood data series of Eastern Spanish Coast (14th-20th centuries). Improving identification of climatic patterns and human factors of flood events from primary documentary sources

    NASA Astrophysics Data System (ADS)

    Alberola, Armando; Barriendos, Mariano; Gil-Guirado, Salvador; Pérez-Morales, Alfredo; Balasch, Carles; Castelltort, Xavier; Mazón, Jordi; Pino, David; Lluís Ruiz-Bellet, Josep; Tuset, Jordi

    2016-04-01

    Historical flood data series of Eastern Spanish Coast (14th-20th centuries). Improving identification of climatic patterns and human factors of flood events from primary documentary sources Armando Alberola, Barriendos, M., Gil-Guirado, S., Pérez Morales, A., Balasch, C., Castelltort, X., Mazón, J., Pino, D., Ruiz-Bellet, J.L., Tuset, J. Historical flood events in eastern spanish coast have been studied by different research groups and projects. Complexity of flood processes, involving atmospheric, surface and human factors, is not easily understandable when long time series are required. Present analysis from PREDIFLOOD Project Consortium defines a new step of flood event databases: Improved access to primary (documentary) and secondary (bibliographical) sources, data collection for all possible locations where floods are detected, and improved system of classification (Barriendos et al., 2014). A first analysis is applied to 8 selected flood series. Long chronologies from PREDIFLOOD Project for Catalonia region (Girona, Barcelona, Tarragona, Lleida, Tortosa). In addition, to cover all sector of spanish mediterranean coast, we introduce Valencia city in Turia River basin. South Eastern sector is cover with Murcia and Caravaca cities, Segura River basin. Extension of area under study required contributions of research teams experienced in work of documentary primary sources (Alberola, 2006; Gil-Guirado, 2013). Flood frequency analysis for long scale periods show natural climatic oscillations into so-called Little Ice Age. There are general patterns, affecting most of basins, but also some local anomalies or singularities. To explain these differences and analogies it is not enough to use purely climatic factors. In this way, we analyze human factors that have been able to influence the variability of floods along last 6 centuries (demography, hydraulic infrastructures, urban development...). This approach improves strongly understanding of mechanisms producing

  12. C-LAMP Subproject Description:Climate Forcing by the Terrestrial Biosphere During the Second Half of the 20th Century

    SciTech Connect

    Covey, Curt; Hoffman, Forrest

    2008-10-02

    This project will quantify selected components of climate forcing due to changes in the terrestrial biosphere over the period 1948-2004, as simulated by the climate / carboncycle models participating in C-LAMP (the Carbon-Land Model Intercomparison Project; see http://www.climatemodeling.org/c-lamp). Unlike other C-LAMP projects that attempt to close the carbon budget, this project will focus on the contributions of individual biomes in terms of the resulting climate forcing. Bala et al. (2007) used a similar (though more comprehensive) model-based technique to assess and compare different components of biospheric climate forcing, but their focus was on potential future deforestation rather than the historical period.

  13. North Atlantic influence on 19th-20th century rainfall in the Dead Sea watershed, teleconnections with the Sahel, and implication for Holocene climate fluctuations

    NASA Astrophysics Data System (ADS)

    Kushnir, Yochanan; Stein, Mordechai

    2010-12-01

    The importance of understanding processes that govern the hydroclimate of the Mediterranean Basin is highlighted by the projected significant drying of the region in response to the increase in greenhouse gas concentrations. Here we study the long-term hydroclimatic variability of the central Levant region, situated in the eastern boundary of the Basin, as reveled by instrumental observations and the Holocene record of Dead Sea level variations. Observations of 19th and 20th century precipitation in the Dead Sea watershed region display a multidecadal, anti-phase relationship to North Atlantic (NAtl) sea surface temperature (SST) variability, such that when the NAtl is relatively cold, Jerusalem experiences higher than normal precipitation and vice versa. This association is underlined by a negative correlation to precipitation in the sub-Saharan Sahel and a positive correlation to precipitation in western North America, areas that are also affected by multidecadal NAtl SST variability. These observations are consistent with a broad range of Holocene hydroclimatic fluctuations from the epochal, to the millennial and centennial time scales, as displayed by the Dead Sea lake level, by lake levels in the Sahel, and by direct and indirect proxy indicators of NAtl SSTs. On the epochal time scale, the gradual cooling of NAtl SSTs throughout the Holocene in response to precession-driven reduction of summer insolation is associated with previously well-studied wet-to-dry transition in the Sahel and with a general increase in Dead Sea lake levels from low stands after the Younger Dryas to higher stands in the mid- to late-Holocene. On the millennial and centennial time scales there is also evidence for an anti-phase relationship between Holocene variations in the Dead Sea and Sahelian lake levels and with proxy indicators of NAtl SSTs. However the records are punctuated by abrupt lake-level drops, which appear to be in-phase and which occur during previously documented

  14. Great Universalist of the 20TH Century

    NASA Astrophysics Data System (ADS)

    Gershtein, S. S.

    2013-06-01

    One of the most prominent physicists of the 20th century, Lev Davidovich Landau, was at the same time a great universalist who made fundamental contributions in diverse areas of physics: quantum mechanics, solid state physics, theory of magnetism, phase transition theory, nuclear and particle physics, quantum electrodynamics (QED), low-temperature physics, fluid dynamics, atomic collision theory, theory of chemical reactions, and other disciplines.

  15. Antimatter and 20th century science

    NASA Astrophysics Data System (ADS)

    Williams, Gary

    2005-03-01

    This article gives an outline of the history of antimatter from the concept first introduced in 1898 up to the present day and is intended to complement the article 'Antihydrogen on Tap’ on page 229. It is hoped that it will provide enough historical background material along with interesting snippets of information for teachers to feel informed about the topic when in the classroom. Antimatter is the perfect example of 20th century science incorporating quantum mechanics and relativity, and showing progression from a theoretical idea to mass production within the space of 100 years. The final section is about using the idea of antihydrogen in the classroom.

  16. Long Term Changes in Thermal Stratification in a Deep Lake: Measurements From the 20th Century and Simulations For the 21st Century

    NASA Astrophysics Data System (ADS)

    Schladow, G.; Sahoo, G. B.; Forrest, A.

    2014-12-01

    Since the late 1960s, temperature profile data have been collected every 10-12 days at Lake Tahoe, USA. Past analyses have shown an overall warming of the lake at all depths, attributable to measured climate warming. The annual average, volume-weighted lake water temperature of the upper 400 m has increased at a rate of 0.011 deg. C/year since 1969 - 2014. There has been a concurrent evolution in the nature of the thermal stratification. While the maximum value of lake stability has not increased in the last 45 years, the length of time the lake remains stratified has been increased by 22 days, mostly occurring as a result of an earlier onset of spring stratification Using statistically downscaled GCM outputs for two different carbon emission scenarios, 1-D numerical simulations of the lake thermal structure over a 100-year period were performed. The results suggest a continuation and intensification of the already observed trends. Depending on the carbon emission scenario assumed, the length of the stratified season will increase by between 65 and 52 days by 2098 over the 1968 value. Most of the future increase will take place at the end of the season with a delay in the onset of winter. The observed impacts of stratification change on past ecosystem and water quality conditions will be presented, and possible future changes will be discussed. Plausible future states could range from climatic eutrophication to climatic oligotrophication.

  17. External control of 20th century temperature by natural and anthropogenic forcings.

    PubMed

    Stott, P A; Tett, S F; Jones, G S; Allen, M R; Mitchell, J F; Jenkins, G J

    2000-12-15

    A comparison of observations with simulations of a coupled ocean-atmosphere general circulation model shows that both natural and anthropogenic factors have contributed significantly to 20th century temperature changes. The model successfully simulates global mean and large-scale land temperature variations, indicating that the climate response on these scales is strongly influenced by external factors. More than 80% of observed multidecadal-scale global mean temperature variations and more than 60% of 10- to 50-year land temperature variations are due to changes in external forcings. Anthropogenic global warming under a standard emissions scenario is predicted to continue at a rate similar to that observed in recent decades.

  18. Trends in 20th Century Global Rainfall Interception as Simulated by a Dynamic Global Vegetation Model: Implications for Global Water Resources

    NASA Astrophysics Data System (ADS)

    Murray, Steve; Prentice, Colin

    2010-05-01

    In order to monitor and forecast regions of potential freshwater stress and surplus, a comprehensive understanding and quantification of the global hydrological cycle and its components is needed. Such work should lead to better constrained estimates of freshwater fluxes and facilitate the identification of regions requiring enhanced water management. The research described here aims to quantify the contribution of climate- and CO2-induced changes in the physical properties of the land surface, mediated by biological processes. Global climate change is expected to bring about substantial latitudinal and altitudinal shifts in vegetation cover. Shifts in species distribution, the potential of increased leaf area index (LAI) but also reduced stomatal conductance in response to rising concentrations of CO2, and variability in precipitation, can all influence rates and spatial variability of the interception-throughfall balance. These effects will have implications for runoff generation and the partitioning between 'green' and 'white' water fluxes. The Land Processes eXchange Dynamic Global Vegetation Model (LPX-DGVM, a development of the LPJ model) was evaluated in terms of its interception component and used to simulate trends in global relative throughfall from 1901-2006, as this is directly relevant for runoff. We estimate that mean global annual runoff was reduced by 164 ±18 km3/year during the twentieth century as a result of biophysical changes controlling relative throughfall generation. Widespread decreases in relative throughfall of typically between 0 and -1% are evident between 1901-1953 and 1954-2006. Changes of up to

  19. Response of Subalpine Conifers in the Sierra Nevada, California, U.S.A., to 20th-Century Warming and Decadal Climate Variability

    Treesearch

    Constance I. Millar; Robert D. Westfall; Diane L. Delany; John C. King; Lisa J. Graumlich

    2004-01-01

    Four independent studies of conifer growth between 1880 and 2002 in upper elevation forests of the central Sierra Nevada, California, U.S.A., showed correlated multidecadal and century-long responses associated with climate. Using tree-ring and ecological plot analysis, we studied annual branch growth of krummholz Pinus albicaulis; invasion by P....

  20. Climatic changes in Estonia during the second half of the 20th century in relationship with changes in large-scale atmospheric circulation

    NASA Astrophysics Data System (ADS)

    Jaagus, J.

    2006-01-01

    Trends in the time series of air temperature, precipitation, snow cover duration and onset of climatic seasons at ten stations in Estonia during 1951-2000 are analysed. Using the conditional Mann-Kendall test, these trends are compared with trends in the characteristics of large-scale atmospheric circulation: the NAO and AO indices, frequency of circulation forms according to the Vangengeim-Girs’ classification, and the northern hemisphere teleconnection indices. The objective of the study is to estimate the influence of trends in circulation on climate changes in Estonia. Statistically significant increasing trends in air temperature are detected in January, February, March, April and May, in winter (DJF), spring (MAM) and in the cold period (NDJFM). The trends in precipitation, as a rule, differ from station to station. Increasing trends are present during the cold half-year - from October until March - and also in June. Snow cover duration has decreased in Estonia by 17-20 days inland and by 21-36 days on the coast. The onsets of early spring and spring have shifted to an earlier date. Some important changes have occurred in the parameters of atmospheric circulation during 1951-2000. Intensity of zonal circulation, i.e. westerlies, has increased during the cold period, especially in February and March. Results of the conditional Mann-Kendall test indicate that the intensification of westerlies in winter is significantly related to climate changes in winter and also in spring. A negative trend in the East Atlantic Jet (EJ) index, i.e. the weakening of the westerlies in May has caused warming during that month. Decrease in northerly circulation, i.e. in frequency of circulation form C and in East Atlantic/West Russia teleconnection index (EW) is related to an increase in precipitation in October.

  1. Influenza pandemics of the 20th century.

    PubMed

    Kilbourne, Edwin D

    2006-01-01

    Three worldwide (pandemic) outbreaks of influenza occurred in the 20th century: in 1918, 1957, and 1968. The latter 2 were in the era of modern virology and most thoroughly characterized. All 3 have been informally identified by their presumed sites of origin as Spanish, Asian, and Hong Kong influenza, respectively. They are now known to represent 3 different antigenic subtypes of influenza A virus: H1N1, H2N2, and H3N2, respectively. Not classified as true pandemics are 3 notable epidemics: a pseudopandemic in 1947 with low death rates, an epidemic in 1977 that was a pandemic in children, and an abortive epidemic of swine influenza in 1976 that was feared to have pandemic potential. Major influenza epidemics show no predictable periodicity or pattern, and all differ from one another. Evidence suggests that true pandemics with changes in hemagglutinin subtypes arise from genetic reassortment with animal influenza A viruses.

  2. Influence of radiation and circulation factors on climate change in Western Siberia at the end of the 20th century and beginning of the 21st century

    NASA Astrophysics Data System (ADS)

    Kharyutkina, E. V.; Loginov, S. V.; Ippolitov, I. I.

    2016-11-01

    An analysis of the air-temperature and atmospheric-pressure fields in Western Siberia is performed based on observations in 1976-2014; a comparison of temperature and pressure variability in two temporal intervals, 1976-2005 and 1985-2014, is carried out. The estimation of contributions from such climate-forming factors as radiation and circulation is performed for the same intervals. It is revealed that an increase in the annual mean ground-air temperature in the investigated region of Western Siberia was still taking place in the period of 1985-2014; however, the warming process was less active than in the 1976-2005 period. Winter months play the largest role in decreasing the temperature growth rate; during these months, the warming process was replaced by a cooling one in the second time interval. It is shown that the circulation factors, that is, the mechanisms described by indices of global circulation, played the dominant role in the period from 1985 to 2014.

  3. Impact of fire on global land surface air temperature and energy budget for the 20th century due to changes within ecosystems

    DOE PAGES

    Li, Fang; Lawrence, David M.; Bond-Lamberty, Ben

    2017-04-03

    Fire is a global phenomenon and tightly interacts with the biosphere and climate. This study provides the first quantitative assessment of fire’s influence on the global land air temperature during the 20th century through its impact on terrestrial ecosystems. We quantify the impact of fire by comparing 20th century fire-on and fire-off simulations with the Community Earth System Model (CESM) as the model platform. Here, results show that fire-induced changes in terrestrial ecosystems increased global land surface air temperature by 0.04 °C. Such changes significantly warmed the tropical savannas and southern Asia mainly by reducing latent heat flux, but cooledmore » Southeast China by enhancing the East Asian winter monsoon. 20% of the early 20th century global land warming can be attributed to fire-induced changes in terrestrial ecosystems, providing a new mechanism for explaining the poorly-understood climate change.« less

  4. How unusual is the 20th century within the Indo-Pacific Warm Pool?

    NASA Astrophysics Data System (ADS)

    Khider, D.; Stott, L. D.; Saikku, R.; Partin, J. W.; Jackson, C. S.; Hammond, D. E.; Newton, A.; Thunell, R.

    2013-12-01

    Over the past 150 years, global temperatures have increased by 0.6°C. It has been suggested that this increase in temperature, especially since 1980, has been unprecedented over the past millennium. In order to put the current warming trend into context, various efforts are underway to reconstruct the longer pre-instrumental history of climate variability. Here, we present a sea surface temperature (SST) record of the Indo-Pacific Warm Pool (IPWP) for the Common Era by combining five high-resolution records of Globigerinoides ruber Mg/Ca from different locations within the Indonesian Seas. The much broader spatial coverage and enhanced temporal resolution of this composite record allows us to assess whether the observed 20th century warming and the rate of 20th century temperature change within IPWP have been unprecedented in the past two millennia. The novelty of this study is in our approach to uncertainty quantification, which entails Monte-Carlo simulations that simultaneously take into account both age model and proxy uncertainties. First, we used a Monte-Carlo process (n=10,000) to generate possible age models for each sedimentary record used in the composite. This Monte-Carlo approach takes into consideration the analytical uncertainty in the 14C and 210Pb measurements used for chronology, the uncertainty in the calibration curve and the reservoir age, and the subjective nature of the interpolation scheme. Second, we take into consideration two sources of error in the SST estimates: the analytical uncertainty for the Mg/Ca results, which was assumed to be normally distributed and independent from sample to sample, and the uncertainty in the calibration equation, which was assumed to be dependent (i.e. each Monte-Carlo record is converted using a solution of the calibration equation). To do so, we use a Bayesian approach to enumerate possible solutions of the calibration equation. Finally, we binned the resulting SSTs into 20-year, 50-year, and 100-year non

  5. Final Scientific Report for "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall"

    SciTech Connect

    Chiang, John C. H.; Wehner, Michael F.

    2012-10-29

    Convergence Zone (ITCZ) over the course of the 20th century prior to the 1980s. This is based on our detection and attribution analysis of 20th century simulations done by international modeling groups as part of the Coupled Model Intercomparison Project phase 3 (CMIP3). We repeated the same analysis with the current CMIP5 multimodel simulations, with essentially similar results. 3.Future projections of the global interhemispheric thermal gradient suggest a pronounced trend that well exceeds the 20th century range of behavior. The major cause of this trend is due to anthropogenic greenhouse gas emissions, acting in such a way as to warm the North more than the South. This result is based on our analysis of the CMIP3 and 5 simulations of future scenarios. The underlying suggestion is that tropical rainfall may concentrate more northwards in the future climate, though further research is required to more firmly establish that result.Taken together, our results shows the important role of the interhemispheric thermal gradient in determining tropical rainfall changes in the 20th century and future. Our analysis specifically highlights high-latitude North Atlantic sea surface temperature, and anthropogenic sulfate aerosols, as important drivers of the interhemispheric gradient over the 20th century; and anthropogenic greenhouse gases in the 21st. The PI has written a review paper in order to promote the awareness of the interhemispheric gradient amongst the climate science community.Our project was instrumental in developing the career of a postdoctoral scholar, as well as contributing to the research training of three Ph.D. candidates.

  6. Simulated Atlantic Meridional Overturning Circulation in the 20th century with an ocean model forced by reanalysis-based atmospheric data sets

    NASA Astrophysics Data System (ADS)

    He, Yan-Chun; Drange, Helge; Gao, Yongqi; Bentsen, Mats

    2016-04-01

    Global ocean hindcast simulations for the period 1871-2009 have been run with the ocean-sea ice component of the Norwegian Earth System Model (NorESM-O), forced by an adjusted version of the Twentieth Century Reanalysis version 2 data set (20CRv2 data set), as well as by the commonly used second version of atmospheric forcing data set for the Coordinated Ocean-ice Reference Experiments phase-II (CORE-II) for the period 1948-2007 (hereafter CORE.v2 data set). The simulated Atlantic Meridional Overturning Circulation (AMOC) in the 20CR and the CORE simulations have comparable variability as well as mean strength during the last three decades of the integration. The simulated AMOC undergoes, however, distinctly different evolutions during the period 1948-1970, with a sharply declining strength in CORE but a gradual increase in 20CR. Sensitivity experiments suggest that differences in the wind forcing between CORE and 20CR have major impact on the simulated AMOCs during this period. It is furthermore found that differences in the air temperature between the two data sets do contribute to the differences in AMOC, but to a much lesser degree than the wind. An additional factor for the diverging AMOC in the two decades following 1948 is the inevitable switching of atmospheric forcing fields in 1948 in the CORE.v2-based runs due to the cyclic spin-up procedure of the ocean model. The latter is a fundamental issue for any ocean hindcast simulation. The ocean initial state mainly influence the actual value but to a lesser degree also the temporal evolution (variability) of AMOC. It may take about two decades for the AMOC to adjust to a new atmospheric state during the spin-up, although a dynamically balanced ocean initial state tends to reduce the adjustment time and the magnitude of the deviation, implying that an ocean model run with atmospheric forcing fields extending back in time, like 20CRv2, can be used to extend the reliable duration of CORE-type of simulations.

  7. Simulated Atlantic Meridional Overturning Circulation in the 20th century with an ocean model forced by reanalysis-based atmospheric data sets

    NASA Astrophysics Data System (ADS)

    He, Yan-Chun; Drange, Helge; Gao, Yongqi; Bentsen, Mats

    2016-04-01

    Global ocean hindcast simulations for the period 1871--2009 have been run with the ocean-sea ice component of the Norwegian Earth System Model (NorESM-O), forced by an adjusted version of the Twentieth Century Reanalysis version 2 data set (20CRv2 data set), as well as by the commonly used second version of atmospheric forcing data set for the Coordinated Ocean-ice Reference Experiments phase-II (CORE-II) for the period 1948--2007 (hereafter CORE.v2 data set). The simulated Atlantic Meridional Overturning Circulation (AMOC) in the 20CR and the CORE simulations have comparable variability as well as mean strength during the last three decades of the integration. The simulated AMOC undergoes, however, distinctly different evolutions during the period 1948--1970, with a sharply declining strength in CORE but a gradual increase in 20CR. Sensitivity experiments suggest that differences in the wind forcing between CORE and 20CR have major impact on the simulated AMOCs during this period. It is furthermore found that differences in the air temperature between the two data sets do contribute to the differences in AMOC, but to a much lesser degree than the wind. An additional factor for the diverging AMOC in the two decades following 1948 is the inevitable switching of atmospheric forcing fields in 1948 in the CORE.v2-based runs due to the cyclic spin-up procedure of the ocean model. The latter is a fundamental issue for any ocean hindcast simulation. The ocean initial state mainly influence the actual value but to a lesser degree also the temporal evolution (variability) of AMOC. It may take about two decades for the AMOC to adjust to a new atmospheric state during the spin-up, although a dynamically balanced ocean initial state tends to reduce the adjustment time and the magnitude of the deviation, implying that an ocean model run with atmospheric forcing fields extending back in time, like 20CRv2, can be used to extend the reliable duration of CORE-type of simulations.

  8. 20th Century Reanalysis Project Ensemble Gateway: 56 Estimates of World Temperature, Pressure, Humidity, and Wind, 1871-2010

    DOE Data Explorer

    This site provides data from the 20th Century Reanalysis Project, offering temperature, pressure, humidity, and wind predictions in 200 km sections all around the earth from 1871 to 2010, every 6 hours, based on historical data. The ensemble mean and standard deviation for each value were calculated over a set of 56 simulations. Data for each of the 56 ensemble members are included here. The dataset consists of files in netCDF 4 format that are available for download from the National Energy Research. The goal of the 20th Century Reanalysis Project is to use a Kalman filter-based technique to produce a global trophospheric circulation dataset at four-times-daily resolution back to 1871. The only dataset available for the early 20th century consists of error-ridden hand-drawn analyses of the mean sea level pressure field over the Northern Hemisphere. Modern data assimilation systems have the potential to improve upon these maps, but prior to 1948, few digitized upper-air sounding observations are available for such a reanalysis. The global tropospheric circulation dataset will provide an important validation check on the climate models used to make 21st century climate projections....[copied from http://portal.nersc.gov/project/20C_Reanalysis/

  9. Global physical water scarcity trajectories for the 20th century

    NASA Astrophysics Data System (ADS)

    Kummu, Matti; de Moel, Hans; Eisner, Stefanie; Flörke, Martina; Siebert, Stefan; Varis, Olli

    2014-05-01

    Food security and the overall wellbeing of human kind are threatened by overexploitation of our freshwater resources. Water scarcity is not only a threat to people, but also to many of the planet's key ecosystems. Due to increasing population pressure, changing water consumption behaviour, and climate change, the threat is projected to become even worse in the future. Water can be physically scarce in two ways: population-driven water shortage occurs in areas where a large population has to depend on a limited resources (indicated by m3/capita/yr), while demand-driven water stress is related to the excessive use of otherwise sufficient water resources (indicated by demand/supply ratio). Although many studies have increased our understanding of current water scarcity and how this may increase in the future, the understanding of trajectories with the past development of the water scarcity is less well understood. To date, studies of past water resources have focused on either water shortage or water stress. We aim to calculate global water scarcity, both water stress and water shortage, for the period 1900-2005. We can thus provide, for the first time, continuous regional trends and local analyses of trajectories of water scarcity for the entire 20th century. By including both dimensions of water scarcity, we can increase the understanding of reasons behind the scarcity. We found that in year 1900 13% of the population (i.e. 0.22 billion people) was living in areas that suffer some kind of water scarcity (<1700 m3/capita/yr or ratio >0.2), while in year 2005 this percentage has increased to 57% (3.80 billion). Especially the population suffering from both high water stress (ratio >0.4) and high water shortage (<1000 m3/capita/yr) has risen considerably, from 2% (29 million people) in 1900, up to 19% (1.2 billion people) in 2005. Geographically these concern mainly northern African regions, the Middle East, Pakistan and parts of India and Northern China. The region of

  10. Reassessment of 20th century global mean sea level rise.

    PubMed

    Dangendorf, Sönke; Marcos, Marta; Wöppelmann, Guy; Conrad, Clinton P; Frederikse, Thomas; Riva, Riccardo

    2017-06-06

    The rate at which global mean sea level (GMSL) rose during the 20th century is uncertain, with little consensus between various reconstructions that indicate rates of rise ranging from 1.3 to 2 mm⋅y(-1) Here we present a 20th-century GMSL reconstruction computed using an area-weighting technique for averaging tide gauge records that both incorporates up-to-date observations of vertical land motion (VLM) and corrections for local geoid changes resulting from ice melting and terrestrial freshwater storage and allows for the identification of possible differences compared with earlier attempts. Our reconstructed GMSL trend of 1.1 ± 0.3 mm⋅y(-1) (1σ) before 1990 falls below previous estimates, whereas our estimate of 3.1 ± 1.4 mm⋅y(-1) from 1993 to 2012 is consistent with independent estimates from satellite altimetry, leading to overall acceleration larger than previously suggested. This feature is geographically dominated by the Indian Ocean-Southern Pacific region, marking a transition from lower-than-average rates before 1990 toward unprecedented high rates in recent decades. We demonstrate that VLM corrections, area weighting, and our use of a common reference datum for tide gauges may explain the lower rates compared with earlier GMSL estimates in approximately equal proportion. The trends and multidecadal variability of our GMSL curve also compare well to the sum of individual contributions obtained from historical outputs of the Coupled Model Intercomparison Project Phase 5. This, in turn, increases our confidence in process-based projections presented in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.

  11. Giddens and late modernity: analysing 20th century life.

    PubMed

    Alaszewski, A; Manthorpe, J

    The final paper of our series on principal figures in sociology examines the work of Anthony Giddens, a British sociologist who is still working. Major components of his analysis of late 20th century life are discussed.

  12. Flood Hazard Trends in the Mekong River during the 20th century due to monsoon variability

    NASA Astrophysics Data System (ADS)

    Delgado, Jose; Merz, Bruno; Apel, Heiko

    2013-04-01

    Flood trends were investigated in four stations of the lower Mekong River. Two types of changes were accounted for: trend in the mean and trend in the variance of the time series. A trend in the mean implies that the average flood events changed with time. A trend in variance implies that the frequency of low and high magnitude floods changed with time (Merz et al., 2012). Results showed that average flood events decreased during the 20th century. However, due to an increase in variance, the frequency of high magnitude floods increased towards the end of the 20th century (Delgado et al., 2010). This increase could not be detected by usual trend tests like Mann Kendall test or the ordinary least squares regression. The results agree with Katz and Brown (1992), who showed that variance changes are more important that changes in mean, when it comes to flood frequency trends. To investigate possible causes for the detected changes in flood variance, we looked at several large scale atmospheric circulation patterns cited in the literature. The Western Pacific monsoon index (Wang, 2001) showed the greatest resemblance with the flood data. A test of step change in variance was conducted which revealed a coinciding step change in variance between annual maximum discharge and the Western Pacific monsoon. A statistical model where monsoon variance forces flood frequency in the 20th century was tested. The results were statistically significant. This has the advantadge of by-passing the use of precipitation, which in this region is collected in a rather sparse network. Concerning climate change projections, a dynamic index like the Western Pacific monsoon index is better simulated by climate models than tropical precipitation (Wang, 2004, Douville et al. 2005). Another important result is the attribution of the detected changes. The Mekong River basin is located in a transition zone between the Indian and the Pacific oceans. Our results showed that the interannual variability

  13. DIMMING OF THE MID-20TH CENTURY SUN

    SciTech Connect

    Foukal, Peter

    2015-12-10

    Area changes of photospheric faculae associated with magnetic active regions are responsible for the bright contribution to variation in total solar irradiance (TSI). Yet, the 102-year white light (WL) facular record measured by the Royal Greenwich Observatory between 1874 and 1976 has been largely overlooked in past TSI reconstructions. We show that it may offer a better measure of the brightening than presently used chromospheric proxies or the sunspot number. These are, to varying degrees, based on magnetic structures that are dark at the photosphere even near the limb. The increased contribution of the dark component to these proxies at high activity leads to an overestimate of solar brightening around peaks of the large spot cycles 18 and 19. The WL facular areas measure only the bright contribution. Our reconstruction based on these facular areas indicates that TSI decreased by about 0.1% during these two cycles to a 20th century minimum, rather than brightening to some of the highest TSI levels in four centuries, as reported in previous reconstructions. This TSI decrease may have contributed more to climate cooling between the 1940s and 1960s than present modeling indicates. Our finding adds to previous evidence that such suppression of solar brightening by an increased area of dark flux tubes might explain why the Sun is anomalously quiet photometrically compared to other late-type stars. Our findings do not change the evidence against solar driving of climate warming since the 1970s.

  14. Dimming of the Mid-20th Century Sun

    NASA Astrophysics Data System (ADS)

    Foukal, Peter

    2015-12-01

    Area changes of photospheric faculae associated with magnetic active regions are responsible for the bright contribution to variation in total solar irradiance (TSI). Yet, the 102-year white light (WL) facular record measured by the Royal Greenwich Observatory between 1874 and 1976 has been largely overlooked in past TSI reconstructions. We show that it may offer a better measure of the brightening than presently used chromospheric proxies or the sunspot number. These are, to varying degrees, based on magnetic structures that are dark at the photosphere even near the limb. The increased contribution of the dark component to these proxies at high activity leads to an overestimate of solar brightening around peaks of the large spot cycles 18 and 19. The WL facular areas measure only the bright contribution. Our reconstruction based on these facular areas indicates that TSI decreased by about 0.1% during these two cycles to a 20th century minimum, rather than brightening to some of the highest TSI levels in four centuries, as reported in previous reconstructions. This TSI decrease may have contributed more to climate cooling between the 1940s and 1960s than present modeling indicates. Our finding adds to previous evidence that such suppression of solar brightening by an increased area of dark flux tubes might explain why the Sun is anomalously quiet photometrically compared to other late-type stars. Our findings do not change the evidence against solar driving of climate warming since the 1970s.

  15. Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability.

    PubMed

    Tokinaga, Hiroki; Xie, Shang-Ping; Mukougawa, Hitoshi

    2017-06-13

    With amplified warming and record sea ice loss, the Arctic is the canary of global warming. The historical Arctic warming is poorly understood, limiting our confidence in model projections. Specifically, Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing. Here, we show that the concurrent phase shift of Pacific and Atlantic interdecadal variability modes is the major driver for the rapid early 20th-century Arctic warming. Atmospheric model simulations successfully reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early 20th-century Arctic warming is associated with positive SST anomalies over the tropical and North Atlantic and a Pacific SST pattern reminiscent of the positive phase of the Pacific decadal oscillation. Atmospheric circulation changes are important for the early 20th-century Arctic warming. The equatorial Pacific warming deepens the Aleutian low, advecting warm air into the North American Arctic. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. Coupled ocean-atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, negative-to-positive phase shift of the Pacific and Atlantic interdecadal modes. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region.

  16. Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability

    PubMed Central

    Tokinaga, Hiroki; Xie, Shang-Ping; Mukougawa, Hitoshi

    2017-01-01

    With amplified warming and record sea ice loss, the Arctic is the canary of global warming. The historical Arctic warming is poorly understood, limiting our confidence in model projections. Specifically, Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing. Here, we show that the concurrent phase shift of Pacific and Atlantic interdecadal variability modes is the major driver for the rapid early 20th-century Arctic warming. Atmospheric model simulations successfully reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early 20th-century Arctic warming is associated with positive SST anomalies over the tropical and North Atlantic and a Pacific SST pattern reminiscent of the positive phase of the Pacific decadal oscillation. Atmospheric circulation changes are important for the early 20th-century Arctic warming. The equatorial Pacific warming deepens the Aleutian low, advecting warm air into the North American Arctic. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. Coupled ocean–atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, negative-to-positive phase shift of the Pacific and Atlantic interdecadal modes. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region. PMID:28559341

  17. Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability

    NASA Astrophysics Data System (ADS)

    Tokinaga, Hiroki; Xie, Shang-Ping; Mukougawa, Hitoshi

    2017-06-01

    With amplified warming and record sea ice loss, the Arctic is the canary of global warming. The historical Arctic warming is poorly understood, limiting our confidence in model projections. Specifically, Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing. Here, we show that the concurrent phase shift of Pacific and Atlantic interdecadal variability modes is the major driver for the rapid early 20th-century Arctic warming. Atmospheric model simulations successfully reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early 20th-century Arctic warming is associated with positive SST anomalies over the tropical and North Atlantic and a Pacific SST pattern reminiscent of the positive phase of the Pacific decadal oscillation. Atmospheric circulation changes are important for the early 20th-century Arctic warming. The equatorial Pacific warming deepens the Aleutian low, advecting warm air into the North American Arctic. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. Coupled ocean-atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, negative-to-positive phase shift of the Pacific and Atlantic interdecadal modes. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region.

  18. 20th Century Northern hemisphere jet stream variability

    NASA Astrophysics Data System (ADS)

    Belmecheri, S.; Babst, F.; Trouet, V.; Betancourt, J. L.

    2015-12-01

    The latitudinal position of the Northern hemisphere Jet stream (NHJ) modulates both long term climate trends and the occurrence and frequency of extreme weather events. Precipitation anomalies in particular are associated with NHJ variability and the resulting floods/droughts can have considerable societal and economic impacts. Therefore a better understanding of NHJs role in regional climate is essential in assessing the natural and socio-economic impacts of projected future change in NHJ features. We developed a new climatology of the 300 hPa NHJ based on its seasonally explicit latitudinal position. We used the 20th Century Reanalysis V2 (20CR) data at monthly resolution from 1930-2012 to define the latitudinal position of NHJ as the latitude with the greatest 300 hPa scalar wind speed (m s-1). From these data, we identified four seasons with coherent NHJ patterns (January-February, April-May, July-August, and October-November) and detected longitudinal sectors (total of 15 sectors for all the seasons) where the seasonal jet shows strong spatial coherence. We examined the influence of seasonal NHJ position on the geographical distribution of precipitation and temperature patterns for all sectors. Furthermore, we compared NHJ positions to atmospheric circulation indices at inter-annual and multi-decadal time scales. We found a significant relationship between the NHJ position and the North Atlantic and Arctic oscillations for all seasons and across the majority of longitudinal sectors. In addition to this, our NHJ data set supports a connection with ocean-atmosphere interactions over the northern Pacific Ocean on various time scales: we found significant correlations between the North Pacific Jet and the Pacific Decadal Oscillation for all seasons and with El Niño Southern Oscillation for the winter season. Our results emphasize the importance of the seasonal and spatial characteristics of NHJ, as well as climate teleconnections, when considering regional

  19. Marl Prairie Vegetation Response to 20th Century Hydrologic Change

    USGS Publications Warehouse

    Bernhardt, Christopher E.; Willard, Debra A.

    2007-01-01

    We conducted geochronologic and pollen analyses from sediment cores collected in solution holes within marl prairies of Big Cypress National Preserve to reconstruct vegetation patterns of the last few centuries and evaluate the stability and longevity of marl prairies within the greater Everglades ecosystem. Based on radiocarbon dating and pollen biostratigraphy, these cores contain sediments deposited during the last ~300 years and provide evidence for plant community composition before and after 20th century water management practices altered flow patterns throughout the Everglades. Pollen evidence indicates that pre-20th century vegetation at the sites consisted of sawgrass marshes in a peat-accumulating environment; these assemblages indicate moderate hydroperiods and water depths, comparable to those in modern sawgrass marshes of Everglades National Park. During the 20th century, vegetation changed to grass-dominated marl prairies, and calcitic sediments were deposited, indicating shortening of hydroperiods and occurrence of extended dry periods at the site. These data suggest that the presence of marl prairies at these sites is a 20th century phenomenon, resulting from hydrologic changes associated with water management practices.

  20. A Historical Perspective on Early 20th-Century Immigration

    ERIC Educational Resources Information Center

    Brophy, Anne M.

    2008-01-01

    Social workers, educators, psychologists, sociologists, and other social planning professionals have been concerned about the children of immigrants for over a century. In the late 19th and early 20th centuries, social policies and practices toward immigrant families were based on negative assumptions about immigrant culture that characterized…

  1. Personal reminiscences of ophthalmology giants of the 20th century.

    PubMed

    Tasman, William

    2013-01-01

    This paper records personal reminiscences of seven 20th century ophthalmologists who each in his own way metaphorically split the atom and, thereby, changed ophthalmology forever. In addition to their major contributions, they each shared some very desirable traits. They were gentlemen who were devoted to their families and their families to them.

  2. The Presidential Timeline of the 20th Century

    ERIC Educational Resources Information Center

    Resta, Paul; Flowers, Betty S.; Tothero, Ken

    2007-01-01

    This article describes the "The Presidential Timeline of the 20th Century," a newly unveiled website jointly created by the Learning Technology Center of The University of Texas at Austin and The National Archives' 12 presidential libraries. This web-based resource provides access to the continually growing store of digitized assets from…

  3. Reproducing an Early-20th-Century Wave Machine

    ERIC Educational Resources Information Center

    Daffron, John A.; Greenslade, Thomas B., Jr.

    2016-01-01

    Physics students often have problems understanding waves. Over the years numerous mechanical devices have been devised to show the propagation of both transverse and longitudinal waves (Ref. 1). In this article an updated version of an early-20th-century transverse wave machine is discussed. The original, Fig. 1, is at Creighton University in…

  4. Educational Expansion and Social Mobility in the 20th Century

    ERIC Educational Resources Information Center

    Breen, Richard

    2010-01-01

    Sociologists consider inequality in educational attainment to be a major cause of inequality between people in their chances of occupying a more advantageous class position. However, there is dispute as to whether educational inequality according to social class background declined during the 20th century. What is not in doubt is the expansion of…

  5. The Presidential Timeline of the 20th Century

    ERIC Educational Resources Information Center

    Resta, Paul; Flowers, Betty S.; Tothero, Ken

    2007-01-01

    This article describes the "The Presidential Timeline of the 20th Century," a newly unveiled website jointly created by the Learning Technology Center of The University of Texas at Austin and The National Archives' 12 presidential libraries. This web-based resource provides access to the continually growing store of digitized assets from…

  6. Educational Expansion and Social Mobility in the 20th Century

    ERIC Educational Resources Information Center

    Breen, Richard

    2010-01-01

    Sociologists consider inequality in educational attainment to be a major cause of inequality between people in their chances of occupying a more advantageous class position. However, there is dispute as to whether educational inequality according to social class background declined during the 20th century. What is not in doubt is the expansion of…

  7. Reproducing an Early-20th-Century Wave Machine

    ERIC Educational Resources Information Center

    Daffron, John A.; Greenslade, Thomas B., Jr.

    2016-01-01

    Physics students often have problems understanding waves. Over the years numerous mechanical devices have been devised to show the propagation of both transverse and longitudinal waves (Ref. 1). In this article an updated version of an early-20th-century transverse wave machine is discussed. The original, Fig. 1, is at Creighton University in…

  8. MECHANICS OF THE LUNG IN THE 20TH CENTURY

    PubMed Central

    Mitzner, Wayne

    2015-01-01

    Major advances in respiratory mechanics occurred primarily in the latter half of the 20th century, and this is when much of our current understanding was secured. The earliest and ancient investigations involving respiratory physiology and mechanics were often done in conjunction with other scientific activities and often lacked the ability to make quantitative measurements. This situation changed rapidly in the 20th century, and this relatively recent history of lung mechanics has been greatly influenced by critical technological advances and applications, which have made quantitative experimental testing of ideas possible. From the spirometer of Hutchinson, to the pneumotachograph of Fleisch, to the measurement of esophageal pressure, to the use of the Wilhelmy balance by Clements, to the unassuming strain gauges for measuring pressure and rapid paper and electronic chart recorders, these enabling devices have generated numerous quantitative experimental studies with greatly increased physiologic understanding and validation of mechanistic theories of lung function in health and disease. PMID:23733695

  9. Borehole Temperatures and a Baseline for 20th-Century Global Warming Estimates

    PubMed

    Harris; Chapman

    1997-03-14

    Lack of a 19th-century baseline temperature against which 20th-century warming can be referenced constitutes a deficiency in understanding recent climate change. Combination of borehole temperature profiles, which contain a memory of surface temperature changes in previous centuries, with the meteorological archive of surface air temperatures can provide a 19th-century baseline temperature tied to the current observational record. A test case in Utah, where boreholes are interspersed with meteorological stations belonging to the Historical Climatological Network, yields a noise reduction in estimates of 20th-century warming and a baseline temperature that is 0.6° ± 0.1°C below the 1951 to 1970 mean temperature for the region.

  10. American Neutrality in The 20th Century: The Impossible Dream

    DTIC Science & Technology

    1995-01-01

    valid OMB control number. 1. REPORT DATE JAN 1995 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE American Neutraility in The...themselves with the power which knowledge gives. JAMES MADISON to W. T. BARRY August 4, 1822 AMERICAN NEUTRALITY IN THE 20TH CENTURY: The Impossible...Myma Morgan INSS publishes McNair Papers to provoke thought and inform discussion on issues of U.S. national security in the post-Cold War era. These

  11. [Development of international health in 20th century].

    PubMed

    Gómez-Dantés, O; Khoshnood, B

    1991-01-01

    The purpose of this paper is to discuss the historical evolution of the concept and activities that have come under the rubric of international health during its modern "formative" years in the 20th century. The analysis seeks to illuminate the changing objectives and key players, the achievements and failures, and the challenges that lie ahead. The emphasis is placed on its institutional component, particularly as it relates to the countries of the American continents.

  12. Early 20th century conceptualization of health promotion.

    PubMed

    Madsen, Wendy

    2016-05-06

    This historical analysis of the term 'health promotion' during the early 20th century in North American journal articles revealed concepts that strongly resonate with those of the 21st century. However, the lineage between these two time periods is not clear, and indeed, this paper supports contentions health promotion has a disrupted history. This paper traces the conceptualizations of health promotion during the 1920s, attempts to operationalize health promotion in the 1930s resulting in a narrowing of the concept to one of health education, and the disappearance of the term from the 1940s. In doing so, it argues a number of factors influenced the changing conceptualization and utilization of health promotion during the first half of the 20th century, many of which continue to present times, including issues around what health promotion is and what it means, ongoing tensions between individual and collective actions, tensions between specific and general causes of health and ill health, and between expert and societal contributions. The paper concludes the lack of clarity around these issues contributed to health promotion disappearing in the mid-20th century and thus resolution of these would be worthwhile for the continuation and development of health promotion as a discipline into the 21st century.

  13. Attributing the increase in Northern Hemisphere hot summers since the late 20th century

    NASA Astrophysics Data System (ADS)

    Kamae, Youichi; Shiogama, Hideo; Watanabe, Masahiro; Kimoto, Masahide

    2014-07-01

    Anomalously high summertime temperatures have occurred with increasing frequency since the late 20th century. It is not clear why hot summers are becoming more frequent despite the recent slowdown in the rise in global surface air temperature. To examine factors affecting the historical variation in the frequency of hot summers over the Northern Hemisphere (NH), we conducted three sets of ensemble simulations with an atmospheric general circulation model. The model accurately reproduced interannual variation and long-term increase in the occurrence of hot summers. Decadal variabilities in the Pacific and Atlantic Oceans accounted for 43 ± 27% of the recent increase over the NH middle latitudes. In addition, direct influence of anthropogenic forcing also contributes to increasing the frequency since the late 20th century. The results suggest that the heat extremes can become more frequent in the coming decade even with the persistent slowdown in the global-mean surface warming.

  14. A Revised Estimate of 20th Century Global Mean Sea Level

    NASA Astrophysics Data System (ADS)

    Hay, C.; Morrow, E.; Kopp, R. E., III; Mitrovica, J. X.

    2014-12-01

    One of the primary goals of paleo-sea level research is to assess the stability of ice sheets and glaciers in warming climates. In this context, the 20th century may be thought of as the most recent, recorded, and studied of all past episodes of warming. Over the past decade, a consensus has emerged in the literature that 20th century global mean sea level (GMSL), inferred from tide gauge records, rose at a mean rate of 1.6-1.9 mm/yr. This sea-level rise can be attributed to multiple sources, including thermal expansion of the oceans, ice sheet and glacier mass flux, and anthropogenic changes in land water storage. The Fifth Assessment Report of the IPCC summarized the estimated contributions of these sources over 1901-1990 and computed a total rate, using a bottom-up approach, of ~1.0 mm/yr, which falls significantly short of the rate inferred from tide gauge records. Using two independent probabilistic approaches that utilize models of glacial isostatic adjustment, ocean dynamics, and the sea-level fingerprints of rapid land-ice melt to analyze tide gauge records (Kalman smoothing and Gaussian process regression), we are able to close the 20th century sea-level budget and resolve the above enigma. Our revised estimate for the rate of GMSL rise during 1901-1990 is 1.1-1.3 mm/yr (90% credible interval). This value, which is ~20-30% less than previous estimates, suggests that the change in the GMSL rate from the 20th century to the last two decades (2.7 ± 0.4 mm/yr, consistent with past estimates) was greater than previous estimates. Moreover, since some forward projections of GMSL change into the next century are based in part on past estimates of GMSL change, our revised rate may impact projections of GMSL rise for the 21st century and beyond.

  15. Major 20th Century Contribution to Sea Level Rise from Uncharted Glaciers

    NASA Astrophysics Data System (ADS)

    Parkes, David; Marzeion, Ben

    2017-04-01

    Global mean sea-level rise (GMSLR) during the 20th century was caused by glacier and ice sheet mass loss, thermal expansion of ocean water, and change of terrestial water storage. Whether based on observations or results of climate models, the sum of estimates of each of these contributors tends to fall short of the observed GMSLR. All estimates of the glacier contribution to GMSLR rely on the application of glacier inventory data, which are known to undersample the smallest glacier size classes. Here we show that these missing glaciers (those that we expect to exist today but which are not represented in the inventories) may have contributed 42.6 mm to GMSLR during the period 1901 to 2015, even though their current ice mass is very small (less than 5 mm sea-level equivalent). Additionally, glaciers that completely melted within the 20th century, and which are therefore not included in global glacier inventories (vanished glaciers), may have contributed 5.1 mm to GMSLR. Together, uncharted glaciers (missing glaciers and vanished glaciers combined) made an estimated contribution of 47.7 mm to GMSLR, and the failure to consider these glaciers may be the cause of difficulties in closing the GMSLR budget during the 20th century. Because of these glaciers' small current ice mass, their potential to impact future GMSLR is much smaller.

  16. The epidemic of the 20(th) century: coronary heart disease.

    PubMed

    Dalen, James E; Alpert, Joseph S; Goldberg, Robert J; Weinstein, Ronald S

    2014-09-01

    Heart disease was an uncommon cause of death in the US at the beginning of the 20th century. By mid-century it had become the commonest cause. After peaking in the mid-1960s, the number of heart disease deaths began a marked decline that has persisted to the present. The increase in heart disease deaths from the early 20th century until the 1960s was due to an increase in the prevalence of coronary atherosclerosis with resultant coronary heart disease, as documented by autopsy studies. This increase was associated with an increase in smoking and dietary changes leading to an increase in serum cholesterol levels. In addition, the ability to diagnose acute myocardial infarction with the aid of the electrocardiogram increased the recognition of coronary heart disease before death. The substantial decrease in coronary heart disease deaths after the mid-1960s is best explained by the decreased incidence, and case fatality rate, of acute myocardial infarction and a decrease in out-of-hospital sudden coronary heart disease deaths. These decreases are very likely explained by a decrease in coronary atherosclerosis due to primary prevention, and a decrease in the progression of nonobstructive coronary atherosclerosis to obstructive coronary heart disease due to efforts of primary and secondary prevention. In addition, more effective treatment of patients hospitalized with acute myocardial infarction has led to a substantial decrease in deaths due to acute myocardial infarction. It is very likely that the 20th century was the only century in which heart disease was the most common cause of death in America. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. A Surprising Alliance: Two Giants of the 20th Century.

    PubMed

    Sade, Robert M

    2017-06-01

    Alexis Carrel and Charles Lindbergh were among the most famous international figures in the 20th century: Carrel, the surgeon-scientist who won a Nobel prize as a young surgeon, and Lindbergh, the aviator-engineer who pioneered aviation and promoted commercial flight throughout his life. Surprisingly, these two amazing individuals came together to collaborate on the early development of extracorporeal circulation. Their work was interrupted by the onset of World War II, which destroyed one of them and nearly destroyed the other. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  18. International traffic in coca through the early 20th century.

    PubMed

    Musto, D F

    1998-01-01

    This paper compiles records of coca exported by the major producing sites, Peru, Bolivia, Java and Formosa, from the late 19th century through the first third of the 20th century. During most of this era coca was legally produced and responsive to market demands. World coca exports did not peak [corrected] until around 1920, followed by a steady decline over the next decade. This export pattern (if not the exact figures) suggests a period of rising cocaine consumption, peaking regionally first in North America, then in Europe and other parts of the world, followed [corrected] by a marked decrease in the drug's popularity and acceptance.

  19. Multidecadal changes in the Etesians-Indian Summer Monsoon teleconnection along the 20th Century

    NASA Astrophysics Data System (ADS)

    Gómez-Delgado, F. de Paula; Vega, Inmaculada; Gallego, David; Peña-Ortiz, Cristina; Ribera, Pedro; García-Herrera, Ricardo

    2017-04-01

    In this work we made use of historical winds record taken aboard ships to reconstruct a series of the prevalent summer northerly winds (Etesian winds) over the Eastern Mediterranean for the entire 20th century. Previous studies have shown a significant link between the frequency and strength of these winds and the strength of the Indian Summer Monsoon (ISM), but this relationship had only been studied in detail for the second half of the 20th century due to the absence of long and continous series of observed wind in the Eastern Mediterranean for previous periods. In this work, a new climatic index, the so-called " Etesian Wind Index " (EWI), is defined as the percentage of days with prevalent northerly wind (wind blowing from 305° to 35°) in a fixed region [20E-30E, 32N-37N]. By using historical wind observations, we have been able to compute this index for the summer (JJAS) since 1880 and analyze the long term variability of the Etesians, as well as to research into its relation with the ISM at an unprecedent temporal coverage. A running coverage analysis revealed a strong and significant positive correlation between the EWI and the strength of the ISM for the period 1960-1980, more markedly in July and August. This result is in accordance with other recent studies. However, we have found that the correalation fades out in the first half of the 20th century (1900-1950) and in the period 1980-2012, even showing significant negative values around the subperiod 1920-1950. Similar indices to the EWI were computed using two different 20th century reanalysis datasets (ERA20C and 20CR-V2C). Despite the fact that both indices show some discrepancies with the EWI before 1950, the correlation analysis with the ISM revealed similar results, pointing out a strong loss of the EWI-ISM correlation in the first half of the 20th century and from 1980 onwards, as well as a marked positive correlated period between 1960 and 1980, specially in August. In this study, we show that

  20. 20th century precipitation changes in the Sahel region: sensitivity studies with ECHAM5-HAM

    NASA Astrophysics Data System (ADS)

    Folini, D.; Baumgartner, D.; Wild, M.

    2012-04-01

    The 20th century has seen an enormous growth in population and industrialization. These changes are accompanied, among others, by a substantial increase in aerosol emission. To learn more about associated consequences for the climate system we have carried out a comparatively large set of transient sensitivity studies with the global atmosphere only climate model ECHAM5-HAM, using aerosol emission data from NIES (National Institute of Environmental Studies, Japan) and prescribed, observation based sea surface temperatures (SSTs) from the Hadley Center. The sensitivity studies cover the period from 1870 to 2005 and comprise ensembles of simulations (up to 13 members per ensemble), which allow to address the role of different aerosol species, greenhouse gases, and prescribed sea surface temperatures. We present a preliminary analysis of these global simulation data for the Sahel region (land within 20W / 35E / 10N / 20N). The annual cycle as well as the overall temporal evolution of precipitation in the Sahel according to CRU (Climate Research Unit, UK) is captured well by the model simulations: two comparatively wet phases in the 1930s and 1950s, a more or less continuous decline thereafter, and a renewed increase in precipitation since the 1980s. This decline / renewed incline since the 1950s is, however, about twice as strong in the CRU data than in the model data. The sensitivity studies reveal SSTs as a prominent factor for the time evolution of precipitation, while the atmosphere only effect of aerosols plays a minor role for the modeled precipitation. The observation based prescribed SSTs may, however, encapsulate and aerosol effect already.

  1. [The 20th century: 100 years of misfortune and splendor].

    PubMed

    Urdaneta-Carruyo, Eliéxer

    2005-01-01

    The 20th century has been one of the most intense and convulsive periods in the History of humanity. A century of paradoxes and contrasts, it began with optimism, it witnessed the apocalypse of two world wars, and finished with unimaginable scientific progress that gave us a new civilization that we cannot yet grasp. In this century, significant events happened that shaped our time and projected their results toward an immediate future. Some of these were providential in understanding man's life, fighting against illnesses and prolonging life, and others were of undeniable social importance for humanity. Some knowledge was based on the work of others. Philosophy was embedded in mathematics, as was science in philosophy, while politics and the economy exercised so decisive an influence in our way of feeling and living that culture and society were affected to the core. Within that century the biggest technological revolution of all the time was also created, as transcendent as it was unimaginable, which put mankind on the road to the stars with the moon landing and in the process created the information society whose signature symbol, the internet, emerged as a new demiurge. However, the 20th century, with all its misfortune and splendor, paradoxes and contrasts, creation and destruction, was the most transcendent in the whole of history and it bequeaths to the future a promising horizon in the search for a renovated meaning of life and a yearning for peaceful coexistence for the whole humanity.

  2. Early 20th century acoustics apparatus in Iowa

    NASA Astrophysics Data System (ADS)

    Hanson, Roger J.

    2004-05-01

    In the first half of the 20th century G. W. Stewart was a physics faculty member at the University of Iowa (UI) with a distinguished record of research and teaching, especially in acoustics. Much of his research focused on the design and use of several types of acoustical filters. Some apparatus which he developed or utilized are still housed in the Department of Physics and Astronomy or are available in detailed diagrams. Demonstration apparatus (apparently homemade) from his era are still available for use. Carl E. Seashore, a renowned psychologist also at UI in the early 20th century, had interdisciplinary interests linking psychology, speech and hearing, music, and acoustics. He was responsible for obtaining an Henrici harmonic analyzer, a mechanical Fourier analyzer manufactured in Switzerland, a special grant from the state legislature during Depression conditions provided the funding. It resides in the Department of Speech Pathology and Audiology at UI. The Grinnell College Physics Historical Museum houses a set of 18 Helmholtz resonators and a Savart bell and resonator. Apparatus at Iowa State University, the University of Northern Iowa, and other Iowa institutions will also be described. Pictures and diagrams as well as some actual apparatus will be exhibited.

  3. Meteorological Effects of Land Cover Changes in Hungary during the 20th Century

    NASA Astrophysics Data System (ADS)

    Drüszler, Á.; Vig, P.; Csirmaz, K.

    2012-04-01

    Geological, paleontological and geomorphologic studies show that the Earth's climate has always been changing since it came into existence. The climate change itself is self-evident. Therefore the far more serious question is how much does mankind strengthen or weaken these changes beyond the natural fluctuation and changes of climate. The aim of the present study was to restore the historical land cover changes and to simulate the meteorological consequences of these changes. Two different land cover maps for Hungary were created in vector data format using GIS technology. The land cover map for 1900 was reconstructed based on statistical data and two different historical maps: the derived map of the 3rd Military Mapping Survey of the Austro-Hungarian Empire and the Synoptic Forestry Map of the Kingdom of Hungary. The land cover map for 2000 was derived from the CORINE land cover database. Significant land cover changes were found in Hungary during the 20th century according to the examinations of these maps and statistical databases. The MM5 non-hydrostatic dynamic model was used to further evaluate the meteorological effects of these changes. The lower boundary conditions for this mesoscale model were generated for two selected time periods (for 1900 and 2000) based on the reconstructed maps. The dynamic model has been run with the same detailed meteorological conditions of selected days from 2006 and 2007, but with modified lower boundary conditions. The set of the 26 selected initial conditions represents the whole set of the macrosynoptic situations for Hungary. In this way, 2×26 "forecasts" were made with 48 hours of integration. The effects of land cover changes under different weather situations were further weighted by the long-term (1961-1990) mean frequency of the corresponding macrosynoptic types, to assume the climatic effects from these stratified averages. The detailed evaluation of the model results were made for three different meteorological

  4. The Expression of Emotions in 20th Century Books

    PubMed Central

    Acerbi, Alberto; Lampos, Vasileios; Garnett, Philip; Bentley, R. Alexander

    2013-01-01

    We report here trends in the usage of “mood” words, that is, words carrying emotional content, in 20th century English language books, using the data set provided by Google that includes word frequencies in roughly 4% of all books published up to the year 2008. We find evidence for distinct historical periods of positive and negative moods, underlain by a general decrease in the use of emotion-related words through time. Finally, we show that, in books, American English has become decidedly more “emotional” than British English in the last half-century, as a part of a more general increase of the stylistic divergence between the two variants of English language. PMID:23527080

  5. Contagious Rhythm: Infectious Diseases of 20th Century Musicians

    PubMed Central

    Sartin, Jeffrey S.

    2010-01-01

    Infectious diseases have led to illness and death for many famous musicians, from the classical period to the rock ’n’ roll era. By the 20th century, as public health improved and orchestral composers began living more settled lives, infections among American and European musicians became less prominent. By mid-century, however, seminal jazz musicians famously pursued lifestyles characterized by drug and alcohol abuse. Among the consequences of this risky lifestyle were tuberculosis, syphilis, and chronic viral hepatitis. More contemporary rock musicians have experienced an epidemic of hepatitis C infection and HIV/AIDS related to intravenous drug use and promiscuity. Musical innovation is thus often accompanied by diseases of neglect and overindulgence, particularly infectious illnesses, although risky behavior and associated infectious illnesses tend to decrease as the style matures. PMID:20660936

  6. Reproducing an Early-20th-Century Wave Machine

    NASA Astrophysics Data System (ADS)

    Daffron, John A.; Greenslade, Thomas B.

    2016-09-01

    Physics students often have problems understanding waves. Over the years numerous mechanical devices have been devised to show the propagation of both transverse and longitudinal waves (Ref. 1). In this article an updated version of an early-20th-century transverse wave machine is discussed. The original, Fig. 1, is at Creighton University in Omaha, NE. The new version, by the authors, is shown in Fig. 2. It was designed in such a way that it can be built relatively easily. Sliders that rest on a rotating helical rail move up and down in approximate simple harmonic motion. When the helix is at rest, the tops of the sliders form a good approximation to a sine wave. In the original, the sliders are double-ended knitting needles, and the handle was taken from an earlier piece of apparatus.

  7. The expression of emotions in 20th century books.

    PubMed

    Acerbi, Alberto; Lampos, Vasileios; Garnett, Philip; Bentley, R Alexander

    2013-01-01

    We report here trends in the usage of "mood" words, that is, words carrying emotional content, in 20th century English language books, using the data set provided by Google that includes word frequencies in roughly 4% of all books published up to the year 2008. We find evidence for distinct historical periods of positive and negative moods, underlain by a general decrease in the use of emotion-related words through time. Finally, we show that, in books, American English has become decidedly more "emotional" than British English in the last half-century, as a part of a more general increase of the stylistic divergence between the two variants of English language.

  8. Contagious rhythm: infectious diseases of 20th century musicians.

    PubMed

    Sartin, Jeffrey S

    2010-07-01

    Infectious diseases have led to illness and death for many famous musicians, from the classical period to the rock 'n' roll era. By the 20th century, as public health improved and orchestral composers began living more settled lives, infections among American and European musicians became less prominent. By mid-century, however, seminal jazz musicians famously pursued lifestyles characterized by drug and alcohol abuse. Among the consequences of this risky lifestyle were tuberculosis, syphilis, and chronic viral hepatitis. More contemporary rock musicians have experienced an epidemic of hepatitis C infection and HIV/AIDS related to intravenous drug use and promiscuity. Musical innovation is thus often accompanied by diseases of neglect and overindulgence, particularly infectious illnesses, although risky behavior and associated infectious illnesses tend to decrease as the style matures.

  9. Healing after disasters in early-20th-century Texas.

    PubMed

    Wall, Barbra Mann

    2008-01-01

    This historical study analyzes 2 disasters in Texas in the early 20th century: the 1937 school explosion in New London and the 1947 Texas City ship explosion. Disaster narratives and commemoration activities are examined as means of healing and restoration after a catastrophic event. Specifically, this article discusses contextual factors of time and place, Coastal and East Texas between 1937 and 1947, and shows how these factors shaped the ways in which people made sense of their disaster experiences. This included not only the influence of geography but also economics, social position, racial characterizations, and religious beliefs. The article also considers conflicting and biased factors that can occur regarding time and place and how these factors influenced narrative constructions.

  10. Marriage in the 20th century: A feminist perspective.

    PubMed

    Rampage, Cheryl

    2002-01-01

    A defining feature of the 20th century in Western civilization was a profound change in the roles women play in both private and public life. The field of couple therapy was influenced by that change and, to a limited extent, participated in it. I will argue that the field has avoided fully embracing the principles of feminism that generated the social changes in gender and marital roles, settling instead for a more token acknowledgment that gender means something, without wanting to specify what that something is. In responding to the other articles in this issue, I make the case that the connection between gender and power in marriage needs to be more fully integrated, in the theory, research, and treatment of couples.

  11. Atmospheric response to orbital forcing and 20th century sea surface temperatures

    NASA Astrophysics Data System (ADS)

    Mantsis, Damianos F.

    This study investigates modes of atmospheric variability in response to changes in Earth's orbit and changes in 20th century sea surface temperatures (SST). The orbital forcing is manifested by a change in obliquity and precession, and changes the distribution of the top-of-atmosphere insolation. A smaller obliquity reduces the annual insolation that the poles receive and increases the annual insolation in the tropics. As the meridional insolation gradient increases, the zonal mean atmospheric-ocean circulation increases. The resulting climate also has a reduced global mean temperature due to the effect of climate feedbacks. This cooling can be attributed to a reduced lapse rate, increased cloud fraction, reduced water vapor in the atmosphere, and an increase in the surface albedo. A change in the precession, as the perihelion shifts from the winter to the summer solstice, causes a strengthening as well as an expansion of the N. Pacific summer subtropical anticyclone. This anticyclonic anomaly can be attributed to the weakening of the baroclinic activity, but also represents the circulation response to remote and local diabatic heating. The remote diabatic heating is associated with monsoonal activity in the SE Asia and North Africa. Regarding the 20th century SST forcing, it is represented by a multidecadal variability in the inter-hemispheric SST difference. This change in the SST causes a latitudinal shift in the ascending branch of the Hadley cell and precipitation in the tropics, as well as an increase in the atmospheric meridional heat transport from the warmer to the colder hemisphere.

  12. Everglades Plant Community Response to 20th Century Hydrologic Changes

    NASA Astrophysics Data System (ADS)

    Willard, D. A.; Bernhardt, C. E.; Holmes, C. W.; Weimer, L. M.

    2002-05-01

    Pollen records in sediment cores from sites in the historic Everglades allowed us to document the natural variability of the ecosystem over the past 2,000 years and contrast it to 20th century changes in wetland plant communities. The natural system included extensive water-lily sloughs, sawgrass ridges, and scattered tree islands extending from Lake Okeechobee southward through Shark River Slough. Between ~1000 AD and 1200 AD, weedy species such as Amaranthus (water hemp) became more abundant, indicating decreased annual rainfall, shorter hydroperiods, and shallower water depths during this time. After ~1200 AD, vegetation returned to its pre-1000 AD composition. During the 20th century, two phases of hydrologic alteration occurred. Completed by 1930, the first phase included construction of the Hoover Dike, canals linking Lake Okeechobee to the Atlantic Ocean, and the Tamiami Trail. Reconstructions of plant communities indicate that these changes shortened hydroperiods and lowered water depths throughout the Everglades. The extent of water-lily slough communities decreased, and tree islands became larger in Shark River Slough. The second phase resulted from construction of canals and levees in the 1950s, creating three Water Conservation Areas. The response of plant communities to these changes varied widely depending on location in the Everglades. In Loxahatchee NWR, weedy and short-hydroperiod plant species became more abundant in marshes, and species composition of tree islands changed. In Water Conservation Area 2A, cattail replaced sawgrass in marshes with high nutrient influx; the ridge and slough structure of the marshes was replaced by more homogeneous sawgrass marshes; sustained high water levels for more than a decade resulted in loss of tree islands that had existed for more than 1,000 years. In Everglades National Park, the extent of slough vegetation decreased further. Near Florida Bay, the rate of mangrove intrusion into fresh-water marshes

  13. Causes of change in 20th century global river discharge

    NASA Astrophysics Data System (ADS)

    Gerten, Dieter; Rost, Stefanie; von Bloh, Werner; Lucht, Wolfgang

    2008-10-01

    A global vegetation and hydrology model (LPJmL) was applied to quantify the contributions of changing precipitation, temperature, atmospheric CO2 content, land use and irrigation to worldwide trends in 20th century river discharge (Q). Consistently with observations, Q decreased in parts of Africa, central/southern Asia and south-eastern Europe, and increased especially in parts of North America and western Asia. Based on the CRU TS2.1 climatology, total global Q rose over 1901-2002 (trend, 30.8 km3 a-2, equaling 7.7%), due primarily to increasing precipitation (individual effect, +24.7 km3 a-2). Global warming (-3.1), rising CO2 (+4.4), land cover changes (+5.9) and irrigation (-1.1) also had discernible effects. However, sign and magnitude of trends exhibited pronounced decadal variability and differed among precipitation forcing datasets. Since recent trends in these and other drivers of Q are mainly anthropogenic, we conclude that humans exert an increasing influence on the global water cycle.

  14. Health in Barbados in the 20th century.

    PubMed

    Walrond, E R

    2001-09-01

    At the beginning of the 20th century, Barbados was described as the most unhealthy place in the British Empire; at the end of the century, it is considered amongst the healthiest of developing countries. At the start of the century the statistics were harsh; for example, there was an infant mortality rate of 400 per 1000 live births. It is now between 10 and 15 per 1000 live births. In the last two-thirds of the century, there was a series of ongoing revolutions in Education, Public Health and Hospital Services that affected the health status favourably. The revolution in education was enhanced by the provision of University education starting with Medicine at Mona, Jamaica. Training of doctors expanded to Barbados in 1967 and has been an essential ingredient in the medical care revolution of the last third of the century. In 1953, the first Public Health Centre was opened and Barbados can now boast the most modern public health and primary care facilities. However, modern lifestyles are associated with an epidemic of obesity, diabetes mellitus and hypertension. HIV/AIDS has emerged as a major problem. Health in the 21st century will need to look at lifestyles--the effects of the internal combustion engine, the availability of tools of violence, the lure of 'illegal drugs', personal relationships and gender as well as the driving forces behind the associated lifestyles.

  15. Nutrition and food commodities in the 20th century.

    PubMed

    Martini, Sharon A; Phillips, Marshall

    2009-09-23

    Nutrition in the 20th century is examined with respect to changes in the American diet due to changes in the economy and evolution from an agrarian to an industrialized society. The American farm family diet from two regions of the United States during the 1930s is studied on the basis of overall availability of food commodities. A discussion of the diet staples and differences in farm family health is presented and related to nutritional deficiencies. Beginning in the 1920s through the early 1930s dietary deficiencies became a major focus of public health officials in the United States. Identification of the cause of these human nutritional deficiencies prompted significant research by government agencies such as the U.S. Department of Agriculture, Food and Drug Administration, and National Institutes of Health. Medical schools, universities, pharmaceutical corporations, and private institutions directed their resources into basic chemical research and clinical trials to assess the role of vitamins, minerals, proteins, lipids, carbohydrates, and nutrients for improving human health and nutrition. Chemists played an important role in the discovery of vitamins, minerals, and essential nutrients, validating the efficacy through tedious clinical trials. They developed synthetic vitamins affording food manufacturers and pharmaceutical companies the opportunity to capitalize upon fortifying foods for consumers. The American chemist was also responsible for the development of commodities to maximize crop yield through pesticides and fertilizers.

  16. Dynamical structure and risk assessment of 20th Century Windstorms

    NASA Astrophysics Data System (ADS)

    Varino, Filipa; Philippe, Arbogast; Bruno, Joly; Gwendal, Rivière; Marie-Laure, Fandeur; Henry, Bovy; Jean-Baptiste, Granier; Mitchell-Wallace, Kirsten

    2017-04-01

    Windstorms play an important role in weather variability over western Europe. Strong winds associated with fronts and sting jets can lead to several social and economic damages. However, in addition to wind intensity, the displacement speed of the storm, its area and position are also important factors in determining loss. In this study we focus on windstorms associated with the highest damages of the 20th century, and we analyse whether the dynamical structure of the storm is related to its impact. First, we apply an extra-tropical storm tracking algorithm to the ECMWF ERA-20C reanalysis that covers the whole twentieth century and for the whole Northern Hemisphere. Secondly, using the same data, we compute the 3-hourly Loss and Meteorological index for 18 different European countries as in Pinto et al. (2012) with a 25km grid resolution. Thirdly, we develop a High-Loss Tracking Method that matches information from the Loss Index results and the trajectories tracked to systematically associate damages over a particular country to a particular storm. Such a combination provides information on the typical life cycle of storms that create strong damages over a particular country. Finally, only storms hitting France are considered. More than 1500 storms are detected over the whole period and their evolution is analyzed by performing various composites depending on their position relative to the jet stream and their region of impact.

  17. Essential shift: Scientific revolution in the 20th century

    NASA Astrophysics Data System (ADS)

    Ismay, David K.

    1993-05-01

    With the publishing of Sir Isaac Newton's Principia Mathematica in 1687, a scientific paradigm was established that clearly dominated society for two and half centuries. Many historians of science have identified the Copenhagen interpretation of the quantum theory, formulated c.1927, as having completed a scientific revolution that ended the reign of classical Newtonian science. A rival claim to contemporary scientific revolution, however, has been put forward by Ilya Prigogine and the Brussels school of thermodynamics based on Prigogine's work in non-equilibrium thermodynamics. Using the historical consensus model of scientific revolution first articulated by Thomas S. Kuhn in 1962, this analysis examines the extent to which the Copenhagen interpretation of the quantum theory and the work of IIya Prigogine complete the conceptual, scientific paradigm-shift necessary for a scientific revolution. The resulting historical evidence shows that the Copenhagen interpretation did not complete a paradigm-shift; instead, it was a self-revelation by the scientific community which revealed the essence and fundamental limitations of Newtonian science. Evidence further indicates that the valid claim to scientific revolution in the 20th century lies with the contemporary work of Prigogine and the Brussels school. By abandoning the deterministic, mechanical world-view of the Newtonian paradigm and accepting a new reality of process and irreversible time, Prigogine and his associates have established the foundations for a revolutionary new scientific paradigm.

  18. The Astronomical Journal in the Early 20th Century

    NASA Astrophysics Data System (ADS)

    Gino, M. C.; Wise, G.

    2004-05-01

    The Astronomical Journal (AJ), one of the longest running scientific journals in the United States, was edited in Albany, New York between 1909 and 1941. That Albany sojourn, occurring just as astronomy was maturing into a scientific profession, provides insight into the evolution of scientific journals and the science behind them. Those journals grew from the personal property of one or a few individuals into the voice of a professional community. Upon taking over the AJ in 1909, its new editor, Dudley Observatory director Lewis Boss, polled that U.S. astronomical community on the advisability of continuing the journal, which had been founded in 1849 by Benjamin Apthorp Gould. The answer he received provides insight into how portions of the astronomical community defined their field, and the policies he subsequently followed illuminate the realities of the role of journal publication in early 20th century astronomy. The correspondence between Boss and members of the astronomical community upon which this research is primarily based is from the Records of the Astronomical Journal spanning the years of 1897 - 1941. These records, which include correspondence, mailing lists, journals, memorandums, proofs, financial records, manuscripts and ledgers, are part of the Dudley Observatory Institutional Archives that have been maintained as the historical collection of the Observatory.

  19. Summer low flows in New England during the 20th Century

    USGS Publications Warehouse

    Hodgkins, G.A.; Dudley, R.W.; Huntington, T.G.

    2005-01-01

    High springtime river flows came earlier by one to two weeks in large parts of northern New England during the 20th Century. In this study it was hypothesized that late spring/early summer recessional flows and late summer/early fall low flows could also be occurring earlier. This could result in a longer period of low flow recession and a decrease in the magnitude of low flows. To test this hypothesis, variations over time in the magnitude and timing of low flows were analyzed. To help understand the relation between low flows and climatic variables in New England, low flows were correlated with air temperatures and precipitation. Analysis of data from 23 rural, unregulated rivers across New England indicated little evidence of consistent changes in the timing or magnitude of late summer/early fall low flows during the 20th Century. The interannual variability in the timing and magnitude of the low flows in northern New England was explained much more by the interannual variability in precipitation than by the interannual variability of air temperatures. The highest correlation between the magnitude of the low flows and air temperatures was with May through November temperatures (r = -0.37, p = 0.0017), while the highest correlation with precipitation was with July through August precipitation (r = 0.67, p < 0.0001). (JAWRA) (Copyright ?? 2005).

  20. Evaluation for sustainable agriculture water use from River, Reservoirs and Groundwater in the 20th century

    NASA Astrophysics Data System (ADS)

    Yoshikawa, S.; Yamada, H.; Hanasaki, N.; Kanae, S.

    2011-12-01

    High water stress due to economic growth and climate change (ex. global warming) will be falling into 2 billion people to 4 billion people in the future. Agricultural water use accounting for about 70% of global water consumption might continue to increase due to production of foods and biofuels occurred by population growth in the future. In particular, water demand, food and biofuel production have an inextricable link. It is very important to evaluate these relationship for sustainable water use from past to the future. In this study, we focused on the objective to assess the impact of water withdrawal from various sources (stream flow, medium-sized reservoirs and nonrenewable nonlocal blue water) in the 20th century by considering irrigation area and climate change. Irrigation water withdrawal is the most important water use sector accounting for about 90% of total water withdrawal. First, we make the global spatial database of equipped irrigation area change and medium-sized reservoirs capacity. Then, water withdrawal from each sources for 50 years from 1950 to 2000 were simulated in global-scale at a resolution of 1.0 degree x 1.0 degree using an integrated global water resources model (hereafter, the H08 model). The H08 model can simulate both natural or anthropogenic water flow and anthropogenic water withdrawals. For comparison with our results, distribution of agricultural, industrial and domestic water withdrawals from 1950 to 2000 were estimated by distributing the country-based withdrawal data from AQUASTAT with irrigation area, urban population and total population, respectively. Groundwater withdrawal was then estimated by distributing the country-based withdrawal data based on statistical data from WRI, IGRAC and AQUASTAT with the total water withdrawal. As a result, agricultural water withdrawal change from nonrenewable nonlocal blue water during the past 50 years agreed well with the observed groundwater abstraction based on statistical data. In

  1. The Uncertainty in 20th Century Carbon Budget due to Land Use Change Emissions

    NASA Astrophysics Data System (ADS)

    Arora, V. K.; Boer, G. J.

    2009-05-01

    The uncertainty in 20th century carbon budget due to land use change (LUC) emissions is assessed using the Canadian Centre for Climate Modelling and Analysis (CCCma) first generation Earth System Model (CanESM1). CanESM1 is based on CCCma third generation coupled general circulation model and includes terrestrial and oceanic carbon cycle components. LUC emissions are modelled interactively on the basis of specified changes in land cover that determine the amount of deforestation as well as the corresponding albedo changes at the land surface. Eight fully coupled climate-carbon cycle simulations are performed using different reconstructions of the 1850-2000 land cover that are based on historical data sets of increase in cropland and pasture area. The reconstructions of 1850-2000 land cover are based on two approaches: in the linear approach the changes in fractional coverage of natural plant functional types (PFTs) are in proportion to changes in cropland and/or pasture area and in the rule-based approach the natural PFTs are deforested in a specified order. These simulations allow to estimate implied LUC emissions, the contribution of increase in cropland versus pasture area on LUC emissions, the uncertainty associated with using different historical data sets of crop area as well as the manner in which the historical land cover is reconstructed. The amount of deforested biomass for the 1850-2000 period ranges from 63 Pg C for the case where only increase in cropland area is taken into account following the rule-based approach to 145 Pg C where increases in cropland and pasture area are both taken into account following the linear approach. In absence of historical LUC the CO2 concentration in the atmosphere is about 20 ppm below the observation-based value of ~370 ppm in the year 2000. Inclusion of increase in pasture area although increases the amount of deforested biomass it does not change the atmospheric CO2 substantially because pastures also sequester CO2

  2. On the Cause of the Great North Atlantic Hurricane Drought of the Late 20th Century

    NASA Astrophysics Data System (ADS)

    Emanuel, K.

    2015-12-01

    By all sensible metrics, North Atlantic tropical cyclone activity underwent a pronounced decline from the middle of the 20th Century through the 1980s, and then recovered. A rich literature is devoted to the causes is this hurricane drought, with some arguing that it is part of a natural, multi-decadal oscillation of North Atlantic climate, and others pointing to time-varying radiative forcing as the main cause of the drought. In this work I show that the net variability of Atlantic tropical cyclone activity in the second half of the 20th Century has two spectral peaks: One around a single decade and another at a period close to 70 years. I hypothesize that the longer period variability, of which the drought was a part, was principally owing to time-varying radiative forcing, while the quasi-decadal signal is part of a natural oscillation of North Atlantic climate. To test this hypothesis, I present evidence that the two main contributors to time-varying radiative forcing over the period were CO2 variations and aerosol forcing brought about by a combination of sulfate originating in European sulfur emissions and natural mineral dust from the Sahara, and then show that most of the longer-period variations can be statistically explained by a combination of these two forcing agents, at the same time demonstrating that the spatial pattern on this variability is consistent with the radiative forcing hypothesis. On the other hand, the spatial pattern of the quasi-decadal variations is closely aligned with that of the EOFs of natural variability in a large suite of unforced, coupled climate models, suggesting that this quasi-decadal signal is part of a natural oscillation of the North Atlantic climate.

  3. [Recent fauna of ground-nesting birds in Transvolga steppes and its dynamics in the 20th century].

    PubMed

    Oparin, M L

    2008-01-01

    It is shown that the structure of the ground-nesting bird fauna in Transvolga steppes has changed during the 20th century. The complex of lark species characteristic of true and dry steppe has disappeared because of climate change and impact of economic activity (the establishment of windbreak and roadside forest strips), which has provided for a sharp increase in the abundance of corvid birds.

  4. The Enigma of 20th century sea level change

    NASA Astrophysics Data System (ADS)

    Cathles, Larry

    2014-05-01

    Sea level has been constant at near-present levels from ~5500 calendar years BP to the end of the Little Ice Age at ~1860 AD. Since ~1900, tide gauge measurements indicate that it has risen steadily at ~2 mm/yr by about 18 cm. The comparative stability of sealevel from 5500 cal yr BP to 1860 AD is robust, being suggested by near-shore Mediterranean archeological sites, the few sea level records that extend back to 1700 AD, and the impossibility of projecting the current sea level rise of ~2 mm/y back 5000 years (it would produce a global 10 m inundation, which is not observed) (Douglas et al., 2001, Academic Press). The post 1870 sea level rise is not due to heating of the upper ocean (Liviticus et al., 2000, Science). Munk (2002, PNAS) characterized it as an "enigma", dismissing an upper ocean steric sea level explanation as "too little" (~3 cm), "too late" (the rise started in 1860), and "too linear" (not accelerating with the accelerating CO2 increase). GRACE gravity measurements show a near zero change in ocean mass. Cazenave et al. (2009, Global and Planetary Change) indicate a slight decrease in ocean mass between 2003 and 2008. The rate of meltwater mass being added to the oceans essentially equals the GIA correction (Chambers et al., 2010, JGR). Different GIA models give ocean mass increase ranging from 0.5 to 2 mm/y of equivalent sea level rise. Our GIA model suggests no ocean mass increases (~0 mm/y of equivalent sea level rise). In this talk I show that the heating of a two layer ocean model driven by the temperature changes that have occurred over the last 1000 years since the peak of the Medieval Warm Period produces a ~2mm/yr linear sea level rise over the last 100 years with much smaller preceding sea level changes. Ocean mass could be unchanging over the last century as well as the last ~5000 years. This result is compatible with GRACE measurements and eclipse data constraints, predictions of our GIA model, and it resolves the enigma the 20th

  5. Distinct causes for two principal U.S. droughts of the 20th century

    NASA Astrophysics Data System (ADS)

    Hoerling, Martin; Quan, Xiao-Wei; Eischeid, Jon

    2009-10-01

    Diagnosis of observational and climate model data reveals that the two major U.S. droughts of the 20th Century had distinct causes. Drought severity over the Southern Plains during 1946-1956 is very likely attributable to remote influences of global sea surface temperatures (SSTs). The Southern Plains and adjacent Southwest are regions particularly sensitive to SST variability, and strong La Niña events that occurred during 1946-1956 exposed that region's drought vulnerability. Drought severity over the Northern Plains during 1932-1939 was likely triggered instead by random atmospheric variability. The Northern Plains lies within a region of comparatively low sensitivity to SST variability, and that region's drought exhibited little sensitivity to SST conditions during the Dust Bowl period. Our results indicate that the southern portions of the Great Plains lie within an epicenter of potentially skillful drought predictions for which an ocean observing system is also a vital drought early warning system.

  6. Changes in world ocean nitrate availability through the 20th century

    NASA Astrophysics Data System (ADS)

    Kamykowski, Daniel; Zentara, Sara-Joan

    2005-09-01

    Conceptual models linking climate change with fluctuations in fish population abundances are based on how cyclic patterns in air-sea interactions influence pelagic food web dynamics. The effect of changing mixed layer dynamics on phytoplankton light and nutrient exposure is a prominent focal point in the overall mechanism. The Extended Reconstruction (ER) of Sea Surface Temperature (SST) version one (ERSSTv1) and version two (ERSSTv2) monthly time series from 1854 to 2003, interpreted with the aid of a historically based global Nitrate Depletion Temperature (NDT) climatology, provide a qualitative tool for examining relative temporal and spatial patterns in nitrate availability in normal salinity areas of the world ocean. After an analysis of local NDT variability at four time series stations demonstrated temporal stability compared to SST, [SST-NDT] as a Nitrate Availability Index (NAI) was calculated for April (boreal spring or austral fall) and October (boreal fall and austral spring) for the whole ERSSTv1 data set and for selected years of the ERSSTv2 data set using the global NDT climatology. The more negative the NAI difference, the greater the expected surface nitrate. The more positive the NAI difference, the greater the intensity of temperature stratification between the surface and the nitracline and thus the less likely that nitrate mixed to the surface. The records from April and October both showed that decreased nitrate availability, defined by both smaller negative NAI differences and larger positive NAI differences, generally though not universally occurred throughout the 20th century in association with global warming. The greatest decreases in nitrate availability occurred in two warming events in the time periods 1909-1937 and 1977-present in the Northern Hemisphere and 1926-1937 and 1950-1990 in the Southern Hemisphere. Different areas of the world ocean were affected in each warming event. Prominent exceptions in the ERSSTv1 analysis where 20th

  7. Temperature changes in Poland from the 16th to the 20th centuries

    NASA Astrophysics Data System (ADS)

    Przybylak, Rajmund; Majorowicz, Jacek; Wójcik, Gabriel; Zielski, Andrzej; Choryczewski, Waldemar; Marciniak, Kazimierz; Nowosad, Wiesaw; Oliski, Piotr; Syta, Krzysztof

    2005-05-01

    A standardized tree-ring width chronology of the Scots pine (Pinus sylvestris L.) along with different types of documentary evidence (e.g. annals, chronicles, diaries, private correspondence, records of public administration, early newspapers) have been used to reconstruct air temperature in Poland. The ground surface temperature (GST) history has been reconstructed based on the continuous temperature logs from 13 wells, using a new method developed recently by Harris and Chapman (1998; Journal of Geophysical Research 103: 7371-7383) which is compared with the functional space inversion (FSI) method applied to all available Polish temperature-depth profiles analysed before.Response function calculations conducted for trees growing in Poland (except in mountainous regions) reveal a statistically significant correlation between the annual ring widths of the Scots pine and the monthly mean air temperatures, particularly from February and March, but also from January and April. Therefore, it was only possible to reconstruct the mean January-April air temperature.The following periods featured a warm late winter/early spring: 1530-90, 1656-70 (the warmest period), 1820-50, 1910-40, and after 1985. On the other hand, a cold January-April occurred in the following periods: 1600-50, 1760-75, 1800-15, 1880-1900, and 1950-80.Reconstructions of thermal conditions using documentary evidence were carried out for winter (December-February) and summer (June-August) from 1501 to 1840 and, therefore, their results cannot be directly compared with reconstructions based on tree-ring widths. Winter temperatures in this period were colder than air temperature in the 20th century. On the other hand, historical summers were generally warmer than those occurring in the 20th century. Such situations dominated in the 16th and 17th centuries, as well as at the turn of the 18th and 19th centuries. Throughout almost the entire period from 1501 to 1840, the thermal continentality of the climate

  8. Evaluating the 20th Century Reanalysis Dataset (1871-2008) (Invited)

    NASA Astrophysics Data System (ADS)

    Compo, G. P.; Whitaker, J. S.; Sardeshmukh, P. D.

    2010-12-01

    Climate change studies are increasingly focused on moving beyond understanding and predicting global scale changes to regional scale changes, especially changes in the statistics of severe weather and droughts. Assessing the evidence for such variations over the last 150 years, and evaluating the quality of models making predictions for the next hundred, requires a sub-daily (as opposed to monthly or longer-term average) tropospheric circulation dataset. The only large-scale dataset available for the early 20th century consists of error-ridden hand-drawn analyses of the mean sea level pressure field over the Northern Hemisphere. Modern data assimilation systems have the potential to improve upon these maps, but prior to 1948, few digitized upper-air sounding observations are available for such a “reanalysis.” National and international plans to study climate change specifically require global gridded reanalysis datasets to achieve their goals. Under the 20th Century Reanalysis Project, we have demonstrated that the quantity of newly recovered surface pressure observations is sufficient to generate useful reanalyses of the entire tropospheric circulation back to the 19th Century. Surprisingly, we have found that using an Ensemble Kalman Filter that blends an ensemble of 6-hour numerical weather prediction model forecasts with the available surface observations, one can produce high-quality reanalyses of even the upper troposphere using only surface pressure observations. For the end of the 19th century, the accuracy of such upper-air circulation fields for the Northern Hemisphere in winter would be comparable to that of modern three-day weather forecasts. These tropospheric circulation fields are the first to have objective uncertainty estimates for every analyzed variable. The utility of these uncertainty fields is discussed.

  9. A Reassessment of 20th Century Global Sea-Level Change

    NASA Astrophysics Data System (ADS)

    Hay, C.; Morrow, E.; Kopp, R. E.; Mitrovica, J. X.

    2015-12-01

    Climatic change in the 20th century is directly and indirectly observable in multiple aspects of the climate system. Some of these changes, such as global mean surface temperature, are widely studied and understood, while others, such as global mean sea-level change (GMSL), remain uncertain. Until the mid-1990s, with the advent of satellite altimeter observations of a significant percentage of the global ocean, point observations of global sea-level change through tide gauges were the primary means of monitoring the changing height of the sea surface relative to the sea floor. Traditionally, there have been two approaches for estimating GMSL from these temporally and spatially sparse tide gauge records. The first approach uses such records to obtain a global mean value by computing and summing representative regional averages through time (e.g., Jevrejeva et al., GRL, 2008). The second approach uses the dominant spatial patterns of sea surface heights from 20 years of satellite altimetry data to interpolate between tide gauge records to reconstruct global sea level over the century (e.g., Church and White, Surv. Geophys., 2011). However, the GMSL estimates obtained using these two methods differ by ~0.5 mm/yr from the mean global rate achieved by summing the data- and model-derived estimates of the underlying contributions (e.g., thermal expansion, mass flux from land ice, etc.) (IPCC, 2014). Here we describe a third approach that estimates GMSL using two probabilistic approaches based on fingerprinting the underlying source contributions from the spatiotemporal patterns of sea-level change captured by the tide gauge records (Hay et al., Nature, 2015). Our revised GMSL rate estimate of 1.2 ± 0.2 mm/yr over 1901-1990 closes the sea-level budget and maintains a good fit with the tide gauge record over the 20th century.

  10. Anthropogenic Influence on the Changes of the Subtropical Gyre Circulation in the South Pacific in the 20th Century

    NASA Astrophysics Data System (ADS)

    Albrecht, F.; Pizarro, O.; Montecinos, A.

    2016-12-01

    The subtropical ocean gyre in the South Pacific is a large scale wind-driven ocean circulation, including the Peru-Chile Current, the westward South Equatorial Current, the East Australian Current, and the eastward South Pacific Current. Large scale ocean circulations play an essential role in the climate of the Earth over long and short term time scales.In the recent years a spin-up of this circulation has been recognized analyzing observations of sea level, temperature and salinity profiles, sea surface temperature and wind. Until now it is not clear whether this spin-up is decadal variability or whether it is a long-term trend introduced by anthropogenic forcing. This study aims to analyze whether and how anthropogenic forcing influences the position and the strength of the gyre in the 20th century. To determine that, yearly means of different variables of an ensemble of CMIP5 models are analyzed. The experiments 'historical' and 'historicalNat' are examined. The 'historical' experiment simulates the climate of the 20th century and the 'historicalNat' experiment covers the same time period, but only includes natural forcings. Comparing the outcomes of these two experiments is supposed to give information about the anthropogenic influence on the subtropical gyre of the South Pacific.The main variable we analyze is sea level change. This is directly related to the gyre circulation. The center of the gyre is characterized by a high pressure zone (high sea level) and the temporal and spatial variability of the sea level height field gives information about changes in the gyre circulation. The CMIP5 databank includes steric and dynamic sea level changes. Steric sea level, that is the contribution of temperature and salinity of the water, describes the major contribution to regional sea level change with respect to the global mean. Density changes contract or expand the water, which also changes the sea surface height. This does not only occur at the surface, but at

  11. Global reconstructed daily surge levels from the 20th Century Reanalysis (1871-2010)

    NASA Astrophysics Data System (ADS)

    Cid, Alba; Camus, Paula; Castanedo, Sonia; Méndez, Fernando J.; Medina, Raúl

    2017-01-01

    Studying the effect of global patterns of wind and pressure gradients on the sea level variation (storm surge) is a key issue in understanding the recent climate change effect on the dynamical state of the ocean. The analysis of the spatial and temporal variability of storm surges from observations is a difficult task to accomplish since observations are not homogeneous in time, scarce in space, and moreover, their temporal coverage is limited. A recent global surge database developed by AVISO (DAC, Dynamic Atmospheric Correction) fulfilled the lack of data in terms of spatial coverage, but not regarding time extent, since it only includes the last two decades (1992-2014). In this work, we use the 20th Century Reanalysis V2 (20CR), which spans the years 1871 to 2010, to statistically reconstruct daily maximum surge levels at a global scale. A multivariate linear regression model is fitted between daily mean ERA-interim sea level pressure fields and daily maximum surge levels from DAC. Following, the statistical model is used to reconstruct daily surges using mean sea level pressure fields from 20CR. The verification of the statistical model shows good agreements between DAC levels and the reconstructed surge levels from the 20CR. The validation of the reconstructed surge with tide gauges, distributed throughout the domain, shows good accuracy both in terms of high correlations and small errors. A time series comparison is also depicted at specific tide gauges for the beginning of the 20th century, showing a high concordance. Therefore, this work provides to the scientific community, a daily database of maximum surge levels; which correspond to an extension of the DAC database, from 1871 to 2010. This database can be used to improve the knowledge on historical storm surge conditions, allowing the study of their temporal and spatial variability.

  12. North Atlantic early 20th century warming and impact on European summer: Mechanisms and Predictability

    NASA Astrophysics Data System (ADS)

    Müller, Wolfgang

    2017-04-01

    During the last century, substantial climate variations in the North Atlantic have occurred, such as the warmings in the 1920s and 1990s. Such variations are considered to be part of the variability known as the Atlantic Multidecadal Variations (AMV) and have a strong impact on local climates such as European summers. Here a synthesis of previous works is presented which describe the occurrence of the warming in the 1920s in the North Atlantic and its impact on the European summer climate (Müller et al. 2014, 2015). For this the 20th century reanalysis (20CR) and 20CR forced ocean experiments are evaluated. It can be shown that the North Atlantic Current and Sub-Polar Gyre are strengthened as a result of an increased pressure gradient over the North Atlantic. Concurrently, Labrador Sea convection and Atlantic meridional overturning circulation (AMOC) increase. The intensified NAC, SPG, and AMOC redistribute sub-tropical water into the North Atlantic and Nordic Seas, thereby increasing observed and modelled temperature and salinity during the 1920s. Further a mechanism is proposed by which North Atlantic heat fluxes associated with the AMV modulate European decadal summer climate (Ghosh et al. 2016). By using 20CR, it can be shown that multi-decadal variations in the European summer temperature are associated to a linear baroclinic atmospheric response to the AMV-related surface heat flux. This response induce a sea level pressure structure modulating meridional temperature advection over north-western Europe and Blocking statistics over central Europe. This structure is shown to be the leading mode of variability and is independent of the summer North Atlantic Oscillation. Ghosh, R., W.A. Müller, J. Bader, and J. Baehr, 2016: Impact of observed North Atlantic multidecadal variations to European summer climate: A linear baroclinic response to surface heating. Clim. Dyn. doi:10.10007/s00382-016-3283-4 Müller W. A., D. Matei, M. Bersch, J. H. Jungclaus, H. Haak, K

  13. Multi-annual modes in the 20th century temperature variability in reanalyses and CMIP5 models

    NASA Astrophysics Data System (ADS)

    Järvinen, Heikki; Seitola, Teija; Silén, Johan; Räisänen, Jouni

    2016-11-01

    A performance expectation is that Earth system models simulate well the climate mean state and the climate variability. To test this expectation, we decompose two 20th century reanalysis data sets and 12 CMIP5 model simulations for the years 1901-2005 of the monthly mean near-surface air temperature using randomised multi-channel singular spectrum analysis (RMSSA). Due to the relatively short time span, we concentrate on the representation of multi-annual variability which the RMSSA method effectively captures as separate and mutually orthogonal spatio-temporal components. This decomposition is a unique way to separate statistically significant quasi-periodic oscillations from one another in high-dimensional data sets.The main results are as follows. First, the total spectra for the two reanalysis data sets are remarkably similar in all timescales, except that the spectral power in ERA-20C is systematically slightly higher than in 20CR. Apart from the slow components related to multi-decadal periodicities, ENSO oscillations with approximately 3.5- and 5-year periods are the most prominent forms of variability in both reanalyses. In 20CR, these are relatively slightly more pronounced than in ERA-20C. Since about the 1970s, the amplitudes of the 3.5- and 5-year oscillations have increased, presumably due to some combination of forced climate change, intrinsic low-frequency climate variability, or change in global observing network. Second, none of the 12 coupled climate models closely reproduce all aspects of the reanalysis spectra, although some models represent many aspects well. For instance, the GFDL-ESM2M model has two nicely separated ENSO periods although they are relatively too prominent as compared with the reanalyses. There is an extensive Supplement and YouTube videos to illustrate the multi-annual variability of the data sets.

  14. 174. Photocopied July 1978. (LGK) EARLY 20TH CENTURY VIEW OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    174. Photocopied July 1978. (LGK) EARLY 20TH CENTURY VIEW OF QUINCY SMELTER WITH QUINCY HILL IN THE BACKGROUND, AS SEEN FROM HOUGHTON, ACROSS PORTAGE LAKE. - Quincy Mining Company, Hancock, Houghton County, MI

  15. 10. Copy of early 20th century photograph of building 'A' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Copy of early 20th century photograph of building 'A' and tennis court looking north. Photograph owned by the Weatherhead Company. - Cleveland-Chandler Motors Corporation, 300 East 131st Street, Cleveland, Cuyahoga County, OH

  16. 2. Copy of early 20th century photograph showing Euclid Avenue ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Copy of early 20th century photograph showing Euclid Avenue facade, looking norh. Photograph owned by H.D. Koblitz. - F. B. Stearns Company, Euclid & Lakeview Avenues, Cleveland, Cuyahoga County, OH

  17. 1. Copy of early 20th Century lithograph looking north showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Copy of early 20th Century lithograph looking north showing aerial view of company. Rendering owned by the Crawford Auto- aviation Museum, 10825 East Blvd, Cleveland, Ohio. - Winton Motor Carriage Company, Berea Road & Madison Avenue, Cleveland, Cuyahoga County, OH

  18. 2. Copy of early 20th Century photograph showing interior of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Copy of early 20th Century photograph showing interior of Assembly Bldg. Photograph owned by the Crawford Auto-Aviation Museum 10825 East Blvd., Cleveland, Ohio. - Winton Motor Carriage Company, Berea Road & Madison Avenue, Cleveland, Cuyahoga County, OH

  19. 3. Copy of early 20th century photograph of Assembly Bldg., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Copy of early 20th century photograph of Assembly Bldg., interior. Photograph owned by: The Crawford Auto-Aviation Museum, 10825 East Blvd., Cleveland, Ohio. - Winton Motor Carriage Company, Berea Road & Madison Avenue, Cleveland, Cuyahoga County, OH

  20. Writing by 20th-Century Women Reflects Era's Female-Male Conflict, Critics Argue.

    ERIC Educational Resources Information Center

    Paul, Angus

    1986-01-01

    Two women's study of writing by women in the 20th century found unexpectedly bitter and persistent anxiety and female-male conflict and a common theme of confinement and suppression of emotions and thoughts. (MSE)

  1. 15. Early 20th century view (from southeast) of the Gault ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Early 20th century view (from southeast) of the Gault Bridge. Source: Searles Library, Nevada City, California. - Gault Bridge, Spanning Deer Creek at South Pine Street, Nevada City, Nevada County, CA

  2. Medieval Warm Period, Little Ice Age and 20th century temperature variability from Chesapeake Bay

    USGS Publications Warehouse

    Cronin, T. M.; Dwyer, G.S.; Kamiya, T.; Schwede, S.; Willard, D.A.

    2003-01-01

    We present paleoclimate evidence for rapid (< 100 years) shifts of ~2-4oC in Chesapeake Bay (CB) temperature ~2100, 1600, 950, 650, 400 and 150 years before present (years BP) reconstructed from magnesium/calcium (Mg/Ca) paleothermometry. These include large temperature excursions during the Little Ice Age (~1400-1900 AD) and the Medieval Warm Period (~800-1300 AD) possibly related to changes in the strength of North Atlantic thermohaline circulation (THC). Evidence is presented for a long period of sustained regional and North Atlantic-wide warmth with low-amplitude temperature variability between ~450 and 1000 AD. In addition to centennial-scale temperature shifts, the existence of numerous temperature maxima between 2200 and 250 years BP (average ~70 years) suggests that multi-decadal processes typical of the North Atlantic Oscillation (NAO) are an inherent feature of late Holocene climate. However, late 19th and 20th century temperature extremes in Chesapeake Bay associated with NAO climate variability exceeded those of the prior 2000 years, including the interval 450-1000 AD, by 2-3oC, suggesting anomalous recent behavior of the climate system.

  3. Drought assessment and trends analysis from 20th century to 21st century over China

    NASA Astrophysics Data System (ADS)

    Yang, X. L.; Ren, L. L.; Tong, R.; Liu, Y.; Cheng, X. R.; Jiang, S. H.; Yuan, F.

    2015-06-01

    Droughts are becoming the most expensive natural disasters in China and have exerted serious impacts on local economic development and ecological environment. The fifth phase of the Coupled Model Intercomparison Project (CMIP5) provides a unique opportunity to assess scientific understanding of climate variability and change over a range of historical and future period. In this study, fine-resolution multimodel climate projections over China are developed based on 7 CMIP5 climate models under RCP8.5 emissions scenarios by means of Bilinear Interpolation and Bias Correction. The results of downscaled CMIP5 models are evaluated over China by comparing the model outputs with the England Reanalysis CRU3.1 from 1951 to 2000. Accordingly, the results from the output of downscaled models are used to calculate the Standardized Precipitation Index (SPI). Time series of SPI has been used to identify drought from 20th century to 21st century over China. The results show that, most areas of China are projected to become wetter as a consequence of increasing precipitation under RCP8.5 scenarios. Detailed examination shows that the SPI show a slightly increasing trend in the future period for the most parts of China, but drought in Southwest region of China will become the norm in the future RCP8.5 scenarios.

  4. Comparative analysis of spatial and seasonal variability: Austrian precipitation during the 20th century

    NASA Astrophysics Data System (ADS)

    Matulla, Christoph; Penlap, Edouard K.; Haas, Patrick; Formayer, Herbert

    2003-11-01

    The purpose of this investigation is to demonstrate the usability of objective methods to study the variability of precipitation and hence to contribute to a better understanding of spatial and seasonal variability of Austria's precipitation climate during the 20th century.This will be achieved by regionalizing the intra-annual variability of seasonal precipitation distributions during three non-overlapping 33 year samples (1901-33, 1934-66, 1967-99). Monthly precipitation totals were extracted at 31 Austrian stations from a homogenized long-term climate dataset provided by the Austrian weather service. Three statistical techniques, namely cluster analysis (CLA), rotated empirical orthogonal functions (REOFs) and an unsupervised learning procedure of artificial neural networks (ANNs), were utilized to find homogeneous precipitation regions.The results of summer (June, July, August (JJA)) and winter (December, January, February (DJF)) seasons are presented. The resulting homogeneous precipitation regions depend on season, period and method in this order. Hence, differences introduced by using different methods are small compared with those inferred by investigating different episodes and especially with those related to the seasons.During winter, three homogeneous precipitation regions are found, independent from the period considered. These regions can be assigned to different airflows dominating Austria's climate and triggering precipitation events during the cold season. The situation during summer is more complicated. Thus, at least four clusters are necessary to record the circumstances, which are caused by spatially inhomogeneous convective events such as thunderstorms.

  5. Reorganization of the flood-prone atmospheric patterns at the onset of the 20th century?

    NASA Astrophysics Data System (ADS)

    Wilhelm, Bruno; Vogel, Hendrik; Anselmetti, Flavio

    2015-04-01

    studied regions. Comparing all the flood reconstructions over the last 250 years aims at tracking these atmospheric pathways and their possible changes over time. Strong similarities in flood frequency are observed from 1750 to 1900 for the western part (Cévennes, Southern French Alps), while no convincing correlation appears between the other records. Around 1900, a drastic change appears with strong similarities between records of the eastern part (Southern Alps, SE French Alps and NW Italian Alps). In particular, the flood frequency largely increased in the Cévennes during the first part of the 20th century, while this period is one of the most 'quiet' in all other records. Hence, these results suggest a reorganization of the flood-prone atmospheric patterns at the onset of the 20th century.

  6. Downscaling and hydrological uncertainties in 20th century hydrometeorological reconstructions over France

    NASA Astrophysics Data System (ADS)

    Vidal, Jean-Philippe; Caillouet, Laurie; Dayon, Gildas; Boé, Julien; Sauquet, Eric; Thirel, Guillaume; Graff, Benjamin

    2017-04-01

    The record length of streamflow observations is generally limited to the last 50 years, which is not enough to properly explore the natural hydrometeorological variability, a key to better understand the effects of anthropogenic climate change. This work proposes a comparison of different hydrometeorological reconstruction datasets over France built on the downscaling of the NOAA 20th century global extended reanalysis (20CR, Compo et al., 2011). It aims at assessing the uncertainties related to these reconstructions and improving our knowledge of the multi-decadal hydrometeorological variability over the 20th century. High-resolution daily meteorological reconstructions over the period 1871-2012 are obtained with two statistical downscaling methods based on the analogue approach: the deterministic ANALOG method (Dayon et al., 2015) and the probabilistic SCOPE method (Caillouet et al., 2016). These reconstructions are then used as forcings for the GR6J lumped conceptual rainfall-runoff model and the SIM physically-based distributed hydrological model, in order to derive daily streamflow reconstructions over a set of around 70 reference near-natural catchments. Results show a large multi-decadal streamflow variability over the last 140 years, which is however relatively consistent over France. Empirical estimates of three types of uncertainty - structure of the downscaling method, small-scale internal variability, and hydrological model structure - show roughly equal contributions to the streamflow uncertainty at the annual time scale, with values as high as 20% of the interannual mean. Caillouet, L., Vidal, J.-P., Sauquet, E., and Graff, B.: Probabilistic precipitation and temperature downscaling of the Twentieth Century Reanalysis over France, Clim. Past, 12, 635-662, doi:10.5194/cp-12-635-2016, 2016. Compo, G. P., Whitaker, J. S., Sardeshmukh, P. D., Matsui, N., Allan, R. J., Yin, X., Gleason, B. E., Vose, R. S., Rutledge, G., Bessemoulin, P., Brönnimann, S

  7. Coralline algal Barium as indicator for 20th century northwestern North Atlantic surface ocean freshwater variability

    PubMed Central

    Hetzinger, S.; Halfar, J.; Zack, T.; Mecking, J. V.; Kunz, B. E.; Jacob, D. E.; Adey, W. H.

    2013-01-01

    During the past decades climate and freshwater dynamics in the northwestern North Atlantic have undergone major changes. Large-scale freshening episodes, related to polar freshwater pulses, have had a strong influence on ocean variability in this climatically important region. However, little is known about variability before 1950, mainly due to the lack of long-term high-resolution marine proxy archives. Here we present the first multidecadal-length records of annually resolved Ba/Ca variations from Northwest Atlantic coralline algae. We observe positive relationships between algal Ba/Ca ratios from two Newfoundland sites and salinity observations back to 1950. Both records capture episodical multi-year freshening events during the 20th century. Variability in algal Ba/Ca is sensitive to freshwater-induced changes in upper ocean stratification, which affect the transport of cold, Ba-enriched deep waters onto the shelf (highly stratified equals less Ba/Ca). Algal Ba/Ca ratios therefore may serve as a new resource for reconstructing past surface ocean freshwater changes. PMID:23636135

  8. Coralline algal barium as indicator for 20th century northwestern North Atlantic surface ocean freshwater variability.

    PubMed

    Hetzinger, S; Halfar, J; Zack, T; Mecking, J V; Kunz, B E; Jacob, D E; Adey, W H

    2013-01-01

    During the past decades climate and freshwater dynamics in the northwestern North Atlantic have undergone major changes. Large-scale freshening episodes, related to polar freshwater pulses, have had a strong influence on ocean variability in this climatically important region. However, little is known about variability before 1950, mainly due to the lack of long-term high-resolution marine proxy archives. Here we present the first multidecadal-length records of annually resolved Ba/Ca variations from Northwest Atlantic coralline algae. We observe positive relationships between algal Ba/Ca ratios from two Newfoundland sites and salinity observations back to 1950. Both records capture episodical multi-year freshening events during the 20th century. Variability in algal Ba/Ca is sensitive to freshwater-induced changes in upper ocean stratification, which affect the transport of cold, Ba-enriched deep waters onto the shelf (highly stratified equals less Ba/Ca). Algal Ba/Ca ratios therefore may serve as a new resource for reconstructing past surface ocean freshwater changes.

  9. Introduction: contexts and concepts of adaptability and plasticity in 20th-century plant science.

    PubMed

    Baranski, Marci; Peirson, B R Erick

    2015-04-01

    Nowhere is the problem of understanding the complex linkages between organisms and their environments more apparent than in the science of plants. Today, efforts by scientists to predict and manage the biological consequences of shifting global and regional climates depend on understanding how organisms respond morphologically, physiologically, and behaviorally to changes in their environments. Investigating organismal "adaptability" (or "plasticity") is rarely straightforward, prompting controversy and discourse among and between ecologists and agricultural scientists. Concepts like agro-climatic adaptation, phenotypic plasticity, and genotype-environment interaction (GxE) are key to those debates, and their complex histories have imbued them with assumptions and meanings that are consequential but often opaque. This special section explores the diverse ways in which organismal adaptability has been conceptualized and investigated in the second half of the 20th century, and the multifarious political, economic, environmental, and intellectual contexts in which those conceptions have emerged and evolved. The papers in this section bring together perspectives from the histories of agriculture, population ecology, evolutionary theory, and plant physiology, cutting across Asian, North American, and British contexts. As a whole, this section highlights not only the diversity of meanings of "adaptability" and "plasticity," but also the complex linkages between those meanings, the scientific practices and technologies in which they are embedded, and the ends toward which those practices and technologies are employed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Surface solar radiation in 20th century Europe: dimming and brightening as seen by ECHAM5-HAM

    NASA Astrophysics Data System (ADS)

    Folini, D.; Wild, M.

    2012-04-01

    The 20th century has seen a tremendous population growth and industrialization on a global scale. One particular 'hot spot' of these developments is Europe. These changes were accompanied, among others, by a substantial increase in aerosol emission. To learn more about associated consequences for the climate system we have carried out a comparatively large set of transient sensitivity studies with the global atmosphere only climate model ECHAM5-HAM, using aerosol emission data from NIES (National Institute of Environmental Studies, Japan) and prescribed, observation based sea surface temperatures (SSTs) from the Hadley Center. The sensitivity studies cover the period from 1870 to 2005 and comprise ensembles of simulations (up to 13 members per ensemble), which allow to address the role of different aerosol species, greenhouse gases, and prescribed sea surface temperatures. Analyzing these simulation data for Europe, we find a clear decrease of surface solar radiation (SSR) from about 1950 to 1980, followed by a renewed increase. This dimming / brightening is well known from observational data. The modeled and observed magnitude of the phenomenon are in good agreement, although dimming in the model ceases too early. One possible explanation for the latter could lie with the prescribed aerosol emissions, in particular too weak SO2 emissions or a too early reduction of black carbon emissions. Modeled SSR changes show substantial regional differences in magnitude and timing, again in line with observations. The model data further suggests a substantial random / natural variability / cloud component with regard to SSR changes under all sky conditions. While some ensemble members show a much more pronounced dimming than the ensemble average, others show hardly any dimming. Interestingly, the brightening signal after 1990 is found to be more robust in this respect. Surface temperatures bear some imprint of the SSR changes, especially in Eastern Europe, but the dominant

  11. Impacts of irrigation on 20th century temperature in the northern Great Plains

    NASA Astrophysics Data System (ADS)

    Mahmood, Rezaul; Foster, Stuart A.; Keeling, Travis; Hubbard, Kenneth G.; Carlson, Christy; Leeper, Ronnie

    2006-11-01

    Land use change can modify root zone moisture distribution, energy partitioning and subsequently, near surface energy balance. Various modeling studies provided evidence of these changes. For example, land use change from natural grass land to irrigated land use would significantly increase and decrease latent and sensible energy flux, respectively. This type of long-term modification of energy balance would in turn change near surface temperatures. The Great Plains of North America experienced significant overturning of land from natural grass land to irrigated land use during the 20th century. This study provides assessment on the changes in the historical near surface temperature records in Nebraska, USA. Long-term mean monthly maximum, minimum, and monthly mean air temperature data from 5 irrigated and 5 non-irrigated sites were analyzed. Length and homogeneity of time series and stability of stations were primary determinants in selection of these stations. The time series include Cooperative Weather Observation Network (COOP) and Historical Climate Network (HCN) data sets. Pairwise comparisons of temperatures between irrigated and non-irrigated locations for pre- and post-1945, -1950, and -1955 periods were completed for both data sets. These breakdowns of time series helped to identify periods of widespread land use change. Results show notably cooler temperatures over irrigated areas. For example, mean maximum growing season temperature at irrigated Alliance was 0.64 °C and 1.65 °C cooler compared to non-irrigated Halsey during pre- and post-1945 period, respectively. Hence, there was a 1.01 °C cooling during post-1945 years. Moreover, there has been a greater cooling during the second half of 20th century. The bootstrap re-sampling method was applied and trend analyses were completed for further verification of results. These assessments largely show a decreasing trend in mean maximum growing season temperatures over irrigated areas. To further verify

  12. Is classical mechanics a prerequisite for learning physics of the 20th century?

    NASA Astrophysics Data System (ADS)

    Walwema, Godfrey B.; French, Debbie A.; Verley, Jim D.; Burrows, Andrea C.

    2016-11-01

    Physics of the 20th century has contributed significantly to modern technology, and yet many physics students are never availed the opportunity to study it as part of the curriculum. One of the possible reasons why it is not taught in high school and introductory physics courses could be because curriculum designers believe that students need a solid background in classical mechanics and calculus in order to study physics of the 20th century such as the photoelectric effect, special and general relativity, the uncertainty principle, etc. This presumption may not be justifiable or valid. The authors of this paper contend that teaching physics of the 20th century aids students in relating physics to modern technology and the real world, making studying physics exciting. In this study, the authors correlated scores for matched questions in the Mechanics Baseline Test and a physics of the 20th century test in order to examine the trend of the scores. The participants included undergraduate students attending an introductory algebra-based physics course with no intention of taking physics at a higher level. The analysis of the scores showed no significant correlation for any of the matched pairs of questions. The purpose of this article is to recommend that even without a solid background in classical mechanics, teachers can introduce physics of the 20th century to their students for increased interest.

  13. 20th century ethane variability from polar firn air and implications for the methane budget

    NASA Astrophysics Data System (ADS)

    Saltzman, E. S.; Verhulst, K. R.; Aydin, K. M.; Battle, M. O.; Montzka, S. A.; Tang, Q.; Prather, M. J.

    2010-12-01

    Methane and ethane are the most abundant hydrocarbons in the atmosphere and they impact both atmospheric chemistry and climate. Both gases are emitted from fossil fuels and biomass burning, while methane alone has large sources from wetlands, agriculture, landfills and wastewater. Here we use measurements in firn air from Greenland and Antarctica to reconstruct the atmospheric variability of ethane during the 20th century. Ethane levels rose from early in the century until the 1980’s when the trend reverses, with a period of decline over the next 20 years. This variability is primarily driven by changes in ethane emissions from fossil fuels that peaked in the 1960’s and 1970’s at 14-16 Tg/y and dropped to 8-10 Tg/y before the end of the century. The reduction in fossil-fuel sources is likely related to changes in light hydrocarbon recovery during petroleum production and use. The ethane-based emission history implies that the decline in the fossil-fuel source of methane may have started prior to the 1980’s and that the magnitude of the decline is larger than previous estimates.

  14. Potential Predictability of the Sea-Surface Temperature Forced Equatorial East Africa Short Rains Interannual Variability in the 20th Century

    NASA Astrophysics Data System (ADS)

    Bahaga, T. K.; Gizaw, G.; Kucharski, F.; Diro, G. T.

    2014-12-01

    In this article, the predictability of the 20th century sea-surface temperature (SST) forced East African short rains variability is analyzed using observational data and ensembles of long atmospheric general circulation model (AGCM) simulations. To our knowledge, such an analysis for the whole 20th century using a series of AGCM ensemble simulations is carried out here for the first time. The physical mechanisms that govern the influence of SST on East African short rains in the model are also investigated. It is found that there is substantial skill in reproducing the East African short rains variability, given that the SSTs are known. Consistent with previous recent studies, it is found that the Indian Ocean and in particular the western pole of the Indian Ocean dipole (IOD) play a dominant role for the prediction skill, whereas SSTs outside the Indian Ocean play a minor role. The physical mechanism for the influence of the western Indian Ocean on East African rainfall in the model is consistent with previous findings and consists of a gill-type response to a warm (cold) anomaly that induces a westerly(easterly) low-level flow anomaly over equatorial Africa and leads to moisture flux convergence (divergence) over East Africa. On the other hand, a positive El Nino-Southern Oscillation (ENSO) anomaly leads to a spatially non-coherent reducing effect over parts of East Africa, but the relationship is not strong enough to provide any predictive skill in our model. The East African short rains prediction skill is also analyzed within a model-derived potential predictability framework and it is shown that the actual prediction skill is broadly consistent with the model potential prediction skill. Low-frequency variations of the prediction skill are mostly related to SSTs outside the Indian Ocean region and are likely due to an increased interference of ENSO with the Indian Ocean influence on East African short rains after the mid-1970s climate shift.

  15. Consistent QBO-dependent effect of geomagnetic activity on the Northern Annular Mode during the 20th century

    NASA Astrophysics Data System (ADS)

    Maliniemi, Ville; Asikainen, Timo; Mursula, Kalevi

    2016-04-01

    Several earlier studies have shown that geomagnetic activity (GA), as a proxy for energetic particle precipitation into the atmosphere, affects the winter-time Northern Annular Mode (NAM), which is the dominant circulation pattern in the northern hemisphere during winter. It has also been found that the quasi-biennial oscillation (QBO) modulates the relationship between GA and NAM. However, some of the earlier studies on this QBO modulation have been mutually conflicting, with some studies suggesting a stronger positive relation in the easterly phase of the QBO, while other studies suggest a stronger positive relation in the westerly phase of the QBO. Here we study the QBO-GA-NAM relationship using a QBO reconstruction covering the whole 20th century. We find that the QBO modulation of the GA-NAM relation is temporally variable, which explains the earlier, seemingly differing results. Positive GA-NAM relation is found to be valid in the easterly QBO phase at 30 hPa during the whole 20th century. We also find that the QBO at 30 hPa represents the Holton-Tan relation for the surface circulation better than QBO at 50 hPa, and that the Holton-Tan relation is only observed during early/mid winter, while an anti-Holton-Tan relation is found in the late winter for strong geomagnetic activity. These results emphasize the variable but systematic response of NAM to energetic particle precipitation during the entire 20th century, and underline the importance of considering the preconditioning of the atmosphere when studying the solar-related effects upon climate.

  16. Catholic nursing sisters and brothers and racial justice in mid-20th-century America.

    PubMed

    Wall, Barbra Mann

    2009-01-01

    This historical article considers nursing's work for social justice in the 1960s civil rights movement through the lens of religious sisters and brothers who advocated for racial equality. The article examines Catholic nurses' work with African Americans in the mid-20th century that took place amid the prevailing social conditions of poverty and racial disempowerment, conditions that were linked to serious health consequences. Historical methodology is used within the framework of "bearing witness," a term often used in relation to the civil rights movement and one the sisters themselves employed. Two situations involving nurses in the mid-20th century are examined: the civil rights movement in Selma, Alabama, and the actions for racial justice in Chicago, Illinois. The thoughts and actions of Catholic sister and brother nurses in the mid-20th century are chronicled, including those few sister nurses who stepped outside their ordinary roles in an attempt to change an unjust system entirely.

  17. Physicians as detectives in detective fiction of the 20th century.

    PubMed

    Anderson, Daryll

    2002-10-01

    Surprisingly few detectives are physicians in 20th-century detective fiction. Potential books with physician-detective characters were located by pursuing all mentions of characters referred to as 'Doctor" in any of several reference materials pertaining to mystery and detective fiction. As a result of the search, 53 authors whose detective characters are physicians were found. Examination of novels by these authors revealed that early in the 20th century, physicians applied their own specialized scientific knowledge to detection. Mid-century physicians worked by intuition. In the 1990s, science returned to detective fiction in the form of standard forensic procedure, and the level of violence dramatically increased. The relation between science and violence at the end of the 20th century may not be accidental.

  18. Potential forest fire danger over Northern Eurasia: Changes during the 20th century

    NASA Astrophysics Data System (ADS)

    Groisman, Pavel Ya.; Sherstyukov, Boris G.; Razuvaev, Vyacheslav N.; Knight, Richard W.; Enloe, Jesse G.; Stroumentova, Nina S.; Whitfield, Paul H.; Førland, Eirik; Hannsen-Bauer, Inger; Tuomenvirta, Heikki; Aleksandersson, Hans; Mescherskaya, Anna V.; Karl, Thomas R.

    2007-04-01

    Significant climatic changes over Northern Eurasia during the 20th century have been reflected in numerous variables of economic, social, and ecological interest, including the natural frequency of forest fires. For the former USSR, we are now using the Global Daily Climatology Network and a new Global Synoptic Data Network archive, GSDN, created jointly by U.S. National Climatic Data Center and Russian Research Institute for Hydrometeorological Information. Data from these archives (approximately 1500 of them having sufficiently long meteorological time series suitable for participation in our analyses) are employed to estimate systematic changes in indices used in the United States and Russia to assess potential forest fire danger. We use four indices: (1) Keetch-Byram Drought Index, (KBDI; this index was developed and widely used in the United States); (2) Nesterov, (3) Modified Nesterov, and (4) Zhdanko Indices (these indices were developed and widely used in Russia). Analyses show that after calibration, time series of the days with increased potential forest fire danger constructed using each of these three indices (a) are well correlated and (b) deliver similar conclusions about systematic changes in the weather conditions conducive to forest fires. Specifically, over the Eastern half of Northern Eurasia (Siberia and the Russian Far East) statistically significant increases in indices that characterize the weather conditions conducive to forest fires were found. These areas coincide with the areas of most significant warming during the past several decades south of the Arctic Circle. West of the Ural Mountains, the same indices show a steady decrease in the frequency of "dry weather summer days" during the past 60 yr. This study is corroborated with available statistics of forest fires and with observed changes in drought statistics in agricultural regions of Northern Eurasia.

  19. A Comparison of Variable Total and Ultraviolet Solar Irradiance Inputs to 20 th Century Global Warming

    NASA Astrophysics Data System (ADS)

    Foukal, P. V.

    2002-05-01

    Analysis of spaceborne radiometry has shown that the total solar irradiance variation over the past two activity cycles was approximately proportional to the weighted difference between areas of dark spots and bright faculae and enhanced network. Empirical models of ultraviolet irradiance variation indicate that its behavior is dominated by changes in area of the bright component alone, whose photometric contrast increases at shorter wavelength.This difference in time behavior of total and UV irradiances could help to discriminate between their relative importance in forcing of global warming. Our recent digitization of archival Ca K images from Mt Wilson and NSO provides the first direct measurement of variations in area of the bright component, extending between 1915 and 1999 (previous models have relied on the sunspot number or other proxies to estimate the bright - component contribution). We use these more direct measurements to derive the time behavior of solar total and UV irradiance variation, over this period .We find that they are significantly different;the total irradiance variation accounts for over 80 percent of the variance in global temperature during this period, while the ultraviolet irradiance variation accounts for only about 20 percent. The amplitude of total irradiance variation in our model is smaller than required to influence global warming,in current climate models.Also, the impact of sulfate aerosol variations on the extended cooling between the 1940's and 1970's must be better understood before the significance of correlations between 20 th century global warming, and any solar activity index can be properly assessed. Despite these caveats, the lower correlation we find between global temperature and UV,compared to total, irradiance requires consideration in the search for physical mechanisms linking solar activity and climate. This work was supported in part under NASA grant NAG5-7607 to CRI, Inc., and NAG5-10998 to the Applied Physics

  20. A Statistical Investigation on a Seismic Transient Occurred in Italy Between the 17th and 20th Centuries

    NASA Astrophysics Data System (ADS)

    Bragato, P. L.

    2017-03-01

    According to the historical earthquake catalog of Italy, the country experienced a pulse of seismicity between the 17th century, when the rate of destructive events increased by more than 100%, and the 20th century, characterized by a symmetric decrease. In the present work, I performed a statistical analysis to verify the reliability of such transient, considering different sources of bias and uncertainty, such as completeness and declustering of the catalog, as well as errors on magnitude estimation. I also searched for a confirmation externally to the catalog, analyzing the correlation with the volcanic activity. The similarity is high for the eruptive history of Vesuvius, which agrees on both the main rate changes of the 17th and 20th centuries and on minor variations in the intermediate period. Of general interest, beyond the specific case of Italy, the observed rate changes suggest the existence of large-scale crustal processes taking place within decades and lasting for centuries, responsible for the synchronous activation/deactivation of remote, loosely connected faults in different tectonic domains. Although their origin is still unexplained (I discuss a possible link with the climate changes and the consequent variations of the sea level), their existence and long lasting is critical for seismic hazard computation. In fact, they introduce a hardly predictable time variability that undermines any hypothesis of regularity of the earthquake cycle on individual faults and systems of interconnected faults.

  1. A Statistical Investigation on a Seismic Transient Occurred in Italy Between the 17th and 20th Centuries

    NASA Astrophysics Data System (ADS)

    Bragato, P. L.

    2016-11-01

    According to the historical earthquake catalog of Italy, the country experienced a pulse of seismicity between the 17th century, when the rate of destructive events increased by more than 100%, and the 20th century, characterized by a symmetric decrease. In the present work, I performed a statistical analysis to verify the reliability of such transient, considering different sources of bias and uncertainty, such as completeness and declustering of the catalog, as well as errors on magnitude estimation. I also searched for a confirmation externally to the catalog, analyzing the correlation with the volcanic activity. The similarity is high for the eruptive history of Vesuvius, which agrees on both the main rate changes of the 17th and 20th centuries and on minor variations in the intermediate period. Of general interest, beyond the specific case of Italy, the observed rate changes suggest the existence of large-scale crustal processes taking place within decades and lasting for centuries, responsible for the synchronous activation/deactivation of remote, loosely connected faults in different tectonic domains. Although their origin is still unexplained (I discuss a possible link with the climate changes and the consequent variations of the sea level), their existence and long lasting is critical for seismic hazard computation. In fact, they introduce a hardly predictable time variability that undermines any hypothesis of regularity of the earthquake cycle on individual faults and systems of interconnected faults.

  2. Translating Music Intelligibly: Musical Paraphrase in the Long 20th Century

    ERIC Educational Resources Information Center

    Orosz, Jeremy White

    2013-01-01

    This dissertation is a study of the practice of musical paraphrase in the long 20th century. Musical paraphrase is defined as the adaptation, alteration, or embellishment of musical material, often borrowed from another source. My project is built around a single guiding question: If a composer borrows music from another source and alters it for…

  3. Visual Preferences of Young School Children for Paintings from the 20th Century

    ERIC Educational Resources Information Center

    Kuscevic, Dubravka; Kardum, Goran; Brajcic, Marija

    2014-01-01

    The aim of this study was to investigate the differences of young school children in the visual preferences of paintings from the 20th century. The study was conducted at 4 elementary schools around Split, Croatia. A total of 200 children participated in the study, of which 87 were girls and 113 were boys aged 6-10 years. Visual preference testing…

  4. The wings of Daedalus: The convergence of myth and technology in 20th century culture

    NASA Technical Reports Server (NTRS)

    Kowitt, Mark E.; Kaplan, Michael S.

    1993-01-01

    In the second half of the 20th century, age-old human fantasies of leaving the Earth and touching the stars have been fulfilled by advances in space science and technology, whose roots are threaded through our history. Current advances are so explosive that the fundamental orientation of Western culture is being radically altered.

  5. Wildlife of southern forests habitat & management (Chapter 3): Natural Resources-Into the 20th Century

    Treesearch

    James G. Dickson

    2003-01-01

    At the beginning of the 20th century descendants of the early European settlers who first colonized the coasts of Virginia, the Carolinas, and Georgia were established throughout the region. Most all of the native people had been displaced. Cotton was king. The mature forests were being eliminated. And wildlife populations had been seriously depleted by the...

  6. Dancetime! 500 Years of Social Dance. Volume II: 20th Century. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This 50-minute VHS videotape is the second in a 2-volume series that presents 500 years of social dance, music, and fashion. It features dance and music of the 20th century, including; 1910s: animal dances, castle walk, apache, and tango; 1920s: black bottom and charleston; 1930s: marathon, movie musicals, big apple, and jitterbug; 1940s: rumba;…

  7. The Devolution of 20th Century Presidential Campaign Rhetoric: A Call for "Rhetorical Service."

    ERIC Educational Resources Information Center

    Heinemann, Robert L.

    Over the course of the 20th century, American Presidential campaign rhetoric has undergone various metamorphoses. Most of these changes can be traced to developments in technology and media. Furthermore, many of these changes have had the unfortunate effect of undermining a rational choice of the electorate, and thus threaten our democracy. Like…

  8. 10. Photocopy, WATER TOWERS, late 19th or early 20th century. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Photocopy, WATER TOWERS, late 19th or early 20th century. Original Photograph at State Historical Society of North Dakota, file No. TF899 - Fort Totten, 12 miles southwest of Devils Lake City off Route 57, Devils Lake, Ramsey County, ND

  9. 1. Photocpy of early 20th century photograph, looking east, of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocpy of early 20th century photograph, looking east, of east facade of assembly building on Euclid Ave. Photo owned by the Cleveland Public Library. - Ford Motor Company, Cleveland Branch Assembly Plant, Euclid Avenue & East 116th Street, Cleveland, Cuyahoga County, OH

  10. 2. Photocopy of early 20th century photo, showing the Euclid ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of early 20th century photo, showing the Euclid Avenue facade of the branch assembly building. Photograph owned by the Cleveland Public Library. - Ford Motor Company, Cleveland Branch Assembly Plant, Euclid Avenue & East 116th Street, Cleveland, Cuyahoga County, OH

  11. 2. Photocopy of early 20th century drawing, looking south from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of early 20th century drawing, looking south from the air. Drawing owned by the Crawford Auto-Aviation Museum, 10825 East Blvd., Cleveland, Ohio. - Peerless Motor Car Company, East Ninety-third Street & Quincy Avenue, Cleveland, Cuyahoga County, OH

  12. 1. Photocopy of early 20th century rendering showing aerial veiw, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopy of early 20th century rendering showing aerial veiw, looking south. Rendering owned by the Crawford Auto-Aviation Museum, 10825 East Blvd., Cleveland, Ohio. - Peerless Motor Car Company, East Ninety-third Street & Quincy Avenue, Cleveland, Cuyahoga County, OH

  13. The wings of Daedalus: The convergence of myth and technology in 20th century culture

    NASA Technical Reports Server (NTRS)

    Kowitt, Mark E.; Kaplan, Michael S.

    1993-01-01

    In the second half of the 20th century, age-old human fantasies of leaving the Earth and touching the stars have been fulfilled by advances in space science and technology, whose roots are threaded through our history. Current advances are so explosive that the fundamental orientation of Western culture is being radically altered.

  14. Dancetime! 500 Years of Social Dance. Volume II: 20th Century. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This 50-minute VHS videotape is the second in a 2-volume series that presents 500 years of social dance, music, and fashion. It features dance and music of the 20th century, including; 1910s: animal dances, castle walk, apache, and tango; 1920s: black bottom and charleston; 1930s: marathon, movie musicals, big apple, and jitterbug; 1940s: rumba;…

  15. Blackness and Whiteness as Historical Forces in the 20th Century United States

    ERIC Educational Resources Information Center

    Greason, Walter

    2009-01-01

    At the core of the epistemology of black identity in the 20th century United States is the assertion that freedom is a human right, not a privilege to be earned. By the late 19th century, an ideology of racial uplift had emerged that revolved around four concepts--compassion, service, education, and a commitment to social and economic justice for…

  16. Cultivating Swedishness? Examples of Imagined Kinship during the First Half of the 20th Century

    ERIC Educational Resources Information Center

    Thomasson, Adrian

    2015-01-01

    Different representations of "Swedishness," as expressions of altered kinds of imagined kinship in the Swedish educational system during the first half of the 20th century, are discussed. It is argued that even though the curriculum changed, from a more religious one focusing on fostering loyalty and moral commitment to "God, the…

  17. From Generation to Generation: Oral Histories of Scientific Innovations from the 20th Century

    ERIC Educational Resources Information Center

    Bedrossian, Mindy J.

    2010-01-01

    The 20th century saw some of the most important technological and scientific discoveries in the history of humankind. The space shuttle, the internet, and other modern advances changed society forever, and yet many students cannot imagine what life was like before these technologies existed. In the project described here, students take a firsthand…

  18. From Generation to Generation: Oral Histories of Scientific Innovations from the 20th Century

    ERIC Educational Resources Information Center

    Bedrossian, Mindy J.

    2010-01-01

    The 20th century saw some of the most important technological and scientific discoveries in the history of humankind. The space shuttle, the internet, and other modern advances changed society forever, and yet many students cannot imagine what life was like before these technologies existed. In the project described here, students take a firsthand…

  19. Blackness and Whiteness as Historical Forces in the 20th Century United States

    ERIC Educational Resources Information Center

    Greason, Walter

    2009-01-01

    At the core of the epistemology of black identity in the 20th century United States is the assertion that freedom is a human right, not a privilege to be earned. By the late 19th century, an ideology of racial uplift had emerged that revolved around four concepts--compassion, service, education, and a commitment to social and economic justice for…

  20. Visual Preferences of Young School Children for Paintings from the 20th Century

    ERIC Educational Resources Information Center

    Kuscevic, Dubravka; Kardum, Goran; Brajcic, Marija

    2014-01-01

    The aim of this study was to investigate the differences of young school children in the visual preferences of paintings from the 20th century. The study was conducted at 4 elementary schools around Split, Croatia. A total of 200 children participated in the study, of which 87 were girls and 113 were boys aged 6-10 years. Visual preference testing…

  1. Figuring The Value of Literacy Education in the Late 19th and Early 20th Centuries.

    ERIC Educational Resources Information Center

    George, D'Ann

    As part of the research for a dissertation on composition at Bryn Mawr College during the late 19th and early 20th centuries, hundreds of student essays and daily themes were read. Over and over students affirmed the essential worth and significance of events in their daily lives and of their college education in general. More often than not,…

  2. Ottoman Greek Education System and Greek Girls' Schools in Istanbul (19th and 20th Centuries)

    ERIC Educational Resources Information Center

    Daglar Macar, Oya

    2010-01-01

    Modernization efforts in education, which were initiated in the 19th century, can be seen as forerunners of the modernization attempts in the Republic period. In this article, Greek education system in the Ottoman Empire will be discussed and the effects and importance of the changes observed in Greek girls' education in 19th and 20th centuries on…

  3. Exploring 20th Century History through Photographs: Integrating Multiple Disciplines through Social Studies.

    ERIC Educational Resources Information Center

    Fogler, Karen; Hoffman, Mala

    1994-01-01

    Students at Hunter College Elementary School chose 10 events in the 20th century, 1 per decade, and completed research, art, and writing projects that would represent their viewpoint on each of the events. Students made collages containing photographs and headlines relating to their selected events and wrote autobiographical statements connecting…

  4. Unsettling the Body: The Institutionalization of Physical Activity at the Turn of the 20th Century

    ERIC Educational Resources Information Center

    Azzarito, Laura; Munro, Petra; Solmon, Melinda

    2004-01-01

    The turn of the 20th century was a time of major political and economic fluctuation and demographic shifts in American cities. As a result, physical health and physical supremacy became serious concerns. Between 1880 and 1930, the Progressive Era, politicians, doctors, and educators advocated for physical activity with the intent to improve…

  5. From Card Catalogues to WebPACs: Celebrating Cataloguing in the 20th Century.

    ERIC Educational Resources Information Center

    Gorman, Michael

    This paper provides an overview of cataloging in the 20th century. Highlights include: (1) issues in 1901, including the emerging cooperative cataloging system and the work of Charles Ammi Cutter; (2) the 1908 code, i.e., "Catalog Rules: Author and Title Entries," published in British and American editions; (3) the Vatican rules, a code…

  6. Exploring 20th Century History through Photographs: Integrating Multiple Disciplines through Social Studies.

    ERIC Educational Resources Information Center

    Fogler, Karen; Hoffman, Mala

    1994-01-01

    Students at Hunter College Elementary School chose 10 events in the 20th century, 1 per decade, and completed research, art, and writing projects that would represent their viewpoint on each of the events. Students made collages containing photographs and headlines relating to their selected events and wrote autobiographical statements connecting…

  7. Translating Music Intelligibly: Musical Paraphrase in the Long 20th Century

    ERIC Educational Resources Information Center

    Orosz, Jeremy White

    2013-01-01

    This dissertation is a study of the practice of musical paraphrase in the long 20th century. Musical paraphrase is defined as the adaptation, alteration, or embellishment of musical material, often borrowed from another source. My project is built around a single guiding question: If a composer borrows music from another source and alters it for…

  8. Cultivating Swedishness? Examples of Imagined Kinship during the First Half of the 20th Century

    ERIC Educational Resources Information Center

    Thomasson, Adrian

    2015-01-01

    Different representations of "Swedishness," as expressions of altered kinds of imagined kinship in the Swedish educational system during the first half of the 20th century, are discussed. It is argued that even though the curriculum changed, from a more religious one focusing on fostering loyalty and moral commitment to "God, the…

  9. Coral Records of Late 20th Century Warming and Freshening in the Central Tropical Pacific

    NASA Astrophysics Data System (ADS)

    Nurhati, I. S.; Cobb, K. M.; Charles, C. D.

    2007-12-01

    Tropical Pacific climate variability strongly impacts global temperature and rainfall patterns. The evolution of tropical Pacific climate under anthropogenic greenhouse warming is unclear, observational and modeling studies support both a strengthening (Cane et al.,1997) and a weakening (Vecchi et al.,2006) of the tropical Pacific zonal sea-surface temperature (SST) gradient. Corals from the central tropical Pacific (CTP) have provided monthly-resolved climate proxy records that contain late 20th century trends toward more negative oxygen isotopic (d18O) values, suggesting that regional warming and/or freshening has occurred over the last several decades (Urban et al.,2000; Cobb et al.,2001). It is important to identify the physical mechanisms that underlie these trends in order to better predict low-frequency changes in tropical Pacific climate over the next decades. One potential mechanism involves a reduction in the tropical Pacific zonal SST gradient, which would warm the CTP by reducing upwelling while increasing rainfall (thereby decreasing salinity). On the other hand, warming might have occurred absent any change in the zonal SST gradient, and the freshening may signal changes in the location and/or intensity of the Inter-Tropical Convergence Zone (ITCZ). Here we apply d18O and Sr/Ca proxies to modern corals from Palmyra, Fanning and Christmas Islands (2-6°N,157-162°W) in order to reconstruct SST and sea-surface salinity (SSS) over the last several decades. While coral d18O changes in SST and/or the d18O of seawater (d18Osw, which is linearly related to salinity in this region), coral Sr/Ca is mainly controlled by SST. When used together, these two proxies allow us to quantify recent climate trends in the CTP with respect to SST and SSS, particularly because Palmyra, Fanning and Christmas span strong gradients in SST and SSS. The islands are aligned in a NW-SE fashion, such that Christmas (2°N) is bathed by the South Equatorial Current and dominated by

  10. Multidecadal Signal of Solar Variability in the Upper Troposphere During the 20th Century

    NASA Astrophysics Data System (ADS)

    Brönnimann, S.; Ewen, T.; Griesser, T.; Jenne, R.

    2006-08-01

    Studies based on data from the past 25 45 years show that irradiance changes related to the 11-yr solar cycle affect the circulation of the upper troposphere in the subtropics and midlatitudes. The signal has been interpreted as a northward displacement of the subtropical jet and the Ferrel cell with increasing solar irradiance. In model studies on the 11-yr solar signal this could be related to a weakening and at the same time broadening of the Hadley circulation initiated by stratospheric ozone anomalies. Other studies, focusing on the direct thermal effect at the Earth’s surface on multidecadal scales, suggest a strengthening of the Hadley circulation induced by an increased equator-to-pole temperature gradient. In this paper we analyse the solar signal in the upper troposphere since 1922, using statistical reconstructions based on historical upper-air data. This allows us to address the multidecadal variability of solar irradiance, which was supposedly large in the first part of the 20th century. Using a simple regression model we find a consistent signal on the 11-yr time scale which fits well with studies based on later data. We also find a significant multidecadal signal that is similar to the 11-yr signal, but somewhat stronger. We interpret this signal as a poleward shift of the subtropical jet and the Ferrel cell. Comparing the magnitude of the two signals could provide important information on the feedback mechanisms involved in the solar climate relationship with respect to the Hadley and Ferrel circulations. However, in view of the uncertainty in the solar irradiance reconstructions, such interpretations are not currently possible.

  11. Seasonal Antarctic Station-Based Pressure Reconstruction Variability and Trends During the 20th Century

    NASA Astrophysics Data System (ADS)

    Goergens, C.; Fogt, R. L.

    2016-12-01

    A key component in understanding climate variations across Antarctica, whether from the Southern Annular Mode (SAM) or from tropical teleconnections, is understanding changes in the atmospheric circulation. Yet, as with much of Antarctic data, researchers are left with neither long-term point (station) measurements of pressure variations across Antarctica, nor gridded pressure data from reanalyses or models that can be deemed reliable, given very little in situ data to constrain the solution across the high southern latitudes. This presentation will briefly discuss the methodology/evaluation of seasonal pressure reconstructions at 18 Antarctic staffed stations that extend back to 1905, but will primarily be focused on the variability and trends seen in these pressure reconstructions, especially in summer and winter, as these seasons were reconstructed with the greatest skill. During the summer, there is considerable interannual variability that is spatially uniform across the continent. Several years of interest (e.g. 1911/1912 and 1925/1926) where high pressure anomalies were found at all stations also coincided with the negative phase of the SAM and El Niño events, further suggesting confidence in the reconstructions. Also, notable negative pressure trends in the summer season have been seen in the last 40 years across the entire continent which are unique in the context of 30-year trends throughout the entire 20th century, suggesting a strong component of anthropogenic forcing on the recent summer trends. Unlike the summer season, winter across the continent is dominated by low-frequency, multidecadal-scale variability, and no significant pressure trends were seen in this season. Current work includes conducting a spatial Antarctic-wide pressure reconstruction back until 1905.

  12. Global reconstructed daily storm surge levels from the 20th century reanalysis (1871-2010)

    NASA Astrophysics Data System (ADS)

    Cid, Alba; Camus, Paula; Castanedo, Sonia; Mendez, Fernando; Medina, Raul

    2015-04-01

    The study of global patterns of wind and pressure gradients, and more specifically, their effect on the sea level variation (storm surge), is a key issue in the understanding of recent climate changes. The local effect of storm surges on coastal areas (zones particularly vulnerable to climate variability and changes in sea level), is also of great interest in, for instance, flooding risk assessment. Studying the spatial and temporal variability of storm surges from observations is a difficult task to accomplish since observations are not homogeneous in time and scarce in space, and moreover, their temporal coverage is limited. The development of a global storm surge database (DAC, Dynamic Atmospheric Correction by Aviso, Carrère and Lyard, 2003) fulfils the lack of data in terms of spatial coverage, but not regarding time extent since it only includes last couple of decades (1992-2014). In this work, we propose the use of the 20CR ensemble (Compo et al., 2011) which spans from 1871 to 2010 to statistically reconstruct storm surge at a global scale and for a long period of time. Therefore, the temporal and spatial variability of storm surges can be fully studied and with much less effort than performing a dynamical downscaling. The statistical method chosen to carry out the reconstruction is based on multiple linear regression between an atmospheric predictor and the storm surge level at daily scale (Camus et al., 2014). The linear regression model is calibrated and validated using daily mean sea level pressure fields (and gradients) from the ERA-interim reanalysis and daily maxima surges from DAC. The obtained daily database of maximum daily surges has allowed us to estimate global trends at a centennial scale and analyse the effect of the changing climate on storm surges during the 20th century. Hence, this work improves the knowledge on historical storm-surge conditions and provides helpful information to the community concern on marine climate evolution and

  13. Large-Scale Modeling Shows Little Impact of 20th-Century Changes in Temperature and Fire on the Central Canadian Boreal Forest

    NASA Astrophysics Data System (ADS)

    Bond-Lamberty, B.; Peckham, S.; Ahl, D. E.; Gower, S. T.

    2006-12-01

    Boreal forests are predicted to experience relatively large climate change (IPCC 2001), and the fire dynamics of this region may not be in equilibrium with the changing climate (Flannigan et al. 1998, Kasischke & Stocks 2000). Here we investigate how well a biogeochemical model can simulate observed 20^{th}-century changes in the structure and function of the boreal forest. Biome-BGC was used to simulate a 1000 km x 1000 km section (6-8% of the global boreal forest) of central Canadian forest at 1 km2 resolution. Historical climate, disturbance, and CO2 forcing data were used to drive the model; three dynamic vegetation types (evergreen needleleaf tree, broadleaf deciduous tree, and moss) were employed. Soil type, drainage, and other site conditions were represented as accurately as available data allowed. Assuming that the forest was at a carbon-neutral steady state in 1948, CO2 and disturbance frequency changes had small (<20 g C m-2 yr-1) and opposite effects on forest C balance by 2005; in particular, the C losses from more frequent fires were almost balanced by the C uptake of post-disturbance deciduous forests. Precipitation changes had the largest effects on C balance, with the overall forest shifting from being neutral to a small source of C, while interannual variability increased. Such a shift is smaller than can be measured using current biometric and eddy covariance techniques.

  14. Variation in surface air temperature of China during the 20th century

    NASA Astrophysics Data System (ADS)

    Soon, Willie; Dutta, Koushik; Legates, David R.; Velasco, Victor; Zhang, Weijia

    2011-10-01

    The 20th century surface air temperature (SAT) records of China from various sources are analyzed using data which include the recently released Twentieth Century Reanalysis Project dataset. Two key features of the Chinese records are confirmed: (1) significant 1920s and 1940s warming in the temperature records, and (2) evidence for a persistent multidecadal modulation of the Chinese surface temperature records in co-variations with both incoming solar radiation at the top of the atmosphere as well as the modulated solar radiation reaching ground surface. New evidence is presented for this Sun-climate link for the instrumental record from 1880 to 2002. Additionally, two non-local physical aspects of solar radiation-induced modulation of the Chinese SAT record are documented and discussed.Teleconnections that provide a persistent and systematic modulation of the temperature response of the Tibetan Plateau and/or the tropospheric air column above the Eurasian continent (e.g., 30°N-70°N; 0°-120°E) are described. These teleconnections may originate from the solar irradiance-Arctic-North Atlantic overturning circulation mechanism proposed by Soon (2009). Also considered is the modulation of large-scale land-sea thermal contrasts both in terms of meridional and zonal gradients between the subtropical western Pacific and mid-latitude North Pacific and the continental landmass of China. The Circum-global teleconnection (CGT) pattern of summer circulation of Ding and Wang (2005) provides a physical framework for study of the Sun-climate connection over East Asia. Our results highlight the importance of solar radiation reaching the ground and the concomitant importance of changes in atmospheric transparency or cloudiness or both in motivating a true physical explanation of any Sun-climate connection. We conclude that ground surface solar radiation is an important modulating factor for Chinese SAT changes on multidecadal to centennial timescales. Therefore, a

  15. Surface solar radiation and hydrological cycle in 20th century China: sensitivity studies with ECHAM5-HAM

    NASA Astrophysics Data System (ADS)

    Folini, D.; Wild, M.

    2012-04-01

    The world, and China in particular, has seen a tremendous population growth and industrialization in the 20th century. These changes were accompanied, among others, by a substantial increase in aerosol emission. To learn more about associated consequences for the climate system we have carried out a comparatively large set of transient sensitivity studies with the global atmosphere only climate model ECHAM5-HAM, using aerosol emission data from NIES (National Institute of Environmental Studies, Japan) and prescribed, observation based sea surface temperatures (SSTs) from the Hadley Center. The sensitivity studies cover the period from 1870 to 2005 and comprise ensembles of simulations (up to 13 members per ensemble), which allow to address the role of different aerosol species, greenhouse gases, and prescribed sea surface temperatures. Here we analyze these simulation data with particular focus on surface solar radiation, temperature, and the hydrological cycle in China. Physical mechanisms able to explain the results will be discussed. We generally find the strongest effects in the east of the country, where urbanization and industrialization is strongest and emissions increased most. The decrease of surface solar radiation (SSR) under clear sky conditions reaches up to around -8 W / m2 per decade from 1950 to 1990. Comparable values are found for all sky conditions. Dimming ceases in the second half of the 1990s, when we even see a renewed increase in SSR in some regions. Overall, these findings are in line with observation based estimates. Modeled surface temperatures reflect the decrease in SSR but carry also a substantial SST signature. After remaining roughly constant from 1870 to 1900, we find modeled surface temperatures to increase by about 1 degree Celsius till 1950, then decrease again by -0.2 to -1.2 degree Celsius till 1990, before a renewed increase sets in. Precipitation decreases in our model results from 1950 to 2000 by up to 10% or 150 mm per year

  16. Responses of Multi-Aged Music Students to Mid-20th-Century Art Music: A Replication and Extension

    ERIC Educational Resources Information Center

    Madsen, Clifford K.; Geringer, John M.

    2015-01-01

    This investigation replicates previous research into K-12 students' responses to mid-20th-century art music. The study extends that research to include undergraduates and graduates as well as an additional group of graduate students who had taken a 20th-century music class. Children's responses showed remarkable consistency and indicated that…

  17. Responses of Multi-Aged Music Students to Mid-20th-Century Art Music: A Replication and Extension

    ERIC Educational Resources Information Center

    Madsen, Clifford K.; Geringer, John M.

    2015-01-01

    This investigation replicates previous research into K-12 students' responses to mid-20th-century art music. The study extends that research to include undergraduates and graduates as well as an additional group of graduate students who had taken a 20th-century music class. Children's responses showed remarkable consistency and indicated that…

  18. Lunar and Planetary Robotic Exploration Missions in the 20th Century

    NASA Astrophysics Data System (ADS)

    Huntress, W. T., Jr.; Moroz, V. I.; Shevalev, I. L.

    2003-07-01

    The prospect of traveling to the planets was science fiction at the beginning of the 20th Century and science fact at its end. The space age was born of the Cold War in the 1950s and throughout most of the remainder of the century it provided not just an adventure in the exploration of space but a suspenseful drama as the US and USSR competed to be first and best. It is a tale of patience to overcome obstacles, courage to try the previously impossible and persistence to overcome failure, a tale of both fantastic accomplishment and debilitating loss. We briefly describe the history of robotic lunar and planetary exploration in the 20th Century, the missions attempted, their goals and their fate. We describe how this enterprise developed and evolved step by step from a politically driven competition to intense scientific investigations and international cooperation.

  19. Infant feeding and professional advice in the first half of the 20th century in Greece.

    PubMed

    Pechlivani, Fani; Matalas, Antonia-Leda; Bakoula, Chryssa

    2008-11-01

    This study aims to assess the role that health professional and State policies played in shaping breastfeeding practices and attitudes in Greece during the first half of the 20th century. Original texts were used; including those concerned with breastfeeding traditions, health professionals' attitudes to breastfeeding, infant feeding patterns, partial breastfeeding, artificial feeding and State policies for the promotion of breastfeeding. Content analysis was used and breastfeeding rates were considered. In the first two decades of the 20th century, most Greek women breastfed their children, as advised by other experienced women. In the succeeding decades, health professionals and policy makers wrote books and articles praising breastfeeding albeit stressing the nursing mothers' ignorance of sanitary measures. Many health professionals were influenced by trends in developed countries and advocated novel infant feeding practices. Consequently, full breastfeeding was not promoted.

  20. [Developments and trends in 19th- and 20th-century German nursing historiography].

    PubMed

    Schweikardt, Christoph

    2004-01-01

    This paper analyses important trends in 19th- and 20th-century German nursing historiography. Frequently, the diverse contributions, which were predominantly written by physicians and nurses, were strongly shaped by the occupational background of the author and purposes of professional politics. In recent years, valuable scholarly contributions on nursing organisations have appeared. Anglo-American nursing history research should serve as a model for Germany. The paper calls for the extension of a recently founded nursing history research network.

  1. History of the Women's Health Movement in the 20th century.

    PubMed

    Nichols, F H

    2000-01-01

    The Women's Health Movement (WHM) emerged during the 1960s and the 1970s with the primary goal to improve health care for all women. Despite setbacks in the area of reproductive rights during the 1980s, the WHM made significant gains in women's health at the federal policy level during the 1980s and 1990s. The WHM became a powerful political force. The achievements of the movement in improving women's health during the 20th century were numerous and significant.

  2. Do Higher 20th Century Sea-cliff Retreat Rates Necessarily Imply Recent Acceleration in Sea-cliff Retreat?

    NASA Astrophysics Data System (ADS)

    Mushkin, Amit; Katz, Oded; Porat, Naomi

    2017-04-01

    Inland retreat of sea cliffs in response to post LGM (last glacial maximum) sea-level rise is an ongoing process that affects coastal environments and communities worldwide. Here, we examine a globally recurring pattern where reported sea-cliff retreat rates since the 20th century often appear to exceed longer-term millennial-scale ('background') rates that rarely exceed 0.1 m/yr. Focusing on Israel's 30-km-long Mediterranean 'Sharon' sea-cliff as a case study we demonstrate that such apparent increase in rates may also reflect a widely acknowledged sampling bias in geologic rate estimates inferred from observation time windows ('OTW') shorter than process episodicity. We show that this possible bias leads to an ambiguity in conventional rate estimates obtained by averaging observed retreat distances over OTW, and that as a result despite ubiquitous and robust observations of cliff retreat since the 20th century (e.g., aerial photographs) recent/current retreat rates for many of the world's episodically retreating sea cliffs remain essentially unknown. To address this present limitation in our ability to detect and quantify recent changes in sea-cliff retreat rates we use airborne LiDAR to measure the continuous wave-driven volumetric erosion of collapsed material from the cliff base as an effective upper-bound constraint for the m/yr rate of episodic retreat of the cliff itself. We find that while conventional retreat rate estimates since the 20th century along the Sharon sea cliff artefactually increase up to several m/yr as an inverse function of OTW, the LiDAR-constrained retreat rates are not susceptible to this sampling bias, are comparable to the cliff's background retreat rate of 0.03-0.07 m/yr since the mid Holocene and thus indicate no recent acceleration in retreat. This ability to unambiguously constrain sea-cliff retreat rates with annual to decadal-scale observations directly impacts the global-scale push to quantify, better understand and ultimately

  3. Catholic Nursing Sisters and Brothers and Racial Justice in Mid-20th-Century America

    PubMed Central

    Wall, Barbra Mann

    2009-01-01

    This historical article considers nursing’s work for social justice in the 1960s civil rights movement through the lens of religious sisters and brothers who advocated for racial equality. The article examines Catholic nurses’ work with African Americans in the mid-20th century that took place amid the prevailing social conditions of poverty and racial disempowerment, conditions that were linked to serious health consequences. Historical methodology is used within the framework of “bearing witness,” a term often used in relation to the civil rights movement and one the sisters themselves employed. Two situations involving nurses in the mid-20th century are examined: the civil rights movement in Selma, Alabama, and the actions for racial justice in Chicago, Illinois. The thoughts and actions of Catholic sister and brother nurses in the mid-20th century are chronicled, including those few sister nurses who stepped outside their ordinary roles in an attempt to change an unjust system entirely. PMID:19461224

  4. [The 20th century legal framework regarding risk at work and occupational health in Colombia].

    PubMed

    Arango-Soler, Juan M; Luna-García, Jairo E; Correa-Moreno, Yerson A; Campos, Adriana C

    2013-01-01

    Analyzing the 20th century Colombian legal framework from the point of view of labor law, social security and public health for identifying concepts regarding occupational health and professional risk and trying to establish convergence and differences between such foci and whether they fulfilled a complementary view. This work involved documentary research by means of thematic categorical analysis of the laws and statutes promulgated in 20th century Colombia, considering the main element or entity which should have regulated that related to professional risk or occupational health. The development of the 20th century Colombian legal framework regarding health at work was periodized, revealing the predominance of a view of social law focused on protecting dependent workers' work-related risks, as part of a tendency extending to the Colombian Sistema General de Riesgos Laborales. The proposed stages used for organizing the legal framework concerning social security regarding professional risk and occupational health facilitated some important elements being recognized concerning the social, legal and institutional context from which workers' health laws emerged. Tension was noted concerning statutes orientated towards redress and compensation regarding accidents at work and legislation emphasizing prevention.

  5. Changes in the global freshwater N and P cycles over the 20th century

    NASA Astrophysics Data System (ADS)

    Beusen, Arthur; van Beek, Rens; Bouwman, Lex; Mogollón, José; Middelburg, Jack

    2016-04-01

    Dramatic world-wide changes occurred during the 20th century in both nutrient delivery and in-stream retention. In this paper, we use a combined nutrient-input, hydrology, in-stream nutrient retention model to quantitatively track the changes in the global freshwater N and P cycles over the 20th century. Global nutrient delivery almost doubled due to expanding agriculture and increasing wastewater discharge. Nutrient retention also increased by a factor of two as a result of the rapidly growing number of dams and reservoirs. This increase in nutrient retention could not balance the increase in nutrient delivery to rivers. River export to coastal seas increased during the 20th century from 19 to 37 Tg yr-1 of N and 2 to 4 Tg yr-1 of P. There are important differences in riverine N:P export ratios in various parts of the world resulting from the interplay of multiple processes and economic activities in different river basins. Increasing nutrient loading of freshwater systems is a threat to water quality. Furthermore, the global river export increase in the molar N:P ratio during recent decades may affect the ecology within both the river basins and the coastal system. This ratio change may be driven by the recent stagnation of P fertilizer use in most industrialized countries, in comparison to the ever increasing N fertilizer use.

  6. The process of Danish nurses' professionalization and patterns of thought in the 20th century.

    PubMed

    Beedholm, Kirsten; Frederiksen, Kirsten

    2015-06-01

    In this article, we address how the professionalization process is reflected in the way Danish nursing textbooks present 'nursing' to new members of the profession during the 20th century. The discussion is based on a discourse analysis of seven Danish textbooks on basic nursing published between 1904 and 1996. The analysis was inspired by the work of Michel Foucault, in particular the concepts of rupture and rules of formation. First, we explain how the dominating role of the human body in nursing textbooks disappears in the mid-20th century. This transformation can of course be attributed to changes in tasks and responsibilities for nurses or to the implementation of increasing amounts of knowledge and theories from other disciplines than medicine into the nurses' knowledge base. However, inspired by Foucault, we consider these historical changes to be the conditions of possibilities and not causes. The second part of the analysis shows that along with 'the disappearance of the body', a second discursive change appears: the role of doctors and medicine changes fundamentally from about mid-20th century. Finally, we argue that this discursive reorganization enabling new patterns of thought to emerge was driven by a professional interest in describing nursing as an independent profession.

  7. Disastrous floods and landslides in Portugal in the 20th century

    NASA Astrophysics Data System (ADS)

    Quaresma, Ivânia; Zêzere, José Luis

    2010-05-01

    The record and analysis of statistical information on disaster occurrence, impacts and losses have been made worldwide in recent years. The development of natural disasters databases is crucial for risk management purposes, because it allows improving systems of indicators on disaster risk and vulnerability at national and sub-national scales. During the last century, Portugal was affected by several destructive natural disasters, namely of hydrologic (floods) and geomorphologic (landslides) origin. However, only recently risk prevention and management was assumed to be a national priority by the Portuguese Government. The basic information on past floods and landslides that occurred in Portugal is disperse and incomplete, and this is a shortcoming for the implementation of effective disaster mitigation measures, particularly when it is expectable an increase of frequency, magnitude, dimension and complexity of the hydro-geomorphologic phenomena resulting from climate change. In this work we present a preliminary assessment of hydro-geomorphologic disasters occurred in Portugal during the 20th century, based on the systematic survey of daily national newspapers. We included into a database those floods and landslides that produced, alternatively, dead people, injured people, missing people, evacuated and homeless. A total of 937 hydro-geomorphologic events were registered. In addition to physical and material damages, these events produced economic losses amounting to millions Euros. Our attention will focus on the geographic distribution and the temporal dimension of disastrous floods and landslides occurred in Portugal, and the temporal trends of hydro-geomorphologic disasters will be presented. The preliminary results shown that disastrous floods and landslides have been more frequent on the most populated regions of Portugal: the metropolitan areas of Lisbon and Oporto. In addition, data shows that disastrous hydrologic and geomorphologic phenomena were more

  8. The 20th Century evolution of energy budgets and meridional transports in two AMIP-like experiments

    NASA Astrophysics Data System (ADS)

    Lembo, Valerio; Folini, Doris; Wild, Martin; Lionello, Piero

    2016-04-01

    The 20th century evolution and spatial patterns of the Top-of-Atmosphere (TOA), atmospheric, and surface energy budgets (EB) are investigated in this work. These are computed as the balance between the radiative and heat fluxes at the TOA and at the surface. Total, atmospheric and oceanic meridional energy transports are computed from the EBs. Two AMIP-like ensemble simulations are considered: Integrated Forecast System (IFS) simulations of the ERA-20CM experiment, and ECHAM5-HAM model simulations. With the latter, additional sensitivity experiments are carried out by constraining either Sea-Surface Temperatures (SST) and Sea-Ice Cover (SIC) or aerosol concentrations to climatological values. The recent decades estimates of the EB are in reasonable agreement in the two models, while they are not for what concerns the global scale evolution. Particularly, in the 1970s ERA-20CM shows a fast transition from negative to positive EBs at Top of Atmosphere (TOA) that is not found in ECHAM5-HAM. The impact of aerosols, as evidenced by the sensitivity experiments with ECHAM5-HAM, is seen to set up an inter-hemispheric gradient in the TOA and surface budget after 1960. This is also reflected by an increased total poleward transport in the Northern Hemisphere and decreased in the Southern Hemisphere. This feature is not found in ERA-20CM. SST variations do not seem to induce long-term variations in the patterns of TOA budget and related total meridional transport. Nevertheless most of the surface and atmospheric budget and transport inter-annual variability is attributable to the evolution of SST, and much more agreement is observed among the two models in this respect. Reference: Lembo V, Doris F, Martin W, and Lionello P (2015) Energy budgets and transports: global evolution and spatial patterns during the 20th Century as estimated in two AMIP-like experiments, Clim. Dyn., subm.

  9. Impact of fire on global land surface air temperature and energy budget for the 20th century due to changes within ecosystems

    NASA Astrophysics Data System (ADS)

    Li, Fang; Lawrence, David M.; Bond-Lamberty, Ben

    2017-04-01

    Fire is a global phenomenon and tightly interacts with the biosphere and climate. This study provides the first quantitative assessment and understanding of fire’s influence on the global annual land surface air temperature and energy budget through its impact on terrestrial ecosystems. Fire impacts are quantified by comparing fire-on and fire-off simulations with the Community Earth System Model (CESM). Results show that, for the 20th century average, fire-induced changes in terrestrial ecosystems significantly increase global land annual mean surface air temperature by 0.18 °C, decrease surface net radiation and latent heat flux by 1.08 W m-2 and 0.99 W m-2, respectively, and have limited influence on sensible heat flux (-0.11 W m-2) and ground heat flux (+0.02 W m-2). Fire impacts are most clearly seen in the tropical savannas. Our analyses suggest that fire increases surface air temperature predominantly by reducing latent heat flux, mainly due to fire-induced damage to the vegetation canopy, and decreases net radiation primarily because fire-induced surface warming significantly increases upward surface longwave radiation. This study provides an integrated estimate of fire and induced changes in ecosystems, climate, and energy budget at a global scale, and emphasizes the importance of a consistent and integrated understanding of fire effects.

  10. Adriatic and Black Sea level in the 20th century and projection to the end of the 21st century.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2015-04-01

    Adriatic and Black Sea are semi-enclosed basins characterized by densely populated coasts, industrial compounds and a rich cultural and historical heritage. It appears to be crucial, for the management and the protection of their coastlines, to understand how much they will be impacted by the global sea level (SL) rise, projected by the end of this century. The aim of this work is to develop a method that allows to estimate to which extent the SL of the two basins will depart from the mean global level. The future evolution of global sea level is not a meaningful indicator at this regional scale and past deviations, due to local factors of the Adriatic and Black Sea levels from the global one, have been observed. The Adriatic Sea is the basin of the Mediterranean Sea best covered by past SL observations. In fact, for the Adriatic Sea is possible to obtain, by statistical method based on PCA and Least square Method, a seamless and long time series (from 1900 to 2009) using records of 7 mareographic stations located along the Italian and Croatian coasts (from PSMSL database). Satellite data of SL are available for the whole Mediterranean from 1993 to 2012 and they show a very high correlation (rho > 0.9) with Adriatic time series based on mareographic records. The SL time series of the 20th century in the Black Sea is computed using data of 4 stations, which are available in the PSMSL (Permanent Service for Mean Sea Level) archive, located on the north-east coast. This time series shows a lower correlation (rho about 0.5) with satellite data than in the case of Adriatic Sea. Further it shows a higher interannual variability. All the time series are considered after the subtraction of the Inverse Barometer (IB) effect. A statistical approach, based on a multivariate linear regression model, is used to investigate the link between SL anomaly, computed as the difference between the regional SL and global SL, and three large scale climate variables (sea level pressure

  11. An Eight-Century High-Resolution Paleoclimate Record From the Cariaco Basin: Baseline Variability and the 20th Century

    NASA Astrophysics Data System (ADS)

    Black, D. E.; Thunell, R. C.; Kaplan, A.; Tappa, E. J.; Peterson, L. C.

    2007-12-01

    The Cariaco Basin, Venezuela is well-positioned to record a detailed history of surface ocean changes along the southern margin of the Caribbean and the tropical Atlantic. Varved, high deposition rate sediments deposited under anoxic conditions and an abundance of well-preserved microfossils result in one of the few marine records capable of preserving evidence of interannual- to decadal-scale climate variability in the tropical Atlantic. Here we present Mg/Ca and stable oxygen isotope data with sub-decadal resolution derived from sediments deposited over the last 800 years. Mg/Ca measured on the planktic foraminifer Globigerina bulloides from a Cariaco Basin sediment core strongly correlates with spring (March-May) instrumental SSTs between AD 1870 and 1990. The long-term record displays a surprising amount of variability for a tropical location. The temperature swings are not necessarily related to local upwelling variability, but instead represent wider conditions in the Caribbean and western tropical Atlantic. The Mg/Ca-SST record also captures the decadal and multidecadal variability observed in global land and sea surface temperature anomalies, and correlates with Atlantic tropical storm and hurricane frequency over the late-19th and 20th centuries. On average, 20th century temperatures are not the warmest in the entire record, but they do show the largest increase in magnitude and fastest rate of SST change over the last eight hundred years. Stable oxygen isotope data also correlate well with instrumental SSTs, but not over the full instrumental record. Poor correlations with early instrumental SST data suggest a salinity overprint. However, reconstructing δ- water variability using combined Mg/Ca and δ18O data is not straightforward as the δ- water/salinity relationship varies seasonally in the Cariaco Basin. Comparisons with percent titanium data suggest intervals of both local and regional surface salinity changes over the length of the record.

  12. Ice core evidence for a 20th century increase in surface mass balance in coastal Dronning Maud Land, East Antarctica

    NASA Astrophysics Data System (ADS)

    Philippe, Morgane; Tison, Jean-Louis; Fjøsne, Karen; Hubbard, Bryn; Kjær, Helle A.; Lenaerts, Jan T. M.; Drews, Reinhard; Sheldon, Simon G.; De Bondt, Kevin; Claeys, Philippe; Pattyn, Frank

    2016-10-01

    Ice cores provide temporal records of surface mass balance (SMB). Coastal areas of Antarctica have relatively high and variable SMB, but are under-represented in records spanning more than 100 years. Here we present SMB reconstruction from a 120 m-long ice core drilled in 2012 on the Derwael Ice Rise, coastal Dronning Maud Land, East Antarctica. Water stable isotope (δ18O and δD) stratigraphy is supplemented by discontinuous major ion profiles and continuous electrical conductivity measurements. The base of the ice core is dated to AD 1759 ± 16, providing a climate proxy for the past ˜ 250 years. The core's annual layer thickness history is combined with its gravimetric density profile to reconstruct the site's SMB history, corrected for the influence of ice deformation. The mean SMB for the core's entire history is 0.47 ± 0.02 m water equivalent (w.e.) a-1. The time series of reconstructed annual SMB shows high variability, but a general increase beginning in the 20th century. This increase is particularly marked during the last 50 years (1962-2011), which yields mean SMB of 0.61 ± 0.01 m w.e. a-1. This trend is compared with other reported SMB data in Antarctica, generally showing a high spatial variability. Output of the fully coupled Community Earth System Model (CESM) suggests that, although atmospheric circulation is the main factor influencing SMB, variability in sea surface temperatures and sea ice cover in the precipitation source region also explain part of the variability in SMB. Local snow redistribution can also influence interannual variability but is unlikely to influence long-term trends significantly. This is the first record from a coastal ice core in East Antarctica to show an increase in SMB beginning in the early 20th century and particularly marked during the last 50 years.

  13. Inter-hemispheric asymmetry of the global energy budget and near-surface temperature anomalies throughout the 20th Century

    NASA Astrophysics Data System (ADS)

    Wild, M.; Lembo, V.; Folini, D.; Lionello, P.

    2016-12-01

    The goal of this study is to analyse the evolution of the Energy Budget (EB) at global scale, its effects on the inter-hemispheric temperature difference and cross-equatorial energy transport. To this aim we consider multi-model ensembles based on two different scenarios developed in the framework of the CMIP5 Project. The former includes only a progressively changing greenhouse gas (GHG) forcing component for the 20th Century, while the latter includes a fully realistic evolution of all forcings representative of the 20th Century. In the GHG forcing scenario EB anomalies at Top-of-Atmosphere (TOA) are hemispherically symmetric and a clear inter-hemispheric temperature asymmetry emerges, with the Northern Hemisphere (NH) warming at a faster rate than the Southern Hemisphere (SH). In the historical scenario TOA EB anomalies are hemispherically asymmetric in the multi-model mean. The ratio between near-surface temperatures and TOA EB anomalies denotes an evident inter-hemispheric asymmetry in both scenarios. This is partly explained by the intrinsically different heat capacity of the two hemispheres surfaces, with the NHhaving a smaller heat capacity compared to the SH, due to the lower fraction of ocean surface. However the ratios are also modulated by the cross-equatorial energy transport, differently in the two scenarios. The GHG forcing introduces a southward energy transport anomaly supported by the atmosphere and linked to the inter-hemispheric temperature differences at low latitudes. In the historical scenario the transport anomaly is northwards and supported by the oceans. We believe that these results provide new perspectives on the role of energy absorption asymmetries in the climate system and its subsystems (atmosphere and ocean) and the intrinsic zonal-mean spatial patterns of the near-surface temperature response to a symmetric external forcing.

  14. Potential forest fire danger over Northern Eurasia: Changes during the 20th century

    NASA Astrophysics Data System (ADS)

    Sherstyukov, B. G.; Razuvaev, V. N.; Groisman, P. Y.; Knight, R. W.; Enloe, J. G.

    2004-12-01

    Significant climatic changes over Northern Eurasia during the 20th century have been reflected in numerous variables of economic, social, and ecological interests, including the natural frequency of forest fires. For the former USSR, we are now using the Global Daily Climatology Network (Gleason et al. 2002) and a new Global Synoptic Data Network archive, GSDN, created jointly by NCDC an RIHMI. Data from these archives are employed to estimate systematic changes in indices used in the United States and Russia to assess potential forest fire danger. Within the boundaries of the former USSR, each of the archives, GHCN and GSDN, includes more than 2100 stations with only approximately 1500 of them having sufficiently long meteorological time series suitable for participation in our analyses. We use three indices: (1) Keetch-Byram Drought Index, (KBDI; this index uses only daily data on maximum temperature and precipitation and is developed and widely used in the United States); (2) Modified Nesterov, and (3) Zhdanko Indices (these indices are developed and widely used in Russia; their computation requires synoptic daytime data on temperature and humidity and daily precipitation and snow on the ground). Analyses show that after calibration, time series of the days with increased potential forest fire danger constructed using each of these three indices (a) are well correlated and (b) deliver similar conclusions about systematic changes in the weather conditions conducive to forest fires. Specifically, over the entire Eastern half of Northern Eurasia (Siberia and the Russian Far East) we found a statistically significant increase in indices that characterize the weather conditions conducive to forest fires. These areas coincide with the areas of most significant warming during the past several decades south of the Arctic Circle. West of the Ural Mountains, the same indices show a steady decrease in the frequency of the "dry weather summer days" during the past sixty

  15. Assessing how seasonal hydrological balance has changed during the warming 20th century in the montane forests of Southeast Asian monsoon region using a stable isotope dendroclimatology approach

    NASA Astrophysics Data System (ADS)

    Zhu, M.; Stott, L. D.

    2010-12-01

    Tropical montane forests act as water catchment and host of biodiversity in the Southeast Asian monsoon region, and understanding how their hydrological conditions change with global warming is vitally important. Global climate model simulations project enhanced moisture cycle in the tropics, which would cause stronger summer monsoon precipitations, but on the other hand the adiabatic lapse rate would be shifted towards a moister condition (amplification of warming at high elevation), inhibiting dry season orographic lifting cloud/fog formation (lifting cloud base hypothesis), enhancing evapo-transpiration, and leading to a net moisture loss during winter dry season. In this study, we have attempted to investigate how the seasonal moisture balance in Southeast Asia has evolved in response to these influences through the 20th century using the oxygen isotopic composition (δ18O) of subannual tree cellulose samples extracted from the annual rings of pine trees that grow in Doi Chiang Dao, a limestone mountain in northern Thailand. At this location the δ18O of cellulose exhibits distinctive annual cycles of up to 12‰, which is primarily a reflection of both the so-called ‘isotope amount effect’ that is associated with the strong monsoon precipitation during summer wet season and the moisture availability from different sources during winter dry season. We have demonstrated that tree cellulose δ18O could be used as a proxy for regional monsoon strength by showing that the annual mean cellulose δ18O correlate significantly with All India Rainfall, Webster-Yang monsoon index, as well as with both local and regional monsoon precipitation. ENSO is the dominant influence on interannual rainfall variability and this is well expressed in the interannual cellulose δ18O record. Using a 21-year moving window correlation analysis we find a weakening of ENSO influence after 1980, coinciding with the most rapid atmospheric warming. We expect to analyze older trees to

  16. Why does FGOALS-gl reproduce a weak Medieval Warm Period but a reasonable Little Ice Age and 20th century warming?

    NASA Astrophysics Data System (ADS)

    Guo, Zhun; Zhou, Tianjun

    2013-11-01

    To understand the strengths and limitations of a low-resolution version of Flexible Global Ocean-Atmosphere-Land-Sea-ice (FGOALS-gl) to simulate the climate of the last millennium, the energy balance, climate sensitivity and absorption feedback of the model are analyzed. Simulation of last-millennium climate was carried out by driving the model with natural (solar radiation and volcanic eruptions) and anthropogenic (greenhouse gases and aerosols) forcing agents. The model feedback factors for (model sensitivity to) different forcings were calculated. The results show that the system feedback factor is about 2.5 (W m-2) K-1 in the pre-industrial period, while 1.9 (W m-2) K-1 in the industrial era. Thus, the model’s sensitivity to natural forcing is weak, which explains why it reproduces a weak Medieval Warm Period. The relatively reasonable simulation of the Little Ice Age is caused by both the specified radiative forcing and unforced linear cold drift. The model sensitivity in the industrial era is higher than that of the pre-industrial period. A negative net cloud radiative feedback operates during whole-millennial simulation and reduces the model’s sensitivity to specified forcing. The negative net cloud radiative forcing feedback under natural forcing in the period prior to 1850 is due to the underestimation (overestimation) of the response of cloudiness (in-cloud water path). In the industrial era, the strong tropospheric temperature response enlarges the effective radius of ice clouds and reduces the fractional ice content within cloud, resulting in a weak negative net cloud feedback in the industrial period. The water vapor feedback in the industrial era is also stronger than that in the pre-industrial period. Both are in favor of higher model sensitivity and thus a reasonable simulation of the 20th century global warming.

  17. [Anti-positivist inspiration in European medical historiography in the 20th century].

    PubMed

    Płonka-Syroka, Bozena

    2002-01-01

    The article presents the most important anti-positivist (the neo-romantic, socio-cultural and relativistic) currents in 20th century European medical historiography. The author discusses the genesis of the anti-positivist opposition in the medical historiography, starting with a presentation of the main points of the positivist programme, and shows the reasons behind the earlier broad reception of this programme by medical historians from the medical profession. The author attributes the emergence of an anti-positivist opposition in this milieu mainly to the medical progress which occurred in the first half of the 20th century and which induced some doctors, engaged in research into medical history, to reject the positivist model of teaching and replace it wit another. This factor played a leading role in the formation of the socio-cultural and relativist currents. According to the author, the second important factor in the birth of this opposition is the 20th century progress in the methodology of historical research, which freed itself from the constraints of positivist scientism as the only acceptable method of interpreting facts. The author also discusses the socio-cultural and political conditions which led to the formation and spread of the neo-romantic movement solely in Germany. The article presents the programme principles and the most important representatives of anti-positivist currents in European (mainly German) and the circumstances behind the reception of each current by the community of medical historians, and presents the development prospects of Polish medical historiography on the treshold of the 20th and 21st centuries, in connection with the research into this field of science undertaken by a large and continuously growing number of university-educated researchers.

  18. Canada's Dominion Astrophysical Observatory and the rise of 20th Century Astrophysics and Technology

    NASA Astrophysics Data System (ADS)

    Hesser, James E.; Bohlender, David; Crabtree, Dennis

    2016-10-01

    Construction of Canada's Dominion Astrophysical Observatory (DAO) commenced in 1914 with first light on 6 May 1918. As distinct from the contemporaneous development with private funding of major observatories in the western United States, DAO was (and remains) funded by the federal government. Canada's initial foray into `big science', creation of DAO during the First World War was driven by Canada's desire to contribute significantly to the international rise of observational astrophysics enabled by photographic spectroscopy. In 2009 the Observatory was designated a National Historic Site. DAO's varied, rich contributions to the astronomical heritage of the 20th century continue in the 21st century, with particularly strong ties to Maunakea.

  19. One hundred years ago. Nursing education at the dawn of the 20th century.

    PubMed

    Fondiller, S H

    1999-01-01

    The late 19th and early 20th centuries ushered in a number of significant events that helped advance the nursing profession in its early development. Nursing leaders began to show interest in the reform movements under way, such as woman's suffrage, settlement houses, and labor activities. They knew that nurses were not alone in their struggle to improve the health of the public. Philanthropic groups abounded, working for social betterment as well as for changes needed in overcrowded tenements, food inspection, and information to the nation about healthy living (1). In addition, serious concerns surfaced in the profession relating to the proliferation of training schools and reforms required in the educational system.

  20. A history of spine biomechanics. Focus on 20th century progress.

    PubMed

    Oxland, T R

    2015-12-01

    The application of mechanical principles to problems of the spine dates to antiquity. Significant developments related to spinal anatomy and biomechanical behaviour made by Renaissance and post-Renaissance scholars through the end of the 19th century laid a strong foundation for the developments since that time. The objective of this article is to provide a historical overview of spine biomechanics with a focus on the developments in the 20th century. The topics of spine loading, spinal posture and stability, spinal kinematics, spinal injury, and surgical strategies were reviewed.

  1. Alfred Werner's role in the mid-20th century flourishing of American inorganic chemistry.

    PubMed

    Labinger, Jay A

    2014-01-01

    The development of organic and physical chemistry as specialist fields, during the middle and end of the 19th century respectively, left inorganic behind as a decidedly less highly regarded subfield of chemistry. Despite Alfred Werner's groundbreaking studies of coordination chemistry in the early 20th century, that inferior status remained in place - particularly in the US - until the 1950s, when the beginnings of a resurgence that eventually restored its parity with the other subfields can be clearly observed. This paper explores the extent to which Werner's heritage - both direct, in the form of academic descendants, and indirect - contributed to those advances.

  2. [Famous doctors who stayed on the Croatian coast at the turn of the 20th century].

    PubMed

    Ivanisević, Petar; Lesin, Mladen; Plestina-Borjan, Ivna; Ivanisević, Milan

    2012-01-01

    At the end of the 19th and the beginning of the 20th century many famous persons stayed on the Croatian coast mostly because of touristic and health reasons, than because of natural beauties, scientific or political reasons. Most often they came from Austro-Hungary, Germany or Russia but also from our homelands. Among them were also many famous doctors, some known worldwide. The most distinguished were the surgeon Theodor Billroth, the bacteriologist and a Nobel prize winner Robert Koch, the pathologist Rudolf Virchow, and the psychiatrist Sigmund Freud. They left a deep impression and a big benefit at the area they stayed in.

  3. Life expectancy of the 20th century Venda: a compilation of skeletal and cemetery data.

    PubMed

    L'Abbé, E N; Steyn, M; Loots, M

    2008-01-01

    Little information is available on the 20th century mortality rates of rural black South African groups, such as the Venda. The purpose of this study was to apply abridged life tables in order to estimate life expectancy from both skeletal remains and death registry information of modern South African communities. Comparisons were also made with prehistoric and contemporary groups as a means to better evaluate life expectancy for this time period. The sample consisted of 160 skeletons of known Venda origin and burial registry information for 1364 black South Africans from the Rebecca Street and Mamelodi Cemeteries in Pretoria, South Africa. Standard anthropological techniques were applied to determine sex and estimate age from the skeletal remains. The stationary and non-stationary life table models were used to analyse the data. A high rate of child mortality, low juvenile and adult mortality with a steady increase in mortality after the age of 30 years was observed for both the Venda and the cemetery samples. Throughout the 20th century, life expectancy was shown to increase for black South Africans. However, due to the widespread HIV infection/AIDS of the 21st century, infant and young adult mortality rates continue to rise at such a speed that the decline in mortality seen for South Africans in the last 50 years will most likely to be lost in the next decade due to this disease.

  4. Assortative mating and differential fertility by phenotype and genotype across the 20th century

    PubMed Central

    Laidley, Thomas; Belsky, Daniel W.; Fletcher, Jason M.; Boardman, Jason D.; Domingue, Benjamin W.

    2016-01-01

    This study asks two related questions about the shifting landscape of marriage and reproduction in US society over the course of the last century with respect to a range of health and behavioral phenotypes and their associated genetic architecture: (i) Has assortment on measured genetic factors influencing reproductive and social fitness traits changed over the course of the 20th century? (ii) Has the genetic covariance between fitness (as measured by total fertility) and other traits changed over time? The answers to these questions inform our understanding of how the genetic landscape of American society has changed over the past century and have implications for population trends. We show that husbands and wives carry similar loadings for genetic factors related to education and height. However, the magnitude of this similarity is modest and has been fairly consistent over the course of the 20th century. This consistency is particularly notable in the case of education, for which phenotypic similarity among spouses has increased in recent years. Likewise, changing patterns of the number of children ever born by phenotype are not matched by shifts in genotype–fertility relationships over time. Taken together, these trends provide no evidence that social sorting is becoming increasingly genetic in nature or that dysgenic dynamics have accelerated. PMID:27247411

  5. [TCM societies in Shanghai during the first half of the 20(th) century].

    PubMed

    Yang, Xing-Lin; Lu, Ming; Chen, Pei-Pei; Zhang, Jing-Ying; Yang, Zhi-Qing

    2012-03-01

    In the first half of the 20(th) century, with the introduction of western academic thought and the assemblage of TCM doctors of different factions, the variety of cultures provided an ideological and academic background for TCM societies in Shanghai in modern times. Under the pressure of banning and exclusion, protective measures taken by the TCM circles promoted the establishment of TCM societies. The establishment and development of TCM societies in Shanghai in modern times included four stages - the embryonic stage (1903 - 1911), the development stage (1912 - 1926), the struggling stage (1927 - 1937) and the recovery stage (1938 - 1949). Aiming at academic studies, TCM societies in the early time could be divided into a national society and local societies and both were composed of scholars with the same academic viewpoints. Societies in the later stages aimed at maintaining status and fighting for rights. Activities held by these societies included starting publications, compiling textbooks, publishing, establishing hospitals and schools, prevention and control of infectious disease and innovation of TCM dosage forms. In the first half of the 20(th) century, the influence of TCM societies helped Shanghai become the TCM center in modern times.

  6. The animal as surgical patient: a historical perspective in the 20th century.

    PubMed

    Gardiner, Andrew

    2009-01-01

    Current veterinary history has not engaged significantly with patient histories. In many historical accounts of veterinary medicine, animal patients are backgrounded or completely invisible. Yet modern veterinary medicine, in its dominant form of companion animal practice, has become increasingly patient-centred. The modern animal patient is accorded something near full subject status in many veterinary clinical interactions. Embracing this raises issues of how to handle animals in veterinary history. Animals are the recipients of veterinary medicine, they exert agency in the clinic and field, yet they have remained problematical for the historian and sociologist, who have remained anthropocentric in orientation. This paper explores different constructions of the veterinary surgical patient in the 20th century in an attempt to begin examination of veterinary history as an animal-patient history "from below." In doing so, a trajectory of the development of British 20th-century veterinary medicine is presented which suggests the value of minding animals in historical accounts. Further interdisciplinary studies of veterinary procedures and practices are needed in order to foreground animals more and evaluate their subject status within historical and contemporary veterinary medicine.

  7. Assortative mating and differential fertility by phenotype and genotype across the 20th century.

    PubMed

    Conley, Dalton; Laidley, Thomas; Belsky, Daniel W; Fletcher, Jason M; Boardman, Jason D; Domingue, Benjamin W

    2016-06-14

    This study asks two related questions about the shifting landscape of marriage and reproduction in US society over the course of the last century with respect to a range of health and behavioral phenotypes and their associated genetic architecture: (i) Has assortment on measured genetic factors influencing reproductive and social fitness traits changed over the course of the 20th century? (ii) Has the genetic covariance between fitness (as measured by total fertility) and other traits changed over time? The answers to these questions inform our understanding of how the genetic landscape of American society has changed over the past century and have implications for population trends. We show that husbands and wives carry similar loadings for genetic factors related to education and height. However, the magnitude of this similarity is modest and has been fairly consistent over the course of the 20th century. This consistency is particularly notable in the case of education, for which phenotypic similarity among spouses has increased in recent years. Likewise, changing patterns of the number of children ever born by phenotype are not matched by shifts in genotype-fertility relationships over time. Taken together, these trends provide no evidence that social sorting is becoming increasingly genetic in nature or that dysgenic dynamics have accelerated.

  8. Historical evidence that electrification caused the 20th century epidemic of "diseases of civilization".

    PubMed

    Milham, Samuel

    2010-02-01

    The slow spread of residential electrification in the US in the first half of the 20th century from urban to rural areas resulted by 1940 in two large populations; urban populations, with nearly complete electrification and rural populations exposed to varying levels of electrification depending on the progress of electrification in their state. It took until 1956 for US farms to reach urban and rural non-farm electrification levels. Both populations were covered by the US vital registration system. US vital statistics tabulations and census records for 1920-1960, and historical US vital statistics documents were examined. Residential electrification data was available in the US census of population for 1930, 1940 and 1950. Crude urban and rural death rates were calculated, and death rates by state were correlated with electrification rates by state for urban and rural areas for 1940 white resident deaths. Urban death rates were much higher than rural rates for cardiovascular diseases, malignant diseases, diabetes and suicide in 1940. Rural death rates were significantly correlated with level of residential electric service by state for most causes examined. I hypothesize that the 20th century epidemic of the so called diseases of civilization including cardiovascular disease, cancer and diabetes and suicide was caused by electrification not by lifestyle. A large proportion of these diseases may therefore be preventable.

  9. Urban residential refuse composition and generation rates for the 20th century.

    PubMed

    Walsh, Daniel C

    2002-11-15

    Examination of historical data shows that 3.5 x 10(8) tonnes (t) of residential refuse was discarded in New York City (NYC) during the 20th century. Maximum and minimum rates of per capita mass discard of residential refuse during this time are reported in 1940 (940 kg per capita yr(-1)) and 1961, 1963 (320 kg per capita yr(-1)), respectively. Since 1980, per capita residential refuse discard rates have been steady and comparatively low (430 kg per capita yr(-1) +/- 2.5%). Fuel ash accounted for approximately 34% of residential refuse in NYC during the century. A decline of refuse bulk density (as collected) from approximately 500 to 200 kg m(-3) and an increase in refuse organic matter content from 20% to 80% (by mass) is reported between 1920 and 1990 and is due largely to mass fraction reductions forfuel ash and increases for paper and plastic. Approximately 4.9 x 10(8) t of refuse was disposed in NYC during the 20th century (including commercial and residential refuse), representing a total pool of about 8.0 x 10(7) t of organic carbon (as C) that has entered city landfills and incinerators.

  10. Politics and naturalism in the 20th century psychology of Alfred Binet.

    PubMed

    Foschi, Renato; Cicciola, Elisabetta

    2006-11-01

    Alfred Binet is internationally recognized as the "father" of the first intelligence test as well as the most faithful French representative of laboratory experimentalism. A historical analysis of his work is therefore necessary to get to a thorough comprehension of 20th century psychology. The present article, starting from Binet's intellectual path and from the suggestions of the previous historical literature, aims at providing fresh insights into Binet's work by trying to capture the intersections between Binet, his naturalistic culture and the political context in which he worked in the early 20th century, when he actively tried to apply experimental psychology to the pedagogical area. In fact, it is possible to underline, with reference to those years, an evident turn towards applications in Binet's psychological production. The article reconstructs the political and institutional background of Binet's research and shows how the naturalism and experimentalism he promoted were complementary to the solidarist conceptions that were particularly prevalent among those who supported his work during the Third Republic.

  11. The decline of winter monsoon velocity in the South China Sea through the 20th century: Evidence from the Sr/Ca records in corals

    USGS Publications Warehouse

    Liu, Yajing; Peng, Z.; Chen, T.; Wei, G.; Sun, W.; Sun, R.; He, J.; Liu, Gaisheng; Chou, C.-L.; Zartman, R.E.

    2008-01-01

    A modern massive Porites coral was collected from the Longwan Bay (19??20???N, 110??39???E) on the east coast of the Hainan Island, China. The coral was sectioned vertical to the growth axis into discs of double density-bands representing annual growth. The samples were analyzed for the Sr/Ca ratio by inductively coupled plasma atomic emission spectrometry. The history of winter sea-surface temperature (SST) is reconstructed using the Sr/Ca ratio in winter bands of corals. The winter SST at Xisha in the middle of the South China Sea (SCS) is weakly correlated with the instrument-measured winter monsoon velocity (WMV) with a correlation coefficient of 0.19. The winter SST data from corals at Longwan Bay, Hainan, in the northern SCS are moderately correlated with the WMV (r = 0.40). Interestingly we found that the difference of winter SSTs between the two sites (Xisha and Longwan Bay, Hainan) (the X-H index) is significantly negatively correlated with the WMV (r = - 0.73). This negative correlation may be related to the intrusion of the warm Kuroshio Current into the SCS through the Luzon Strait promoted by the strong northeastern monsoon winds in the winter. Using the relationship between our coralline data and observed WMV, the calculated winter monsoon velocity (WMVc) was obtained for 87??years. This data set in combination with the instrument-measured data between 1993 and 1998 generate a record of WMVc for a period of 93??years from 1906 to 1998. The WMVc in the 20th century shows significant interannual and decadal variability with a trend of persistent decline in the whole 20th century at the rate of decrease of - 0.02 (m/s)/a. The lowest wind velocity occurred during the last two decades of the 20th century. The WMVc has decreased significantly by about 30% from the early to the late of 20th century. The 20th century decline of winter monsoon velocity evidenced from the SCS coral records is consistent with the atmosphere-ocean general circulation models

  12. Dynamics of Arctic and Sub-Arctic Climate and Atmospheric Circulation: Diagnosis of Mechanisms and Model Biases Using data Assimilation

    SciTech Connect

    Sumant Nigam

    2013-02-05

    These five publications are summarized: Key role of the Atlantic Multidecadal Oscillation in 20th century drought and wet periods over the Great Plains; A Sub-Seasonal Teleconnection Analysis: PNA Development and Its Relationship to the NAO; AMO's Structure and Climate Footprint in Observations and IPCC AR5 Climate Simulations; The Atlantic Multidecadal Oscillation in 20th Century Climate Simulations: Uneven Progress from CMIP3 to CMIP5; and Tropical Atlantic Biases in CCSM4.

  13. Systematic recover of long high-resolution rainfall time series recorded by pluviographs during the 20th century.

    NASA Astrophysics Data System (ADS)

    Delitala, Alessandro M. S.; Deidda, Roberto; Mascaro, Giuseppe; Piga, Enrico; Querzoli, Giorgio

    2010-05-01

    During most of the 20th century, precipitation has been continuously measured by means of the so-called "pluviographs", i.e. rain gauges including a mechanical apparatus for continuously recording the depth of water from precipitation on specific strip charts, usually on a weekly basis. The signal recorded on such strips was visually examined by trained personnel on a regular basis, in order to extract the daily precipitation totals and the maximum precipitation intensities over short periods (from a few minutes to hours). The rest of the high-resolution information contained in the signal was usually not extracted, except for specific cases. A systematic recovering of the entire information at high temporal resolution contained in these precipitation signals would provide a fundamental database to improve the characterization of historical rainfall climatology during the previous century. The Department of Land Engineering of the University of Cagliari has recently developed and tested an automatic software, based on image analysis techniques, which is able to acquire the scanned images of the pluviograph strip charts, to automatically digitise the signal and to produce a digital database of continuous precipitation records at the highest possible temporal resolution, i.e. 5 to 10 minutes. Along with that, a significant amount of daily precipitation totals from the late 19th and the 20th century, either elaborated from pluviograph strip charts or simply derived from bucket rain gauges, still exists in paper form, but it has never been digitalized. Within a project partly-funded by the Operational Programme of the European Union "Italia-Francia Marittimo", the Regional Environmental Protection Agency of Sardinia and the University of Cagliari will recover both the high-resolution rainfall signals and the older time series of daily totals recorded by a large number of pluviographs belonging to the historical monitoring networks of the island of Sardinia. Such data

  14. A brief history of 20th century dam construction and a look into the future

    NASA Astrophysics Data System (ADS)

    van de Giesen, Nick

    2010-05-01

    In this presentation, an overview is given of global dam building activities in the 20th century. Political, economical and hydrological factors shaped the building of large dams. The development of the relations between these three factors and dam building over time is examined. One can argue whether or not history is simply "one damn thing after another" but the second half of the 20th century suggests that history is at least reflected by the construction of one dam after another. The financial crisis of the 1930's started the first construction wave of large hydropower dams in the United States. This wave continued into the Second World War. During the Cold War, the weapon race between the USA and USSR was accompanied by a parallel neck-and-neck race in dam construction. By the 1970's, dam construction in the USA tapered off, while that in the USSR continued until its political disintegration. In China, we see two spurts in dam development, the first one coinciding with the disastrous Great Leap Forward and the second with the liberalization of the Chinese economy after the fall of the Berlin Wall. Economic and political events thus shaped to an important extent decisions surrounding the construction of large dams. Clearly, there are some hydrological prerequisites for the construction of dams. The six largest dam building nations are USSR, Canada, USA, China, Brazil, and India, all large countries with ample water resources and mountain ranges. Australia has relatively little reservoir storage for the simple fact that most of this country is flat and dry. A few countries have relatively large amounts of reservoir storage. Especially Uganda (Owens Falls), Ghana (Akosombo), and Zimbabwe (Kariba) are examples of small countries where gorges in major rivers were "natural" places for large dams and reservoirs to be built early on. It seems that, deserts aside, the average potential storage capacity lies for most continents around 10 cm or about 50% of the total

  15. Reconstruction and Trend Analysis of Precipitation Over Shasta Dam Watershed based on 20th Century Reanalysis Dataset

    NASA Astrophysics Data System (ADS)

    Diaz, A. J.; Cawthorne, D.; Ishida, K.; Trinh, T. Q.; Kavvas, M. L.

    2016-12-01

    Understanding long-term trends in atmospheric and hydrologic behavior is increasingly being seen as vital to the future well-being of any water management system. Still, the analysis of such trends is hampered by the lack of long period observation data and the uncertainty of future projections. One approach to tackle these problems is the reconstruction of climate information using reanalysis data. In this study an analysis of the historical precipitation trends over Shasta Dam Watershed (SDW) in Northern California was performed. Using the 20th Century Project (20CRv2c) reanalysis dataset and the Weather Research and Forecasting (WRF) model, climate data for the SDW was reconstructed to produce 159 water years (1852-2010) of hourly precipitation data at a 3 km spatial resolution. The model was calibrated and validated against daily and monthly PRISM data with good results, and then analyzed using the Mann-Kendall test to assess the presence of trends over the study period. The results indicate an increase in annual precipitation over the 159 years, as well as an upward trend in the intensity of 6, 12, 24, 48 and 72 hour extreme storms over the same study period. These results both inform long-term planning decisions regarding the future of Shasta Dam and California's water system, and validate a methodology that can be used in data-sparse basins around the world.

  16. Determination of droughts and high floods of the Bermejo River (Argentina) based on documentary evidence (17th to 20th century)

    NASA Astrophysics Data System (ADS)

    Prieto, M. R.; Rojas, F.

    2015-10-01

    This study reconstructs a series of droughts and high flow volumes of the Bermejo River from the 17th to 20th century based on a content analysis of historic documentary evidence, which is calibrated with instrumental climate data. The historic data series shows an increase in the frequency of extraordinarily high waters beginning in the 19th century and a significant decrease in extreme droughts beginning in 1890. The data are compared to variations in the Mendoza River for the same period, which show that there was a long-standing lack of correlation between the rivers.

  17. The history of blood transfusion prior to the 20th century--part 2.

    PubMed

    Learoyd, P

    2012-12-01

    Although there are a number of descriptions of 'blood infusion' in antiquity, it was the publication of the discovery of the circulation of blood in 1628 by William Harvey and the work of Christopher Wren and Robert Boyle in 1663 on the infusion of different materials into dogs that paved the way to the possible practical attempts at actual blood transfusion. Although these early experiments, principally by Richard Lower in England and Jean Denis in France provided valuable information regarding inter-species incompatibility and the problems of blood coagulation, it was not until the work of James Blundell in the early part of the 19th century that blood transfusion was used as a means of blood replacement. However, blood transfusion was not to become an accepted therapeutic possibility until the discovery of practical anticoagulation and the ABO blood groups at the start of the 20th century. © 2012 The Author. Transfusion Medicine © 2012 British Blood Transfusion Society.

  18. Rapid 20th-century increase in coastal upwelling off northwest Africa.

    PubMed

    McGregor, H V; Dima, M; Fischer, H W; Mulitza, S

    2007-02-02

    Near-shore waters along the northwest African margin are characterized by coastal upwelling and represent one of the world's major upwelling regions. Sea surface temperature (SST) records from Moroccan sediment cores, extending back 2500 years, reveal anomalous and unprecedented cooling during the 20th century, which is consistent with increased upwelling. Upwelling-driven SSTs also vary out of phase with millennial-scale changes in Northern Hemisphere temperature anomalies (NHTAs) and show relatively warm conditions during the Little Ice Age and relatively cool conditions during the Medieval Warm Period. Together, these results suggest that coastal upwelling varies with NHTAs and that upwelling off northwest Africa may continue to intensify as global warming and atmospheric CO2 levels increase.

  19. Considerations for estimating the 20th century trend in global mean sea level

    NASA Astrophysics Data System (ADS)

    Hamlington, B. D.; Thompson, P. R.

    2015-05-01

    Recent efforts in reconstructing historical sea level change have led to a range of published estimates for the global mean sea level trend over the last century. Disagreement in these estimates can be attributed to two factors: (1) differences in analysis and/or reconstruction techniques and (2) differences in tide gauge selection and quality control of the data. Here the impact of tide gauge selection is explored by calculating global mean trends using three different tide gauge data sets that have been utilized in recent reconstruction studies. The inclusion of tide gauge records that are affected by unresolved internal variability and/or unaccounted for vertical land motion are found to significantly impact the estimates of the long-term trend in global mean sea level. In conclusion, several guidelines are presented regarding the selection of tide gauges for use in historical reconstructions focused on estimating the 20th century global mean sea level trend.

  20. A personal retrospective on the second half of the 20th century.

    PubMed

    Nicholas Leibovic, K

    2013-06-01

    During the Second World War scientists and engineers were involved as never before in all technical phases of the war effort. It included intelligence, logistics and large scale automated computation. Much of this required team work which led to the adoption of interdisciplinary perspectives and found expression after the war in new fields of enquiry such as cybernetics, biophysics and artificial intelligence. While Europe was recovering from its devastation, the United States entered an unprecedented age of prosperity beginning in the 1940s and 50s. The political and budgetary environment was favorable for scientific research and it was felt in Europe as well as the U.S.A. I discuss some of these conditions and the figures associated with the work that became the foundation for advances throughout the second half of the 20th century and conclude with a few observations on quantitative neuroscience and the problem of representation.

  1. Sellar Region Surgery in Croatia in the First Half of 20th Century

    PubMed Central

    Fatović Ferenčić, Stella; Gnjidić, Živko

    2006-01-01

    We reconstructed the historical development of surgical approaches to the pituitary gland, which were used in Croatia in the first half of the 20th century, on the basis of earliest clinical case reports and descriptions of initial surgical attempts. The first published case report on surgical treatment of acromegaly was described, as well as the review of 11 patients with pituitary disease admitted to the Ophthalmology Clinic in Zagreb in the period 1925-1927. The earliest 5 reports on pituitary surgery dating from 1925 were analyzed to reveal the circumstances that led to the development of transsphenoidal approach as a method of choice in Croatia, when this technique was becoming obsolete in other parts of the world. Frequent modifications of surgical approaches to sellar region have been shown a suitable historical-medical model for analysis of changes in surgical trends. PMID:16625698

  2. Population evolution in 20th-century Easter Island: endogamy and admixture.

    PubMed

    Hernández, M; García-Moro, C; Moral, P; González-Martín, A

    2000-04-01

    We studied the 20th-century evolution of the Rapanui population of Easter Island, the most geographically isolated in the world, to analyze the current process of admixture. Using parochial birth records, we determined origin of the birth parents based on their surnames. The origin of parents reveals two stages of population evolution: endogamy, due to the isolation of the island, but with a strong rejection of isonymous marriages; and admixture, beginning in 1965 with the opening of the island to the rest of the world. We used Lasker's coefficient (Lasker's Ri) and the Shannon-Weaver coefficient of diversity (H) to characterize both stages. The gene flow evaluated from admixture has increased significantly since 1965. Births from exogamous unions represented 3.5% of total births from 1937 to 1965. increased to 43.2% between 1966 and 1980, and constituted 50.8% of all births between 1981 and 1996.

  3. Acceleration of the global coastal sea level rise during the 20th century re-evaluated

    NASA Astrophysics Data System (ADS)

    Bâki Iz, H.

    2017-02-01

    In contrast to some of the recent investigations, this study shows that far less number of tide gauge stations experienced statistically significant accelerations in sea level rise during the 20th century. Twenty-seven tide gauge stations with century long data were analyzed for the presence of an acceleration in global sea level rise using a kinematic model inclusive of a secular trend, acceleration, and compounded periodicities with autocorrelated random effects. Eight out of twenty-seven stations revealed statistically significant but slow sea level rise acceleration (p<0.01) within the 0.01-0.02 mm/yr2 range compared to the sixteen stations with accelerations estimated using the models by the previous investigations,which did not account for the compounded periodicities and autocorrelations in sea level changes.

  4. Six calendar systems in the European history from 18^{th} to 20^{th} Century

    NASA Astrophysics Data System (ADS)

    Theodossiou, Efstratios; Manimanis, Vassilios N.; Dimitrijević, Milan S.

    The following calendar systems, introduced in Europe from 18^{th} to 20^{th} century, which were in use for a shorter or longer period by a larger or smaller community, were reviewed and discussed: The French Revolutionary Calendar, the Theosebic calendar invented by Theophilos Kairis, the Revolutionary Calendar of the Soviet Union (or 'Bolshevik calendar'), the Fascist calendar in Italy and the calendar of the Metaxas dictatorship in Greece before World War II. Also the unique of them, which is still in use, the New Rectified Julian calendar of the Orthodox Church, adopted according to proposition of Milutin Milanković on the Congress of Orthodox Churches in 1923 in Constantinople, is presented and discussed. At the end, difficulties to introduce a new calendar are discussed as well.

  5. A short history of ocean acidification science in the 20th century: a chemist's view

    NASA Astrophysics Data System (ADS)

    Brewer, P. G.

    2013-11-01

    This review covers the development of ocean acidification science, with an emphasis on the creation of ocean chemical knowledge, through the course of the 20th century. This begins with the creation of the pH scale by Sørensen in 1909 and ends with the widespread knowledge of the impact of the "High CO2 Ocean" by then well underway as the trajectory along the IPCC scenario pathways continues. By mid-century the massive role of the ocean in absorbing fossil fuel CO2 was known to specialists, but not appreciated by the greater scientific community. By the end of the century the trade-offs between the beneficial role of the ocean in absorbing some 90% of all heat created, and the accumulation of some 50% of all fossil fuel CO2 emitted, and the impacts on marine life were becoming more clear. This paper documents the evolution of knowledge throughout this period.

  6. A short history of ocean acidification science in the 20th century: a chemist's view

    NASA Astrophysics Data System (ADS)

    Brewer, P. G.

    2013-05-01

    This review covers the development of ocean acidification science, with an emphasis on the creation of ocean chemical knowledge, through the course of the 20th century. This begins with the creation of the pH scale by Sørensen in 1909 and ends with the widespread knowledge of the impact of the "High CO2 Ocean" by then well underway as the trajectory along the IPCC scenario pathways continues. By mid-century the massive role of the ocean in absorbing fossil fuel CO2 was known to specialists, but not appreciated by the greater scientific community. By the end of the century the trade-offs between the beneficial role of the ocean in absorbing some 90% of all heat created, and the accumulation of some 50% of all fossil fuel CO2 emitted, and the impacts on marine life were becoming clear. This paper documents the evolution of knowledge throughout this period.

  7. [Sexual stereotypes of institutional confinement in Quebec, at the turn of the 20th century].

    PubMed

    Thifault, Marie-Claude

    2010-01-01

    This paper concerning the men and women patients of the Hôpital Saint-Jean-de-Dieu investigates gender stereotyping in mental disorders during the late-19th and early-20th centuries through an analysis of quantitative sources from over 8357 admissions. The asylum records (Registre des idiots de la Providence and the medical record, Form C) reveal that there were few differences between the medical diagnoses given and the behaviours of the patients who had been judged insane by their families. Nevertheless, a number of interesting contrasts emerge. The evidence also indicates gender distinctions; in general, the applicants tended to deny feeble-mindedness in men but recognized it as natural in women.

  8. On the unstable ENSO-Western North Pacific Monsoon relation during the 20th Century

    NASA Astrophysics Data System (ADS)

    Vega Martín, Inmaculada; Gallego Puyol, David; Ribera Rodriguez, Pedro; Gómez Delgado, Francisco de Paula; Peña-Ortiz, Cristina

    2017-04-01

    The concept of the Western North Pacific Summer Monsoon (WNPSM) appeared for the first time in 1987. Unlike the Indian Summer Monsoon and the East Asian summer monsoon, the WNPSM is an oceanic monsoon driven essentially by the meridional gradient of sea surface temperature. Its circulation is characterized by a northwest-southeast oriented monsoon trough with intense precipitation and low-level southwesterlies and upper-tropospheric easterlies in the region [100°-130° E, 5°-15°N]. Although this monsoon is mainly oceanic, it modulates the precipitation of densely populated areas such as the Philippines. To date, the WNPSM has been quantified by the so-called Western North Pacific Monsoon Index (WNPMI), an index based on wind anomalies over large domains of the Western Pacific. The requirement of continuous observed wind over remote oceanic areas to compute the WNPMI has limited its availability to the 1949-2014 period. In this work we have extended the index by almost 100 years by using historical observations of wind direction taken aboard ships. Our Western North Pacific Directional Index (WNPDI), is defined as the sum of the persistence of the low-level westerly winds in [5°-15°N, 100°-130°E] and easterly winds in [20°-30°N, 110°-140°E]. The new WNPDI index is highly correlated to the existent WNPMI for the concurrent period (1948-2014). (r=+0.88, p<0.01), indicating that the new approach based in the use of wind direction alone (a variable that can be considered instrumental even before the 20th Century), captures most of the monsoonal signal. Previous studies found that, during the second part of the 20th Century the WNPSM exhibited two basic characteristics: first a large interannual variability and second, a significant relation between the WNPSM and the El Niño/Southern Oscillation (ENSO) in a way in which a strong (weak) WNPSM tends to occur during the El Niño (La Niña) developing year or/and La Niña (El Niño) decaying year. The analysis of

  9. CHANGES in SKIN TANNING ATTITUDES Fashion Articles and Advertisements in the Early 20th Century

    PubMed Central

    Martin, Jo M.; Ghaferi, Jessica M.; Cummins, Deborah L.; Mamelak, Adam J.; Schmults, Chrys D.; Parikh, Mona; Speyer, Lark-Aeryn; Chuang, Alice; Richardson, Hazel V.; Stein, David

    2009-01-01

    Historical reviews suggest that tanning first became fashionable in the 1920s or 1930s. To quantitatively and qualitatively examine changes in tanning attitudes portrayed in the popular women's press during the early 20th century, we reviewed summer issues of Vogue and Harper's Bazaar for the years 1920, 1927, 1928, and 1929. We examined these issues for articles and advertisements promoting skin tanning or skin bleaching and protection. We found that articles and advertisements promoting the fashionable aspects of tanned skin were more numerous in 1928 and 1929 than in 1927 and 1920, whereas those promoting pale skin (by bleaching or protection) were less numerous. These findings demonstrate a clear shift in attitudes toward tanned skin during this period. PMID:19846688

  10. Transformations in understanding the health impacts of air pollutants in the 20th century

    NASA Astrophysics Data System (ADS)

    Brimblecombe, P.

    2009-02-01

    The transformations of air pollution in the 20th century are well known. The century opened with urban atmospheres polluted by the combustion products of burning coal: smoke and sulfur dioxide. At the millennium these pollutants had almost vanished, replaced by the pollutants, both primary and secondary, a function of fossil-fuelled vehicles. However transitions in terms of health outcomes have been equally dramatic. Fine particulate matter causes notable cardiovascular problems such as increased incidence of stroke and heart attack, although the mechanism remains somewhat unclear. Cancer inducing air pollutants remain a concern, but in addition more recently there has been a rising interest in the presence of neurotoxins and endocrine disrupting substances in the environment.

  11. Migration trends in British rural areas from the 18th to the 20th centuries.

    PubMed

    Pooley, C G; Turnbull, J

    1996-09-01

    "Longitudinal residential histories are used to examine the extent to which three rural areas in Britain had distinctive migration histories from the 18th to the 20th centuries. Migration flows into and out of the regions are used to examine the extent to which the regions were integrated into the British migration system, and the relative importance of rural to urban migration is assessed.... Analysis reveals a high degree of short-distance mobility within regions and emphasises the dominance of London in longer-distance migration.... It is also suggested that the role of towns in the migration system has previously been overemphasised, with much migration taking place between small settlements and some movement from large cities to smaller towns and villages.... The analysis challenges some accepted notions about migration in the past, and contributes to the debate about the extent to which British regions became part of a national economic and social system from the 18th century."

  12. Changes in skin tanning attitudes. Fashion articles and advertisements in the early 20th century.

    PubMed

    Martin, Jo M; Ghaferi, Jessica M; Cummins, Deborah L; Mamelak, Adam J; Schmults, Chrys D; Parikh, Mona; Speyer, Lark-Aeryn; Chuang, Alice; Richardson, Hazel V; Stein, David; Liégeois, Nanette J

    2009-12-01

    Historical reviews suggest that tanning first became fashionable in the 1920s or 1930s. To quantitatively and qualitatively examine changes in tanning attitudes portrayed in the popular women's press during the early 20th century, we reviewed summer issues of Vogue and Harper's Bazaar for the years 1920, 1927, 1928, and 1929. We examined these issues for articles and advertisements promoting skin tanning or skin bleaching and protection. We found that articles and advertisements promoting the fashionable aspects of tanned skin were more numerous in 1928 and 1929 than in 1927 and 1920, whereas those promoting pale skin (by bleaching or protection) were less numerous. These findings demonstrate a clear shift in attitudes toward tanned skin during this period.

  13. A brief history of tuberculosis in Iran during the 19th and 20th centuries.

    PubMed

    Azizi, Mohammad Hossein; Bahadori, Moslem

    2011-05-01

    The history of tuberculosis as a worldwide fatal illness traces back to antiquity, a well-known disease in ancient civilizations. However, its causative agent remained unidentified until the last decades of the 19th century, when discovered by Robert Koch. In due course, preparation of the BCG vaccine, application of the Mantoux intradermal diagnostic tuberculosis test and administration of proper antituberculosis medications eventually controlled tuberculosis. However, despite these significant advancements tuberculosis remained uneradicated, particularly in developing countries after the emergence of both multidrug-resistant tuberculosis and HIV co-infection. Presented here, is a brief review of the history of tuberculosis in the world as well as its historical background in Iran, mainly during the 19th and 20th centuries.

  14. Sub-daily extreme events distribution and changes in Northeastern Brazil in the 20th century

    NASA Astrophysics Data System (ADS)

    Basso, R.; Allasia, D.; Tassi, R.; Bayer, D. M.

    2015-06-01

    The regional analysis of extreme hydrological events is connected with the availability of a dense network of rainfall data that is absent or inaccessible in Brazil, especially for sub-daily information. In engineering, extreme events rainfall information is represented by intensity-duration-frequency (IDF) relationships which are the most commonly used tools in water resources engineering for planning and design. Even if the sub-daily information that is included in the relationships is not available, the extreme rainfall information rest in the fundamentals of the IDF. This paper analyzes spatial distribution and track changes in sub-daily precipitation over Northeastern (NE) Brazil. Precipitation was estimated from IDF relationships information in Brazil based in rainfall measured from 1920's to 1950's (but still used in engineering projects) and information from the last half of the 20th century obtained from several IDFs gathered from municipalities' manuals, local symposia and books in many cases not easily obtainable. Results showed an intensification of extreme events in recent years, especially in shorter duration rainfall (less than 12 h). Hourly rainfall is bigger in almost all the Brazilian region, but especially in littoral and Northern portion, however, 12 and 24 h rainfall exhibit increases in the North, but, lower values in the Southern half of the region in concordance with flood changes reported by Milly et al. (2005). Analyzing the ratio between 1 and 24 h rainfall is possible to confirm its increase in all the region, with up to 35% in some areas. These results were able to show insight of sub-daily extreme events changes during 20th century in NE Brazil were previous reports were not found. The results also alerts for the necessity of engineering projects review, as outdated information is still being used for design purposes.

  15. Abrupt and severe 20th Century changes in the fire regimes of southeastern Australia: Evidence from a 3000 year multi-proxy analysis

    NASA Astrophysics Data System (ADS)

    Baker, Patrick; Mooney, Scott; Allen, Kathryn; Willersdorf, Timothy

    2015-04-01

    Fire is the dominant natural disturbance in southeastern Australia. For millennia it has been the driving force shaping terrestrial ecosystems in the region -- simultaneously killing vegetation and initiating regeneration across whole landscapes. Fire regimes across the region are driven by several factors including climate, vegetation, and ignition sources. Humans have been a significant contributing factor to past and present fire regimes. Prior to European settlement in the late 1700s, Aboriginal Australians used frequent, low-intensity fires to manage vegetation across much of the landscape. European settlement led to the displacement of Aboriginal communities and a shift to active fire suppression and control. This changing approach to fire management is widely believed to have initiated a fundamental shift towards extreme, high-intensity fire events as fuel loads increased. In addition, during the 20th Century prolonged periods of warm, dry conditions have occurred with greater frequency and intensity. The relative importance of climate and fire management practices on contemporary fire regimes is vigorously debated in Australia and is directly relevant to land management policies and their implementation. To put the current fire regime into historical context, we used a multi-proxy approach combining palaeo-charcoal and tree-ring analyses to assess how fire regimes have changed over the last 3000 years in the Snowy Mountains region of southeastern Australia. We found almost no evidence of high-intensity fires in the 3000 years that preceded the 20th Century. However, in the mid-20th Century there is a sudden and dramatic increase in the presence of charcoal and the pulsed establishment of trees across the landscape, suggesting a recent shift from low-intensity fires with minimal charcoal signatures to moderate- to high-intensity fires with substantial charcoal inputs. Importantly, the tree-ring data demonstrate that most of these fires were not stand

  16. Storm Surge reconstruction in Southeast Asia with an analysis of changes in extreme events in the 20th Century

    NASA Astrophysics Data System (ADS)

    Cid Carrera, A.; Chambers, D. P.

    2016-12-01

    Extreme sea level events and, specifically storm surges due to the effect of wind and pressure gradients, are a key issue at coastal areas due to its important contribution to flooding and hazards. Coastal zones are particularly vulnerable to climate variability and sea level changes. Understanding how storm surge variability has varied over the last century is important for flooding risk assessment and coastal management. However, some of the most vulnerable areas have few direct observations of sea level in order to perform such an analysis. One is Southeast Asia. Here, we use a multiple linear regression model in order to examine the variability of extreme sea level events in Southeast Asia. The statistical model is calibrated using daily maxima values of non-tidal residuals from the modern tide gauge data (predictand) and daily sea level pressures and gradients from a global atmospheric reanalysis (predictor). Once the statistical model is evaluated, it is used to reconstruct the storm surge variability at specific sites during the last century using the 20th Century Reanalysis products.

  17. Extreme sea storm in the Mediterranean Sea. Trends during the 2nd half of the 20th century.

    NASA Astrophysics Data System (ADS)

    Pino, C.; Lionello, P.; Galati, M. B.

    2009-04-01

    Extreme sea storm in the Mediterranean Sea. Trends during the 2nd half of the 20th century Piero Lionello, University of Salento, piero.lionello@unisalento.it Maria Barbara Galati, University of Salento, mariabarbara.galati@unisalento.it Cosimo Pino, University of Salento, pino@le.infn.it The analysis of extreme Significant Wave Height (SWH) values and their trend is crucial for planning and managing coastal defences and off-shore activities. The analysis provided by this study covers a 44-year long period (1958-2001). First the WW3 (Wave Watch 3) model forced with the REMO-Hipocas regional model wind fields has been used for the hindcast of extreme SWH values over the Mediterranean basin with a 0.25 deg lat-lon resolution. Subsequently, the model results have been processed with an ad hoc software to detect storms. GEV analysis has been perfomed and a set of indicators for extreme SWH have been computed, using the Mann Kendall test for assessing statistical significance of trends for different parameter such as the number of extreme events, their duration and their intensity. Results suggest a transition towards weaker extremes and a milder climate over most of the Mediterranean Sea.

  18. Intrinsic low-frequency variability in ice sheets, glaciers and ocean dynamics and its relation to the observed 20th century sea level rise

    NASA Astrophysics Data System (ADS)

    Dangendorf, Sönke; Richter, Kristin; Marzeion, Ben; Jensen, Jürgen

    2016-04-01

    The observed 20th century sea level rise represents one of the major consequences of anthropogenic climate change. However, superimposed on any anthropogenic trend there are also considerable decadal to centennial signals linked to intrinsic natural variability in the climate system. Here, we systematically analyze the contributions from 18 major glacier regions, the Greenland ice sheet, and ocean dynamics to the observed 20th century sea level rise and provide evidence for significant long-term correlations in each individual component. This intrinsic low frequency variability enhances previous estimates of the causal uncertainties of observed trends (based on the assumption that natural variations do not persist longer than a few years) in sea level by an average factor of 2.3. Gravitational effects and ocean dynamics further lead to regionally varying imprints of low frequency variability. In the Arctic, for instance, the causal uncertainties are even up to 8 times larger than previously thought. This result is consistent with recent findings that beside the anthropogenic signature, a non-negligible fraction of the observed 20th sea level rise still represents a response to pre-industrial natural climate variations such as the Little Ice Age.

  19. High GUD Incidence in the Early 20th Century Created a Particularly Permissive Time Window for the Origin and Initial Spread of Epidemic HIV Strains

    PubMed Central

    de Sousa, João Dinis; Müller, Viktor; Lemey, Philippe; Vandamme, Anne-Mieke

    2010-01-01

    The processes that permitted a few SIV strains to emerge epidemically as HIV groups remain elusive. Paradigmatic theories propose factors that may have facilitated adaptation to the human host (e.g., unsafe injections), none of which provide a coherent explanation for the timing, geographical origin, and scarcity of epidemic HIV strains. Our updated molecular clock analyses established relatively narrow time intervals (roughly 1880–1940) for major SIV transfers to humans. Factors that could favor HIV emergence in this time frame may have been genital ulcer disease (GUD), resulting in high HIV-1 transmissibility (4–43%), largely exceeding parenteral transmissibility; lack of male circumcision increasing male HIV infection risk; and gender-skewed city growth increasing sexual promiscuity. We surveyed colonial medical literature reporting incidences of GUD for the relevant regions, concentrating on cities, suffering less reporting biases than rural areas. Coinciding in time with the origin of the major HIV groups, colonial cities showed intense GUD outbreaks with incidences 1.5–2.5 orders of magnitude higher than in mid 20th century. We surveyed ethnographic literature, and concluded that male circumcision frequencies were lower in early 20th century than nowadays, with low rates correlating spatially with the emergence of HIV groups. We developed computer simulations to model the early spread of HIV-1 group M in Kinshasa before, during and after the estimated origin of the virus, using parameters derived from the colonial literature. These confirmed that the early 20th century was particularly permissive for the emergence of HIV by heterosexual transmission. The strongest potential facilitating factor was high GUD levels. Remarkably, the direct effects of city population size and circumcision frequency seemed relatively small. Our results suggest that intense GUD in promiscuous urban communities was the main factor driving HIV emergence. Low circumcision rates

  20. Quantifying the role of fire in the Earth system - Part 2: Impact on the net carbon balance of global terrestrial ecosystems for the 20th century

    SciTech Connect

    Li, Fang; Bond-Lamberty, Benjamin; Levis, Samuel

    2014-03-07

    Fire is the primary terrestrial ecosystem disturbance agent on a global scale. It affects carbon balance of global terrestrial ecosystems by emitting carbon to atmosphere directly and immediately from biomass burning (i.e., fire direct effect), and by changing net ecosystem productivity and land-use carbon loss in post-fire regions due to biomass burning and fire-induced vegetation mortality (i.e., fire indirect effect). Here, we provide the first quantitative assessment about the impact of fire on the net carbon balance of global terrestrial ecosystems for the 20th century, and investigate the roles of fire direct and indirect effects. This study is done by quantifying the difference between the 20th century fire-on and fire-off simulations with NCAR community land model CLM4.5 as the model platform. Results show that fire decreases net carbon gain of the global terrestrial ecosystems by 1.0 Pg C yr-1 average across the 20th century, as a results of fire direct effect (1.9 Pg C yr-1) partly offset by indirect effect (-0.9 Pg C yr-1). Fire generally decreases the average carbon gains of terrestrial ecosystems in post-fire regions, which are significant over tropical savannas and part of forests in North America and the east of Asia. The general decrease of carbon gains in post-fire regions is because fire direct and indirect effects have similar spatial patterns and the former (to decrease carbon gain) is generally stronger. Moreover, the effect of fire on net carbon balance significantly declines prior to ~1970 with trend of 8 Tg C yr-1 due to increasing fire indirect effect and increases afterward with trend of 18 Tg C yr-1 due to increasing fire direct effect.

  1. The Evolution of the Surgical Treatment of Sports Injuries in the 20th Century: A Historical Perspective.

    PubMed

    Konstantinos, Markatos; Georgios, Karaoglanis; Konstantinos, Saropoulos; Georgios, Tzagkarakis

    2016-10-01

    Sports injuries have been a major issue in medicine, surgery, and especially in orthopedics since the classical antiquity era. The 20th century, with its progress and innovations, changed the general concept of treating these injuries forever. The purpose of this review is to show how innovations in surgery in the 20th century changed the rationale of treating sports injuries. In this historical review, we present innovations concerning fracture treatment, spine injury treatment, and anterior cruciate ligament reconstruction related to sports injuries. In addition, we present and record those surgical techniques and the pioneer surgeons who first used them.

  2. The distribution of an illustrated timeline wall chart and teacher's guide of 20th century physics

    SciTech Connect

    Schwartz, Brian

    2000-12-26

    The American Physical Society's part of its centennial celebration in March of 1999 decided to develop a timeline wall chart on the history of 20th century physics. This resulted in eleven consecutive posters, which when mounted side by side, create a 23-foot mural. The timeline exhibits and describes the millstones of physics in images and words. The timeline functions as a chronology, a work of art, a permanent open textbook, and a gigantic photo album covering a hundred years in the life of the community of physicists and the existence of the American Physical Society. Each of the eleven posters begins with a brief essay that places a major scientific achievement of the decade in its historical context. Large portraits of the essays' subjects include youthful photographs of Marie Curie, Albert Einstein, and Richard Feynman among others, to help put a face on science. Below the essays, a total of over 130 individual discoveries and inventions, explained in dated text boxes with accompanying images, form the backbone of the timeline. For ease of comprehension, this wealth of material is organized into five color-coded story lines the stretch horizontally across the hundred years of the 20th century. The five story lines are: Cosmic Scale, relate the story of astrophysics and cosmology; Human Scale, refers to the physics of the more familiar distances from the global to the microscopic; Atomic Scale, focuses on the submicroscopic world of atoms, nuclei and quarks; Living World, chronicles the interaction of physics with biology and medicine; Technology, traces the applications of physic to everyday living. Woven into the bottom border of the timeline are period images of significant works of art, architecture, and technological artifacts such as telephones, automobiles, aircraft, computers, and appliances. The last poster, covering the years since 1995, differs from the others. Its essay concerns the prospect for physics into the next century, and is illustrated

  3. Santorini Volcano's 20th Century Eruptions: A Combined Petrogenetical, Volcanological, Sociological and Environmental Study

    NASA Astrophysics Data System (ADS)

    Drymoni, Kyriaki; Magganas, Andreas; Pomonis, Panagiotis

    2014-05-01

    Santorini, the famous stratovolcano in the Aegean Sea, erupted three time periods during the 20th century (1925-1928, 1939-1941, 1950) and since then remains dormant. This study tried to combine and evaluate new and published volcanological, petrological, geochemical, environmental and sociological data of these three phases of Santorini's activity, which practically restricted to the caldera center on the Nea Kameni Islet. After field work on the formed dacite flows, pyroclastics and domes, representative rock samples and enclaves were collected and investigated for their texture, physical parameters, mineralogy and chemical composition by polarizing light microscope, scanning electron microscope (SEM-EDS), XRD, Raman spectroscopy and ICP-MS. The petrogenetic evaluation of the data obtained suggests slight but significant changes in the solid and aerial phases produced during the three explosion stages, which can be attributed to minor variations in the magmatic differentiation and magma chamber physicochemical conditions. These variations were also expressed by decrease of duration and intensity of the eruptions, as well as in their volume of ejecta and lava. Probably, the subsequent relatively long dormant period of the volcano is also related to this tension of decrease. The first compared results were collected from scientific literature, old photos as well as local and regional press and state documents from the different periods of volcanism, record the past hazard case scenarios and civil defense planning of the individual eruptions. As part of the disaster management a pilot survey, in which personal interviews with aged local islanders that were eye-witnesses of the events and elderly people or tourists that they indirectly experienced or have heard about them, was also conducted. This event-tracing, along with air pollution software models using volcanological data have shown the social impacts and the environmental consequences of the volcanic

  4. Increasing cloud cover in the 20th century: review and new findings in Spain

    NASA Astrophysics Data System (ADS)

    Sanchez-Lorenzo, A.; Calbó, J.; Wild, M.

    2012-04-01

    Visual observations of clouds have been performed since the establishment of meteorological observatories during the early instrumental period, and have become more systematic and reliable after the mid-19th century due to the establishment of the first national weather services. During the last decades a large number of studies have documented the trends of the total cloud cover (TCC) and cloudy types; most of these studies are focused on the trends since the second half of the 20th century. Due to the lower reliability of former observations, and the fact that most of this data is not accessible in digital format, there is a lack of studies focusing on the trends of cloudiness since the mid-19th century. In the first part, this work attempts to review the previous studies analyzing TCC changes with information covering at least the first half of the 20th century. Then, the study analyses a database of cloudiness observations in Southern Europe (Spain) since the second third of the 19th century. Specifically, monthly TCC series were reconstructed since 1866 by means of a so-called parameter of cloudiness, calculated from the number of cloudless and overcast days. This estimated TCC series show a high interannual and decadal correlation with the observed TCC series originally measured in oktas. After assessing the temporal homogeneity of the estimated TCC series, the mean annual and seasonal series for the whole of Spain and several subregions were calculated. The mean annual TCC shows a general tendency to increase from the beginning of the series until the 1960s; at this point, the trend becomes negative. The linear trend for the annual mean series, estimated over the 1866-2010 period, is a highly remarkable (and statistically significant) increase of +0.44% per decade, which implies an overall increase of more than +6% during the analyzed period. These results are in line with the major part of the previous trends observed at many areas of the World, especially

  5. Increasing cloud cover in the 20th century: review and new findings in Spain

    NASA Astrophysics Data System (ADS)

    Sanchez-Lorenzo, A.; Calbó, J.; Wild, M.

    2012-07-01

    Visual observations of clouds have been performed since the establishment of meteorological observatories during the early instrumental period, and have become more systematic and reliable after the mid-19th century due to the establishment of the first national weather services. During the last decades a large number of studies have documented the trends of the total cloud cover (TCC) and cloudy types; most of these studies focus on the trends since the second half of the 20th century. Due to the lower reliability of former observations, and the fact that most of this data is not accessible in digital format, there is a lack of studies focusing on the trends of cloudiness since the mid-19th century. In the first part, this work attempts to review previous studies analyzing TCC changes with information covering at least the first half of the 20th century. Then, the study analyses a database of cloudiness observations in Southern Europe (Spain) since the second half of the 19th century. Specifically, monthly TCC series were reconstructed since 1866 by means of a so-called parameter of cloudiness, calculated from the number of cloudless and overcast days. These estimated TCC series show a high interannual and decadal correlation with the observed TCC series originally measured in oktas. After assessing the temporal homogeneity of the estimated TCC series, the mean annual and seasonal series for the whole of Spain and several subregions were calculated. The mean annual TCC shows a general tendency to increase from the beginning of the series until the 1960s; at this point, the trend becomes negative. The linear trend for the annual mean series, estimated over the 1866-2010 period, is a highly remarkable (and statistically significant) increase of +0.44% per decade, which implies an overall increase of more than +6% during the analyzed period. These results are in line with the majority of the trends observed in many areas of the world in previous studies, especially

  6. Reducing Uncertainties in Future Climate Projections by Quantifying Human COntributions to 20th Century Climate Change

    SciTech Connect

    Gabriele Hegerl and IDAG members

    2011-07-31

    This report focuses on the period to 2010 including, after which the new round of the International Detection and Attribution group, led by Claudia Tebaldi, started. In 2011, some final work on report has been done, and outstanding tasks completed. However, most participants are now working on the new grant and hence the citations and work reported is focusing largely on the regular grant period.

  7. Impacts of the EA and SCA patterns on the 20th century NAO-winter precipitation relationship in Europe

    NASA Astrophysics Data System (ADS)

    Comas-Bru, Laia; McDermott, Frank

    2013-04-01

    Much of the 20th century multi-decadal variability in the NAO-winter precipitation relationship over the N. Atlantic / European sector can be ascribed to the combined effects of the North Atlantic Oscillation (NAO) and either the East Atlantic pattern (EA) or the Scandinavian pattern (SCA). The NAO, EA and SCA indices employed here are defined as the three leading vectors of the cross-correlation matrix calculated from monthly sea-level pressure anomalies for 138 complete winters from the 20CRv2 dataset (Compo et al., 2011). Winter precipitation data over Europe for the entire 20th century is derived from the high resolution CRU-TS3.1 climate dataset (Mitchell and Jones, 2005). Here we document for the first time, that different NAO/EA and NAO/SCA combinations systematically influence winter precipitation conditions in Europe as a consequence of NAO dipole migrations. We find that the zero-correlated line of the NAO-winter precipitation relationship migrates southwards when the EA is in the opposite phase to the NAO. This can be related to a south-westwards migration of the NAO dipole under these conditions, as shown by teleconnectivity maps. Similarly, a clockwise movement of the NAO-winter climate correlated areas occurs when the phase of the SCA is opposite to that of the NAO, reflecting a clockwise movement of the NAO dipole under these conditions. An important implication of these migrations is that they influence the spatial and temporal stationarity of climate-NAO relationships. As a result, the link between winter precipitation patterns and the NAO is not straightforward in some regions such as the southern UK, Ireland and France. For instance, much of the inter-annual variability in the N-S winter precipitation gradient in the UK, originally attributed to inter-annual and inter-decadal variability of the NAO, reflects the migration of the NAO dipole, linked to linear combinations of the NAO and the EA. Our results indicate that when the N-S winter

  8. The 20th century transitions in basic and extreme monsoon rainfall indices in India: Comparison of the ETCCDI indices

    NASA Astrophysics Data System (ADS)

    Panda, Dileep K.; Panigrahi, P.; Mohanty, S.; Mohanty, R. K.; Sethi, R. R.

    2016-11-01

    The mean and extreme matrices of the monsoon rainfall in India not only play an important role in depicting the global monsoon climate, but also their spatiotemporal patterns influence the socio-economic profile of a major proportion of the country's huge population. Given the reported conflicting trends at the global and national scales, the present study investigates the 20th century (1901-2004) changes in monsoon rainfall of India, particularly focusing the indices developed by the Expert Team on Climate Change Detection and Indices (ETCCDI) to facilitate a global comparison. Result of this comprehensive analysis, which includes the response of fifteen indices over two study periods (i.e., 1901-1940 and 1961-2004), indicates clear signals of change with respect to the period and region of study and the choice of the ETCCDI indices. While wet day frequency, low-to-moderate events and consecutive wet days (CWD) exhibit a prominent transition from a pre-1940 wetting to a post-1960 drying tendency over a large part of the central-north India (CNI), both the wet and dry extremes have occurred in a spatially less consistent manner during the recent decades. For consecutive dry days (CDD), the reported less clear global signals could be related to the timescale of analysis, as our sub-seasonal scale results display consistent changes compared to that of the seasonal and annual scales. The Palmer Drought Severity Index (PDSI) provides clear indications of a post-1960 non-stationarity, showing changes in the mean as well as variance. Based on the partial Mann-Kendall test (PMK), some of the identified rainfall trends during 1961-2004 are found to be influenced more by the tropical Indian Ocean sea surface temperatures than the El Niño-Southern Oscillation index. These results have important implications for formulating the water resource management strategy, particularly over the drying central and northern parts of the country.

  9. High-resolution record of pyrogenic polycyclic aromatic hydrocarbon deposition during the 20th century.

    PubMed

    Lima, Ana Lúcia C; Eglinton, Timothy I; Reddy, Christopher M

    2003-01-01

    A high-resolution record of polycyclic aromatic hydrocarbon (PAH) deposition in Rhode Island over the past approximately 180 years was constructed using a sediment core from the anoxic Pettaquamscutt River basin. The record showed significantly more structure than has hitherto been reported and revealed four distinct maxima in PAH flux. The characteristic increase in PAH flux at the turn of the 20th century was captured in detail, leading to an initial maximum prior to the Great Depression. The overall peak in PAH flux in the 1950s was followed by a maximum that immediately preceded the 1973 Organization of Petroleum Exporting Countries (OPEC) oil embargo. During the most recent portion of the record, an abrupt increase in PAH flux between 1996 and 1999 has been found to follow a period of near constant fluxes. Because source-diagnostic ratios indicate that petrogenic inputs are minor throughout the record, these trends are interpreted in terms of past variations in the magnitude and type of combustion processes. For the most recent PAH maximum, energy consumption data suggest that diesel fuel combustion, and hence traffic of heavier vehicles, is the most probable cause for the increase in PAH flux. Systematic variations in the relative abundance of individual PAHs in conjunction with the above changes in flux are interpreted in relation to the evolution of combustion processes. Coronene, retene, and perylene are notable exceptions, exhibiting unique down-core profiles.

  10. [Pollock, Warhol, Basquiat, Haring 20th century American painters from a psychological perspective].

    PubMed

    Petôvári, Csaba

    2010-01-01

    Pollock, Warhol, Basquiat and Haring made an international reputation for themselves with their art foremost of the American artists of the 20th century, and became pop cultural icons for the man in the street and for the media as well. Accordingly to the habits of the consumer society their art and even themselves become product and consumer's goods. Their not mistaken, individual style - which also became their trademark - makes that possible. The connection between the four artists is that each of them had a dependent personality, their fine art activity was arguable in their period, and after all themselves and his artworks get into the increased attention of the media. These four artists embody the brand-new artist type, who steps into a star status. Besides the artworks the artist also get into the focus of interest. Through psychological aspect their artworks tell a lot about their way of life, their personality, and the social estate around them. Four of them were catalysts, they set new art trends. The influence of Basquiat and Haring stretched over to the 21st century, and keeps going in the graffiti street-art which gets into the "high art" at last, and captivates the art galleries and critics as well.

  11. A history of leprosy in Iran during the 19th and 20th centuries.

    PubMed

    Azizi, Mohammad Hossein; Bahadori, Moslem

    2011-11-01

    From ancient time leprosy has been regarded as a terrifying, stigmatized disease; nevertheless, its cause remained unidentified up to the late 19th century. For centuries numerous leprosy victims worldwide suffered from its morbidity and were socially isolated. The afflicted individuals were segregated because they were considered 'unclean' and had to live in leper colonies, generally under very poor conditions. Physicians believed that leprosy was an incurable, highly contagious, and hereditary disease. In 1873 the Norwegian physician, Gerhard Armauer Hansen (1841-1912), ended the myth of leprosy and discovered its causative agent, known as Mycobacterium leprae. Hansen's discovery was a great triumph in the fight against leprosy. In the 1930's, the first effective antileprosy drug, dapsone, was introduced and in the early 1980's multi-drug therapy was popularized because of high efficacy in resistant cases. Here, we have presented a brief look at the history of leprosy in the world with special focus on the historical account of leprosy in Iran, particularly during the 19th and 20th centuries.

  12. Lake sedimentary DNA accurately records 20(th) Century introductions of exotic conifers in Scotland.

    PubMed

    Sjögren, Per; Edwards, Mary E; Gielly, Ludovic; Langdon, Catherine T; Croudace, Ian W; Merkel, Marie Kristine Føreid; Fonville, Thierry; Alsos, Inger Greve

    2017-01-01

    Sedimentary DNA (sedDNA) has recently emerged as a new proxy for reconstructing past vegetation, but its taphonomy, source area and representation biases need better assessment. We investigated how sedDNA in recent sediments of two small Scottish lakes reflects a major vegetation change, using well-documented 20(th) Century plantations of exotic conifers as an experimental system. We used next-generation sequencing to barcode sedDNA retrieved from subrecent lake sediments. For comparison, pollen was analysed from the same samples. The sedDNA record contains 73 taxa (mainly genus or species), all but one of which are present in the study area. Pollen and sedDNA shared 35% of taxa, which partly reflects a difference in source area. More aquatic taxa were recorded in sedDNA, whereas taxa assumed to be of regional rather than local origin were recorded only as pollen. The chronology of the sediments and planting records are well aligned, and sedDNA of exotic conifers appears in high quantities with the establishment of plantations around the lakes. SedDNA recorded other changes in local vegetation that accompanied afforestation. There were no signs of DNA leaching in the sediments or DNA originating from pollen.

  13. Quantifying the quiet epidemic: Diagnosing dementia in late 20(th)-century Britain.

    PubMed

    Wilson, Duncan

    2014-12-01

    During the late 20(th) century numerical rating scales became central to the diagnosis of dementia and helped transform attitudes about its causes and prevalence. Concentrating largely on the development and use of the Blessed Dementia Scale, I argue that rating scales served professional ends during the 1960s and 1970s. They helped old age psychiatrists establish jurisdiction over conditions such as dementia and present their field as a vital component of the welfare state, where they argued that 'reliable modes of diagnosis' were vital to the allocation of resources. I show how these arguments appealed to politicians, funding bodies and patient groups, who agreed that dementia was a distinct disease and claimed research on its causes and prevention should be designated 'top priority'. But I also show that worries about the replacement of clinical acumen with technical and depersonalized methods, which could conceivably be applied by anyone, led psychiatrists to stress that rating scales had their limits and could be used only by trained experts.

  14. Cancer survival in England and Wales at the end of the 20th century

    PubMed Central

    Rachet, B; Woods, L M; Mitry, E; Riga, M; Cooper, N; Quinn, M J; Steward, J; Brenner, H; Estève, J; Sullivan, R; Coleman, M P

    2008-01-01

    Survival has risen steadily since the 1970s for most cancers in adults in England and Wales, but persistent inequalities exist between those living in affluent and deprived areas. These differences are not seen for children. For many of the common adult cancers, these inequalities in survival (the ‘deprivation gap') became more marked in the 1990s. This volume presents extended analyses of survival for adults diagnosed during the 14 years 1986–1999 and followed up to 2001, including trends in overall survival in England and Wales and trends in the deprivation gap in survival. The analyses include individual tumour data for 2.2 million cancer patients. This article outlines the structure of the supplement – an article for each of the 20 most common cancers in adults, followed by an expert commentary from one of the leading UK clinicians specialising in malignancies of that organ or system. The available data, quality control and methods of analysis are described here, rather than repeated in each of the 20 articles. We open the discussion between clinicians and epidemiologists on how to interpret the observed trends and inequalities in cancer survival, and we highlight some of the most important contrasts in these very different points of view. Survival improved substantially for adult cancer patients in England and Wales up to the end of the 20th century. Although socioeconomic inequalities in survival are remarkably persistent, the overall patterns suggest that these inequalities are largely avoidable. PMID:18813248

  15. Historical documents on epilepsy: From antiquity through the 20th century.

    PubMed

    Panteliadis, Christos P; Vassilyadi, Photios; Fehlert, Julia; Hagel, Christian

    2017-02-26

    Historical documents dating back almost 4500years have alluded to the condition of epilepsy, describing signs and symptoms that are well-known today. Epilepsy was thought to be a mystical disorder by almost all Ancient cultures, including the Babylonians, Egyptians, Greeks, Indians, Iranians and Chinese. Hippocrates was the first to de-mystify the condition of epilepsy, providing a more scientific approach to the condition. As the signs and symptoms of epilepsy occurred without an obvious cause, the idea stood that it was a mystical phenomenon of divine punishment. This portrayal persisted through the early centuries of the common era, including the Middle Ages. It was not until the 16th and 17th century that Paracelsus, le Pois and Sylvius started to investigate internal causes for epilepsy. By the beginning of the 18th century, the general opinion on epilepsy was that it was an idiopathic disease residing in the brain and other inner organs. This resulted in Tissot writing the first modern book on epilepsy. Research continued in the 19th century with Jackson describing different types of seizures and many researchers showing interest in electroencephalography (EEG). The 20th century saw more detailed research being done on epilepsy and EEG, in addition to the establishment of many epilepsy-associated medical societies. The goal of this historical documentation is to provide an overview of the most important milestones in the history of epilepsy.

  16. Reappraisal of the 20th-century version of amino acid metabolism.

    PubMed

    Katagiri, Masayuki; Nakamura, Masahiko

    2003-12-05

    In this article, we advocate the radical revision of the 20th-century version of amino acid metabolism as follows. (1) Classic studies on the incorporation of [15N]ammonia into glutamate, once considered to be an epoch-making event, are not distinctive proof of the ability of animals to utilize ammonia for the synthesis of alpha-amino nitrogen. (2) Mammalian glutamate dehydrogenase has been implicated to function as a glutamate-synthesizing enzyme albeit lack of convincing proof. This enzyme, in combination with aminotransferases, is now known to play an exclusive role in the metabolic removal of amino nitrogen and energy production from excess amino acids. (3) Dr. William C Rose's "nutritionally nonessential amino acids" are, of course, essential in cellular metabolism; the nutritional nonessentiality is related to their carbon skeletons, many of which are intermediates of glycolysis or the TCA cycle. Obviously, the prime importance of amino acid nutrition should be the means of obtaining amino nitrogen. (4) Because there is no evidence of the presence of any glutamate-synthesizing enzymes in mammalian tissues, animals must depend on plants and microorganisms for preformed alpha-amino nitrogen. This is analogous to the case of carbohydrates. (5) In contrast, individual essential amino acids, similar to vitamins and essential fatty acids, should be considered important nutrients that must be included regularly in sufficient amounts in the diet.

  17. Breast cancer: from the earliest times through to the end of the 20th century.

    PubMed

    Ekmektzoglou, Konstantinos A; Xanthos, Theodoros; German, Vasilios; Zografos, Georgios C

    2009-07-01

    Breast cancer is a daunting disease and constitutes a continuing medical health problem through the ages for millions of women worldwide. Physicians, from the early periods of recorded history have tried to heal breast cancer patients, with results that were fairly promising at times and disappointing at others. The science of medicine evolved through the ages under the careful scrutiny and critical thought of the many prominent scholars and researchers of their times who constantly added to the therapeutic armamentarium. Surgeons described new therapeutic approaches, and anatomists, through their elaborate descriptions, added useful insights on the art of healing. Theories about the origin of cancer change as new scientific data are presented and validated. Although the Middle Ages hindered temporarily any progress in the field of medicine, the Renaissance became the vaulting horse for science in its broadest sense. However, it was not until the 19th century, with the discovery of anesthesia, the introduction of antisepsis, and the establishment of microscopy that giant scientific leaps in the field of breast cancer treatment occurred. The 20th century with the development of chemotherapy and radiation and the undertaking of numerous clinical trials offered new insights regarding breast cancer management. This article attempts a historical journey through the ages unfolding the problem of breast cancer through the different eras.

  18. René leriche and the development of 20th century surgery

    PubMed Central

    IONCIOAIA, BOGDAN; BUD, IOAN TEODOR; MURESAN, MIRCEA

    2016-01-01

    René Leriche (1879–1955) was a 20th century French surgeon generally known in medicine for the syndrome that carries his name, namely the Leriche syndrome in the aorto-iliac occlusive disease. This paper is published to mark the commemoration of 60 year since Leriche’s death. Although Dr. Leriche’s legacy resides in the domain of vascular medicine, his research enclosed bone pathology and surgical management of pain. Having his surgical training done under professors Mathieu Jaboulay and Antonin Poncet, his friendship and association with Alexis Carrel and William Halsted have contributed to René Leriche’s development as a surgeon, researcher and thinker. Following the footsteps of his mentors, he produced outstanding clinical and academic work which had earned him a good reputation among his students and colleagues. Surgeons such as Jean Kunlin, Jao Cid dos Santos, Michael DeBakey, René Fontaine and others came to study and learn from him. These future generations of surgeons would themselves bring much contribution to the understanding and treatment of vascular diseases and medicine in general. René Leriche pioneered medicine with his research and ideas. His assiduous work of teaching, research and clinical practice made his influence last to our present. PMID:27004042

  19. Stationarity analysis of historical flood series in France and Spain (14th-20th centuries)

    NASA Astrophysics Data System (ADS)

    Barriendos, M.; Coeur, D.; Lang, M.; Llasat, M. C.; Naulet, R.; Lemaitre, F.; Barrera, A.

    Interdisciplinary frameworks for studying natural hazards and their temporal trends have an important potential in data generation for risk assessment, land use planning, and therefore the sustainable management of resources. This paper focuses on the adjustments required because of the wide variety of scientific fields involved in the reconstruction and characterisation of flood events for the past 1000 years. The aim of this paper is to describe various methodological aspects of the study of flood events in their historical dimension, including the critical evaluation of old documentary and instrumental sources, flood-event classification and hydraulic modelling, and homogeneity and quality control tests. Standardized criteria for flood classification have been defined and applied to the Isère and Drac floods in France, from 1600 to 1950, and to the Ter, the Llobregat and the Segre floods, in Spain, from 1300 to 1980. The analysis on the Drac and Isère data series from 1600 to the present day showed that extraordinary and catastrophic floods were not distributed uniformly in time. However, the largest floods (general catastrophic floods) were homogeneously distributed in time within the period 1600-1900. No major flood occurred during the 20th century in these rivers. From 1300 to the present day, no homogeneous behaviour was observed for extraordinary floods in the Spanish rivers. The largest floods were uniformly distributed in time within the period 1300-1900, for the Segre and Ter rivers.

  20. [Evolution of surgical education through the 20th Century into the 21st Century.

    PubMed

    Dudrick, Stanley J

    2011-01-01

    An abridged overview of the development of surgery and early surgical education, training and practice is presented, beginning in colonial America in the 18th century, extending throughout the 19th century, evolving rapidly during the 20th century, and progressing into the first decade of the 21st century. The metamorphosis and transformation of surgery training programs in the United States are described and discussed, together with some of the most relevant rationale and justifications for the many changes introduced, established, mandated and in progress. The current accreditation requirements, oversight, and governance of general surgery training programs; the incorporation of multiple technical and technological advances into general surgical practice; the addition of required training modules and systems to the programs; and their secondary implications, consequences, and impact upon the programs, are presented. These include financial and other resource impediments, the 80-h work week implications and constraints, the technological explosion, the demands of the required expanded general surgical curriculum and operative case experience, the continued erosion of general surgery by surgical and medical specialists, the increasing workload coupled with decreasing reimbursement for surgeons and their services; and the challenges and difficulties of amalgamating all of these confounding or conflicting factors into an effective and viable general surgery program. Finally, some of the personal insights, opinions, experiences, and philosophy of the author are incorporated into the narrative.

  1. [Hoshi Pharmaceutical Company and Korea in the early half of the 20th century].

    PubMed

    Misawa, Miwa; Chiba, Yoshihiko; Ushikubo, Hiroko

    2008-01-01

    Hajime Hoshi, the founder of Hoshi Pharmaceutical Company and Hoshi University, was called "the medicine manufacturing king of Asia." He played active parts in the world including the USA, Europe, Asia and South America. In the present study, we investigated the footprint of brisk activities of Hajime Hoshi and Hoshi Pharmaceutical Company in terms of relevance to Korea in the early half of the 20th century, and considered their historical implications. He built a large pharmacy store chain network throughout the Korean Peninsula, appealing to customers with a family-like intimateness and providing good drugs to Korean people. His activities took the initiative at a time far earlier than other Japanese drug companies. Furthermore, Hoshi Pharmaceutical School in Japan, which was founded by him, educated a number of Korean-based pharmacy store owners and their children. After graduating and going back to Korea, they played a key role in the Hoshi chain-store network. It was at the time of Japan's annexation of Korea, but Hoshi's work can be called pioneering activities that will always be remembered in the Korean history of pharmacy.

  2. Age-specific measles mortality during the late 19th-early 20th centuries.

    PubMed

    Shanks, G D; Waller, M; Briem, H; Gottfredsson, M

    2015-12-01

    Measles mortality fell prior to the introduction of vaccines or antibiotics. By examining historical mortality reports we sought to determine how much measles mortality was due to epidemiological factors such as isolation from major population centres or increased age at time of infection. Age-specific records were available from Aberdeen; Scotland; New Zealand and the states of Australia at the end of the 19th and beginning of the 20th centuries. Despite the relative isolation of Australia, measles mortality was concentrated in very young children similar to Aberdeen. In the more isolated states of Tasmania, Western Australia and Queensland adults made up 14-15% of measles deaths as opposed to 8-9% in Victoria, South Australia and New South Wales. Mortality in Iceland and Faroe Islands during the 1846 measles epidemic was used as an example of islands isolated from respiratory pathogens. The transition from crisis mortality across all ages to deaths concentrated in young children occurred prior to the earliest age-specific mortality data collected. Factors in addition to adult age of infection and epidemiological isolation such as nutritional status and viral virulence may have contributed to measles mortality outcomes a century ago.

  3. Molecular evolution of Zika virus during its emergence in the 20(th) century.

    PubMed

    Faye, Oumar; Freire, Caio C M; Iamarino, Atila; Faye, Ousmane; de Oliveira, Juliana Velasco C; Diallo, Mawlouth; Zanotto, Paolo M A; Sall, Amadou Alpha

    2014-01-01

    Zika virus (ZIKV) is a mosquito-borne flavivirus first isolated in Uganda in 1947. Although entomological and virologic surveillance have reported ZIKV enzootic activity in diverse countries of Africa and Asia, few human cases were reported until 2007, when a Zika fever epidemic took place in Micronesia. In the context of West Africa, the WHO Collaborating Centre for Arboviruses and Hemorrhagic Fever at Institut Pasteur of Dakar (http://www.pasteur.fr/recherche/banques/CRORA/) reports the periodic circulation of ZIKV since 1968. Despite several reports on ZIKV, the genetic relationships among viral strains from West Africa remain poorly understood. To evaluate the viral spread and its molecular epidemiology, we investigated 37 ZIKV isolates collected from 1968 to 2002 in six localities in Senegal and Côte d'Ivoire. In addition, we included strains from six other countries. Our results suggested that these two countries in West Africa experienced at least two independent introductions of ZIKV during the 20(th) century, and that apparently these viral lineages were not restricted by mosquito vector species. Moreover, we present evidence that ZIKV has possibly undergone recombination in nature and that a loss of the N154 glycosylation site in the envelope protein was a possible adaptive response to the Aedes dalzieli vector.

  4. René leriche and the development of 20(th) century surgery.

    PubMed

    Ioncioaia, Bogdan; Bud, Ioan Teodor; Muresan, Mircea

    2016-01-01

    René Leriche (1879-1955) was a 20(th) century French surgeon generally known in medicine for the syndrome that carries his name, namely the Leriche syndrome in the aorto-iliac occlusive disease. This paper is published to mark the commemoration of 60 year since Leriche's death. Although Dr. Leriche's legacy resides in the domain of vascular medicine, his research enclosed bone pathology and surgical management of pain. Having his surgical training done under professors Mathieu Jaboulay and Antonin Poncet, his friendship and association with Alexis Carrel and William Halsted have contributed to René Leriche's development as a surgeon, researcher and thinker. Following the footsteps of his mentors, he produced outstanding clinical and academic work which had earned him a good reputation among his students and colleagues. Surgeons such as Jean Kunlin, Jao Cid dos Santos, Michael DeBakey, René Fontaine and others came to study and learn from him. These future generations of surgeons would themselves bring much contribution to the understanding and treatment of vascular diseases and medicine in general. René Leriche pioneered medicine with his research and ideas. His assiduous work of teaching, research and clinical practice made his influence last to our present.

  5. The mid 19th and early 20th Century Pull of a Nearby Eclipse Shadow Path

    NASA Astrophysics Data System (ADS)

    Bonifácio, Vitor

    2012-09-01

    The unique observing conditions allowed by total solar eclipses made them a highly desirable target of 19th and early 20th century astronomical expeditions, particularly after 1842. Due to the narrowness of the lunar shadow at the Earth's surface this usually implied traveling to faraway locations with all the subsequent inconveniences, in particular, high costs and complex logistics. A situation that improved as travel became faster, cheaper and more reliable. The possibility to observe an eclipse in one's own country implied no customs, no language barriers, usually shorter travelling distances and the likely support of local and central authorities. The eclipse proximity also provided a strong argument to pressure the government to support the eclipse observation. Sometimes the scientific elite would use such high profile events to rhetorically promote broader goals. In this paper we will analyse the motivation, goals, negotiating strategies and outcomes of the Portuguese eclipse expeditions made between 1860 and 1914. We will focus, in particular, on the observation of the solar eclipses of 22 December 1870 and 17 April 1912. The former allowed the start-up of astrophysical studies in the country while the movie obtained at the latter led Francisco da Costa Lobo to unexpectedly propose a polar flattening of the Moon.

  6. Increased baseflow in Iowa over the second half of the 20th Century

    USGS Publications Warehouse

    Schilling, K.E.; Libra, R.D.

    2003-01-01

    Historical trends in annual discharge characteristics were evaluated for 11 gauging stations located throughout Iowa. Discharge records from nine eight-digit hydrologic unit code (HUC-8) watersheds were examined for the period 1940 to 2000, whereas data for two larger river systems (Cedar and Des Moines Rivers) were examined for a longer period of record (1903 to 2000). In nearly all watersheds evaluated, annual baseflow, annual minimum flow, and the annual baseflow percentage significantly increased over time. Some rivers also exhibited increasing trends in total annual discharge, whereas only the Maquoketa River had significantly decreased annual maximum flows. Regression of stream discharge versus precipitation indicated that more precipitation is being routed into streams as baseflow than as stormflow in the second half of the 20th Century. Reasons for the observed streamflow trends are hypothesized to include improved conservation practices, greater artificial drainage, increasing row crop production, and channel incision. Each of these reasons is consistent with the observed trends, and all are likely responsible to some degree in most watersheds.

  7. Measles epidemics of variable lethality in the early 20th century.

    PubMed

    Shanks, G Dennis; Hu, Zheng; Waller, Michael; Lee, Seung-eun; Terfa, Daniel; Howard, Alan; van Heyningen, Elizabeth; Brundage, John F

    2014-02-15

    Until the mid-20th century, mortality rates were often very high during measles epidemics, particularly among previously isolated populations (e.g., islanders), refugees/internees who were forcibly crowded into camps, and military recruits. Searching for insights regarding measles mortality rates, we reviewed historical records of measles epidemics on the Polynesian island of Rotuma (in 1911), in Boer War concentration camps (in 1900-1902), and in US Army mobilization camps during the First World War (in 1917-1918). Records classified measles deaths by date and clinical causes; by demographic characteristics, family relationships (for Rotuma islanders and Boer camp internees), and prior residences; and by camp (for Boer internees and US Army recruits). During the Rotuman and Boer War epidemics, measles-related mortality rates were high (up to 40%); however, mortality rates differed more than 10-fold across camps/districts, even though conditions were similar. During measles epidemics, most deaths among camp internees/military recruits were due to secondary bacterial pneumonias; in contrast, most deaths among Rotuman islanders were due to gastrointestinal complications. The clinical expressions, courses, and outcomes of measles during first-contact epidemics differ from those during camp epidemics. The degree of isolation from respiratory pathogens other than measles may significantly determine measles-related mortality risk.

  8. Water-quality trends in New England rivers during the 20th century

    USGS Publications Warehouse

    Robinson, Keith W.; Campbell, Jean P.; Jaworski, Norbert A.

    2003-01-01

    Water-quality data from the Merrimack, Blackstone, and Connecticut Rivers in New England during parts of the 20th century were examined for trends in concentrations of sulfate, chloride, residue upon evaporation, nitrate, and total phosphorus. The concentrations of all five of these constituents show statistically significant trends during the century. Annual concentrations of sulfate and total phosphorus decreased during the second half of the century, whereas annual concentrations of nitrate, chloride, and residues increased throughout the century. In the Merrimack River, annual chloride concentrations increased by an order of magnitude. Annual nitrate concentrations also increased by an order of magnitude in the Merrimack and Connecticut Rivers. These changes in the water quality probably are related to changing human activities. Most notable is the relation between increasing use of road de-icing salts and chloride concentrations in rivers. In addition, changes in concentrations of nitrate and phosphorus probably are related to agricultural use of nitrogen and phosphorus fertilizers. For all the water-quality constituents assessed, concentrations were greatest in the Blackstone River. The Blackstone River Basin is smaller and more highly urbanized than the other basins studied. Data-collection programs that span multiple decades can provide valuable insight on the effects of changing human population and societal activities on the water quality of rivers. This study was done as part of the U.S. Geological Survey's National Water-Quality Assessment Program.

  9. An Epistemological Approach to French Syllabi on Human Origins during the 19th and 20th Centuries

    ERIC Educational Resources Information Center

    Quessada, Marie-Pierre; Clement, Pierre

    2007-01-01

    This study focuses on how human origins were taught in the French Natural Sciences syllabuses of the 19th and 20th centuries. We evaluate the interval between the publication of scientific concepts and their emergence in syllabuses, i.e., didactic transposition delay (DTD), to determine how long it took for scientific findings pertaining to our…

  10. Beyond the Standard Measures: Physical Education's Impact on the Dialogue about Obesity in the 20th Century

    ERIC Educational Resources Information Center

    Wrynn, Alison M.

    2011-01-01

    As numerous Homans' lecturers have attested, Amy Morris Homans was a significant and visionary leader who set the foundation for women's physical education for the first half of the 20th century. Her reign at the Boston Normal School for Gymnastics (BNSG) was ironclad, and through the BNSG she controlled her student's lives, including their…

  11. Discursive Discrimination against the "Deaf-Mute"/"Deaf" and the Importance of Categorization in 20th Century Sweden

    ERIC Educational Resources Information Center

    Boreus, Kristina

    2007-01-01

    This article sheds light on issues concerning discrimination in the history of deaf people in Sweden in the 20th century. With the help of a specific typology of concepts for analysing discrimination exercised through the use of language, it is shown how the categorization of the hearing impaired has changed over time and how, in this process of…

  12. Representations of Technology in the "Technical Stories" for Children of Otto Witt, Early 20th Century Swedish Technology Educator

    ERIC Educational Resources Information Center

    Axell, Cecilia; Hallström, Jonas

    2013-01-01

    Children's fiction in school libraries have played and still play a role in mediating representations of technology and attitudes towards technology to schoolchildren. In early 20th century Sweden, elementary education, including textbooks and literature that were used in teaching, accounted for the main mediation of technological knowledge to…

  13. Beyond the Standard Measures: Physical Education's Impact on the Dialogue about Obesity in the 20th Century

    ERIC Educational Resources Information Center

    Wrynn, Alison M.

    2011-01-01

    As numerous Homans' lecturers have attested, Amy Morris Homans was a significant and visionary leader who set the foundation for women's physical education for the first half of the 20th century. Her reign at the Boston Normal School for Gymnastics (BNSG) was ironclad, and through the BNSG she controlled her student's lives, including their…

  14. DIGEST MATERIALS FOR IMPROVING AND EXTENDING THE JUNIOR HIGH SCHOOL ORCHESTRA REPERTORY. VOLUME 4, 20TH CENTURY.

    ERIC Educational Resources Information Center

    MOORE, JUNE

    PREPARED AS PART OF "PROJECT IMPROVING AND EXTENDING THE JUNIOR HIGH SCHOOL ORCHESTRA REPERTORY," THIS VOLUME CONTAINS CURRICULAR MATERIALS REPRESENTING THE 20TH CENTURY PERIOD. A MUSICAL HISTORY OF THE PERIOD IS GIVEN, AS WELL AS HISTORIES OF THE COMPOSERS AND THEIR INDIVIDUAL COMPOSITIONS. THE MATERIALS ARE PREPARED FOR 3 DEGREES OF TECHNICAL…

  15. Reconciling past changes in Earth's rotation with 20th century global sea-level rise: Resolving Munk's enigma.

    PubMed

    Mitrovica, Jerry X; Hay, Carling C; Morrow, Eric; Kopp, Robert E; Dumberry, Mathieu; Stanley, Sabine

    2015-12-01

    In 2002, Munk defined an important enigma of 20th century global mean sea-level (GMSL) rise that has yet to be resolved. First, he listed three canonical observations related to Earth's rotation [(i) the slowing of Earth's rotation rate over the last three millennia inferred from ancient eclipse observations, and changes in the (ii) amplitude and (iii) orientation of Earth's rotation vector over the last century estimated from geodetic and astronomic measurements] and argued that they could all be fit by a model of ongoing glacial isostatic adjustment (GIA) associated with the last ice age. Second, he demonstrated that prevailing estimates of the 20th century GMSL rise (~1.5 to 2.0 mm/year), after correction for the maximum signal from ocean thermal expansion, implied mass flux from ice sheets and glaciers at a level that would grossly misfit the residual GIA-corrected observations of Earth's rotation. We demonstrate that the combination of lower estimates of the 20th century GMSL rise (up to 1990) improved modeling of the GIA process and that the correction of the eclipse record for a signal due to angular momentum exchange between the fluid outer core and the mantle reconciles all three Earth rotation observations. This resolution adds confidence to recent estimates of individual contributions to 20th century sea-level change and to projections of GMSL rise to the end of the 21st century based on them.

  16. A Novel Remote Sensing Approach for Determining 20th Century Multi-Decadal Glacial Change Across the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Miller, P. E.; Mills, J. P.; Fox, A. J.; Clarke, L. E.; King, M. A.

    2014-12-01

    The Antarctic Peninsula (AP) is a mountain glacier system comprised of over 400 glaciers, and is an important contributor to historical and future sea level rise. Assessment and monitoring of AP glaciers is crucial for understanding sensitivity to climate change. However, whilst retreat of glacier fronts and the behaviour of individual glaciers has been extensively documented, wide-area assessment of AP glacier mass change is lacking. This research addresses this by unlocking a unique historical archive of aerial imagery through a remote sensing approach. This is enabling quantitative, wide-area assessment of glacier change across the AP. Understanding AP change over the 20th Century is vital for modelling future changes. However, satellite measurements span only a few decades, and to-date there has been no means of quantifying change over longer periods. However, this research presents a novel methodology to extract 3D measurements from an archive of > 30,000 aerial images dating back to the 1940s. This overcomes the requirement for ground control by employing an automated registration technique. Control is derived from digital elevations models (DEMs) generated from present-day ASTER satellite imagery. Through least squares surface matching, DEMs extracted from archival imagery are registered to scale-stable ASTER DEMs to determine relative change. This minimises offsets between the two DEMs, allowing robust determination of elevation changes. The spatial pattern of 20thC change is being assessed at 50 benchmark glaciers distributed across the AP, for periods of up to 65 years. In complement, a temporally refined assessment is being undertaken at 10 glaciers with multiple epochs of aerial imagery. Results to-date indicate a general trend of surface lowering, most notably over frontal regions. Spatial and temporal patterns of change will be used to investigate the drivers of AP change and establish a suite of benchmark glaciers for future monitoring.

  17. [Reform and innovation: medical education in the 20th century USA].

    PubMed

    Putnam, Constance E

    2006-01-01

    Medical education in the USA today is remarkably varied despite the shared mission of training doctors, hardly surprising given that there are today 125 medical schools in the United States. In this paper, a brief introduction to six of those institutions--describing how they and their mandates differ--illustrates some of the variety of US medical education currently available, while providing some specific details of just how those six schools differ from each other. These are only samples, of course; the variety is far greater than can be made clear in such a short review. Three private institutions are included: Dartmouth Medical School (the nation's fourth-oldest medical school), Duke University School of Medicine (a 20th-century creation, in the South), and Mount Sinai School of Medicine (a newcomer in the crowded medical world of New York City). Three state-supported schools are also described: the University of Arizona College of Medicine (one of the nation's newer schools), Oregon Health & Science University School of Medicine (an institution that has gone through many permutations, thanks to a variety of mergers), and Southern Illinois University School of Medicine (another new school that has focused on serving its immediate locale while creating a national model for some kinds of student assessment). General remarks are made about changes over recent years in three separate areas of influence. One is the fact that forty new medical schools were established between 1960 and 1980; a short explanation is provided of the reasons for this and how this mammoth task was achieved. Secondly, a few of the numerous innovative programs and new emphases that have become part of the medical school curriculum in one institution or another are discussed briefly. And then, thirdly, a small sample is given of ways in which a few other particular medical schools have reformed their curricula in recent years; what went into the most influential of these curricular reforms

  18. Did the naval wars in the North Atlantic and adjacent North and Baltic Sea during WWI and WWII played a significant role in the two climatic shifts of the 20th Century, the Arctic warming (1919 to 1939) and the global cooling (1940 to mid 1970)?

    NASA Astrophysics Data System (ADS)

    Bernaerts, Arnd

    2010-05-01

    A better understanding of the perfect time correlation between the two most devastating naval wars during the last century, and the most prominent climatic changes in the Northern Hemisphere, the first at the end of WWI, and the second immediately after WWII commencement, could highlight the role of the ocean and adjacent seas in climate change matters, and of anthropogenic activities in the marine environment. The study provides an overview of decisive links between naval activities and a change of air temperatures, showing that the Arctic warming (1919 to 1939) was based on a different mechanism as the cooling period (1940 to mid 1970), which needs to be subdivided in two distinct periods, and three main regions. From autumn 1939 to winter 1941/42 naval war was primarily fought in the North- and Baltic Sea and the most eastern part of the Northern North Atlantic. Only after the U.S.A. became a war party in December 1941, the naval war took place everywhere in the North Atlantic for more than two years, and with increasing intensity in the Western North Pacific from 1942 to August 1945. Particular attention is given to the role of the North and Baltic Sea concerning the three extreme cold winters in Europe 1939/40, 1940/41 and 1941/42 that marked the start of a three decade long global cooling, and had been the coldest for more than 100 years. The most affected locations lay close to those sea areas with the highest naval activities, e.g. the North Sea section from The Netherlands to Denmark, and in the Southern and Central Baltic Sea in winter 1939/40. Similar observations can be made for the two subsequent war winters. After the invasion of Norway in 1940 the Skagerrak region experienced a record cold winter. The next most severe winter conditions in 1941/42 can be attributed to the realm of the Eastern Baltic Sea where naval force had been active since Germany had attacked Russia in June 1941. A significant fact of the three extreme winters is their appearance

  19. Genomic analysis of the emergence of 20th century epidemic dysentery.

    PubMed

    Rohmer, Laurence; Jacobs, Michael A; Brittnacher, Mitchell J; Fong, Christine; Hayden, Hillary S; Hocquet, Didier; Weiss, Eli J; Radey, Matthew; Germani, Yves; Talukder, Kaisar Ali; Hager, Anthony J; Kemner, John M; Sims-Day, Elizabeth H; Matamouros, Susana; Hager, Kyle R; Miller, Samuel I

    2014-05-10

    Shigella dysenteriae type 1 (Sd1) causes recurrent epidemics of dysentery associated with high mortality in many regions of the world. Sd1 infects humans at very low infectious doses (10 CFU), and treatment is complicated by the rapid emergence of antibiotic resistant Sd1 strains. Sd1 is only detected in the context of human infections, and the circumstances under which epidemics emerge and regress remain unknown. Phylogenomic analyses of 56 isolates collected worldwide over the past 60 years indicate that the Sd1 clone responsible for the recent pandemics emerged at the turn of the 20th century, and that the two world wars likely played a pivotal role for its dissemination. Several lineages remain ubiquitous and their phylogeny indicates several recent intercontinental transfers. Our comparative genomics analysis reveals that isolates responsible for separate outbreaks, though closely related to one another, have independently accumulated antibiotic resistance genes, suggesting that there is little or no selection to retain these genes in-between outbreaks. The genomes appear to be subjected to genetic drift that affects a number of functions currently used by diagnostic tools to identify Sd1, which could lead to the potential failure of such tools. Taken together, the Sd1 population structure and pattern of evolution suggest a recent emergence and a possible human carrier state that could play an important role in the epidemic pattern of infections of this human-specific pathogen. This analysis highlights the important role of whole-genome sequencing in studying pathogens for which epidemiological or laboratory investigations are particularly challenging.

  20. Billions of Planetary Systems: Turning Point at Mid-20th Century

    NASA Astrophysics Data System (ADS)

    Dick, S. J.

    2002-12-01

    The search for planetary systems, an elusive goal for most of the 20th century, is reminiscent of the search for stellar parallax in earlier centuries. Of the latter, John Herschel once wrote that it seemed within reach of the astronomer, "only to elude his seizure when apparently just within his grasp, continually hovering just beyond the limits of his distinct apprehension, and so leading him on in hopeless, endless, and exhausting pursuit." Such was the case for planetary systems, until the discovery of pulsar planets in 1992, and of planets around solar-type stars beginning in 1995. For the early decades of the century the Jeans-Jeffreys tidal theory of planet formation via close stellar encounters predicted that planets should be very rare. But the 15 years between 1943 and 1958 saw a remarkable turning point in the fortunes of planetary systems. It began with Russell's criticism of the Jeans-Jeffreys theory, but was fueled by the revival of a modified nebular hypothesis (von Weizsacker, 1944), developments in fields as diverse as double star astronomy (Kuiper, 1951), the measurement of stellar rotation periods (Struve, 1950), and geochemistry (Urey, 1952) and - most surprising of all - by claims that planetary systems, or their effects had actually been observed (Strand, 1943; Reuyl and Holmberg, 1943). Struve (1952) even suggested a means for planet detection by the radial velocity method. As Harlow Shapley made clear in his work Of Stars and Men: Human Response to an Expanding Universe (1958), the new cosmology was a continual force in the background favoring abundant planetary systems. All this work was in the background as Peter van de Kamp played out his solitary search for planetary systems, culminating in the announcement (1963) of a planet around Barnard's star. The limits that Herschel spoke of have now been breached, and the search is no longer solitary.

  1. Canada's Dominion Astrophysical Observatory and the rise of 20th Century Astrophysics and Technology

    NASA Astrophysics Data System (ADS)

    Hesser, James E.; Bohlender, David; Crabtree, Dennis

    2015-08-01

    Construction of Canada’s Dominion Astrophysical Observatory (DAO) commenced in 1914 with first light on 6 May 1918. Its varied, rich contributions to the astronomical heritage of the 20th century continue into the 21st century. The first major research observatory built with public funding on the West Coast of North America, it was Canada’s first ‘big science’ project. DAO welcomed scientists from around the world to use its 1.8m telescope designed by John Stanley Plaskett working in close collaboration with the Warner and Swasey Company of Cleveland, OH. Their original design was copied seven times around the globe, the last occasion being in the 1960s. From Day 1 the DAO welcomed the public for viewing and interaction with the small scientific staff whose early efforts would today be characterized as ‘Key Projects’. Those efforts included measuring the radial velocities of O and B stars that, interpreted through Oort’s ideas of differential rotation, determined the most reliable estimate of the size and mass of the Milky Way available until radio astronomical techniques emerged in the 1950s. The first organic molecule in interstellar space, CH, was discovered by a DAO astronomer. The first, very puzzling estimate of ~3K for the temperature of interstellar space was deduced from interstellar CN observations a year after interstellar CH and CN were discovered. DAO’s heritage of innovative instrumentation continues to the present day where expertise in optically efficient, mechanically stable spectrographs and adaptive optics are much in evidence at Mauna Kea’s CFHT, Gemini and Subaru observatories. In 2009 the DAO was designated a National Historic Site. This presentation will draw links between DAO, developments of Canadian astronomy and the emergence of Mauna Kea as an exceptional global astronomical reserve.

  2. Coral microatolls and 20th century sea level in the eastern Indian Ocean

    NASA Astrophysics Data System (ADS)

    Smithers, Scott G.; Woodroffe, Colin D.

    2001-08-01

    Coral microatolls are discoid intertidal corals that are limited in their upward growth by subaerial exposure during low tides. Microatoll upper surface morphology preserves a filtered record of changes in the height of living coral (HLC), the upper limit to which corals can grow, and by proxy a historical record of former constraining water levels. Chronologies for these variations in HLC were established in this study using annual skeletal density bands revealed when skeletal slices were X-radiographed, supplemented by annual fluorescent bands visible when samples were illuminated with ultra-violet light. The upper surface morphologies of two large microatolls from separate reef-flat sites on the Cocos (Keeling) Islands are well correlated and indicate that the upper limit to coral growth has fluctuated by more than 5 cm since the early 1900s. The upper surfaces of these microatolls also indicate that there has been little net rise in sea level in the eastern Indian Ocean during the 20th century. Microatoll surface morphology suggests that average rates of sea-level rise in the eastern Indian Ocean over this period were less than 0.35 mm yr-1, a rate considerably lower than the rate of average global sea-level change determined from aggregated tide-gauge data. The broad surface undulations do not appear to correlate directly with either El Niño-Southern Oscillation events or occurrence of the Indian Ocean dipole mode of ocean-atmosphere circulation. Microatolls provide a simple and effective method for extrapolating broad variations in sea level beyond the tide-gauge record in remote mid-oceanic settings.

  3. Conceptual Revolution of the 20th Century Leading to One Grand Unified Concept -- The Quantum Vacuum

    NASA Astrophysics Data System (ADS)

    Sreekantan, B. V.

    2014-07-01

    Concepts and the relations between concepts are the basis for all our scientific understanding and explanation of the wide variety of constituents and phenomena in nature. Some of the fundamental concepts like space, time, matter, radiation, causality, etc. had remained unchanged for almost four hundred years from the time of the dawn of science. However all these underwent a drastic transformation in the 20th century because of two reasons. One, in the light of certain experimental findings two radical theories namely theory of relativity and theory of quantum mechanics replaced the classical theory that had dominated since Newton's time. Secondly, the science-technology spiral resulted in the discovery of very many new features of the universe both on the micro scale and on the mega scale. There was an exponential increase in our knowledge. These new facts could not be fitted into the old concepts. Apart from drastic revision, many new concepts had to be brought in. Despite all this, one very encouraging trend has been to discern a holistic synthesis and unification of the different concepts -- an endeavor that has been helped by experiments over a wide scale of energy and distances and most importantly from theoretical insights triggered by mathematical underpinnings. These developments in physics and astrophysics are pointing to one grand concept, namely, the "quantum vacuum" endowed with certain special properties, as the substratum from which all the constituents of the universe as well as the processes of the universe emerge, including the creation of the universe itself. This is the view, at least of some of the scientists. In this brief article the essence of these approaches toward unification is highlighted. Maybe life sciences can take a clue from these developments in physical sciences.

  4. Ochres and earths: Matrix and chromophores characterization of 19th and 20th century artist materials

    NASA Astrophysics Data System (ADS)

    Montagner, Cristina; Sanches, Diogo; Pedroso, Joana; Melo, Maria João; Vilarigues, Márcia

    2013-02-01

    The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using μ-Fourier Transform Infrared Spectroscopy (μ-FTIR), Raman microscopy, μ-Energy Dispersive X-ray fluorescence (μ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. μ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. μ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.

  5. Decrease in water clarity of the southern and central North Sea during the 20th century.

    PubMed

    Capuzzo, Elisa; Stephens, David; Silva, Tiago; Barry, Jon; Forster, Rodney M

    2015-06-01

    Light in the marine environment is a key environmental variable coupling physics to marine biogeochemistry and ecology. Weak light penetration reduces light available for photosynthesis, changing energy fluxes through the marine food web. Based on published and unpublished data, this study shows that the central and southern North Sea has become significantly less clear over the second half of the 20th century. In particular, in the different regions and seasons investigated, the average Secchi depth pre-1950 decreased between 25% and 75% compared to the average Secchi depth post-1950. Consequently, in summer pre-1950, most (74%) of the sea floor in the permanently mixed area off East Anglia was within the photic zone. For the last 25+ years, changes in water clarity were more likely driven by an increase in the concentration of suspended sediments, rather than phytoplankton. We suggest that a combination of causes have contributed to this increase in suspended sediments such as changes in sea-bed communities and in weather patterns, decreased sink of sediments in estuaries, and increased coastal erosion. A predicted future increase in storminess (Beniston et al., 2007; Kovats et al., 2014) could enhance the concentration of suspended sediments in the water column and consequently lead to a further decrease in clarity, with potential impacts on phytoplankton production, CO2 fluxes, and fishery production. © 2015 Crown copyright. Global Change Biology published by John Wiley & Sons Ltd. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

  6. [Tobacco smoking in Wielkopolska towards the end of 20th century].

    PubMed

    Ramlau, Rodryg; Didkowska, Joanna; Wojciechowska, Urszula; Tarkowski, Wojciech

    2005-01-01

    Tobacco smoking is the cause of 30% of deaths among men and 7% among women in Poland. Such data call for detailed analysis. Previous researche on frequency of smoking was focused on the analysis of all-Poland population. The following research was aimed at the description of tobacco smoke exposure in population of Wielkopolska in the late 1990s. Smoking habits in Wielkopolska is more prevalent in men than women and this prevalence is sustained in time. The smoking habit among men decreased during the last 5 years of the 20th century, however it is higher among women (1996: 47.5% men and 27.7% women, 2000: 41.9% men and 29.9% women). The positive fact is the raising percentage of both men and women who give up smoking. The results show that the level of education is a strong predictor of smoking among men: the higher education, the lower percentage of smokers. This relation does not seem to be that obvious in women. The place of living is another factor influencing the percentage of smoking people--the prevalence is lower in cities, especially among men. Presented results show that there are similar changes in smoking habits in Wielkopolska as observed nationwide. The difference concerns slightly lower percentage of tobacco users among men and higher among women in Wielkopolska than in nationwide population. Distribution of involvement of subsequent categories (i.e. gender, age, education and place of living) follow the pattern observed in general population. The knowledge about smoking habits in Wielkopolska forms the ground for actions within the frame of evidence based medicine, systematic assessment of frequency of smoking would allow taking up appropriate preventive actions such as youth education and therapeutic (treatment of smoking habit) actions.

  7. Knee osteoarthritis has doubled in prevalence since the mid-20th century.

    PubMed

    Wallace, Ian J; Worthington, Steven; Felson, David T; Jurmain, Robert D; Wren, Kimberly T; Maijanen, Heli; Woods, Robert J; Lieberman, Daniel E

    2017-08-29

    Knee osteoarthritis (OA) is believed to be highly prevalent today because of recent increases in life expectancy and body mass index (BMI), but this assumption has not been tested using long-term historical or evolutionary data. We analyzed long-term trends in knee OA prevalence in the United States using cadaver-derived skeletons of people aged ≥50 y whose BMI at death was documented and who lived during the early industrial era (1800s to early 1900s; n = 1,581) and the modern postindustrial era (late 1900s to early 2000s; n = 819). Knee OA among individuals estimated to be ≥50 y old was also assessed in archeologically derived skeletons of prehistoric hunter-gatherers and early farmers (6000-300 B.P.; n = 176). OA was diagnosed based on the presence of eburnation (polish from bone-on-bone contact). Overall, knee OA prevalence was found to be 16% among the postindustrial sample but only 6% and 8% among the early industrial and prehistoric samples, respectively. After controlling for age, BMI, and other variables, knee OA prevalence was 2.1-fold higher (95% confidence interval, 1.5-3.1) in the postindustrial sample than in the early industrial sample. Our results indicate that increases in longevity and BMI are insufficient to explain the approximate doubling of knee OA prevalence that has occurred in the United States since the mid-20th century. Knee OA is thus more preventable than is commonly assumed, but prevention will require research on additional independent risk factors that either arose or have become amplified in the postindustrial era.

  8. The 20th-century development and expansion of Louisiana shelf hypoxia, Gulf of Mexico

    USGS Publications Warehouse

    Osterman, L.E.; Poore, R.Z.; Swarzenski, P.W.; Senn, D.B.; DiMarco, S.F.

    2009-01-01

    Since systematic measurements of Louisiana continental-shelf waters were initiated in 1985, hypoxia (oxygen content <2 mg L-1) has increased considerably in an area termed the dead zone. Monitoring and modeling studies have concluded that the expansion of the Louisiana shelf dead zone is related to increased anthropogenically derived nutrient delivery from the Mississippi River drainage basin, physical and hydrographical changes of the Louisiana Shelf, and possibly coastal erosion of wetlands in southern Louisiana. In order to track the development and expansion of seasonal low-oxygen conditions on the Louisiana shelf prior to 1985, we used a specific low-oxygen foraminiferal faunal proxy, the PEB index, which has been shown statistically to represent the modern Louisiana hypoxia zone. We constructed a network of 13 PEB records with excess 210Pb-derived chronologies to establish the development of low-oxygen and hypoxic conditions over a large portion of the modern dead zone for the last 100 years. The PEB index record indicates that areas of low-oxygen bottom water began to appear in the early 1910s in isolated hotspots near the Mississippi Delta and rapidly expanded across the entire Louisiana shelf beginning in the 1950s. Since ???1950, the percentage of PEB species has steadily increased over a large portion of the modern dead zone. By 1960, subsurface low-oxygen conditions were occurring seasonally over a large part of the geographic area now known as the dead zone. The long-term trends in the PEB index are consistent with the 20th-century observational and proxy data for low oxygen and hypoxia. ?? 2009 US Government.

  9. Knee osteoarthritis has doubled in prevalence since the mid-20th century

    PubMed Central

    Wallace, Ian J.; Worthington, Steven; Felson, David T.; Jurmain, Robert D.; Wren, Kimberly T.; Maijanen, Heli; Woods, Robert J.; Lieberman, Daniel E.

    2017-01-01

    Knee osteoarthritis (OA) is believed to be highly prevalent today because of recent increases in life expectancy and body mass index (BMI), but this assumption has not been tested using long-term historical or evolutionary data. We analyzed long-term trends in knee OA prevalence in the United States using cadaver-derived skeletons of people aged ≥50 y whose BMI at death was documented and who lived during the early industrial era (1800s to early 1900s; n = 1,581) and the modern postindustrial era (late 1900s to early 2000s; n = 819). Knee OA among individuals estimated to be ≥50 y old was also assessed in archeologically derived skeletons of prehistoric hunter-gatherers and early farmers (6000–300 B.P.; n = 176). OA was diagnosed based on the presence of eburnation (polish from bone-on-bone contact). Overall, knee OA prevalence was found to be 16% among the postindustrial sample but only 6% and 8% among the early industrial and prehistoric samples, respectively. After controlling for age, BMI, and other variables, knee OA prevalence was 2.1-fold higher (95% confidence interval, 1.5–3.1) in the postindustrial sample than in the early industrial sample. Our results indicate that increases in longevity and BMI are insufficient to explain the approximate doubling of knee OA prevalence that has occurred in the United States since the mid-20th century. Knee OA is thus more preventable than is commonly assumed, but prevention will require research on additional independent risk factors that either arose or have become amplified in the postindustrial era. PMID:28808025

  10. Ochres and earths: matrix and chromophores characterization of 19th and 20th century artist materials.

    PubMed

    Montagner, Cristina; Sanches, Diogo; Pedroso, Joana; Melo, Maria João; Vilarigues, Márcia

    2013-02-15

    The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using μ-Fourier Transform Infrared Spectroscopy (μ-FTIR), Raman microscopy, μ-Energy Dispersive X-ray fluorescence (μ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. μ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. μ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Hydrologic Drought of Water Year 2006 Compared with Four Major Drought Periods of the 20th Century in Oklahoma

    USGS Publications Warehouse

    Tortorelli, Robert L.

    2008-01-01

    Water Year 2006 (October 1, 2005, to September 30, 2006) was a year of extreme hydrologic drought and the driest year in the recent 2002-2006 drought in Oklahoma. The severity of this recent drought can be evaluated by comparing it with four previous major hydrologic droughts, water years 1929-41, 1952-56, 1961-72, and 1976-81. The U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, completed an investigation to summarize the Water Year 2006 hydrologic drought and compare it to the four previous major hydrologic droughts in the 20th century. The period of water years 1925-2006 was selected as the period of record because before 1925 few continuous record streamflow-gaging sites existed and gaps existed where no streamflow-gaging sites were operated. Statewide annual precipitation in Water Year 2006 was second driest and statewide annual runoff in Water Year 2006 was sixth driest in the 82 years of record. Annual area-averaged precipitation totals by the nine National Weather Service Climate Divisions from Water Year 2006 are compared to those during four previous major hydrologic droughts to show how rainfall deficits in Oklahoma varied by region. Only two of the nine climate divisions, Climate Division 1 Panhandle and Climate Division 4 West Central, had minor rainfall deficits, while the rest of the climate divisions had severe rainfall deficits in Water Year 2006 ranging from only 65 to 73 percent of normal annual precipitation. Regional streamflow patterns for Water Year 2006 indicate that Oklahoma was part of the regionwide below-normal streamflow conditions for Arkansas-White-Red River Basin, the sixth driest since 1930. The percentage of long-term stations in Oklahoma (with at least 30 years of record) having below-normal streamflow reached 80 to 85 percent for some days in August and November 2006. Twelve long-term streamflow-gaging sites with periods of record ranging from 62 to 78 years were selected to show how streamflow

  12. 20th century global warming favoured enhanced intensity of extreme torrential events - a proglacial sediment record in NW French Alps

    NASA Astrophysics Data System (ADS)

    Wilhelm, B.; Arnaud, F.; Legaz, A.; Allignol, F.; Enters, D.; Revillon, S.

    2009-04-01

    During the past few yeas, considerable climate changes have been observed at high elevation areas of the European Alps. Additionally, one of the main results of high resolution climate modelling is a trend towards both dryer summer conditions and enhanced risk of extreme floods. This should have particularly dramatic consequences in alpine areas. Indeed, the development of tourism during the 20th century in the Alps and the rise of population density resulted in an increasing potential risk from natural hazards. Among them, torrential floods are some of the most common and widespread ones. They cause both loss of human life and high damage to property and infrastructure and are particularly destructive in mountain areas. For example, in August 2005, an unusual meteorological situation resulted in a series of catastrophic floods in most regions of the European Alps and particularly in the catchment of the Vorz river, downstream of proglacial Lac Blanc (2170 m a.s.l., Belledonne range, NW French Alps). We studied a series of sediment cores from Lac Blanc, spanning the last ca. 250 years. Through a coupled high resolution sedimentological and geochemical approach we documented about 100 flood deposits and measured their thickness. The age of each deposit has been assessed by radiochemical dating and the recognition of historically-known events - major earthquakes and historical atmospheric lead deposition. Furthermore, a detailed study of regional and local historical archives was conducted allowing us to relate the recognised flood deposits to the ones reported by local population. We hence obtained a flood calendar from 1740 to 2005 with the respective intensity of each event assessed by the thickness of the associated deposit. The flood frequency shows an important and punctual increase at the early end of the Little Ice Age (1830 - 1860) as a response to the beginning warming period, which was emphasized by the synchronous local glacier retreat. On the other hand

  13. 20th century changes in carbon isotopes and water-use efficiency: tree-ring-based evaluation of the CLM4.5 and LPX-Bern models

    NASA Astrophysics Data System (ADS)

    Keller, Kathrin M.; Lienert, Sebastian; Bozbiyik, Anil; Stocker, Thomas F.; Churakova (Sidorova), Olga V.; Frank, David C.; Klesse, Stefan; Koven, Charles D.; Leuenberger, Markus; Riley, William J.; Saurer, Matthias; Siegwolf, Rolf; Weigt, Rosemarie B.; Joos, Fortunat

    2017-05-01

    Measurements of the stable carbon isotope ratio (δ13C) on annual tree rings offer new opportunities to evaluate mechanisms of variations in photosynthesis and stomatal conductance under changing CO2 and climate conditions, especially in conjunction with process-based biogeochemical model simulations. The isotopic discrimination is indicative of the ratio between the CO2 partial pressure in the intercellular cavities and the atmosphere (ci/ca) and of the ratio of assimilation to stomatal conductance, termed intrinsic water-use efficiency (iWUE). We performed isotope-enabled simulations over the industrial period with the land biosphere module (CLM4.5) of the Community Earth System Model and the Land Surface Processes and Exchanges (LPX-Bern) dynamic global vegetation model. Results for C3 tree species show good agreement with a global compilation of δ13C measurements on leaves, though modeled 13C discrimination by C3 trees is smaller in arid regions than measured. A compilation of 76 tree-ring records, mainly from Europe, boreal Asia, and western North America, suggests on average small 20th century changes in isotopic discrimination and in ci/ca and an increase in iWUE of about 27 % since 1900. LPX-Bern results match these century-scale reconstructions, supporting the idea that the physiology of stomata has evolved to optimize trade-offs between carbon gain by assimilation and water loss by transpiration. In contrast, CLM4.5 simulates an increase in discrimination and in turn a change in iWUE that is almost twice as large as that revealed by the tree-ring data. Factorial simulations show that these changes are mainly in response to rising atmospheric CO2. The results suggest that the downregulation of ci/ca and of photosynthesis by nitrogen limitation is possibly too strong in the standard setup of CLM4.5 or that there may be problems associated with the implementation of conductance, assimilation, and related adjustment processes on long-term environmental

  14. The Loss of Balance between the Art and Science of Management: Observations on the British Experience of Education for Management in the 20th Century

    ERIC Educational Resources Information Center

    Guerriero Wilson, Robbie

    2015-01-01

    This essay considers the developments in education for management in 20th-century Britain. In the late 19th and early 20th centuries, that is, the highpoint of the United Kingdom's economic success, management was considered more of an art than a science, and formal education specifically for management was limited. After the Second World War,…

  15. The Loss of Balance between the Art and Science of Management: Observations on the British Experience of Education for Management in the 20th Century

    ERIC Educational Resources Information Center

    Guerriero Wilson, Robbie

    2015-01-01

    This essay considers the developments in education for management in 20th-century Britain. In the late 19th and early 20th centuries, that is, the highpoint of the United Kingdom's economic success, management was considered more of an art than a science, and formal education specifically for management was limited. After the Second World War,…

  16. 20th Century Russian ice variability: results from a new digital dataset

    NASA Astrophysics Data System (ADS)

    Mahoney, A. R.; Barry, R. G.; Fetterer, F.

    2007-12-01

    As the Arctic sea ice pack retreats to record-breaking minimum extents, it is increasingly important to be able to set these changes in a longer-term context. Here, we present a recently digitized set of sea ice charts provided by the Arctic and Antarctic Research Institute (AARI), St Petersburg, Russia. The earliest chart dates back to July 1933 making the AARI ice charts perhaps the longest-lived systematic sea ice record in existance. Converting the ice charts to equal area scaleable Earth (EASE) grid format, we compare the sea ice concentrations reported in the AARI ice charts with those from two other datasets: the National Ice Center (NIC) gridded sea ice charts; and the Hadley Centre Global Sea Ice and Sea Surface Temperature (HadISST) dataset. Where the data overlap spatially and temporally, we are able to identify long term and seasonal differences between the datasets. By identifying the underlying causes of these differences, we present the basis for assimilating the concentration data with the view of creating an optimal hybrid sea ice data set for the Arctic. We also present an analysis of sea ice and air temperature variability in the Russian Arctic, derived from the AARI ice charts and meteorological station data, respectively. These results reveal three distinct periods of variability: a period of warm winters and decreasing summer and fall sea ice extent (period A), followed by a cool period of stable or slightly increasing extent (period B) before a period of year-round warm temperatures and ice loss (period C). In magnitude and seasonality, the warming and ice loss during period C are more significant that those during period A. However, the Russian Arctic ice pack did not fully recover during period B, suggesting that the early 20th Century warming during period A may have preconditioned the Arctic for greater change in recent decades. At the end of period B, there is a rapid expansion of both first year and multi year ice extent, which may also

  17. [Occult medicine in the 20th century: pharmacotherapy by Demeter Georgievitz-Weitzer, known as Surya (1873 - 1949)].

    PubMed

    Helmstädter, Axel

    2011-01-01

    Demeter Georgievitz-Weitzer (1873-1949), called "Surya", Sanskrit for "sun", was an important representative of medical occultism in the first half of the 20th century. He worked as a journal editor and published a 13-volume book series about occult medicine, mainly written by himself. His hypotheses were closely related to the "Lebensreform" movement around 1900. Regarding diagnostics, he relied on astrology, cheiromancy, and clairvoyance, while therapeutics were dominated by diet and spagyric remedies according to Cesare Mattei (1809-1896) and Carl-Friedrich Zimpel (1801-1879). In his later years, he developed his own healing system, initially comprising eight, later only two preparations. Surya remedies were commercially available until the end of the 20th century,

  18. Lessons Learned and Present Day Challenges of Addressing 20th Century Radiation Legacies of Russia and the United States

    SciTech Connect

    KRISTOFZSKI, J.G.

    2000-10-26

    The decommissioning of nuclear submarines, disposal of highly-enriched uranium and weapons-grade plutonium, and processing of high-level radioactive wastes represent the most challenging issues facing the cleanup of 20th century radiation legacy wastes and facilities. The US and Russia are the two primary countries dealing with these challenges, because most of the world's fissile inventory is being processed and stored at multiple industrial sites and nuclear weapons production facilities in these countries.

  19. The little death: Rigoni-Stern and the problem of sex and cancer in 20th-century biomedical research.

    PubMed

    Aviles, Natalie B

    2015-06-01

    Approaches to the organization and conduct of cancer research changed dramatically throughout the 20th century. Despite marked differences between the epidemiological approaches of the first half of the century and molecular techniques that gained dominance in the 1980s, prominent 20th-century researchers investigating the link between sexual activity and anogenital cancers continuously invoked the same 1842 treatise by Italian surgeon Domenico Rigoni-Stern, who is said to originate the problem of establishing a causal link between sex and cancer. In this article, I investigate 20th-century references to Rigoni-Stern as a case of a broader phenomenon: scientists situating their work through narratives of venerated ancestors, or originators. By explaining shifting versions of originator narratives in light of their authors' cultural context and research practices, we can reimagine as meaningful cultural symbols the references that previous scholars have treated as specious rhetorical maneuvers. In this case, references to Rigoni-Stern provide an interpretive anchor for American scientists to construct continuity between their work and a diverse historical legacy of cancer research.

  20. ​​​History of Cholera Outbreaks in Iran during the 19th and 20th Centuries

    PubMed Central

    Azizi, MH; Azizi, F

    2010-01-01

    Cholera is an acute infectious disease with high mortality if left untreated. Historically, between the 19th and 20th centuries seven great pandemics of cholera occurred and worldwide, thousands of people died. Based on an old theory, cholera was considered an air-born disease and the emergence of its outbreaks were attributed to bad weather or miasma. However later in the 18th century, British physician John Snow (1813-1858) explained the association of a terrible cholera outbreak in London in 1849 to contamination of the drinking water supply with human excreta. Despite his finding, the causative agent of this dreaded illness was unidentified until later in the 19th century. In 1854, Filippo Pacini (1812-1883) an anatomist from Italy and then in 1883, Robert Koch (1843-1910) the German bacteriologist, discovered ‘vibrio cholerae’ as the etiologic agent. During the major pandemics of cholera in 19th and 20th centuries this illness reached Iran and led to vast depopulation and a crucial impact on the country’s socioeconomic status. Poor public health conditions, lack of a well-organized public health authority for implementing preventive and quarantine measures as well as Iran’s specific geographic location were the main facilitating factors of the emergence of various epidemics, including cholera in Iran. The present paper briefly reviews the cholera outbreaks in Iran during the 19th and 20th centuries. PMID:25197514

  1. Possible role of the dimming/brightening in observed temperatures across Europe since the second half of the 20th century

    NASA Astrophysics Data System (ADS)

    van den Besselaar, E. J. M.; Sanchez-Lorenzo, A.; Wild, M.; Klein Tank, A. M. G.

    2012-04-01

    The surface solar radiation (SSR) is the fundamental source of energy in the climate system, and consequently the source of life on our planet, due to its central role in the surface energy balance. Therefore, a significant impact on temperatures is expected due to the widespread dimming/brightening phenomenon observed since the second half of the 20th century (Wild, 2009). Previous studies pointed out the effects of SSR trends in temperatures series over Europe (Makowski et al., 2009; Philipona et al., 2009), although the lack of long-term SSR series limits these results. This work describes an updated sunshine duration (SS) dataset compiled by the European Climate Assessment and Dataset (ECA&D) project based on around 300 daily time series over Europe covering the 1961-2010 period. The relationship between the SS and temperature series is analysed based on four temperature variables: maximum (TX), minimum (TN) and mean temperature (TG), as well as the diurnal temperature range (DTR). Regional and pan-European mean series of SS and temperatures are constructed. The analyses are performed on annual and seasonal scale, and focusing on the interannual and decadal agreement between the variables. The results show strong positive correlations on interannual scales between SS and temperatures over Europe, especially for the DTR and TX during the summer period and regions in Central Europe. Interestingly, the SS and temperatures series show a tendency towards higher correlations in the smoothed series, both for different regions and temperature variables. These results confirm the relationship between temperature and SS trends over Europe since the second half of the 20th century, which has been speculated to partially decrease (increase) temperatures during the dimming (brightening) period (Makowski et al., 2009; Wild, 2009). Further research is needed to confirm this cause-effect relationship currently found only using correlation analysis.

  2. Europe experienced a "warming hole" in autumn in the second half of the 20th century

    NASA Astrophysics Data System (ADS)

    Cahynova, M.; Pokorna, L.; Huth, R.

    2012-12-01

    Recent global warming has not been ubiquitous - there might be seasons, regions, and time periods with clearly discernible zero or downward air temperature trends. Regions that are not warming or are even cooling - also known as "warming holes" - have been previously detected mainly in autumn in the second half of the 20th century in large parts of North America as well as in central and eastern Europe. In this study we use daily maximum and minimum temperature (TX and TN, respectively) and daily temperature range (DTR) at 136 stations from the ECA&D database in Europe and the Mediterranean in the period 1961-2000 to precisely locate their seasonal and sub-seasonal trends in space and within the course of the year, and to assess the effect of circulation changes on these observed trends. Linear trends are calculated for moving "seasons" of differing lengths (10, 20, 30, 60, and 90 days), each shifted by one day. Thus we obtain 365 values of "moving trends" for each station and each variant of season length. The day-to-day variability of these trends is greatest for short "seasons" of 10 and 20 days. Trends of the 90-day seasons are the most stable throughout the year and also bear the lowest trend magnitudes. Cluster analysis of the annual course of "moving trends" reveals relatively well-defined regions with similar trend behavior. Over most of Europe, the observed warming is greatest in winter, and the highest trend magnitudes are reached by TN in eastern Europe. Two regions stand out of this general picture: in Iceland and the Mediterranean, winter shows almost no trends, while in summer we see a pronounced warming. Significant autumn cooling centered on mid-November was found in eastern and southeastern Europe for both TX and TN; in many other regions trends are close to zero in the same period. Other clearly non-warming (or even cooling) periods occur in western and central Europe in April and June. Trends of DTR are largely inconclusive and no general picture

  3. Trends in fire risk and burned area in Brazil in the 20th century

    NASA Astrophysics Data System (ADS)

    Silva, P.; Bastos, A.; DaCamara, C.; Libonati, R.

    2016-12-01

    Fire has a significant contribution to the global greenhouse gas emissions and vast ecological and climatic impacts. Worldwide, Brazil is one of the areas most affected by fire, which highly influences the state of the vegetation cover, the ecological diversity of the region and has significant consequences to the global CO2 balance [1]. Hence, with the increasing evidence of human induced climate change, it becomes essential to understand the present and future trends of fire risk in Brazil. Although a large number of fires in Brazil are anthropogenic, it has been shown that the burned area is mainly controlled by meteorological conditions [2], therefore being partially determined by fire risk. In this study we use a fire danger index specifically tailored for the Brazilian climate and biome characteristics, the MFDI developed by INPE, to assess the patterns and trends of fire risk in Brazil. The index relies on values of maximum temperature, accumulated precipitation over different periods, minimum relative humidity and vegetation cover to estimate the likelihood of fire occurrence. We test the sensitivity of the index to different climate reanalyses and evaluate the trends in fire risk in Brazil during the past four decades for different biomes. We further assess the link between the calculated fire risk and observed fire occurrence and burned area. Finally, we compare the results with fire risk simulated by a regional climate model (RCA4 forced by EC-Earth from CORDEX) in order to evaluate its suitability for future projections of fire risk and burned area. [1] Bowman, D. M. et al. Fire in the earth system. Science, v. 324, p. 481-484, 24 apr. 2009. [2] Libonati, R. et al. An Algorithm for Burned Area Detection in the Brazilian Cerrado Using 4 μm MODIS Imagery. Remote Sensing, v. 7, p. 15782-15803, 2015.

  4. Phenology in Germany in the 20th century : methods, analyses and models

    NASA Astrophysics Data System (ADS)

    Schaber, Jörg

    2002-07-01

    The length of the vegetation period (VP) plays a central role for the interannual variation of carbon fixation of terrestrial ecosystems. Observational data analysis has indicated that the length of the VP has increased in the last decades in the northern latitudes mainly due to an advancement of bud burst (BB). This phenomenon has been widely discussed in the context of Global Warming because phenology is correlated to temperatures. Analyzing the patterns of spring phenology over the last century in Southern Germany provided two main findings: - The strong advancement of spring phases especially in the decade before 1999 is not a singular event in the course of the 20th century. Similar trends were also observed in earlier decades. Distinct periods of varying trend behavior for important spring phases could be distinguished. - Marked differences in trend behavior between the early and late spring phases were detected. Early spring phases changed as regards the magnitude of their negative trends from strong negative trends between 1931 and 1948 to moderate negative trends between 1948 and 1984 and back to strong negative trends between 1984 and 1999. Late spring phases showed a different behavior. Negative trends between 1931 and 1948 are followed by marked positive trends between 1948 and 1984 and then strong negative trends between 1984 and 1999. This marked difference in trend development between early and late spring phases was also found all over Germany for the two periods 1951 to 1984 and 1984 to 1999. The dominating influence of temperature on spring phenology and its modifying effect on autumn phenology was confirmed in this thesis. However, - temperature functions determining spring phenology were not significantly correlated with a global annual CO2 signal which was taken as a proxy for a Global Warming pattern. - an index for large scale regional circulation patterns (NAO index) could only to a small part explain the observed phenological variability in

  5. Extension of the SIM Hydrometeorological Reanalysis Over the Entire 20th Century by Combination of Observations and Statistical Downscaling

    NASA Astrophysics Data System (ADS)

    Minvielle, M.; Céron, J.; Page, C.

    2013-12-01

    The SAFRAN-ISBA-MODCOU (SIM) system is a combination of three different components: an atmospheric analysis system (SAFRAN) providing the atmospheric forcing for a land surface model (ISBA) that computes surface water and energy budgets and a hydrological model (MODCOU) that provides river flows and level of several aquifers. The variables generated by the SIM chain constitute the SIM reanalysis and the current version only covers the 1958-2012 period. However, long climate datasets are required for evaluation and verification of climate hindcasts/forecasts and to isolate the contribution of natural decadal variability from that of anthropogenic forcing to climate variations. The aim of this work is to extend of the fine-mesh SIM reanalysis to the entire 20th century, especially focusing on temperature and rainfall over France, but also soil wetness and river flows. This extension will first allow a detailed investigation of the influence of decadal variability on France at very fine spatial scales and will provide crucial information for climate model evaluation. Before 1958, the density of available observations from Météo-France necessary to force SAFRAN (rainfall, snow, wind, temperature, humidity, cloudiness) is much lower than today, and not sufficient to produce a correct SIM reanalysis. That's why is has been decided to use the available atmospheric observations over the past decades combined to a statistical downscaling algorithm to overcome the lack of observations. The DSCLIM software package implemented by the CERFACS and using a weather typing based statistical methodology will be used as statistical downscaling method to reconstruct the atmospheric variables necessary to force the ISBA-MODCOU hydrological component. The first stage of this work was to estimate and compare the bias and strengths of the two approaches in their ability to reconstruct the past decades. In this sense, SIM hydro-meteorological experiments were performed for some recent

  6. Hydrologic drought of water year 2011 compared to four major drought periods of the 20th century in Oklahoma

    USGS Publications Warehouse

    Shivers, Molly J.; Andrews, William J.

    2013-01-01

    Water year 2011 (October 1, 2010, through September 30, 2011) was a year of hydrologic drought (based on streamflow) in Oklahoma and the second-driest year to date (based on precipitation) since 1925. Drought conditions worsened substantially in the summer, with the highest monthly average temperature record for all States being broken by Oklahoma in July (89.1 degrees Fahrenheit), June being the second hottest and August being the hottest on record for those months for the State since 1895. Drought conditions continued into the fall, with all of the State continuing to be in severe to exceptional drought through the end of September. In addition to effects on streamflow and reservoirs, the 2011 drought increased damage from wildfires, led to declarations of states of emergency, water-use restrictions, and outdoor burning bans; caused at least $2 billion of losses in the agricultural sector and higher prices for food and other agricultural products; caused losses of tourism and wildlife; reduced hydropower generation; and lowered groundwater levels in State aquifers. The U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an investigation to compare the severity of the 2011 drought with four previous major hydrologic drought periods during the 20th century – water years 1929–41, 1952–56, 1961–72, and 1976–81. The period of water years 1925–2011 was selected as the period of record because few continuous record streamflow-gaging stations existed before 1925, and gaps in time existed where no streamflow-gaging stations were operated before 1925. In water year 2011, statewide annual precipitation was the 2d lowest, statewide annual streamflow was 16th lowest, and statewide annual runoff was 42d lowest of those 87 years of record. Annual area-averaged precipitation totals by the nine National Weather Service climate divisions from water year 2011 were compared to those during four previous major hydrologic drought

  7. Carbon cycling in extratropical terrestrial ecosystems of the Northern Hemisphere during the 20th century: A modeling analysis of the influences of soil thermal dynamics

    USGS Publications Warehouse

    Zhuang, Q.; McGuire, A.D.; Melillo, J.M.; Clein, J.S.; Dargaville, R.J.; Kicklighter, D.W.; Myneni, R.B.; Dong, J.; Romanovsky, V.E.; Harden, J.; Hobbie, J.E.

    2003-01-01

    There is substantial evidence that soil thermal dynamics are changing in terrestrial ecosystems of the Northern Hemisphere and that these dynamics have implications for the exchange of carbon between terrestrial ecosystems and the atmosphere. To date, large-scale biogeochemical models have been slow to incorporate the effects of soil thermal dynamics on processes that affect carbon exchange with the atmosphere. In this study we incorporated a soil thermal module (STM), appropriate to both permafrost and non-permafrost soils, into a large-scale ecosystem model, version 5.0 of the Terrestrial Ecosystem Model (TEM). We then compared observed regional and seasonal patterns of atmospheric CO2 to simulations of carbon dynamics for terrestrial ecosystems north of 30??N between TEM 5.0 and an earlier version of TEM (version 4.2) that lacked a STM. The timing of the draw-down of atmospheric CO2 at the start of the growing season and the degree of draw-down during the growing season were substantially improved by the consideration of soil thermal dynamics. Both versions of TEM indicate that climate variability and change promoted the loss of carbon from temperate ecosystems during the first half of the 20th century, and promoted carbon storage during the second half of the century. The results of the simulations by TEM suggest that land-use change in temperate latitudes (30-60??N) plays a stronger role than climate change in driving trends for increased uptake of carbon in extratropical terrestrial ecosystems (30-90??N) during the recent decades. In the 1980s the TEM 5.0 simulation estimated that extratropical terrestrial ecosystems stored 0.55 Pg C yr-1. with 0.24 Pg C yr-1 in North America and 0.31 Pg C yr-1 in northern Eurasia. From 1990 through 1995 the model simulated that these ecosystems stored 0.90 Pg C yr-1, with 0.27 Pg C yr-1 stored in North America and 0.63 Pg C yr-1 stored in northern Eurasia. Thus, in comparison to the 1980s, simulated net carbon storage in the

  8. The observed widening of the tropics during the late 20th century and its mechanisms

    NASA Astrophysics Data System (ADS)

    Reichler, T.

    2007-12-01

    Several lines of research indicate that the Tropics have been widening by a few degree latitudes over the past decades and that this widening may continue into the future. Associated with this widening are important shifts in precipitation and other climate elements, raising the question of what are the exact reasons behind the expansion. There is evidence that the increase in tropospheric static stability associated with global warming is driving this shift, but there may be other still unknown factors. Here, we investigate the relative roles of various stratospheric and tropospheric processes for the tropical expansion and conduct attribution experiments with stratosphere and non-stratosphere resolving versions of the latest GFDL general circulation model. The model is forced with different combinations of sea surface temperatures, carbon dioxide, halogen, and ozone concentrations. The impact of each of these factors and of stratospheric model resolution is isolated by comparing different pairs of simulations that differ by only one of these factors. The results highlight that both, tropospheric and stratospheric climate change, play a prominent role for the recent observed widening of the Tropics. We discuss the significance of these results for the future evolution of the tropical width and its realistic prediction.

  9. Jeewanu, or the 'particles of life'. The approach of Krishna Bahadur in 20th century origin of life research.

    PubMed

    Grote, Mathias

    2011-09-01

    Starting in the 1960s, the Indian chemist Krishna Bahadur, from the University of Allahabad, published on organic and inorganic particles that he had synthesized and baptized 'Jeewanu', or 'particle of life'. Bahadur conceived of the Jeewanu as a simple form of the living. These studies are presented in a historical perspective and positioned within mid-20th century research on the origin of life, notably the so-called 'coacervate theory' of the Soviet biochemist Aleksandr I Oparin. The concepts of life proposed by Bahadur, Oparin and others are discussed from a historical standpoint.

  10. The influence of inequality on the standard of living: worldwide anthropometric evidence from the 19th and 20th centuries.

    PubMed

    Blum, Matthias

    2013-12-01

    We provide empirical evidence on the existence of the Pigou-Dalton principle. The latter indicates that aggregate welfare is - ceteris paribus - maximized when incomes of all individuals are equalized (and therefore marginal utility from income is as well). Using anthropometric panel data on 101 countries during the 19th and 20th centuries, we determine that there is a systematic negative and concave relationship between height inequality and average height. The robustness of this relationship is tested by means of several robustness checks, including two instrument variable regressions. These findings help to elucidate the impact of economic inequality on welfare.

  11. The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years

    NASA Astrophysics Data System (ADS)

    Osborn, Timothy J.; Briffa, Keith R.

    2006-02-01

    Periods of widespread warmth or cold are identified by positive or negative deviations that are synchronous across a number of temperature-sensitive proxy records drawn from the Northern Hemisphere. The most significant and longest duration feature during the last 1200 years is the geographical extent of warmth in the middle to late 20th century. Positive anomalies during 890 to 1170 and negative anomalies during 1580 to 1850 are consistent with the concepts of a Medieval Warm Period and a Little Ice Age, but comparison with instrumental temperatures shows the spatial extent of recent warmth to be of greater significance than that during the medieval period.

  12. The spatial extent of 20th-century warmth in the context of the past 1200 years.

    PubMed

    Osborn, Timothy J; Briffa, Keith R

    2006-02-10

    Periods of widespread warmth or cold are identified by positive or negative deviations that are synchronous across a number of temperature-sensitive proxy records drawn from the Northern Hemisphere. The most significant and longest duration feature during the last 1200 years is the geographical extent of warmth in the middle to late 20th century. Positive anomalies during 890 to 1170 and negative anomalies during 1580 to 1850 are consistent with the concepts of a Medieval Warm Period and a Little Ice Age, but comparison with instrumental temperatures shows the spatial extent of recent warmth to be of greater significance than that during the medieval period.

  13. International dimensions of higher education in nursing in Canada: tapping the wisdom of the 20th century while embracing possibilities for the 21st century.

    PubMed

    Ogilvie, Linda D; Paul, Pauline; Burgess-Pinto, Elizabeth

    2007-01-01

    New focus on the internationalization of universities occurred in the late 20th century and higher education in nursing has been quick to embrace the opportunities. In this manuscript, writers provide a brief overview of the nursing and more general literature from the late 20th century relating to key dimensions of internationalization, as well as present data from a survey conducted in 1995-96 of the international activities and dimensions at Canadian faculties/schools of nursing. While it is clear that nurses in Canadian universities were engaged in significant international endeavours in the 20th century, the literature and our experience suggest that the extent of such activity has increased substantially in recent years. Discussion centres on examination of how knowledge generated in the 20th century can inform current internationalization initiatives and on identification of key questions that merit consideration as we move forward in the 21st century.

  14. Dimming over the Oceans: Transient Anthropogenic Aerosol Plumes in the 20th Century

    NASA Astrophysics Data System (ADS)

    Dallafior, Tanja; Folini, Doris; Knutti, Reto; Wild, Martin

    2015-04-01

    Anthropogenic aerosols reduce incoming surface solar radiation (SSR), but the magnitude of this effect for reducing sea surface temperature (SST) is still debated. Using simulations from the global climate model ECHAM5 with the Hamburg Aerosol Module (HAM) and prescribed SSTs, we quantify anthropogenic aerosol dimming over sea surfaces by comparing ensembles, which only differ in anthropogenic aerosol emissions. We isolate the anthropogenic aerosol effect on SSR with sufficiently large ensemble sizes to provide statistically significant results. The following simulation results are obtained: Dimming plumes extend from their source regions with clear seasonality. The latter is predominantly shaped by atmospheric circulation, while interdecadal changes follow the gradual increase in anthropogenic aerosol emissions. Comparing the 1990s with the 1870s, on average, 9.4% (clearsky SSR) or 15.4% (allsky SSR) of the entire ocean surface was affected by anthropogenic aerosol dimming larger than -4 W m-2 (annual mean). Comparing the same time periods, global average anthropogenic dimming over oceans is -2.3 W m-2and -3.4 W m-2 for clearsky and allsky SSR, respectively. Surface dimming is hemispherically asymmetrical with stronger Northern Hemispheric dimming by 2.3 W m-2 and 4.5 W m-2 for clearsky and allsky SSR, respectively. Zonal average clearsky dimming reaches its maximum (5.5 W m-2 ) near the Equator. Allsky dimming peaks at 40° N (-8 W m-2 ) and is regionally larger than clearsky dimming. Regionally, surface dimming can go beyond -20 W m-2 (clearsky) and -40 W m-2 (allsky). Results are a contribution towards better quantifying spatially heterogeneous and time-dependent anthropogenic dimming effects on SSTs.

  15. The Destiny of an Eastern Observatory Follows the Dramatic One of this Part of Europe During the 20th Century

    NASA Astrophysics Data System (ADS)

    Stavinschi, M.

    Founded at the dawn of the 20th century (1908), the Astronomical Observatory of Bucharest had an evolution that followed the destiny of its country. After about half a century along which it lives the usual life of any European institution for research and education, it leaves the education after the World War II, becoming an institute of the Academy. A short period of progress is followed by an unprecedented, total isolation, even from the neighbouring countries. The fall of the communist system in the last decade of the 20th century brings new endeavours, but also a hard competition with the worldwide astronomy. What is important is that in each situation the Romanian astronomers have found the interior resources to resist and to keep the national astronomy competitive, at least as regards some of its fields. Moreover, by setting the South-Eastern Branch of the European Astronomical Society, it wishes to contribute to the finding of local solutions, with the goal of increasing the level of astronomy in countries that face the same problems, the same difficulties.

  16. The global tuberculosis situation. Progress and problems in the 20th century, prospects for the 21st century.

    PubMed

    Cegielski, J Peter; Chin, Daniel P; Espinal, Marcos A; Frieden, Thomas R; Rodriquez Cruz, Rodolfo; Talbot, Elizabeth A; Weil, Diana E C; Zaleskis, Richard; Raviglione, Mario C

    2002-03-01

    Mycobacterium tuberculosis has been identified in prehistoric remains of humans. Despite references to TB by Hippocrates and Galen, humankind had limited understanding of and few tools to defend itself against TB until the later 19th century. Subsequently, landmark advances in the 20th century provided the means to control and prevent this disease. At the same time, epidemiological developments and fundamental problems related to human behavior, socioeconomic conditions, and political circumstances continue to thwart efforts to diminish the burden of suffering and death caused by TB. This article reviewed some of these issues including the global failure of TB control in the late 20th century, the worldwide emergence of drug-resistant TB, the extensive spread of HIV infection and its impact on TB incidence; and changing health care and political environments. The obstacles to TB control remain and will remain challenges in the coming years. Still, recent developments in immunology, biochemistry, and molecular biology suggest that new knowledge and tools are just around the corner. These will enhance the ability to conquer this microbe by the end of the current century.

  17. Regional-scale land-cover change during the 20th century and its consequences for biodiversity.

    PubMed

    Cousins, Sara A O; Auffret, Alistair G; Lindgren, Jessica; Tränk, Louise

    2015-01-01

    Extensive changes in land cover during the 20th century are known to have had detrimental effects on biodiversity in rural landscapes, but the magnitude of change and their ecological effects are not well known on regional scales. We digitized historical maps from the beginning of the 20th century over a 1652 km(2) study area in southeastern Sweden, comparing it to modern-day land cover with a focus on valuable habitat types. Semi-natural grassland cover decreased by over 96 % in the study area, being largely lost to afforestation and silviculture. Grasslands on finer soils were more likely to be converted into modern grassland or arable fields. However, in addition to remaining semi-natural grassland, today's valuable deciduous forest and wetland habitats were mostly grazed grassland in 1900. An analysis of the landscape-level biodiversity revealed that plant species richness was generally more related to the modern landscape, with grazing management being a positive influence on species richness.

  18. Changes in the African American female profile as depicted in fashion magazines during the 20th century.

    PubMed

    Yehezkel, Shaul; Turley, Patrick K

    2004-04-01

    This study evaluated changes in the profiles of African American women presented in fashion magazines during the 20th century. Twenty-six variables were measured on a total of 119 profile photographs collected from various fashion magazines published in the 1940s through the 1990s. The photographs were divided into 6 groups corresponding to the decade in which they were published. A 1-way analysis of variance was performed, and between-group differences were examined with a Tukey multiple comparison procedure. Significant between-group differences (P <.01) were found for anteroposterior lip position, nasolabial angle, and interlabial angle, with increased fullness and more anteriorly positioned lips in the more recent decades. No significant differences were found for the frontonasal angle, the nasal tip angle, and the relationship of the chin to the upper face (total facial angle). Esthetic standards for the African-American female profile changed during the 20th century and, similar to the standards for the white profile, show a trend toward fuller and more anteriorly positioned lips.

  19. Changes in Extreme Warm and Cold Temperatures Associated with 20th Century Global Warming

    NASA Astrophysics Data System (ADS)

    Sardeshmukh, P. D.; Compo, G. P.; McColl, C.; Penland, C.

    2015-12-01

    Has 20thcentury global warming resulted in increases of extreme warm temperatures and decreases of extreme cold temperatures around the globe? One would certainly expect this to be so if the changes in the extreme temperature probabilities were determined only by the mean shift and not by changes in the width and/or shape of the temperature distribution. In reality, however, the latter two effects could also be important. Even ignoring changes of shape, it is easily shown that a 25% reduction of standard deviation, for example, can completely offset the effect of a mean positive shift of 0.5 standardized units on the probabilities of extreme positive values. A 25% increase of standard deviation can similarly offset the effect of the mean shift on the probabilities of extreme negative values. It is possible for such changes of standard deviation to occur in regions of large circulation and storminess changes associated with global warming. With this caveat in mind, we have investigated the change in probability of extreme weekly-averaged near-surface air temperatures, in both winter and summer, from the first half-century (1901-1950) to the last half-century (1960-2009) of the 1901 to 2009 period. We have done this using two newly available global atmospheric datasets (ERA-20C and 20CR-v2c) and large ensembles of global coupled climate model simulations of this period, plus very large ensembles of uncoupled atmospheric model simulations of our own. The results are revealing. In the tropics, the changes in the extreme warm and cold temperature probabilities are indeed generally consistent with those expected from the mean shift of the distribution. Outside the tropics, however, they are generally significantly inconsistent with the mean temperature shift, with many regions showing little or no change in the positive temperature extremes and in some instances even a decrease. In such regions, it is clear that the change in the temperature standard deviation is

  20. Carbon and water balance of European croplands throughout the 20th century

    NASA Astrophysics Data System (ADS)

    Gervois, SéBastien; Ciais, Philippe; de Noblet-Ducoudré, Nathalie; Brisson, Nadine; Vuichard, Nicolas; Viovy, Nicolas

    2008-06-01

    We assessed the effects of rising atmospheric CO2, changing climate, and farmers' practice on the carbon and water balance of European croplands during the past century (1901-2000). The coupled vegetation-crop model ORCHIDEE-STICS is applied over western Europe for C3 crops (winter wheat) and for maize, with prescribed historical agricultural practice changes. Not surprisingly, the enormous crop yield increase observed in all European regions, 300-400% between 1950 and 2000, is found to be dominantly explained by improved practice and varieties selection, rather than by rising CO2 (explaining a ˜11% uniform increase in yield) and changing climate (no further change in yield on average, but causing a decrease of ˜19% in the southern Iberian Peninsula). Agricultural soil carbon stocks in Europe are modeled to have decreased between 1950 and 1970, and since then to have increased again. Thus, the current stocks only differ by 1 ± 6 tC ha-1 from their 1900 value. Compensating effects of increasing yields on the one hand (increasing stocks) and of higher harvest index values and ploughing on the other hand (decreasing stocks) occur. Each of these processes taken individually has the potential to strongly alter the croplands soil carbon balance in the model. Consequently, large uncertainties are associated to the estimated change in carbon stocks between 1901 and 2001, roughly ±6 tC ha-1 a-1. In our most realistic simulation, the current cropland carbon balance is a net sink of 0.16 ± 0.15 tC ha-1 a-1. The annual water balance of cropland soils is influenced by increasing crop water use efficiency, one third of which is caused by rising CO2. However, increasing water use efficiency occurred mainly in spring and winter, when water is not limiting for plant growth, whereas no strong savings of soil water are achieved in summer through elevated CO2. Overall, trends in cultivation practices have caused a 3 times larger increase of water use efficiency than rising CO2.

  1. Changes in the geodiversity of Dutch peatlands inferred from 19th and 20th century landscape paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter Dirk; van den Ancker, Hanneke; Wevers, Nina

    2013-04-01

    Geodiversity is the natural and cultural range of geological, geomorphological and soil features. We analysed the large database of 19th and early 20th century paintings of Simonis and Buunk (www.Simonis-Buunk.com) to track changes in the geodiversity of Dutch peatlands since pre-photographic times. Peat dominated in two of the eight main landscapes of the Netherlands: the Lowland peats in the Holocene west and the Highland peats in the sandy Pleistocene eastern parts. Painters were mainly attracted by the lowland peats. Since more than thousand years, peat plays a major role in Dutch military security, economy, ecology and cultural life. Natural variety and cultural use resulted in a geodiversity that is unique in Europe. There are more than 100 place names with 'veen' (= peat), and surnames with 'veen' are common. Proof of the exploitation of peat for salt and fuel exists from the Roman times onwards. In the 9th century, peatlands were drained and reclaimed for growing wheat. Already in the 11th century, it was necessary to build dikes to prevent flooding, to control waterlevels to avoid further oxidation, and to convert landuse to grassland. But subsidence continued, and in the 14th century windmills were needed to drain the lands and pump the water out. In the 16th century industrial peat exploitation fuelled the rise of industries and cities. All this draining and digging caused the peat surface to shrink. The few remaining living peats are conserved by nature organisations. Geodiversity and landscape paintings In the peat landscapes, popular painting motives were high water levels, the grasslands of the 'Green Heart', the winding streams and remaining lakes. The paintings of landscapes where peat had been removed, show watermanagement adaptations: wind mills, different water levels, canals made for the transport of fuel, bridges, tow paths and the 'plassen', i.e. the lakes left after peat exploitation. The droogmakerijen (reclaimed lakes), now 2 to 5 m below

  2. A Comparison of 20th Century and Holocene Historical Lake Areas and Implications for Reconstruction of Holocene Moisture Balance.

    NASA Astrophysics Data System (ADS)

    Plank, C. P.; Ferreira, M.; Shuman, B.; Ito, E.

    2005-12-01

    for a subset of the lakes included in the historical aerial photo analysis. Interpretation of the GPR profiles reveals that the apparent frequency of erosional events increased towards the west, mimicking the behavior of modern drought response. However, unlike the modern drought response, we detect some large magnitude lake area changes throughout Minnesota during the Holocene. The preservation of well defined packages of lake strata appears to increase eastward, with thicker units between unconformities, but we find low elevation unconformities throughout the state. Taken together, we observe that an east-west gradient of lake area variability has remained in place throughout the Holocene, even if the magnitude of some water level changes was much larger in the past than during the 20th century. The influence of basin morphometry on the clarity of the lake level signal is, however, significant and records are commonly complicated by the evolution of the sedimentary basins from more complex, in some cases multi-basinal forms, to less complex flat-bottom forms.

  3. Seasonally resolved Alpine and Greenland ice core records of anthropogenic HCl emissions over the 20th century

    NASA Astrophysics Data System (ADS)

    Legrand, Michel; Preunkert, Susanne; Wagenbach, Dietmar; Fischer, Hubertus

    2002-06-01

    The continuous highly resolved records of Cl-, Na+, and Ca2+ in ice cores from Col du Dôme (4250 m elevation, French Alps) and Summit (3240 m elevation, central Greenland) are used to reconstruct the history of atmospheric HCl pollution over Europe and Greenland since the early 20th century. The evaluation of the HCl amount in summer snow deposits at high-elevation Alpine sites is complex since continental emissions (soils, halide evaporites, and possibly manure-fertilized fields) account for 80% of the chloride budget and only one fifth of Cl- is related to HCl. During the preindustrial era the HCl content of summer Alpine snow layers fluctuated between 0 and 6 ng g-1, likely in relation with a highly variable interannual biomass burning activity in western Europe. From 1925 to 1960 the HCl levels were slightly higher (3-9 ng g-1), mainly due to growing coal burning emissions in western Europe. In the late 1960s a sharp increase of HCl levels (up to 17 ng g-1) took place as a result of the setup of waste incineration in western Europe, this process contributing 3-4 times more than coal combustion to the HCl budget of summer Alpine snow layers deposited between 1970 and 1990. In winter, sea spray emissions dominate (~78%) the total Cl- level of Alpine snow layers. The HCl trend in these snow layers remained limited to ~2 ng g-1 over the 20th century, likely in relation to waste incineration after 1965. In Greenland snow layers most of particulate Cl- originates from sea spray, 1/3 to 2/3 of Cl- being present as HCl in spring and summer, respectively. The Greenland HCl ice core records indicate a preindustrial HCl level close to 4 ng g-1, which is found to be mainly due to the sea-salt dechlorination, while the contribution of passive volcanic HCl emissions at high northern latitudes can be neglected. The input from sea-salt dechlorination has been enhanced by a factor of 2-3 during the second half of the 20th century similarly to the increase of the atmospheric

  4. Evapotranspiration trends over the eastern United States during the 20th century

    USGS Publications Warehouse

    Kramer, Ryan J.; Bounoua, Lahouari; Zhang, Ping; Wolfe, Robert E.; Huntington, Thomas G.; Imhoff, Marc L.; Thome, Kurtis; Noyce, Genevieve L.

    2015-01-01

    Most models evaluated by the Intergovernmental Panel for Climate change estimate projected increases in temperature and precipitation with rising atmospheric CO2 levels. Researchers have suggested that increases in CO2 and associated increases in temperature and precipitation may stimulate vegetation growth and increase evapotranspiration (ET), which acts as a cooling mechanism, and on a global scale, may slow the climate-warming trend. This hypothesis has been modeled under increased CO2 conditions with models of different vegetation-climate dynamics. The significance of this vegetation negative feedback, however, has varied between models. Here we conduct a century-scale observational analysis of the Eastern US water balance to determine historical evapotranspiration trends and whether vegetation greening has affected these trends. We show that precipitation has increased significantly over the twentieth century while runoff has not. We also show that ET has increased and vegetation growth is partially responsible.

  5. Large scale statistical fluctuations of precipitation in Portugal during the 20th century

    NASA Astrophysics Data System (ADS)

    de Lima, M. P.; Espírito Santo, F.

    2012-12-01

    The impact of changes in climate variables on society and the environment is a major issue worldwide. For example, variations in precipitation over daily, seasonal, annual, and decadal time-scales have an impact on water balances. Although large ranges of spatial and temporal scales are involved, the local impact can be affected by local conditions and regional specificities. This is particularly true and relevant for Portugal, where climate variables are very irregular in space and time. In this study we explore the statistics and temporal structure of precipitation from Portugal over wide ranges of scales using scaling and multifractal methods. In particular, spectral analysis locates the dominant frequencies, and is a useful exploratory tool to identify the upper and lower scales that bound scale-invariant regimes. Moreover, it allows us to investigate climatic fluctuations in the data, over the largest scales, as well as high frequency dynamics revealed by the small scales. The instrumental data investigated are from various locations scattered across Portugal; some of the time series date back to the 19th century. These precipitation time series are the longest available in this geographic region. The focus is on the low frequency weather regime characterized by a spectral plateau with relatively small spectral exponent defined by the power spectrum. This regime extends out to the time scale after which the spectral exponent increases again (i.e. with decreasing frequency), which is interpreted as the signature of the climate regime. The results highlight scaling properties in the data from different origins and identify scaling regimes of special interest for the understanding of climate multi-decadal variability and trends and the establishment of climate change scenarios.

  6. Rapid warming of the ocean around South Georgia, Southern Ocean, during the 20th century: Forcings, characteristics and implications for lower trophic levels

    NASA Astrophysics Data System (ADS)

    Whitehouse, M. J.; Meredith, M. P.; Rothery, P.; Atkinson, A.; Ward, P.; Korb, R. E.

    2008-10-01

    The Southern Ocean is known to have warmed considerably during the second half of the 20th century but there are few locations with data before the 1950s. In addition, assessments of change in this region are hampered by the strong seasonal bias in sampling, with the vast majority of data collected during the austral summer. However, oceanographic measurements near South Georgia span most of the last century, and we here consider almost year-round data from this location over an 81-year period (1925-2006). We observe significant warming between the early and late 20th century, with differential warming between summer and winter months and an indication that late 20th century summer temperatures peaked ˜6 days earlier. To quantify the long-term warming trend in this highly variable data, a mixed model utilising a Residual Maximum Likelihood (REML) method was used. Over the 81-year period, a mean increase of ˜0.9 °C in January and ˜2.3 °C in August was evident in the top 100 m of the water column. Warming diminished below 100 m and approached 0 at 200 m. Thus the long-term warming around South Georgia is substantial—more so than documented previously for the circumpolar warming of the Southern Ocean. We examine potential causal effects of this trend, including local atmospheric and cryospheric change, the influence of upstream waters and the role of coupled modes of climate variability such as El Niño/Southern Oscillation and the Southern Annular Mode (SAM). It is likely that all of these play a part in the observed temperature increase. However, the role of the SAM is strongly indicated, via its likely role in the circumpolar warming trend in the Southern Ocean, and also by the atypical response of the South Georgia region to changes in heat fluxes associated with the SAM. Furthermore, the combination of a regional decline in ice extent and strong upstream warming likely explains a significant part of the strong seasonal variation apparent in the warming

  7. Is the 20th century warming unprecedented in the Siberian north?

    NASA Astrophysics Data System (ADS)

    Sidorova, Olga V.; Saurer, Matthias; Andreev, Andrei; Fritzsche, Diedrich; Opel, Thomas; Naurzbaev, Mukhtar M.; Siegwolf, Rolf

    2013-08-01

    To answer the question "Has the recent warming no analogues in the Siberian north?" we analyzed larch tree samples (Larix gmelinii Rupr.) from permafrost zone in the eastern Taimyr (TAY) (72°N, 102°E) using tree-ring and stable isotope analyses for the Climatic Optimum Period (COP) 4111-3806 BC and Medieval Warm Period (MWP) 917-1150 AD, in comparison to the recent period (RP) 1791-2008 AD. We developed a description of the climatic and environmental changes in the eastern Taimyr using tree-ring width and stable isotope (δ13C, δ18O) data based on statistical verification of the relationships to climatic parameters (temperature and precipitation). Additionally, we compared our new tree-ring and stable isotope data sets with earlier published July temperature and precipitation reconstructions inferred from pollen data of the Lama Lake, Taimyr Peninsula, δ18O ice core data from Akademii Nauk ice cap on Severnaya Zemlya (SZ) and δ18O ice core data from Greenland (GISP2), as well as tree-ring width and stable carbon and oxygen isotope data from northeastern Yakutia (YAK). We found that the COP in TAY was warmer and drier compared to the MWP but rather similar to the RP. Our results indicate that the MWP in TAY started earlier and was wetter than in YAK. July precipitation reconstructions obtained from pollen data of the Lama Lake, oxygen isotope data from SZ and our carbon isotopes in tree cellulose agree well and indicate wetter climate conditions during the MWP. Consistent large-scale patterns were reflected in significant links between oxygen isotope data in tree cellulose from TAY and YAK, and oxygen isotope data from SZ and GISP2 during the MWP and the RP. Finally, we showed that the recent warming is not unprecedented in the Siberian north. Similar climate conditions were recorded by tree-rings, stable isotopes, pollen, and ice core data 6000 years ago.

  8. Downward shortwave radiation trends in Europe since the 20th century: what we know from direct measurements and sunshine duration records

    NASA Astrophysics Data System (ADS)

    Sanchez-Lorenzo, A.; Wild, M.; Calbo Angrill, J.; Brunetti, M.; van den Besselaar, E.; Guijarro, J. A.; Sanchez-Romero, A.; Klein Tank, A.; Manara, V.; Vicente-Serrano, S. M.; Palle Bago, E.; Wang, K.; Hakuba, M.; Trentmann, J.

    2014-12-01

    The first part of this work presents results based on the longest series measuring downward shortwave radiation (DSR) available at the Global Energy Balance Archive (GEBA) over Europe. Particular emphasis is placed upon the quality control and homogenization of the dataset, which has been checked for temporal homogeneity by means of different relative homogeneity tests. The mean annual DSR series shows an increase from the 1930s to the early 1950s (i.e. early brightening period), followed by a reduction until mid-1980s (i.e., dimming period), and ending with an increase up to the present (i.e., brightening period). Unfortunately, there exists a substantial gap in direct measurements of DSR as only few stations in Europe provide records before the 1960s. To overcome the lack of direct measurements, the analysis can be supported with other proxy variables more widely measured, such as sunshine duration (SD) records. Thus, in this work we also present the reconstructed DSR variations since late 19th century in Europe based on the SD series over Europe with around one century of records, some of them starting in the 1880s. The reconstructed DSR variations have been estimated by using the relationship found between the SD series and a satellite-derived DSR dataset (0.03 x 0.03 of spatial resolution), provided by the EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF), during the common 1983-2005 subperiod. The reconstructed records have been validated by using the GEBA series described in the first part of this work. The temporal evolution of the mean DSR annual series since the 1950s is characterized by the well-known dimming and brightening periods. Moreover, an early brightening period is also detected during the first half of the 20th century, although regional differences are observed with areas over Europe where the DSR show no increase in this subperiod. Interestingly, the reconstructed DSR also highlight an absolute minimum in 1912, which

  9. Wartime infections and tragedies at the beginning of the 20th century in the Eastern part of Turkey.

    PubMed

    Karagoz, Ergenekon; Turhan, Vedat; Hatipoglu, Mustafa; Ozkuzugudenli, Bulent

    2017-03-01

    In the early 20th century, Europe and the Ottoman Empire as a whole experienced a large number of epidemic diseases, and several wars. During World War I (WW1) a general mobilization of the medical services under Ottoman Empire rule was enacted. However, shortages of food and water, unfavourable weather and poor sanitary conditions resulted in numerous diseases at the battle fronts. Indeed, during the Ottoman-Russian war on the Eastern Front, the Turks suffered massive loss of life. This article therefore emphasises that during WW1, such loss of life in the Ottoman Army on the Eastern Front, which was one of the key fronts of the war, was mainly due to epidemic diseases rather than battles.

  10. Geologic and hydrologic hazards in glacierized basins in North America resulting from 19th and 20th century global warming

    USGS Publications Warehouse

    O'Connor, J. E.; Costa, J.E.

    1993-01-01

    Alpine glacier retreat resulting from global warming since the close of the Little Ice Age in the 19th and 20th centuries has increased the risk and incidence of some geologic and hydrologic hazards in mountainous alpine regions of North America. Abundant loose debris in recently deglaciated areas at the toe of alpine glaciers provides a ready source of sediment during rainstorms or outburst floods. This sediment can cause debris flows and sedimentation problems in downstream areas. Moraines built during the Little Ice Age can trap and store large volumes of water. These natural dams have no controlled outlets and can fail without warning. Many glacier-dammed lakes have grown in size, while ice dams have shrunk, resulting in greater risks of ice-dam failure. The retreat and thinning of glacier ice has left oversteepened, unstable valley walls and has led to increased incidence of rock and debris avalanches. ?? 1993 Kluwer Academic Publishers.

  11. Antagonism and accommodation: interpreting the relationship between public health and medicine in the United States during the 20th century.

    PubMed Central

    Brandt, A M; Gardner, M

    2000-01-01

    Throughout the course of the 20th century, many observers have noted important tensions and antipathies between public health and medicine. At the same time, reformers have often called for better engagement and collaboration between the 2 fields. This article examines the history of the relationship between medicine and public health to examine how they developed as separate and often conflicting professions. The historical character of this relationship can be understood only in the context of institutional developments in professional education, the rise of the biomedical model of disease, and the epidemiologic transition from infectious disease to the predominance of systemic chronic diseases. Many problems in the contemporary burden of disease pose opportunities for effective collaborations between population-based and clinical interventions. A stronger alliance between public health and medicine through accommodation to a reductionist biomedicine, however, threatens to subvert public health's historical commitment to understanding and addressing the social roots of disease. PMID:10800418

  12. Metallographic study of articles of the Kamensk iron foundry and iron works produced in the 18th-20th centuries

    NASA Astrophysics Data System (ADS)

    Schastlivtsev, V. M.; Gizhevski, B. A.; Khlebnikova, Yu. V.; Naumov, S. V.; Egorova, L. Yu.

    2016-02-01

    Results have been presented for studies of the microstructure and chemical composition of a number of articles made of iron and cast iron at the Kamensk plant, which cover the period from the start of the production of iron on the territory of the city of Kamensk-Ural'skii at the turn of the 17th-18th centuries to the beginning of the 20th century. Differences in the composition of the Kamensk cast iron and modern grades of foundry cast iron have been established. Possible sources of technological difficulties and production waste at the Kamensk plant have been revealed. The potential of metallographic studies for the attribution of historical articles made of ferrous metals are shown.

  13. The Lowland Rivers of The Netherlands - Geodiversity and Cultural Heritage on 19th and early 20th century Landscape Paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter Dirk; van den Ancker, Hanneke; Moes, Constance

    2015-04-01

    One of the major Dutch landscapes is formed by lowland rivers. They divide the country in a southern and a northern part, both physically and culturally. We screened the freely available database of 19th and early 20th century paintings of Simonis & Buunk, www.simonis-buunk.com, looking for lowland river landscapes depicting geodiversity and cultural heritage relationships (See References for other landscapes). Emperor Napoleon declared The Netherlands as naturally belonging to his empire as its lands originated from muds originating in France and transported there by the big rivers. A description that may have given rise to the idea of the Netherlands as a delta, but from a geomorphological perspective The Netherlands consists of series of river plains of terrestrial origin, of which the north-western part are subsiding and invaded by the sea. Now, the rivers Meuse and Rhine (including its branches Waal and IJssel) meander through ever larger river plains before reaching the North Sea. They end in estuaries, something one would not expect of rivers with catchments discharging a large part of Western Europe. Apart from the geological subsidence, the estuaries might be due to human interference, the exploitation of peat and building of dikes since the 11th century, heavy storms and the strong tidal currents. Archaeological finds show Vikings and Romans already used the river Rhine system for trading and transporting goods. During the Roman Empire the Rhine was part of The Limes, the northern defence line of the empire. Romans already influenced the distribution of water over the different river branches. Since the middle of the 19th century groins and canalization drastically changed the character of the rivers. The 19th and early 20th century landscape paintings illustrate this change as well as changes in land use. Examples of geodiversity and cultural heritage relationships shown: - meanders and irregular banks disappear as river management increases, i.a. bends

  14. The pioneering use of a questionnaire to investigate a food borne disease outbreak in early 20th century Britain

    PubMed Central

    Morabia, A.; Hardy, A.

    2005-01-01

    This paper describes the investigation by a British local government board inspector in 1902, H Timbrell Bulstrode, into the cause of an outbreak of enteric fever after a mayoral banquet given at Winchester. This investigation helped to confirm the role of oysters as an agent of transmission of typhoid fever. The data are also reanalysed using a modern approach, which confirmed the role of oysters (odds ratio = 11.2, 95% CI 2.5 to 50.1). This episode is illustrative of the role of British public health inspectors at the turn of the 20th century as well as of the conditions in which the technique of investigating outbreaks of food borne diseases using a standardised menu was developed. Current methods of outbreak investigations that differ from Bulstrode's pioneering work are also discussed. PMID:15650138

  15. Borders, Laborers, and Racialized Medicalization Mexican Immigration and US Public Health Practices in the 20th Century

    PubMed Central

    2011-01-01

    Throughout the 20th century, US public health and immigration policies intersected with and informed one another in the country's response to Mexican immigration. Three historical episodes illustrate how perceived racial differences influenced disease diagnosis: a 1916 typhus outbreak, the midcentury Bracero Program, and medical deportations that are taking place today. Disease, or just the threat of it, marked Mexicans as foreign, just as much as phenotype, native language, accent, or clothing. A focus on race rendered other factors and structures, such as poor working conditions or structural inequalities in health care, invisible. This attitude had long-term effects on immigration policy, as well as on how Mexicans were received in the United States. PMID:21493932

  16. The evolution of casualty evacuation in the British Army in the 20th century (Part 2)--1918 to 1945.

    PubMed

    Bricknell, M C M

    2002-09-01

    This is the second in a series of papers that examine the evolution of the military casualty evacuation chain during the 20th century. The Spanish Civil War demonstrated to the world the revolutionary tactic of 'Blitzkrieg' developed by the Germans. This and the experience of the British Expeditionary Force in 1940 emphasised the need for mobility in forward medical units. The campaign in the Western Desert led to the creation of a number of new units such as the Field Surgical Unit and the Field Transfusion Unit which were introduced across the British Army as a result of the findings of the Hartgill Committee. The aeroplane transformed the evacuation chain from CCSs to base hospitals and beyond.

  17. The Decline of Smoking among Female Birth Cohorts in China in the 20(th) Century: A Case of Arrested Diffusion?

    PubMed

    Hermalin, Albert I; Lowry, Deborah S

    2012-08-01

    The smoking prevalence by age of women in China is distinct from most other countries in showing more frequent smoking among older women than younger. Using newly developed birth cohort histories of smoking, the authors demonstrate that although over one quarter of women born 1908-1912 smoked, levels of smoking declined across successive cohorts. This occurred despite high rates of smoking by men and the wide availability of cigarettes. The analysis shows how this pattern is counter to that predicted by the leading theoretical perspectives on the diffusion of smoking and suggests that it arose out of a mix of Confucian traditions relating to gender and the socio-economic and political events early in the 20(th) century which placed emerging women's identities in conflict with national identities. That a similar pattern of smoking is evident in Japan and Korea, two countries with strong cultural affinities to China, is used to buttress the argument.

  18. [Open circuit: the exchange of medical and scientific knowledge in Latin American in the early 20th century].

    PubMed

    Almeida, Marta de

    2006-01-01

    This article discusses the Latin American Medical Congresses and International Exhibitions on Hygiene held in the first few decades of the 20th century as a strategy for underpinning and influencing medical knowledge within the specialized community itself and for public authorities, which were fundamental for presenting to society at large as they were seen as the vehicles of official know-how on the art of medicating. These events made up part of a broader movement to internationalize and coordinate the professional field of medicine in Latin America. The article further suggests that the activities that took place during these events played a key role in the propagation of ideas and exchange of experience between Latin American nations, forming a network of scientific exchange in the continent.

  19. Sante De Sanctis (1862-1935), a forerunner of the 20th century research on sleep and dreaming.

    PubMed

    Foschi, Renato; Lombardo, Giovanni Pietro; Morgese, Giorgia

    2015-01-01

    This article aims to reconstruct the elements of continuity and/or discontinuity in Sante De Sanctis' (1862-1935) contributions in the scientific understanding of sleep and dreaming as compared to the scientific research of his time. An Italian psychologist and psychiatrist, De Sanctis, in his work conducted between the 19th and 20th centuries, has framed the study of dreams using multi-methodology. In addition, De Sanctis experimentally established the correspondence between the deep and desynchronization phases of sleep with respect to dreaming. In this context, De Sanctis' subjects described the periodicity of sleep and consciousness, influencing the explanations of the themes that modern sleep research has, after decades, systematically studied. We demonstrate that De Sanctis' work has been underestimated, and in our opinion, deserves to be reconsidered as a source of the psychophysiological explanation of dreams and sleep. Finally, we present a graphical representation of De Sanctis' psycho- and neurophysiological model of dreaming.

  20. [The delayed emergence of the printing chronograph in French observatories (late 19th - early 20th centuries].

    PubMed

    Lamy, Jérôme; Soulu, Frédéric

    2015-01-01

    Western observatories became scientific factories from the mid-19th century. Astrometry symbolized the transition to an industrious economy of scientific practices. The printing chronograph, which reduced the personal equations of the observers, was, first in the United States, then in England, the symbolic instrument of this transformation. In France, the initiatives of the astronomer Liais were prototypical. In the practices of the Hendaye Observatory, and thanks to the abbé Verschaffel, the printing chronograph made its definitive entry in French observatories at the beginning of the 20th century. Excessive centralization of French astronomy, the authoritarianism of Urbain Le Verrier, the director of the Paris Observatory, and the poor market for scientific instruments explain why the printing chronograph took root, belatedly, in France.

  1. The Decline of Smoking among Female Birth Cohorts in China in the 20th Century: A Case of Arrested Diffusion?

    PubMed Central

    Hermalin, Albert I.; Lowry, Deborah S.

    2012-01-01

    The smoking prevalence by age of women in China is distinct from most other countries in showing more frequent smoking among older women than younger. Using newly developed birth cohort histories of smoking, the authors demonstrate that although over one quarter of women born 1908–1912 smoked, levels of smoking declined across successive cohorts. This occurred despite high rates of smoking by men and the wide availability of cigarettes. The analysis shows how this pattern is counter to that predicted by the leading theoretical perspectives on the diffusion of smoking and suggests that it arose out of a mix of Confucian traditions relating to gender and the socio-economic and political events early in the 20th century which placed emerging women's identities in conflict with national identities. That a similar pattern of smoking is evident in Japan and Korea, two countries with strong cultural affinities to China, is used to buttress the argument. PMID:22904585

  2. Louis Nico Marie Duysens (March 15, 1921-September 8, 2015): a leading biophysicist of the 20th century.

    PubMed

    Govindjee; Pulles, M P J

    2016-06-01

    Louis Nico Marie (L. N. M.) Duijsens (Duysens) was one of the giants in the biophysics of photosynthesis. His PhD thesis "Transfer of Excitation Energy in Photosynthesis" (Duysens, 1952) is a classic; he introduced light-induced absorption difference spectroscopy to photosynthesis research and proved the existence of reaction centers, introducing advanced methods from physics to understand biological processes. Further, it is his 1959-1961 seminal work, with Jan Amesz, that provided evidence for the existence of the series scheme for the two light reactions in oxygenic photosynthesis. In one word, he was one of the master biophysicists of the 20th century-who provided direct measurements on many key intermediates, and made us understand the intricacies of photosynthesis with a simplicity that no one else ever did. We present here our personal perspective of the scientist that Lou Duysens was. For an earlier perspective, see van Grondelle and van Gorkom (Photosynth Res 120: 3-7, 2014).

  3. The history of ‘Female Sexual Dysfunction’ as a mental disorder in the 20th century

    PubMed Central

    Angel, Katherine

    2010-01-01

    Purpose of review To provide an overview of conceptualizations of female sexual problems, and ‘Female Sexual Dysfunction’ in particular, throughout the 20th century, especially in relation to psychiatry and mental illness. Recent findings In the past 15 years, there has been an increase in both medical and public discourse about ‘Female Sexual Dysfunction’. I discuss a variety of literature sources dealing with female sexual problems, where these are understood variously as problems of developmental psychopathology, as technical phenomena to be resolved through education, or as medical problems to be addressed pharmaceutically. Summary The stigma of mental illness shapes much recent discussion of female sexual problems, as does the legacy of the postwar critique of psychodynamic psychiatry. PMID:20802336

  4. 2014 Beller Lectureship: Chinese Physicists Educated in the Great Britain during the First Half of the 20th Century

    NASA Astrophysics Data System (ADS)

    Yin, Xiaodong

    2014-03-01

    More than 30 Chinese students went to Great Britain to study physics during the first half of the 20th century. They were concentrated in London University (13), Cambridge University (9), Edinburgh University (5) and Manchester University (3) and so on. All these students returned to China after finishing their study and most of them later became excellent physicists. They contributed to the development of physics in China. Based on newly discovered primary materials concerning these Chinese physicists, I examine their study in UK and subsequent accomplishments after their return to China. I will then analyze these British-trained Chinese physicists and compare them with those studying in Japan and America. I would argue that Chinese physicists educated in Britain have high degree of specialization as a whole and formed unique style. They made certain unique contributions to Chinese physics development.

  5. Borders, laborers, and racialized medicalization Mexican immigration and US public health practices in the 20th century.

    PubMed

    Molina, Natalia

    2011-06-01

    Throughout the 20th century, US public health and immigration policies intersected with and informed one another in the country's response to Mexican immigration. Three historical episodes illustrate how perceived racial differences influenced disease diagnosis: a 1916 typhus outbreak, the midcentury Bracero Program, and medical deportations that are taking place today. Disease, or just the threat of it, marked Mexicans as foreign, just as much as phenotype, native language, accent, or clothing. A focus on race rendered other factors and structures, such as poor working conditions or structural inequalities in health care, invisible. This attitude had long-term effects on immigration policy, as well as on how Mexicans were received in the United States.

  6. Reproduction in cold water: paradigm changes in the 20th century and a role for cidaroid sea urchins

    NASA Astrophysics Data System (ADS)

    Pearse, John S.; Lockhart, Susanne J.

    2004-07-01

    At the beginning of the 20th century, powerful ideas about the biology of marine animals in cold waters (polar and deep sea) were in early stages of development. (1) General similarities between some Arctic and Antarctic species suggested a past or present continuity between the poles, possibly through tropical submergence. (2) The discovery of subantarctic species brooding their offspring suggested that supposedly harsh polar conditions select against species with pelagic, dispersive larvae. (3) The linkage between seasonal temperature changes and seasonal reproduction suggested that where temperatures were constant, as in polar and deep seas, reproduction would be aseasonal or continuous throughout the year. (4) Recognition of the phenomenon of metabolic temperature adaptation suggested that animals living in cold water should exhibit rates of physiological processes similar to rates in warmer environments. Observations and experiments throughout the first half of the 20th century generally supported and reinforced these ideas. During the second half of the 20th century, however, the generality of these paradigms broke down. Detailed analyses of fuller data indicated that Arctic, Antarctic, and deep-sea faunas are not the same and probably have different phylogenies reflecting different vicariant histories. Moreover, many species in these habitats have pelagic larvae, they generally spawn seasonally, and their physiological processes (respiration, gametogenesis, development, feeding, growth) are slow, showing little evidence of the expected temperature adaptation. Nevertheless, entering the 21st century, we are challenged by important exceptions that do support many of the earlier ideas. Bipolarity in some groups does indicate relict distributions, and other groups show equatorial submergence. Moreover, major species-rich clades in the Antarctic (unlike the Arctic) do brood their young. Most species with pelagic larvae produce non-feeding (lecithotrophic) larvae

  7. Historical Analyses of Disordered Handwriting: Perspectives on Early 20th-Century Material From a German Psychiatric Hospital.

    PubMed

    Schiegg, Markus; Thorpe, Deborah

    2017-01-01

    Handwritten texts carry significant information, extending beyond the meaning of their words. Modern neurology, for example, benefits from the interpretation of the graphic features of writing and drawing for the diagnosis and monitoring of diseases and disorders. This article examines how handwriting analysis can be used, and has been used historically, as a methodological tool for the assessment of medical conditions and how this enhances our understanding of historical contexts of writing. We analyze handwritten material, writing tests and letters, from patients in an early 20th-century psychiatric hospital in southern Germany (Irsee/Kaufbeuren). In this institution, early psychiatrists assessed handwriting features, providing us novel insights into the earliest practices of psychiatric handwriting analysis, which can be connected to Berkenkotter's research on medical admission records. We finally consider the degree to which historical handwriting bears semiotic potential to explain the psychological state and personality of a writer, and how future research in written communication should approach these sources.

  8. Fetal alcohol syndrome at the turn of the 20th century. An unexpected explanation of the Kallikak family.

    PubMed

    Karp, R J; Qazi, Q H; Moller, K A; Angelo, W A; Davis, J M

    1995-01-01

    At the turn of the 20th century, studies of a family known in the literature as the Kallikaks were used to document the hereditary nature of mental retardation, poverty, and antisocial behavior. This family was said to authenticate eugenic theory, which states that heritable characteristics carried by individuals on "independent unit characters are unalterable determinants of behavior and performance. A review of the original Kallikak data, however, suggests that in utero exposure to alcohol rather than heredity contributed significantly to the transgenerational learning failure seen throughout the Kallikak pedigree. However, eugenic theory was so thoroughly accepted that the promotion and acceptance of "hereditary feeblemindedness" as the principal cause of the developmental problems in the affected offspring smothered the research efforts on in utero effects of alcohol until long after the eugenic concepts were abandoned later in the century.

  9. Specific features of the spread of tuberculosis in Russia at the end of the 20th century.

    PubMed

    Shilova, M V

    2001-12-01

    This study shows the dynamics of the epidemiological process over the last decade and presents the causes of the deterioration in TB control. Explanations are given for the TB mortality rate increase, the trustworthiness of the data, and the factors influencing its formation. The present-day TB epidemiological situation in Russia is characterized by an increase in exogenous infection. Peaks of epidemiological deterioration were registered in 1993 and 1999. Marked deterioration of the epidemiological situation in 1999 resulted from an economic crisis in August 1998 and a consequent dramatic decrease in the living standards of the population. In the 1990s this trend has changed. TB infection spreads according to trends that are quite similar to those at the beginning of 20th century. The official TB morbidity rate does not reflect the true level of incidence because of undetected TB cases (approx. 10%).

  10. [The construction of a medical discipline and its challenges: Orthopedics in Switzerland during the 19th and 20th centuries].

    PubMed

    Kaba, Mariama

    2015-07-01

    During the 19th century, numerous figures, with different qualifications, claimed to practice orthopedics: doctors, surgeons, inventors of equipment and instruments, and other empiricists. They performed certain types of techniques, massages, surgical operationsand/or fitted prostheses. The polysemous notion of orthopedics had created conflicts of interest that would reach their height at the end of the 19th century. The integration of orthopedics into the training at the university level enhanced its proximity to surgery, a discipline that has dominated the so-called modern medicine. During the 20th century, various medical branches defend the legitimacy of certain orthopedic practices, thereby threating to a degree the title itself of this specialization. By examining the challenges that have shaped the history of orthopedics in Switzerland, this article also seeks to shed light on the strategies that were implemented in adopting a medical and technical discipline within a transforming society.

  11. Changes in orographic extreme rain events over Meghalaya Hills in Northeast India in the 20th century

    NASA Astrophysics Data System (ADS)

    Prokop, Pawel; Walanus, Adam

    2014-05-01

    The interaction between large-scale circulation and the local topography plays a crucial role in determining the spatial distribution of rainfall over the Meghalaya Hills. The Meghalaya plateau forms the first orographic barrier for the humid southwest monsoon winds, on their way from the Bay of Bengal to the Himalayas. The annual rainfall distribution varies from 12,000 mm in Cherrapunji (1300 m a.s.l.) located at the southern edge of the plateau to 2200 mm in Shillong (1598 m a.s.l.) and only 1600 mm in Gauhati (54 m a.s.l.), located to the north in the Brahmaputra valley. The daily rainfall data for the 20th century, from these three stations across the region, constitute the basis for statistical analysis. However, the low signal-to-noise ratio makes it difficult to find any significant departure from the simplest null hypothesis of stability of rain record at individual stations. Comparing the two halves of the century, provided strongly significant results in the numbers of days with extreme rain. The number of Fourier Transform extreme amplitudes also differed significantly. Increasingly heavy events during the summer monsoon season, and partly in the pre- and post-monsoon seasons, are offset by a weakening in the winter monsoon season, so that the annual mean rainfall does not show a significant trend over the Meghalaya Hills. Apart from a greater number of years with noticeable extreme rainfall events in the second half of the 20th century, we can also observe a more pronounced quasi-periodicity of the 10-20 and 30-60 days during the same period.

  12. 20th Century Black Carbon and Dust Deposition on South Cascade Glacier, Washington Reconstructed from the South Cascade Ice Core

    NASA Astrophysics Data System (ADS)

    Pittenger, D.; Kaspari, S.

    2014-12-01

    Glaciers and seasonal snowpack in Washington State have undergone significant decline over the past 50 years. While warming global temperatures are widely recognized as the cause of glacial decline, the deposition of light absorbing impurities (LAI) can also contribute to increased melt. The primary sources of LAI are dust and black carbon (BC). These particles are subject to atmospheric transport and undergo both wet and dry deposition. When LAI are deposited, the albedo of the glacial surface is lowered resulting in increased energy absorption and melt. We analyzed a 158 m long ice core collected from the South Cascade Glacier in the North Cascades of Washington State to reconstruct 20th century LAI deposition. The ice core was analyzed for BC using a Single Particle Soot Photometer (SP2), and for dust using gravimetric filtration and ICP-MS. Pb210 analysis indicates that the bottom age of the ice core is 1916 +/- 18 AD, and tritium analysis is being conducted to further constrain the depth-age scale. Background and peak BC concentrations increased with depth over the top third of the core, indicating higher atmospheric BC loading at the time of deposition. Several segments of the ice core contained visible black impurity layers and analysis determined these outlying samples contained BC concentrations exceeding 100ng/g (maximum = 558 ng/g). These visible impurity layers are distributed throughout the entire length of the core and may originate from regional forest fire activity, a major natural source of BC. Dust concentrations were variable throughout the entire record, with elevated concentrations occurring between 48 - 60 m and 96 - 102 m. The BC and Fe ICPMS data are used to estimate the relative absorption of BC and dust. The chronology of LAI deposition throughout the 20th century will enable the modeling of historic albedo reductions on South Cascade Glacier, and aid in assessing the contribution of LAI to glacial melt.

  13. Stature in 19th and early 20th century Copenhagen. A comparative study based on skeletal remains.

    PubMed

    Jørkov, Marie Louise S

    2015-12-01

    Individual stature depends on multifactorial causes and is often used as a proxy for investigating the biological standard of living. While the majority of European studies on 19th and 20th century populations are based on conscript heights, stature derived from skeletal remains are scarce. For the first time in Denmark this study makes a comparison between skeletal stature and contemporary Danish conscript heights and investigates stature of males and females temporally and between socially distinct individuals and populations in 19th and early 20th century Copenhagen. A total of 357 individuals (181 males, 176 females) excavated at the Assistens cemetery in Copenhagen is analyzed. Two stature regression formulae (Trotter, 1970; Boldsen, 1990) are applied using femur measurements and evaluated compared to conscript heights. The results indicate that mean male stature using Boldsen follows a similar trend as the Danish conscript heights and that Trotter overestimate stature by ca. 6cm over Boldsen. At an inter population level statistically significant differences in male stature are observed between first and second half of the 19th century towards a slight stature decrease and larger variation while there are no significant changes observed in female stature. There are insignificant differences in stature between middle and high class individuals, but male stature differs statistically between cemeteries (p=0.000) representing middle/high class, paupers and navy employees, respectively. Female stature had no significant wealth gradient (p=0.516). This study provides new evidence of stature among males and females during the 19th century and suggests that males may have been more sensitive to changes in environmental living and nutrition than females.

  14. Spatiotemporal patterns of terrestrial carbon cycle during the 20th century

    NASA Astrophysics Data System (ADS)

    Piao, Shilong; Ciais, Philippe; Friedlingstein, Pierre; de Noblet-Ducoudré, Nathalie; Cadule, Patricia; Viovy, Nicolas; Wang, Tao

    2009-12-01

    We evaluated how climate change, rising atmospheric CO2 concentration, and land use change influenced the terrestrial carbon (C) cycle for the last century using a process-based ecosystem model. Over the last century, the modeled land use change emitted about 129 Pg of C to the atmosphere. About 76% (or 98 Pg C) of this emission, however, was offset by net C uptake on land driven by climate changes and rising atmospheric CO2 concentration. Thus, the modeled net release of C from the terrestrial ecosystems to the atmosphere from 1901 to 2002 is about 31 Pg C. Global net primary productivity (NPP) has significantly increased by 14% during the last century, especially since the 1970s. From 1980 to 2002, global NPP increased with an average increase rate of 0.4% yr-1. At global scale, such an increase seems to be primarily attributed to the increase in atmospheric CO2 concentration, and then to precipitation change. Over the last 2 decades, climate change and rising CO2 forced the land carbon sink (1.6 Pg C yr-1 for 1980s and 2.2 Pg C yr-1 for 1990s) to be larger than land use change driven carbon emissions (1.0 Pg C yr-1 for 1980s and 1.2 Pg C yr-1 for 1990s), resulting a net land sink of 0.5 Pg C yr-1 in the 1980s and of 1.0 Pg C yr-1 in the 1990s. The largest C emission from land use change appeared in tropical regions with an average emission of 0.6 Pg C yr-1 in 1980s and 0.7 Pg C yr-1 in 1990s, which is slightly larger than net carbon uptake due to CO2 fertilization and climate change. Thus, net carbon balance of tropical lands is close to neutral over the past 2 decades (about 0.13 Pg C yr-1 in 1980s and 0.03 Pg C yr-1 in 1990s). We also found that current global warming has already started accelerating C loss from terrestrial ecosystems, by enhanced decomposition of soil organic carbon. In response to warming trends only, the global net carbon uptake significantly decreased, offsetting about 70% of the increase in global net carbon uptake owing to CO2

  15. United States History: Eyes on the Economy. Volume Two: Through the 20th Century.

    ERIC Educational Resources Information Center

    Schug, Mark C.; Caldwell, Jean; Wentworth, Donald R.; Kraig, Beth; Highsmith, Robert J.

    This lesson guide is designed to help U.S. history teachers and students in grades 8-11 examine historic events through basic economic reasoning. It lends itself to instruction grounded in inquiry learning, direct instruction, and cooperative learning. It calls for students to be engaged in case studies, simulation exercises, and group work, as…

  16. Tree ring evidence for limited direct CO2 fertilization of forests over the 20th century

    NASA Astrophysics Data System (ADS)

    Gedalof, Ze'ev; Berg, Aaron A.

    2010-09-01

    The effect that rising atmospheric CO2 levels will have on forest productivity and water use efficiency remains uncertain, yet it has critical implications for future rates of carbon sequestration and forest distributions. Efforts to understand the effect that rising CO2 will have on forests are largely based on growth chamber studies of seedlings, and the relatively small number of FACE sites. Inferences from these studies are limited by their generally short durations, artificial growing conditions, unnatural step-increases in CO2 concentrations, and poor replication. Here we analyze the global record of annual radial tree growth, derived from the International Tree ring Data Bank (ITRDB), for evidence of increasing growth rates that cannot be explained by climatic change alone, and for evidence of decreasing sensitivity to drought. We find that approximately 20 percent of sites globally exhibit increasing trends in growth that cannot be attributed to climatic causes, nitrogen deposition, elevation, or latitude, which we attribute to a direct CO2 fertilization effect. No differences were found between species in their likelihood to exhibit growth increases attributable to CO2 fertilization, although Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa), the two most commonly sampled species in the ITRDB, exhibit a CO2 fertilization signal at frequencies very near their upper and lower confidence limits respectively. Overall these results suggest that CO2 fertilization of forests will not counteract emissions or slow warming in any substantial fashion, but do suggest that future forest dynamics may differ from those seen today depending on site conditions and individual species' responses to elevated CO2.

  17. Large scale changes in 20th century black carbon deposition to Antarctica

    NASA Astrophysics Data System (ADS)

    Bisiaux, M. M.; Edwards, R.; McConnell, J. R.; Curran, M. A. J.; van Ommen, T. D.; Smith, A. M.; Neumann, T. A.; Pasteris, D. R.; Penner, J. E.; Taylor, K.

    2011-10-01

    Refractory black carbon aerosols (rBC) emitted by biomass burning (fires) and fossil fuel combustion, affect global climate and atmospheric chemistry. In the Southern Hemisphere (SH), rBC is transported in the atmosphere from low latitudes to Antarctica and deposited to the polar ice sheet preserving a history of emissions and atmospheric transport. Here, we present two high-resolution Antarctic rBC ice core records drilled from the West Antarctic Ice Sheet divide and Law Dome on the periphery of the East Antarctic ice sheet. Separated by ~3500 km, the records span calendar years 1850-2001 and reflect the rBC distribution over the Indian and Pacific ocean sectors of the Southern Ocean. Highly correlated over the past 60 yr, the records show that coherent large-scale changes in SH rBC occurred at decadal to inter-annual time scales, notably in ENSO-like periodicities. Decadal trends in the records are similar to inventories of SH rBC emissions from grass fires and biofuels. The combined records suggest a large-scale reduction in rBC from 1950 to 1990 over the remote Southern Hemisphere.

  18. A comparison of two exceptional snowstorms during the early 20th century

    NASA Technical Reports Server (NTRS)

    Weiss, Alan D.; Kocin, Paul J.; Wagner, Joseph J.

    1989-01-01

    Two East-Coast snowstorms of the early twentieth century, which generated massive accumulations over portions of the Atlantic coastal plain, are described. The 'Christmas Storm' of December 25-26, 1909 produced snowfalls of greater than 25 cm over most of the Northeast Corridor from Maryland to southern New England, while the 'Knickerbocker Storm' of January 27-29, 1922 produced a total of 71 cm at Washington, DC. The storms are examined by constructing surface-weather analyses based on original data; surface observations for the continental United States at 0100 and 1300 UTC are obtained from the National Climatic Data Center (NCDC), ship reports from American vessels are taken from the NCDC archives, and the 1300 UTC data is supplemented by Canadian observations and European ship reports. In spite of the vast differences in the evolutions of the storms, it is found that both produced similarly massive snowfalls, therefore, it is concluded that a wide range of synoptic conditions can give rise to major snowstorms along the East Coast.

  19. Heat and mortality in New York City since the beginning of the 20th century

    PubMed Central

    Petkova, Elisaveta P.; Gasparrini, Antonio; Kinney, Patrick L.

    2014-01-01

    Background Heat is recognized as one of the deadliest weather-related phenomena. Although the impact of high temperatures on mortality has been a subject of extensive research, few previous studies have assessed the impact of population adaptation to heat. Methods We examined adaptation patterns by analyzing daily temperature and mortality data spanning more than a century in New York City. Using a distributed-lag non linear model, we analyzed the heat-mortality relationship in adults age 15 years or older in New York City during two periods: 1900 to 1948 and 1973 to 2006, in order to quantify population adaptation to high temperatures over time. Results During the first half of the century, the decade-specific relative risk of mortality at 29 °C vs. 22 °C ranged from 1.30 (95% confidence interval=1.25 to 1.36) in the 1910s to 1.43 (1.37 to 1.49) in the 1900s. Since the 1970s, however, there was a gradual and substantial decline in the relative risk, from 1.26 (1.22 to 1.29) in the 1970s to 1.09 (1.05 to 1.12) in the 2000s. Age-specific analyses indicated a greater risk for people age 65 years and older in the first part of the century but there was less evidence for enhanced risk among this older age group in more recent decades. Conclusion The excess mortality with high temperatures observed between 1900 and 1948 was substantially reduced between 1973 and 2006, indicating population adaption to heat in recent decades. These findings may have implications for projecting future impacts of climate change on mortality. PMID:24802366

  20. Changes in the timing of high river flows in New England over the 20th Century

    USGS Publications Warehouse

    Hodgkins, G.A.; Dudley, R.W.; Huntington, T.G.

    2003-01-01

    The annual timing of river flows is a good indicator of climate-related changes, or lack of changes, for rivers with long-term data that drain unregulated basins with stable land use. Changes in the timing of annual winter/spring (January 1 to May 31) and fall (October 1 to December 31) center of volume dates were analyzed for 27 rural, unregulated river gaging stations in New England, USA with an average of 68 years of record. The center of volume date is the date by which half of the total volume of water for a given period of time flows past a river gaging station, and is a measure of the timing of the bulk of flow within the time period. Winter/spring center of volume (WSCV) dates have become significantly earlier (p < 0.1) at all 11 river gaging stations in areas of New England where snowmelt runoff has the most effect on spring river flows. Most of this change has occurred in the last 30 years with dates advancing by 1-2 weeks. WSCV dates were correlated with March through April air temperatures (r = -0.72) and with January precipitation (r = -0.37). Three of 16 river gaging stations in the remainder of New England had significantly earlier WSCV dates. Four out of 27 river gaging stations had significantly earlier fall center of volume dates in New England. Changes in the timing of winter/spring and fall peak flow dates were consistent with the changes in the respective center of volume dates, given the greater variability in the peak flow dates. Changes in the WSCV dates over the last 30 years are consistent with previous studies of New England last-frost dates, lilac bloom dates, lake ice-out dates, and spring air temperatures. This suggests that these New England spring geophysical and biological changes all were caused by a common mechanism, temperature increases.

  1. Heat and mortality in New York City since the beginning of the 20th century.

    PubMed

    Petkova, Elisaveta P; Gasparrini, Antonio; Kinney, Patrick L

    2014-07-01

    Heat is recognized as one of the deadliest weather-related phenomena. Although the impact of high temperatures on mortality has been a subject of extensive research, few previous studies have assessed the impact of population adaptation to heat. We examined adaptation patterns by analyzing daily temperature and mortality data spanning more than a century in New York City. Using a distributed-lag nonlinear model, we analyzed the heat-mortality relation in adults age 15 years or older in New York City during 2 periods: 1900-1948 and 1973-2006, to quantify population adaptation to high temperatures over time. During the first half of the century, the decade-specific relative risk of mortality at 29°C vs. 22°C ranged from 1.30 (95% confidence interval [CI]= 1.25-1.36) in the 1910s to 1.43 (1.37-1.49) in the 1900s. Since the 1970s, however, there was a gradual and substantial decline in the relative risk, from 1.26 (1.22-1.29) in the 1970s to 1.09 (1.05-1.12) in the 2000s. Age-specific analyses indicated a greater risk for people age 65 years and older in the first part of the century, but there was less evidence for enhanced risk among this older age group in more recent decades. The excess mortality with high temperatures observed between 1900 and 1948 was substantially reduced between 1973 and 2006, indicating population adaption to heat in recent decades. These findings may have implications for projecting future impacts of climate change on mortality.

  2. Borehole temperatures reveal details of 20th century warming at Bruce Plateau, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Zagorodnov, V.; Nagornov, O.; Scambos, T. A.; Muto, A.; Mosley-Thompson, E.; Pettit, E. C.; Tyuflin, S.

    2012-06-01

    (altitudinal, adjusted for latitude: Γa(l)). Good temporal and spatial consistency of Γa(l) over the last 35 yr are observed, implying that the climate trends observed here are regional and consistent over a broad altitude range.

  3. Principles, exemplars, and uses of history in early 20th century genetics.

    PubMed

    Skopek, Jeffrey M

    2011-06-01

    This paper is concerned with the uses of history in science. It focuses in particular on Anglo-American genetics and on university textbooks--where the canon of a science is consolidated, as the heterogeneous approaches and controversies of its practice are rendered unified for its reproduction. Tracing the emergence and eventual standardization of geneticists' use of a case-based method of teaching in the 1920s-1950s, this paper argues that geneticists created historical environments in their textbooks-spaces in which students developed an understanding of the laws of genetics through simulations of their discovery and use. Witnessing the unfolding of Mendel's and Morgan's experiments and performing genetic crosses on paper, students learned not only the rules that were explicitly taught as such, but also the experientially-based, tacit skills needed to find and follow these rules. This didactic system taught them how to go on when confronting new situations, and in doing so, provided geneticists with an important disciplinary tool, freeing the first steps of their student's enculturation from the physical infrastructure of the laboratory. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Spatiotemporal dynamics of soil phosphorus and crop uptake in global cropland during the 20th century

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Beusen, Arthur H. W.; Van Apeldoorn, Dirk F.; Mogollón, José M.; Yu, Chaoqing; Bouwman, Alexander F.

    2017-04-01

    Phosphorus (P) plays a vital role in global crop production and food security. In this study, we investigate the changes in soil P pool inventories calibrated from historical countrywide crop P uptake, using a 0.5-by-0.5° spatially explicit model for the period 1900-2010. Globally, the total P pool per hectare increased rapidly between 1900 and 2010 in soils of Europe (+31 %), South America (+2 %), North America (+15 %), Asia (+17 %), and Oceania (+17 %), while it has been stable in Africa. Simulated crop P uptake is influenced by both soil properties (available P and the P retention potential) and crop characteristics (maximum uptake). Until 1950, P fertilizer application had a negligible influence on crop uptake, but recently it has become a driving factor for food production in industrialized countries and a number of transition countries like Brazil, Korea, and China. This comprehensive and spatially explicit model can be used to assess how long surplus P fertilization is needed or how long depletions of built-up surplus P can continue without affecting crop yield.

  5. Are Antarctic minke whales unusually abundant because of 20th century whaling?

    PubMed

    Ruegg, Kristen C; Anderson, Eric C; Scott Baker, C; Vant, Murdoch; Jackson, Jennifer A; Palumbi, Stephen R

    2010-01-01

    Severe declines in megafauna worldwide illuminate the role of top predators in ecosystem structure. In the Antarctic, the Krill Surplus Hypothesis posits that the killing of more than 2 million large whales led to competitive release for smaller krill-eating species like the Antarctic minke whale. If true, the current size of the Antarctic minke whale population may be unusually high as an indirect result of whaling. Here, we estimate the long-term population size of the Antarctic minke whale prior to whaling by sequencing 11 nuclear genetic markers from 52 modern samples purchased in Japanese meat markets. We use coalescent simulations to explore the potential influence of population substructure and find that even though our samples are drawn from a limited geographic area, our estimate reflects ocean-wide genetic diversity. Using Bayesian estimates of the mutation rate and coalescent-based analyses of genetic diversity across loci, we calculate the long-term population size of the Antarctic minke whale to be 670,000 individuals (95% confidence interval: 374,000-1,150,000). Our estimate of long-term abundance is similar to, or greater than, contemporary abundance estimates, suggesting that managing Antarctic ecosystems under the assumption that Antarctic minke whales are unusually abundant is not warranted.

  6. Evaluating 20th century warming trends with modern Porites corals from the western Indian Ocean

    NASA Astrophysics Data System (ADS)

    Pfeiffer, M.; Zinke, J.; Dullo, W.-C.; Cahyarini, S. Y.

    2009-04-01

    Recent studies suggest that instrumental records of sea surface temperature (SST) are unreliable prior to 1965 due to changes in the measurement procedures. Thompson et al. (2008) identified an artificial cool bias of up to 0.3˚ C in global mean SSTs between 1945 and the mid-1960s. Geochemical parameters in skeletons of massive corals can be used to infer past changes in climate on seasonal to centennial time scales. The Sr/Ca ratio of coral aragonite is a widely used tool for deriving high-resolution proxy records of past sea surface temperatures. Application of the Sr/Ca paleothermometer relies on the assumption that coral Sr/Ca varies predictably with temperature and that seawater Sr/Ca is invariant on millennial timescales due to the long residence time of Sr and Ca in the ocean. In contrast, the oxygen isotope ratios (^18O) of coral aragonite vary in response to temperature and changes in the ^18O of seawater, the latter depending on the freshwater balance. Thus, coral ^18O may be used as a record of past sea surface temperatures only at sites were ^18O seawater variations are negligible. SST in the western tropical Indian Ocean closely follows global mean temperature trends (Funk et al., 2008). Here we present a set of Porites coral Sr/Ca and/or oxygen isotope records from the tropical Indian Ocean covering the past 120-336 years (Seychelles, Chagos Archipelago). We computed a composite sea surface temperature record for the Western Indian Ocean using ^18O (Seychelles) and Sr/Ca (Chagos). This record clearly follows instrumental SST trends in the Western tropical Indian Ocean, except in the 1945-1965 interval, were instrumental SST data show a pronounced cooling not evident in the coral proxy index (the linear correlation coefficient between the coral index and instrumental SST is r=0.86 if we omit the most problematic time period from 1945 to 1960). However, the coral index follows the global land surface air temperature trend, which is free of systematic

  7. A Record of Rising 20th Century Snow Accumulation from the Denali Ice Core

    NASA Astrophysics Data System (ADS)

    Osterberg, E. C.; Winski, D.; Ferris, D. G.; Wake, C. P.; Kreutz, K. J.; Campbell, S.

    2015-12-01

    Snow accumulation records derived from ice cores are one of the only direct archives of precipitation changes that extend prior to the instrumental period. In Alaska, the development of centennial scale precipitation records is needed to contextualize the current rapid changes in precipitation and glacial mass balance occurring along the North Pacific margin. Here, we investigate precipitation changes over the last three centuries using an ice core collected to bedrock from Mt. Hunter (63° N, 151° W, 4,000 meters above sea level) in Denali National Park, Alaska. To develop the snow accumulation record, we calculated water equivalent annual layer thicknesses in the ice core by identification of annual peaks in major ions (MSA, Cl-, NO3-, SO42-, Na+, NH4+, K+, Mg2+, and Ca2+) and water isotopes. We then corrected the annual layer thickness for thinning using three different flow models (Nye, Hooke and Dansgaard-Johnsen) that have been widely used to simulate layer thickness with depth near an ice divide. Each of these models is optimized such that the discrepancy between the annual layer counted age scale and the modeled age scale is minimized. Our results show that water equivalent annual accumulation has increased from 1.43 meters in 1900 to 2.03 meters by 2012, an increase of 42%. The Mt. Hunter accumulation record is regionally representative of precipitation in southwest and central Alaska based on strong correlations with reanalysis precipitation data. Comparisons with ERA-Interim reanalysis data show that years of high accumulation on Denali are associated with stronger southerly winds, warmer sea surface and air temperatures, and pressure anomalies resembling a positive phase of the East Pacific-North Pacific Pattern. Together, this analysis shows that precipitation on Mt. Hunter has a strong positive correlation (R2=0.73) with annual average meridional wind strength in southwestern Alaska, which is related to atmospheric pressure gradients between the

  8. Using the PDSI to Estimate Summer Stream Discharge in the Greater Yellowstone Ecosystem: Implications for 20th Century Riparian Habitat Variability

    NASA Astrophysics Data System (ADS)

    Persico, L.; Meyer, G. A.

    2013-12-01

    predictors of discharge (α < 0.05). The 1930s Dust Bowl drought was one of the most severe droughts in the past 300 years; from 1934-1935, average August discharge was reduced by 25-40% with respect to the anomalously wet early 20th century pluvial. Discharge estimates using reconstructed PDSI values for the 2- and 10-year MCA droughts (PDSI = -6 and -5, respectively) indicate that 60% of stream reaches where beaver were active in the late Holocene became ephemeral in these droughts. This analysis is supported by observations during the extreme drought of the 2000s, when ephemeral flow occurred along streams with known historical beaver activity in northern Yellowstone. Model predictions indicate that by 2030-2039 the GYE will endure persistent severe drought (mean annual PDSI = -4 to -6) (Dai, 2011), thus riparian area is likely to decrease in the coming decades. The early 20th century has been suggested to be an ideal reference for riparian habitat restoration despite anomalously wet conditions unlike current or likely future climate. Future efforts to restore riparian habitat by reducing elk browsing and increasing beaver damming will be hampered by reduced flows on small streams.

  9. Effect of hemostasis and electrosurgery on the development and evolution of brain tumor surgery in the late 19th and early 20th centuries.

    PubMed

    Vender, John R; Miller, Jason; Rekito, Andy; McDonnell, Dennis E

    2005-04-15

    Hemostatic options available to the surgeon in the late 19th and early 20th centuries were limited. The surgical ligature was limited in value to the neurological surgeon because of the unique structural composition of brain tissue as well as the approaches and operating angles used in this type of surgery. In this manuscript the authors review the options available and the evolution of surgical hemostatic techniques and electrosurgery in the late 19th and early 20th centuries and the impact of these methods on the surgical management of tumors of the brain and its coverings.

  10. Quantifying and tracing sediment mobilized during the 20th century in the South River watershed, western Massachusetts

    NASA Astrophysics Data System (ADS)

    Dow, S.; Snyder, N. P.; Ouimet, W. B.; Martini, A. M.; Yellen, B.; Woodruff, J. D.; Newton, R. M.

    2016-12-01

    New England has a long history of anthropogenic activity affecting the landscape, including deforestation, land use changes, and the construction of dams. Dams in particular have the ability to impound vast quantities of sediment eroded off the landscape. The South River in western Massachusetts is an example of a watershed where mill dam construction coincided with deforestation during the 17th-19th centuries, leading to the impoundment of legacy sediment. Along the river, these deposits act as a source of sediment being released back into the river. The Conway Electric Dam (CED), a 17 m tall dam built in 1906, is located downstream of the mill dams (most of which are no longer intact), and provides a 20th century depositional record for the watershed. The purpose of this study is to quantify sedimentation behind the CED and link this to erosion of upstream mill pond and glacial sediment sources using aerial photography, sediment cores, grainsize, and geochemical analyses. We used aerial photographs to map areal changes of the reservoir from 1940-1980, and topographic profiles generated from LiDAR to estimate a volume of 244,000 m3 of sediment stored behind the CED. We dated layers in cores collected at the site with Hg and 137Cs analyses. Overall, the reservoir exhibits a decreasing rate of sediment infilling occurring from 1940-1980, except for a potentially anomalous increase from 1940-1952. Discharge data containing large storm events were compared to sediment infilling rates to identify if a frequency of large storms could account for high rates of erosion and sediment transport; however, sedimentation at the site does not appear to be solely dependent on these large storm events. Preliminary Hg analyses of deposits from the watershed upstream of the CED indicate higher concentrations in mill pond sediment than glacial sediment. Ongoing work with geochemical tracers can potentially provide a robust understanding of sources and 20th century sediment

  11. The early vs the late 20th century Arctic warming: The role of energy and aerosol fluxes in reanalysis driven datasets

    NASA Astrophysics Data System (ADS)

    Wegmann, Martin; Broennimann, Stefan

    2014-05-01

    During the last two decades, the Arctic was put into the scientific focus as one of the most impacted regions worldwide concerning anthropogenic global warming. However, the warming between 1920 and 1940 proofs the importance of internal variability on yearly and decadal scale. Therefore, it is important to further investigate the role of external and internal forcings on the Arctic climate attribute process and causes leading to changes in the Arctic climate regime (Serreze & Barry 2009). Although much research effort was spent to understand the links and influences of and on the Arctic climate, there is still a need for further insights concerning this topic. Especially the results and discussion about anthropogenic global warming and Arctic amplification put the Arctic into the public and academic focus (Serreze & Barry 2011). However, the early 20th century Arctic warming, although discovered immediately, was scientifically forgotten until recently (Delworth & Knutson 2000, Bengtsson et al 2004, Grant et al 2009, Bekryaev et al 2010). The comparison of this earlier Arctic warming and the recent warming period grants a chance to deepen knowledge about the drivers of Arctic climate and can be used to evaluate the anthropogenic impact. The authors use the Twentieth Century Reanalysis (20CR) dataset and a nudged, reanalysis-driven Aerosol Global Circulation Model (A-GCM) to investigate the impact of atmospheric energy and aerosol fluxes into the Arctic during the 20th century. The 20CR dataset covers the period of 1871 - 2010 with a temporal resolution of 6hr and a spatial resolution of 2° x 2°. For the first time, this dataset (and ist 56 ensemble member) is used to compute the atmospheric energy flux, consisting of sensble heat, latent heat, potential energy and kinetic energy. The values are integrated around 70° N and between 1000 - 100 hPa. Aerosol fluxes for the same domain but for the years 1957 - 2000 are calculated based on the A-GCM nudged to the ECMWF

  12. Key role of the Atlantic Multidecadal Oscillation in 20th century drought and wet periods over the Great Plains

    NASA Astrophysics Data System (ADS)

    Nigam, Sumant; Guan, Bin; Ruiz-Barradas, Alfredo

    2011-08-01

    The Great Plains of North America are susceptible to multi-year droughts, such as the 1930s ‘Dust Bowl’. The droughts have been linked to SST variability in the Pacific and Atlantic basins. This observationally rooted analysis shows the SST influence in multi-year droughts and wet episodes over the Great Plains to be significantly more extensive than previously indicated. The remarkable statistical reconstruction of the major hydroclimate episodes attests to the extent of the SST influence in nature, and facilitated evaluation of the basin contributions. We find the Atlantic SSTs to be especially influential in forcing multi-year droughts; often, more than the Pacific ones. The Atlantic Multidecadal Oscillation (AMO), in particular, contributed the most in two of the four reconstructed episodes (Dust Bowl Spring, 1980s fall wetness), accounting for almost half the precipitation signal in each case. The AMO influence on continental precipitation was provided circulation context from analysis of NOAA's 20th Century Atmospheric Reanalysis. A hypothesis for how the AMO atmospheric circulation anomalies are generated from AMO SSTs is proposed to advance discussion of the influence pathways of the mid-to-high latitude SST anomalies. Our analysis suggests that the La Nina-US Drought paradigm, operative on interannual time scales, has been conferred excessive relevance on decadal time scales in the recent literature.

  13. Changes in the social class gradient of cirrhosis mortality in England and Wales across the 20th century.

    PubMed

    Crombie, Iain K; Precious, Elaine

    2011-01-01

    To explore the nature of the social class gradient of cirrhosis mortality in England and Wales across the 20th century. Data on male cirrhosis mortality by social class were obtained from the Registrar General's Decennial Supplements for the years 1921-1991. Data for 1941 were not collected because of the second World War. In 1921, cirrhosis mortality was substantially higher among the professional and managerial classes (I and II) than among the other social classes (III-V). This marked social class difference persisted until 1961 when the differences between the social classes were inconsistent. By 1991, the gradient had reversed and the lower social classes (IV and V) had the higher mortality. The excess mortality was greatest for social class V. The change in the mortality gradient is stark: in 1921social classes I and II had a cirrhosis mortality at least twice that of social classes IV and V, but by 1991 this ratio had reversed. The reversal in the social class gradient of cirrhosis mortality indicates a major change in risk factor distribution across social classes. Differential changes in alcohol consumption are a possible explanation for this change, although the 1991 social class gradient in cirrhosis is inconsistent with alcohol consumption data from national surveys. Further research is required to clarify the explanation for the observed gradient, so that appropriate preventive measures can be put into place.

  14. Fighting for Anatomy. Overview regarding two prestigious Romanian anatomists of the 20th century: Victor Papilian and Grigore T. Popa.

    PubMed

    Bârsu, Cristian

    2016-01-01

    During many centuries, the progress of Anatomy was based on the perseverant and laborious activities done by anatomists. Their work can be considered as a fight for Anatomy. A particular problem arouse when this fight is excessively done and it limits the ability to correctly analyze the contribution made by other scientists in the same domain. This situation was identified at different personalities who lived in the same time and were involved in the same fundamental field of research. If, theoretically, the similarities between scientists should get them closer, in order to have a better communication, the antagonisms can lead them to rivalry. Our paper exemplifies a historical case in which the personages are Victor Papilian (1888-1956) and Grigore T. Popa (1892-1948). The resemblances between these two famous Romanian anatomists from the first half of the 20th century induced an evident scientific rivalry. Papilian and Popa brought a significant contribution in anatomy. Each of them was very much appreciated by his students. It is interesting that both of them had achievements in literature. We present the reasons of their disagreement and its consequences. Paradoxically, not the contrasts, but the resemblances between their strong characters produced a sort of animosity between them. This attitude diminished in time and their successors - Ioan Albu from the Cluj Faculty of Medicine and Ion Iancu from the Jassy Faculty of Medicine - had a long lasting and successful cooperation.

  15. Fighting the 'microbe of sporting mania': Australian science and Antarctic exploration in the early 20th century.

    PubMed

    Roberts, Peder

    2004-09-01

    The 'Heroic Age' of Antarctic exploration, which occurred during the first 15 years of the 20th century, captured headlines around the world. Australia was no exception, especially as Australian scientists played important roles in several expeditions. Through participation in the British Antarctic Expedition of 1907-1909, two Australian scientists - T.W. Edgeworth David (1858-1934) and Douglas Mawson (1882-1958) - became genuine national heroes, mainly through being members of the first party to reach the South Magnetic Pole area. At a superficial level, the vehicle of Antarctic exploration placed science at the forefront of public awareness, fulfilling David's ambition for greater recognition of science and scientists, especially considering the high level of public interest in sport. However, although David and Mawson gave Antarctic exploration a scientific veneer, simply through their status as scientists, the public viewed them as heroes because they had endured great hardships and conquered a point on the map in the name of science and the Empire.

  16. Heinz Werner: His Life, Ideas, and Contributions to Developmental Psychology in the First Half of the 20th Century.

    PubMed

    Ostler, Teresa

    2016-01-01

    The author provides an overview of Heinz Werner's life and contributions to the field of developmental psychology during the first half of the 20th century. She focuses on his early work in Vienna and Munich as well as his tenure at the Psychological Institute in Hamburg, up through the time when he became a named Professor in Psychology at Clark University. Recognized as one of the founders of developmental psychology, Heinz Werner worked in the areas of perceptual development, comparative psychology, and symbol formation. Versatile in rigorous experimental methodologies, and in observational and phenomenological methodologies, Werner's approach to development stood in contrast to other approaches of development, both past and current. For Werner, development was a heuristic, a way of looking at processes in a variety of domains, including ontogeny, phylogeny, microgenesis, biology, developmental psychopathology, neuropsychology, and comparative psychology. Werner viewed development as proceeding from a state of relative globality and lack of differentiation to a state of increasing differentiation, articulation, and hierarchical integration, but he also stressed that individuals can function at different developmental levels under different times and conditions. Werner's holistic, organismic, comparative, and contextual approach to development transcended interdisciplinary boundaries, allowing him to study the interrelatedness between thought, language, feeling, perception, and culture.

  17. "Can Breast Feeding Help You in Later Life? Evidence from German Military Heights in the Early 20th Century"*

    PubMed Central

    Haines, Michael R.; Kintner, Hallie J.

    2008-01-01

    Considerable literature exists on the benefits of breast feeding on the health and survival of infants and young children, but there is less on the effects on later life outcomes. One such measure of health and well-being that has received attention in the historical literature is terminal adult stature. Information on height is rather widely available; however, it is much more difficult to obtain data on breast feeding. One country that does have such information is Imperial Germany (1871–1919). A number of physicians and local health officials collected information on the incidence and duration of breast feeding early in the 20th century, particularly because of concern about the unusually high infant mortality rates in parts of Germany. Hallie Kintner has surveyed the published results of these studies. The information on the prevalence of breast feeding for the period 1903/10 has been inputed into a database of demographic and economic variables for the counties (Regierungsbezirke) of Germany (1850–1939) There are also published data on heights of military recruits from the Imperial German military forces in 1906. These can be linked to areas in the database and related to breast feeding practices and infant mortality both contemporaneously and approximately 20 years previous to 1906. Results indicate a significant effect of infant feeding practices on later life outcomes operating through infant health conditions, proxied by the infant mortality rate. PMID:18715833

  18. 1910s' brains revisited. Cortical complexity in early 20th century patients with intellectual disability or with dementia praecox.

    PubMed

    Sandu, A-L; Paillère Martinot, M-L; Artiges, E; Martinot, J-L

    2014-09-01

    The idea of cortical surface anomalies in subjects with intellectual disability (mental retardation) and schizophrenia can be traced back to early 20th century qualitative observations. Since it is unknown whether modern quantitative measures of cortical complexity and folding would retrieve those early empirical observations, we measured fractal dimension and sulcal span index in photographs of human brains taken in the 1910's. Brain photographs were compared between 36 patients with mental retardation and 21 patients with dementia praecox for the fractal dimension and sulcal span index. Also, a mental retardation subgroup with no-or-non-understandable speech (n = 12) was compared with a subgroup with comprehensible speech (n = 23). Mental retardation group had a lower whole-brain fractal dimension than dementia praecox, and a higher sulcal span index in left posterior cortex. The mental retardation subgroup with comprehensible speech had a lower fractal dimension in left hemisphere than the subgroup with no-or-non-understandable speech and a lower sulcal index in left posterior cortex. Measures of cortical complexity and folding suggest differences between mental retardation and dementia praecox, and regional variations according to language abilities in mental retardation. The findings provide a unique picture of cortical surface changes in their original untreated form, one century ago. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. [Veterinary relations between Germany and Turkey on the military level at the beginning of the 20th century].

    PubMed

    Doğanay-Feldhaus, S

    1991-09-01

    At the beginning of the 20th century the veterinary relations between Turkey and Germany intensified at the military level. After the Balkan Wars there were urgent attempts to reorganize the army, which lead to the visit of a German military mission under General L. von Sanders, who was appointed to review the army. Along with other members of the German military mission A. Thieme (1881-1949) belonged to the staff of the Turkish Army's Supreme Command as orderly officer and as advisory army veterinarian. During the First World War (1914-1918) there were 44 German veterinary officers, 23 in Turkish and 21 in German uniform. The veterinary officers in Turkish formations were assigned to the military mission, where the veterinary major Dr. K. Dreyer served as official adviser. Moreover mixed German-Turkish special units were formed under German leadership in Turkey, which included German veterinary officers in German uniform. The higher salaries were paid to the German veterinary officers than their Turkish colleagues by the Turkish government. As far as can gathered three German officers perished in Turkey.

  20. The world's road to water scarcity: shortage and stress in the 20th century and pathways towards sustainability.

    PubMed

    Kummu, M; Guillaume, J H A; de Moel, H; Eisner, S; Flörke, M; Porkka, M; Siebert, S; Veldkamp, T I E; Ward, P J

    2016-12-09

    Water scarcity is a rapidly growing concern around the globe, but little is known about how it has developed over time. This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20(th) century. Water scarcity is analysed using the fundamental concepts of shortage (impacts due to low availability per capita) and stress (impacts due to high consumption relative to availability) which indicate difficulties in satisfying the needs of a population and overuse of resources respectively. While water consumption increased fourfold within the study period, the population under water scarcity increased from 0.24 billion (14% of global population) in the 1900s to 3.8 billion (58%) in the 2000s. Nearly all sub-national trajectories show an increasing trend in water scarcity. The concept of scarcity trajectory archetypes and shapes is introduced to characterize the historical development of water scarcity and suggest measures for alleviating water scarcity and increasing sustainability. Linking the scarcity trajectories to other datasets may help further deepen understanding of how trajectories relate to historical and future drivers, and hence help tackle these evolving challenges.

  1. The world’s road to water scarcity: shortage and stress in the 20th century and pathways towards sustainability

    NASA Astrophysics Data System (ADS)

    Kummu, M.; Guillaume, J. H. A.; de Moel, H.; Eisner, S.; Flörke, M.; Porkka, M.; Siebert, S.; Veldkamp, T. I. E.; Ward, P. J.

    2016-12-01

    Water scarcity is a rapidly growing concern around the globe, but little is known about how it has developed over time. This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20th century. Water scarcity is analysed using the fundamental concepts of shortage (impacts due to low availability per capita) and stress (impacts due to high consumption relative to availability) which indicate difficulties in satisfying the needs of a population and overuse of resources respectively. While water consumption increased fourfold within the study period, the population under water scarcity increased from 0.24 billion (14% of global population) in the 1900s to 3.8 billion (58%) in the 2000s. Nearly all sub-national trajectories show an increasing trend in water scarcity. The concept of scarcity trajectory archetypes and shapes is introduced to characterize the historical development of water scarcity and suggest measures for alleviating water scarcity and increasing sustainability. Linking the scarcity trajectories to other datasets may help further deepen understanding of how trajectories relate to historical and future drivers, and hence help tackle these evolving challenges.

  2. The frequency of metopism in Anatolian populations dated from the Neolithic to the first quarter of the 20th century.

    PubMed

    Eroğlu, S

    2008-09-01

    Metopism, which is defined as a condition in which the two pieces of the frontal bone fail to merge in early childhood, displays varying degrees of incidence. In this study, the variation of the frequency of metopism across historical periods is investigated on the skulls of 487 adults from 12 different Ancient Anatolian populations dated to various periods of history ranging from the Neolithic to the first quarter of the 20th century. In addition, the study also examines the relationship of metopism to sex and cranial form. It is revealed that the frequency of metopism showed a relative increase across time periods in Anatolia after the Neolithic Period, with the exception of the Cevizcioğlu Ciftliği population. However, no significant relationship was found between metopism and cranial form or sex. It is found that the frequency of metopism in Ancient Anatolia had a distribution range of 3.3-14.9%. This distribution shows that the inhabitants of Anatolia have a heterogeneous genetic make-up due to the geographical situation of Anatolia, which has been open to gene flow both in the past and at present. (c) 2008 Wiley-Liss, Inc.

  3. Diversity trends in bread wheat in Italy during the 20th century assessed by traditional and multivariate approaches.

    PubMed

    Ormoli, Leonardo; Costa, Corrado; Negri, Stefano; Perenzin, Maurizio; Vaccino, Patrizia

    2015-02-25

    A collection of 157 Triticum aestivum accessions, representative of wheat breeding in Italy during the 20(th) century, was assembled to describe the evolutionary trends of cultivated varieties throughout this period. The lines were cultivated in Italy, in two locations, over two growing seasons, and evaluated for several agronomical, morphological and qualitative traits. Analyses were conducted using the most common univariate approach on individual plant traits coupled with a correspondance multivariate approach. ANOVA showed a clear trend from old to new varieties, leading towards earliness, plant height reduction and denser spikes with smaller seeds. The average protein content gradually decreased over time; however this trend did not affect bread-making quality, because it was counterbalanced by a gradual increase of SDS sedimentation volume, achieved by the incorporation of favourable alleles into recent cultivars. Correspondence analysis allowed an overall view of the breeding activity. A clear-cut separation was observed between ancient lines and all the others, matched with a two-step gradient, the first, corresponding roughly to the period 1920-1940, which can be ascribed mostly to genetics, the second, from the 40s onward, which can be ascribed also to the farming practice innovations, such as improvement of mechanical devices and optimised use of fertilizers.

  4. 20th-Century “medical Marco Polos” in the origins of preventive cardiology and cardiovascular disease epidemiology.

    PubMed

    Blackburn, Henry

    2012-03-01

    In mid-20th century, several streams of knowledge converged to create the new academic discipline of cardiovascular disease epidemiology and the new practice of preventive cardiology. One stream was modern cardiology, with the ability to diagnose myocardial infarction, to characterize and count its victims, and to report vital statistics on cardiovascular causes of death. Another stream came from burgeoning clinical and laboratory research and greater understanding of the underlying processes of atherosclerosis and hypertension. A third stream came from the observations of intellectually curious "medical Marco Polos," who brought back from travels their tales of unusual population frequencies of heart attacks, along with ideas about sociocultural causes. This led to more formal research about cardiovascular disease risk and causes among populations and about mechanisms in the clinic and laboratory. The broad river of investigation thus formed produced a risk paradigm of the multiple biologic, behavioral, and societal factors in causal pathways to the common cardiovascular diseases. An evidence base was built for sound clinical and public health approaches to prevention. Here, the author tells brief stories about 5 early and particularly observant world travelers and their influence on knowledge and thinking about prevention.

  5. Raman analysis of complex pigment mixtures in 20th century metal knight shields of the Order of the Elephant.

    PubMed

    Lauridsen, Clara Bratt; Sanyova, Jana; Simonsen, Kim Pilkjær

    2015-11-05

    The pigment composition of six painted metal knight shields of the Order of the Elephant dating from the second half of the 20th century belonging to the Danish royal collection were studied using Raman microscopy. By focusing a 785 nm laser with a 50× objective on particles in paint cross sections, it was possible to identify the following 20 compounds: hematite, goethite, chrome red/orange, chrome yellow, zinc chrome yellow, carbon black, toluidine red PR3, chlorinated para red PR4, dinitroaniline orange PO5, phthalocyanine blue PB15, indanthrone blue PB60, ultramarine, Prussian blue, lead white, anatase, rutile, calcium carbonate, barium sulphate, gypsum and dolomite. The components were frequently present in complex pigment mixtures. Additional information was obtained by elemental analysis with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) to identify cobalt blue, zinc white and cadmium red, as well as to indicate the presence of zinc white in some pigment mixtures. The study allowed a comparison between the industrially applied preparation layers and the artistic paint layers applied by the heraldic painter. Differences in the choice of paint and pigment types were observed on the earliest knight shields, demonstrating a general delay of industrial materials into artist paints.

  6. Predicting U.S. food demand in the 20th century: a new look at system dynamics

    NASA Astrophysics Data System (ADS)

    Moorthy, Mukund; Cellier, Francois E.; LaFrance, Jeffrey T.

    1998-08-01

    The paper describes a new methodology for predicting the behavior of macroeconomic variables. The approach is based on System Dynamics and Fuzzy Inductive Reasoning. A four- layer pseudo-hierarchical model is proposed. The bottom layer makes predications about population dynamics, age distributions among the populace, as well as demographics. The second layer makes predications about the general state of the economy, including such variables as inflation and unemployment. The third layer makes predictions about the demand for certain goods or services, such as milk products, used cars, mobile telephones, or internet services. The fourth and top layer makes predictions about the supply of such goods and services, both in terms of their prices. Each layer can be influenced by control variables the values of which are only determined at higher levels. In this sense, the model is not strictly hierarchical. For example, the demand for goods at level three depends on the prices of these goods, which are only determined at level four. Yet, the prices are themselves influenced by the expected demand. The methodology is exemplified by means of a macroeconomic model that makes predictions about US food demand during the 20th century.

  7. Late 20th Century benthic foraminiferal distribution in Central San Francisco Bay, California: Influence of the Trochammina hadai invasion

    USGS Publications Warehouse

    McGann, Mary L.

    2014-01-01

    Samples collected from 1965 onward were also compared with those from 1998 to investigate how the distribution of benthic foraminifera in Central Bay has changed over the latter half of the 20th Century, particularly in response to the invasion by Trochammina hadai. In 1998, T. hadai was recovered at 46 of 55 sites in Central Bay, comprising from 0.3 to 97% (mean = 23%) of the foraminiferal fauna. With the species’ affiliation for shallow environments, it is not unexpected that it dominated the fauna of the Shallow Subtidal Biofacies (68-97%, mean = 77%) and was also a significant component of the Intermediate Subtidal Biofacies (7-51%, averaging 28%). In the deeper waters west of Alcatraz Island, the abundance of T. hadai was significantly less (mean = 8%), most likely reflecting allochthonous specimens that were the result of post-mortem transport. A cluster analysis clearly distinguishes pre- and post-invasion biofacies, illustrating how dominant T. hadai has become in Central Bay.

  8. Sediment accumulation in San Leandro Bay, Alameda County, California, during the 20th century - A preliminary report

    SciTech Connect

    Nolan, K.M.; Fuller, C.C.

    1986-01-01

    Major changes made in the configuration of San Leandro Bay, Alameda County, California, during the 20th century have caused rapid sedimentation within parts of the Bay. Comparison of bathymetric surveys indicates that sedimentation in the vicinity of the San Leandro Bay channel averaged 0.7 cm/annum between 1856 and 1984. Lead-210 data collected at four shallow water sites east of the San Leandro Bay channel indicated that sedimentation rates have averaged between 0.06 and 0.28 cm/annum. Because bioturbation of bottom sediments cannot be discounted, better definition of this range in sedimentation rates would require measuring the activity of lead-210 on incoming sediments. In addition to sediment deposited in the vicinity of the San Leandro Bay channel and open, shallow areas to the east, 850,740 cu m of sediment was deposited between 1948 and 1983 in an area dredged at the mouth of San Leandro Creek. All available data indicate that between 1,213,000 and 1,364,000 cu m of sediment was deposited in San Leandro Bay between 1948 and 1983. Sediment yield data from an adjacent drainage basin, when combined with inventories of lead-210 and cesium-137, indicate that most of the sediment deposited in San Leandro Bay is coming from resuspension of bottom sediments or from erosion of marshes or shorelines of San Leandro or San Francisco Bay. 31 refs., 7 figs., 4 tabs.

  9. The world’s road to water scarcity: shortage and stress in the 20th century and pathways towards sustainability

    PubMed Central

    Kummu, M.; Guillaume, J. H. A.; de Moel, H.; Eisner, S.; Flörke, M.; Porkka, M.; Siebert, S.; Veldkamp, T. I. E.; Ward, P. J.

    2016-01-01

    Water scarcity is a rapidly growing concern around the globe, but little is known about how it has developed over time. This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20th century. Water scarcity is analysed using the fundamental concepts of shortage (impacts due to low availability per capita) and stress (impacts due to high consumption relative to availability) which indicate difficulties in satisfying the needs of a population and overuse of resources respectively. While water consumption increased fourfold within the study period, the population under water scarcity increased from 0.24 billion (14% of global population) in the 1900s to 3.8 billion (58%) in the 2000s. Nearly all sub-national trajectories show an increasing trend in water scarcity. The concept of scarcity trajectory archetypes and shapes is introduced to characterize the historical development of water scarcity and suggest measures for alleviating water scarcity and increasing sustainability. Linking the scarcity trajectories to other datasets may help further deepen understanding of how trajectories relate to historical and future drivers, and hence help tackle these evolving challenges. PMID:27934888

  10. Carbon profile of the managed forest sector in Canada in the 20th century: sink or source?

    PubMed

    Chen, Jiaxin; Colombo, Stephen J; Ter-Mikaelian, Michael T; Heath, Linda S

    2014-08-19

    Canada contains 10% of global forests and has been one of the world's largest harvested wood products (HWP) producers. Therefore, Canada's managed forest sector, the managed forest area and HWP, has the potential to significantly increase or reduce atmospheric greenhouse gases. Using the most comprehensive carbon balance analysis to date, this study shows Canada's managed forest area and resulting HWP were a sink of 7510 and 849 teragrams carbon (TgC), respectively, in the period 1901-2010, exceeding Canada's fossil fuel-based emissions over this period (7333 TgC). If Canadian HWP were not produced and used for residential construction, and instead more energy intensive materials were used, there would have been an additional 790 TgC fossil fuel-based emissions. Because the forest carbon increases in the 20th century were mainly due to younger growing forests that resulted from disturbances in the 19th century, and future increases in forest carbon stocks appear uncertain, in coming decades most of the mitigation contribution from Canadian forests will likely accrue from wood substitution that reduces fossil fuel-based emissions and stores carbon, so long as those forests are managed sustainably.

  11. Extreme precipitation in the Polish Carpathians in the 20th century in the context of last 500 years

    NASA Astrophysics Data System (ADS)

    Limanowka, Danuta; Cebulak, Elzbieta; Pyrc, Robert

    2010-05-01

    Extreme weather phenomena together with their exceptional course and intensity have always been dangerous for people. In the historical documents such phenomena were marked as basic disasters. First notes about weather phenomena were made in Polish lands in the 10th century. Most information concerns floods caused by intensive rains. Using the data base created within the Millennium project, extreme precipitation cases exceeding 100 mm were analysed. In each case, the intensive precipitation was followed by a summer flood in the Polish Carpathians in the Upper Vistula River basin. Data from the period of instrumental measurements in the 20th century were studied in detail by the analysis of the frequency of occurrence and the spatial and temporal distribution. The results were referred to last 500 years. The information obtained gives approximate image of extreme precipitation in the historical times in Polish lands. All available multi-proxy data were used. Newspapers' notes concerning described phenomena from 1848-1850 published in Kraków were used to complete and verify the quality of data from the early instrumental period and also to complete the data from the period of the Second World War.

  12. [Wilhelm Troll (1897-1978). The tradition of idealistic morphology in the German botanical sciences of the 20th century].

    PubMed

    Meister, Kay

    2005-01-01

    During the first half of the 19th century, idealistic morphology developed into an influential research program in the German biosciences. This program was based on the concept of an ideal connection existing between various living beings. The growth of Darwinian thought and its new paradigm of historical explanation supplanted the idealistic morphology. Yet in the first half of the 20th century the principles of idealistic morphology experienced a powerful revival. Wilhelm Troll (1897-1978) was one of the most significant figures in this renaissance. Guided by the ideas of J.W. von Goethe, Troll established a research program rejecting causal, functional, and phylogenetic explanations as well as the idea of evolutionary adaptation. Instead, he attempted to create a 'pure' morphology based on the descriptions of various plant species. Governed by some explicitly metaphysical presumptions, Troll based his theory on the description of the organismal Gestalt. In consequence, his theory was actually a return to the proper idealistic morphology as it was known in the early 19th century. It lead German botanical morphology to a period of methodological and epistemological return.

  13. B. F. Skinner and Technology's Nation: Technocracy, Social Engineering, and the Good Life in 20th-Century America.

    PubMed

    Rutherford, Alexandra

    2017-04-13

    Psychologist B. F. Skinner developed and promoted a technology of behavior as the basis for widespread social reform over much of his career. In 1948, he published his behaviorally engineered vision of the good life in his utopian novel Walden Two (Skinner, 1948). Skinner's efforts were part of a much larger social engineering tradition that received one of its fullest expressions in the Technocracy Movement of the 1930s. Fifteen years before Skinner's Walden Two, at the height of the Technocracy Movement's public visibility in the United States, technocrat Harold Loeb (1933/1996) published his utopia, Life in a Technocracy: What It Might Be Like. In this article, I place the socially engineered visions of the good life promoted by the Technocracy Movement and by Skinner on an intellectual and ideological continuum to amplify and explore American attitudes toward psychology, technology, and social engineering during the middle decades of the 20th century. I argue that responses to both reveal the possibilities and limits of the social engineering enterprise, and suggest that historians of technology might consider how the history of psychology and other psy-disciplines can deepen conceptualizations of the relationships among the psychological, the social, and the technological in this period. (PsycINFO Database Record

  14. Trends in Streamflow, River Ice, and Snowpack for Coastal River Basins in Maine During the 20th Century

    USGS Publications Warehouse

    Dudley, Robert W.; Hodgkins, Glenn A.

    2002-01-01

    Trends over the 20th Century were examined in streamflow, river ice, and snowpack for coastal river basins in Maine. Trends over time were tested in the timing and magnitude of seasonal river flows, the occurrence and duration of river ice, and changes in snowpack depth, equivalent water content, and density. Significant trends toward earlier spring peak flow and earlier center-of-volume runoff dates were found in the extended streamflow record spanning 1906-21 and 1929-2000. Only one of the six coastal rivers in the study analyzed for trends in cumulative runoff had a significant change in total annual runoff volume. Last spring river-ice-off dates at most coastal streamflow-gaging stations examined are trending to earlier dates. Trends in later fall initial onset of ice also are evident, although these trends are significant at fewer stations than that observed for ice-off dates. Later ice-on dates in the fall and (or) earlier ice-off dates in the spring contribute to a statistically significant decrease over time in the total number of days of ice occurrence at most gaging stations on coastal rivers in Maine. The longest, most complete snow records in coastal Maine indicate an increase in snow density for the March 1 snow-survey date during the last 60 years. The historical trends in streamflow, ice, and snow are all consistent with an earlier onset of hydrologic spring conditions in coastal Maine.

  15. Biologizing social facts: an early 20th century debate on Kraepelin's concepts of culture, neurasthenia, and degeneration.

    PubMed

    Roelcke, V

    1997-12-01

    This paper uses an historical approach to elucidate two alternative modes of conceptualizing the relation between social factors and psychological phenomena perceived as pathological. The core features of Neo-Kraepelinian psychiatric nosology associated with the introduction of DSM-III in 1980 were also at the center of a debate in early 20th century Germany. The protagonists were Emil Kraepelin and Oswald Bumke. Kraepelin's empirical research selectively focused on somatic factors as independent variables, such as alcohol, syphilitic infection, and heredity. The ensuing nosology marginalised social factors which might contribute to the etiology and symptom formation of psychiatric conditions. For Bumke, the disorders in question (including the category of neurasthenia) did not represent qualitative deviations from normal psychological states, but quantitative variations of ubiquitous psychological functions caused by a multitude of somatic, psychological, and social factors. The main arguments of the historical debate are reconstructed, with special regard to the professional and political context. The paper illustrates the importance of context-bound pre-'scientific' decisions for the process of formulating theoretical concepts in psychiatry and related disciplines.

  16. Biologizing social facts: an early 20th century debate on Kraepelin's concepts of culture, neurasthenia, and degeneration.

    PubMed

    Roelcke, V

    1997-01-01

    This paper uses an historical approach to elucidate two alternative modes of conceptualizing the relation between social factors and psychological phenomena perceived as pathological. The core features of Neo-Kraepelinian psychiatric nosology associated with the introduction of DSM-III in 1980 were also at the center of a debate in early 20th century Germany. The protagonists were Emil Kraepelin and Oswald Bumke. Kraepelin's empirical research selectively focused on somatic factors as independent variables, such as alcohol, syphilitic infection, and heredity. The ensuing nosology marginalised social factors which might contribute to the etiology and symptom formation of psychiatric conditions. For Bumke, the disorders in question (including the category of neurasthenia) did not represent qualitative deviations from normal psychological states, but quantitative variations of ubiquitous psychological functions caused by a multitude of somatic, psychological, and social factors. The main arguments of the historical debate are reconstructed, with special regard to the professional and political context. The paper illustrates the importance of context-bound pre-'scientific' decisions for the process of formulating theoretical concepts in psychiatry and related disciplines.

  17. World War I origins of the syphilis epidemic among 20th century black Americans: a biohistorical analysis.

    PubMed

    Miles, T P; McBride, D

    1997-07-01

    Syphilis outbreaks and differentials have been an ongoing issue in modern preventive medicine and public health. Since the early 20th Century, a variety of approaches has been employed to explain demographic and temporal variations in the prevalence of syphilis in the U.S. Public health experts and physicians have tended to rely on case-by-case approaches to explain group-specific patterns. This study, however, shows that population-level disease dynamics cannot be ascertained from these individual-level studies. We offer a biohistorical methodology to study syphilis prevalence differentials in U.S. populations. Using historical health data, this study suggests that the social disruption brought on by World War I was the critical and unique environmental condition which ignited an epidemic of syphilis among black Americans. By establishing this beginning point for the epidemic, this study further shows the persistence of the epidemic for the next 40 years and its decline. This biohistorical methodology could be applied to the analysis of STD epidemics in other populations and regions experiencing mass exposure events.

  18. "Winged sponges": houseflies as carriers of typhoid fever in 19th- and early 20th-century military camps.

    PubMed

    Cirillo, Vincent J

    2006-01-01

    Typhoid fever was the scourge of 19th- and early 20th-century armies. During the Spanish-American War (1898) and the Anglo-Boer War (1899- 1902), typhoid killed more soldiers than enemy bullets. Walter Reed and his coworkers investigated the cause of the typhoid epidemics in the U.S. Army camps and concluded that, next to human contact, the housefly (Musca domestica) was the most active agent in the spread of the disease. British medical officers in South Africa, facing even worse typhoid epidemics, reached the same conclusion. The experiences of the American and British armies finally convinced the medical profession and public health authorities that these insects conveyed typhoid. The housefly was now seen as a health menace. Military and civilian sanitarians waged fly-eradication campaigns that prevented the housefly's access to breeding places (especially human excrement), and that protected food and drink from contamination. Currently, M. domestica is recognized as the mechanical vector of a wide variety of viral, bacterial, and protozoal pathogens. Fly control is still an important public health measure in the 21st century, especially in developing countries.

  19. Composition of `Marbrite Fauquez' 20th-century opalescent glass: results of historical study and laboratory analyses

    NASA Astrophysics Data System (ADS)

    Dekeyser, L.; Wouters, H. J. M.; Ligovich, G.; Verdonck, A.; De Clercq, H.

    Belgian Marbrite Fauquez opalescent glass is an innovative material developed at the take-off of the 20th century. S.A. Verreries de Fauquez produced this from 1922 onwards. Low maintenance requirements and appropriate properties in terms of hygienic aspects make these mass coloured glass plates popular as finishes for bathrooms, kitchens, hospitals, store fronts, decorative façade cladding,... Since production of Marbrite stopped in the 1960s, replacement of its applications in the framework of restoration procedures is almost impossible. Limited knowledge of the composition and production results in the lack of a proper conservation strategy. In order to improve the existing knowledge a historical research was conducted. Archive records including patents, literature, building specifications, plans, journals, advertisements, interviews with former directors of the glassworks, etc. were considered and evaluated. Onsite lifted samples of Marbrite glass were submitted to a laboratory investigation using optical and scanning electron microscopy. The results revealed crucial information about the original formula and components. This paper discusses the composition of Marbrite, a peculiar Belgian opalescent glass. This interdisciplinary research - a cooperation between the Vrije Universiteit Brussel and Royal Institute for Cultural Heritage - aims to improve the knowledge of Marbrite glass in order to develop repair and renovation techniques.

  20. ["W. Bölsche's precious book". Freud and German evolutionism in the beginning of the 20th century].

    PubMed

    Amouroux, Rémy

    2004-01-01

    Wilhelm Bölsche (1861-1939) is the author of a poetic history of the evolution of love entitled Das Liebesleben in der Natur (1898-1903). This work, inspired by the writings of biologist Ernst Haeckel, was greatly successful in Germany at the beginning of the 20th century. Freud kept a copy of the three volumes in his London library and cites the text in his lectures on an Introduction to psychoanalysis. Bölsche develops an Entwicklungsgeschichte (history of evolution) of the distinguishing sexuality of several types of love (oral, anal and urinary). In addition, he describes the "zoological reactionary" homosexual and ties this sexual behaviour to the history of the development of anal sexuality. This paper will address an excerpt on this topic from Bölsche's text that has been translated for the occasion. The task at hand is to prepare the ground for a study of German evolutionism, both popular and scientific, and its ties to psychoanalysis.

  1. Snow cover and permafrost evolution in Siberia as simulated by the MGO regional climate model in the 20th and 21st centuries

    NASA Astrophysics Data System (ADS)

    Shkolnik, I. M.; Nadyozhina, E. D.; Pavlova, T. V.; Molkentin, E. K.; Semioshina, A. A.

    2010-01-01

    An approach to ground thermodynamics description using a coupled system of atmospheric regional climate and ground heat transfer models is improved by accounting for the time varying snow density. The simulations are compared to available observational analyses, and the sensitivity of the ground thermal regime to variable snow density is analysed. Projected changes of the ground thermal regime in the 21st century relative to the late 20th century are shown and compared to earlier estimates.

  2. Nostalgic for What? The Epidemic of Images of the Mid 20th Century Classroom in American Media Culture and What it Means

    ERIC Educational Resources Information Center

    Otto, Stacy

    2005-01-01

    Within this paper the author examines the current nostalgia for a never-present past through critical analysis of images of the mid 20th century American classroom in media culture. The author uses theories of nostalgia and the history of the photographic image to trouble the numerous equity issues surrounding the unchallenged canonization of the…

  3. American Journalism Historians Association Annual Convention (London, Ontario, Canada, October 3-5, 1996). Part II: Selecting Papers Covering the 20th Century.

    ERIC Educational Resources Information Center

    American Journalism Historians' Association.

    The 17 papers in this collection all deal with 20th-century journalism, journalists, and mass media. The papers and their authors are: "Building One's Own Gallows: The Trade Publications' Reaction to a Federal Shield Law, 1972-1974" (Karla Gower); "The Useful Ogre: Sweden's Use and Views of American Television, 1956-62" (Ulf…

  4. Historiography for Educational Leadership in Mathematics: Content Analysis of a 1904 K-8 Mathematics Series and the Early 20th Century Context of Its Use

    ERIC Educational Resources Information Center

    Goodwin, Diana

    2012-01-01

    Math education is as important today as it was 100 years ago when the early 20th century was transforming from the old world into an era of factories, airplanes, atomic energy, and medical breakthroughs. Educational leaders of the era were wrestling with how long children should stay in school, meeting the diverse needs of an influx of immigrants,…

  5. Atomic Pioneers, Book 2, From the Mid-19th to the Early 20th Century. A World of the Atom Series Booklet.

    ERIC Educational Resources Information Center

    Hiebert, Ray; Hiebert, Roselyn

    This booklet is concerned with the last half of the 19th and the beginning of the 20th century when a great surge of knowledge vital to atomic science took place, as illustrated by work by Faraday, Mendeleev, Roentgen, Becquerel and the Curies. Each succeeding discovery brought atomic science closer to the great breakthrough that marked the close…

  6. Nostalgic for What? The Epidemic of Images of the Mid 20th Century Classroom in American Media Culture and What it Means

    ERIC Educational Resources Information Center

    Otto, Stacy

    2005-01-01

    Within this paper the author examines the current nostalgia for a never-present past through critical analysis of images of the mid 20th century American classroom in media culture. The author uses theories of nostalgia and the history of the photographic image to trouble the numerous equity issues surrounding the unchallenged canonization of the…

  7. Changes in the Spatial Distribution of Elementary Schools and Their Impact on Rural Communities in Czechia in the Second Half of the 20th Century

    ERIC Educational Resources Information Center

    Kucerova, Silvie; Kucera, Zdenek

    2012-01-01

    This article addresses the changes in the spatial distribution of elementary schools in Czechia in the second half of the 20th century and the consequences of these changes on the functioning of rural communities. The spatial distribution of elementary schools, the shape of their catchment areas, and the regional and local communities connected…

  8. Reconciling past changes in Earth’s rotation with 20th century global sea-level rise: Resolving Munk’s enigma

    PubMed Central

    Mitrovica, Jerry X.; Hay, Carling C.; Morrow, Eric; Kopp, Robert E.; Dumberry, Mathieu; Stanley, Sabine

    2015-01-01

    In 2002, Munk defined an important enigma of 20th century global mean sea-level (GMSL) rise that has yet to be resolved. First, he listed three canonical observations related to Earth’s rotation [(i) the slowing of Earth’s rotation rate over the last three millennia inferred from ancient eclipse observations, and changes in the (ii) amplitude and (iii) orientation of Earth’s rotation vector over the last century estimated from geodetic and astronomic measurements] and argued that they could all be fit by a model of ongoing glacial isostatic adjustment (GIA) associated with the last ice age. Second, he demonstrated that prevailing estimates of the 20th century GMSL rise (~1.5 to 2.0 mm/year), after correction for the maximum signal from ocean thermal expansion, implied mass flux from ice sheets and glaciers at a level that would grossly misfit the residual GIA-corrected observations of Earth’s rotation. We demonstrate that the combination of lower estimates of the 20th century GMSL rise (up to 1990) improved modeling of the GIA process and that the correction of the eclipse record for a signal due to angular momentum exchange between the fluid outer core and the mantle reconciles all three Earth rotation observations. This resolution adds confidence to recent estimates of individual contributions to 20th century sea-level change and to projections of GMSL rise to the end of the 21st century based on them. PMID:26824058

  9. Development of Formal Agricultural Education in Canada (Based on the Analysis of Scientific Periodicals of the 19th-Early 20th Centuries)

    ERIC Educational Resources Information Center

    Havrylenko, Kateryna

    2016-01-01

    The article states that one of the world leaders in agricultural sector training is Canada, which has gained a great scientific and practical experience. The paper examines the role of periodicals of the 19th-early 20th centuries, preserved in the Canadian book funds for the establishment and development of formal agricultural education of this…

  10. Role Model Effects of Female STEM Teachers and Doctors on Early 20th Century University Enrollment in California. Research & Occasional Paper Series: CSHE.10.16

    ERIC Educational Resources Information Center

    Bleemer, Zach

    2016-01-01

    What was the role of imperfect local information in the growth, gender gap, and STEM (Science, Technology, Engineering and Math) major selection of early 20th century American universities? In order to examine pre-1950 American higher education, this study constructs four rich panel datasets covering most students, high school teachers, and…

  11. Affordances and Constraints in Social Studies Curriculum-Making: The Case of "Jewish Social Studies" in the Early 20th Century

    ERIC Educational Resources Information Center

    Jacobs, Benjamin M.

    2009-01-01

    This document-based historical study explores the nature of the Jewish social studies curriculum in American Jewish schools in the early 20th century (c.1910-1940), a period of significant growth and reform in the modern American Jewish education enterprise. "Jewish social studies" refers to school programs in which Jewish history, Jewish…

  12. History at the Mercy of Politicians and Ideologies: Germany, England, and the Netherlands in the 19th and 20th Centuries

    ERIC Educational Resources Information Center

    Wilschut, Arie H. J.

    2010-01-01

    The paper analyses and compares developments in history teaching in Germany, England, and the Netherlands in the 19th and 20th centuries. The development of history teaching in the three countries shows striking similarities. National politics have always used history education for purposes which did not necessarily tally with distanced critical…

  13. History at the Mercy of Politicians and Ideologies: Germany, England, and the Netherlands in the 19th and 20th Centuries

    ERIC Educational Resources Information Center

    Wilschut, Arie H. J.

    2010-01-01

    The paper analyses and compares developments in history teaching in Germany, England, and the Netherlands in the 19th and 20th centuries. The development of history teaching in the three countries shows striking similarities. National politics have always used history education for purposes which did not necessarily tally with distanced critical…

  14. Rural Women Workers in the 20th Century: An Annotated Bibliography. Center for Rural Manpower and Public Affairs Special Paper No. 15.

    ERIC Educational Resources Information Center

    Moser, Collette; Johnson, Deborah Kohn

    This annotated bibliography is dedicated to rural women workers and their roles during the 20th century (1875-1971). It is concerned with materials which consider both the questions of rural manpower and rural womanpower. There are a variety of source materials (books, articles, research papers, etc.) and some 338 entries. Divided into six…

  15. Teachers and the Education of the People: Elementary School Teachers and Images of Citizenship in Scandinavia during the 19th and 20th Centuries.

    ERIC Educational Resources Information Center

    Kivinen, Osmo; Rinne, Risto

    This paper explores the historical formation of the teaching profession in Scandinavia in the 19th and 20th centuries, with special reference to developments in Finland. It focuses on the process by which mass education has assigned teachers a crucial role in the initiation ceremonies characteristic of modern society in relation to changing models…

  16. Development of Formal Agricultural Education in Canada (Based on the Analysis of Scientific Periodicals of the 19th-Early 20th Centuries)

    ERIC Educational Resources Information Center

    Havrylenko, Kateryna

    2016-01-01

    The article states that one of the world leaders in agricultural sector training is Canada, which has gained a great scientific and practical experience. The paper examines the role of periodicals of the 19th-early 20th centuries, preserved in the Canadian book funds for the establishment and development of formal agricultural education of this…

  17. Historiography for Educational Leadership in Mathematics: Content Analysis of a 1904 K-8 Mathematics Series and the Early 20th Century Context of Its Use

    ERIC Educational Resources Information Center

    Goodwin, Diana

    2012-01-01

    Math education is as important today as it was 100 years ago when the early 20th century was transforming from the old world into an era of factories, airplanes, atomic energy, and medical breakthroughs. Educational leaders of the era were wrestling with how long children should stay in school, meeting the diverse needs of an influx of immigrants,…

  18. National Gender Policy in Public Education in the Russian Empire in the Latter Half of the 19th-Early 20th Centuries

    ERIC Educational Resources Information Center

    Saifullova, Razilia Rauilovna; Maslova, Inga Vladimirovna; Krapotkina, Irina Evgenevna; Kaviev, Airat Farkhatovich; Nasyrova, Liliya Gabdelvalievna

    2016-01-01

    This article presents the national gender policy in public education in the Russian Empire in the latter half of the 19th-early 20th centuries. In the course of work the authors have used special historical research methods enabling to hammer out the facts and to approach historical sources from a critical standpoint. The comparative method…

  19. "More than Measurable Human Products": Catholic Educators' Responses to the Educational Measurement Movement in the First Half of the 20th Century

    ERIC Educational Resources Information Center

    Ryan, Ann Marie

    2009-01-01

    During the first half of the 20th century, Catholic educators in the United States used theological arguments both to resist and embrace the progressive educational reform effort of educational measurement. The significant expansion of Catholic schooling and the increased number of students attending them, along with increased state oversight, led…

  20. Detecting long-term metabolic shifts using isotopomers: CO2-driven suppression of photorespiration in C3 plants over the 20th century

    PubMed Central

    Ehlers, Ina; Augusti, Angela; Betson, Tatiana R.; Nilsson, Mats B.; Marshall, John D.; Schleucher, Jürgen

    2015-01-01

    Terrestrial vegetation currently absorbs approximately a third of anthropogenic CO2 emissions, mitigating the rise of atmospheric CO2. However, terrestrial net primary production is highly sensitive to atmospheric CO2 levels and associated climatic changes. In C3 plants, which dominate terrestrial vegetation, net photosynthesis depends on the ratio between photorespiration and gross photosynthesis. This metabolic flux ratio depends strongly on CO2 levels, but changes in this ratio over the past CO2 rise have not been analyzed experimentally. Combining CO2 manipulation experiments and deuterium NMR, we first establish that the intramolecular deuterium distribution (deuterium isotopomers) of photosynthetic C3 glucose contains a signal of the photorespiration/photosynthesis ratio. By tracing this isotopomer signal in herbarium samples of natural C3 vascular plant species, crops, and a Sphagnum moss species, we detect a consistent reduction in the photorespiration/photosynthesis ratio in response to the ∼100-ppm CO2 increase between ∼1900 and 2013. No difference was detected in the isotopomer trends between beet sugar samples covering the 20th century and CO2 manipulation experiments, suggesting that photosynthetic metabolism in sugar beet has not acclimated to increasing CO2 over >100 y. This provides observational evidence that the reduction of the photorespiration/photosynthesis ratio was ca. 25%. The Sphagnum results are consistent with the observed positive correlations between peat accumulation rates and photosynthetic rates over the Northern Hemisphere. Our results establish that isotopomers of plant archives contain metabolic information covering centuries. Our data provide direct quantitative information on the “CO2 fertilization” effect over decades, thus addressing a major uncertainty in Earth system models. PMID:26644588

  1. Detecting long-term metabolic shifts using isotopomers: CO2-driven suppression of photorespiration in C3 plants over the 20th century.

    PubMed

    Ehlers, Ina; Augusti, Angela; Betson, Tatiana R; Nilsson, Mats B; Marshall, John D; Schleucher, Jürgen

    2015-12-22

    Terrestrial vegetation currently absorbs approximately a third of anthropogenic CO2 emissions, mitigating the rise of atmospheric CO2. However, terrestrial net primary production is highly sensitive to atmospheric CO2 levels and associated climatic changes. In C3 plants, which dominate terrestrial vegetation, net photosynthesis depends on the ratio between photorespiration and gross photosynthesis. This metabolic flux ratio depends strongly on CO2 levels, but changes in this ratio over the past CO2 rise have not been analyzed experimentally. Combining CO2 manipulation experiments and deuterium NMR, we first establish that the intramolecular deuterium distribution (deuterium isotopomers) of photosynthetic C3 glucose contains a signal of the photorespiration/photosynthesis ratio. By tracing this isotopomer signal in herbarium samples of natural C3 vascular plant species, crops, and a Sphagnum moss species, we detect a consistent reduction in the photorespiration/photosynthesis ratio in response to the ∼100-ppm CO2 increase between ∼1900 and 2013. No difference was detected in the isotopomer trends between beet sugar samples covering the 20th century and CO2 manipulation experiments, suggesting that photosynthetic metabolism in sugar beet has not acclimated to increasing CO2 over >100 y. This provides observational evidence that the reduction of the photorespiration/photosynthesis ratio was ca. 25%. The Sphagnum results are consistent with the observed positive correlations between peat accumulation rates and photosynthetic rates over the Northern Hemisphere. Our results establish that isotopomers of plant archives contain metabolic information covering centuries. Our data provide direct quantitative information on the "CO2 fertilization" effect over decades, thus addressing a major uncertainty in Earth system models.

  2. Nelson's wound: treatment of spinal cord injury in 19th and early 20th century military conflicts.

    PubMed

    Hanigan, William C; Sloffer, Chris

    2004-01-15

    During the first half of the 19th century, warfare did not provide a background for a systematic analysis of spinal cord injury (SCI). Medical officers participating in the Peninsular and Crimean Wars emphasized the dismal prognosis of this injury, although authors of sketchy civil reports persuaded a few surgeons to operate on closed fractures. The American Medical and Surgical History of the War of the Rebellion was the first text to provide summary of results in 642 cases of gunshot wounds of the spine. The low incidence of this injury (0.26%) and the high mortality rate (55%) discouraged the use of surgery in these cases. Improvements in diagnoses and the introduction of x-ray studies in the latter half of the century enabled Sir G. H. Makins, during the Boer War, to recommend delayed intervention to remove bone or bullet fragments in incomplete injuries. The civil experiences of Elsberg and Frazier in the early 20th century promoted a meticulous approach to treatments, whereas efficient transport of injured soldiers during World War I increased the numbers of survivors. Open large wounds or cerebrospinal fluid leakage, signs of cord compression in recovering patients, delayed clinical deterioration, or intractable pain required surgical exploration. Wartime recommendations for urological and skin care prevented sepsis, and burgeoning pension systems provided specialized longterm rehabilitation. By the Armistice, the effective surgical treatment and postoperative care that had developed through decades of interaction between civil and military medicine helped reduce incidences of morbidity and dispel the hopelessness surrounding the combatant with an SCI.

  3. Spanish flu and early 20th-century expansion of a coronary heart disease-prone subpopulation.

    PubMed

    Azambuja, Maria Inês Reinert

    2004-01-01

    According to Stephen Jay Gould, "we have a strong preference for seeing trends as entities moving somewhere." However, trends may instead be the product of relative expansions and contractions of different subpopulations constituting the system. Variation in attributes of coronary heart disease cases during the decline in coronary heart disease mortality suggests a change in the primary source-subpopulation of cases over time. It is proposed that an early 20th-century expansion of a coronary heart disease-prone subpopulation, characterized by high serum-cholesterol phenotype and high case-fatality--which contributed to most of the coronary heart disease cases and deaths during the 1960s--may have been a late result of the 1918 influenza pandemic. The same unusual immune response to infection that in 1918 killed preferentially men, whites, and those born from 1880 to 1900 (20-40 years old) may have "primed" survivors of those birth cohorts to late coronary heart disease mortality. Ecologic evidence in favor of a birth cohort and geographic association between both epidemics is presented. Cross-reactive auto-immune response upon reinfection could explain the excess coronary heart disease deaths reported during influenza epidemics from the late 1920s onward. Mimicry between the viral hemagglutinin and the apolipoprotein B or the low-density lipoprotein receptor could be the link between infection and hypercholesterolemia. The extinction of those birth cohorts would result in a relative increase in cases coming from a 2nd subpopulation, which was characterized by insulin resistance and chronic expression of low-grade inflammation markers and was comparatively less vulnerable to die acutely from coronary heart disease.

  4. Sediment accumulation in San Leandro Bay, Alameda County, California, during the 20th century : a preliminary report

    USGS Publications Warehouse

    Nolan, K.M.; Fuller, C.C.

    1986-01-01

    Major changes made in the configuration of San Leandro Bay, Alameda County, California, during the 20th century have caused rapid sedimentation within parts of the Bay. Opening of the Oakland tidal channel and removal of 97% of the marshlands formerly surrounding the Bay have decreased tidal velocities and volumes. Marshland removal has decreased the tidal prism by about 25%. Comparison of bathymetric surveys indicates that sedimentation in the vicinity of the San Leandro Bay channel averaged 0.7 cm/annum between 1856 and 1984. Lead-210 data collected at four shallow water sites east of the San Leandro Bay channel indicated that sedimentation rates have averaged between 0.06 and 0.28 cm/annum. Because bioturbation of bottom sediments cannot be discounted, better definition of this range in sedimentation rates would required measuring the activity of lead-210 on incoming sediments. In addition to sediment deposited in the vicinity of the San Leandro Bay channel and open, shallow areas to the east, 850,740 cu m of sediment was deposited between 1948 and 1983 in an area dredged at the mouth of San Leandro Creek. All available data indicate that between 1 ,213,000 and 1,364,000 cu m of sediment was deposited in San Leandro Bay between 1948 and 1983. Sediment yield data from an adjacent drainage basin, when combined with inventories of lead-210 and cesium-137, indicate that most of the sediment deposited in San Leandro Bay is coming from resuspension of bottom sediments or from erosion of marshes or shorelines of San Leandro or San Francisco Bay. (Author 's abstract)

  5. Anthropic disturbances in the sedimentological characteristics of a Northern Patagonian lake: evidencing the impacts of the 20th century settlement

    NASA Astrophysics Data System (ADS)

    Araneda, A.; Muñoz, V.; Valenzuela, B.; Alvarez, D.; Torrejon, F.; Pedreros, P.; Urrutia, R.

    2013-12-01

    Traditionally Patagonia has been seen as a very pristine area, being an important reserve of wildlife and clean waters. Nonetheless it was dramatically affected by the first settlers at the beginning of the 20th century, that generated large fires for clearing the land originally covered by native forest. Those fires produced a dramatic impact left behind thousands of dead trees, increasing soil erosion, altering nutrient inputs in the aquatic ecosystems, which in turn affected the aquatic biota. However those impacts have been barely asses, then through the study of the sediment record of lake La Esponja (45°S) we want to evaluate the magnitude of the changes produced by the fires and to determine the resilience capacity of the lake. We analyzed magnetic susceptibility, organic content, charcoal, total phosphorous and a biological proxy (Chironomidae) in a sediment sequence of 60 cm long. Magnetic susceptibility shows a very variable behavior along the profile, being possible to identify a decreasing trend since the bottom, up to the most recent part of the record. An opposite behavior describes the organic content, showing a noticeable increase toward the surficial sediments. The number of charcoal particles -a direct indicator of fires occurrence, shows a peak of fires approximately at seven cm depth, diminishing toward the recent part. Total phosphorous also follow the trend recognized by charcoal, which allow inferring a probable trophic increase of the lake. This trend is partially recognized by chironomid assemblages through the increasing of some taxa typical of a higher nutrient status. Acknowledgements: Fondecyt projects 1120765 and 1120807.

  6. 20th Century Trends In The Maximum And Minimum Temperatures In Colorado’s San Juan Mountains

    NASA Astrophysics Data System (ADS)

    Rangwala, I.; Miller, J. R.

    2009-12-01

    We examine the maximum (Tmax) and minimum (Tmin) temperature changes in San Juan Mountain (SJM) region of southwestern Colorado between 1895-2005. We analyze monthly averaged observations from 6 National Weather Service (NWS) stations between 1895-1949, and 25 NWS stations between 1950-2005. These changes are evaluated on annual, seasonal and monthly bases. Annually, our results suggest a long-term gradual warming trend in Tmin and no such discernable trend in Tmax. However, between 1990 and 2005, the region experiences a rapid warming trend with both Tmax and Tmin increasing by 1 degree C. Between 1950 and 1985, there is a regional cooling trend during which there are significant decreases in Tmax and almost no trend in Tmin. Similar to the annual trends, only Tmin shows a gradual warming trend during the 20th century during all seasons. Furthermore, during fall and summer, there is a lower correlation between Tmax and Tmin as compared to winter and spring. Between 1990-2005, Tmax increases more than Tmin during summer and spring, whereas Tmin shows greater increases during winter. We also examine Tmax and Tmin trends from 23 Snow Telemetry (SNOTEL) sites in the region between 1984-2005. We find strong correlation between NWS and SNOTEL observations, both annually and seasonally. Between 1990-2005, the largest warming at the SNOTEL sites occurs during summer while it is largest during winter at the NWS sites. Spatially, there are similar increases in Tmax and Tmin except in the central mountain region, where increases in Tmin started earlier and are greater. Physical mechanisms for these observed trends in Tmax and Tmin will be discussed.

  7. Long-term changes in nitrate conditions over the 20th century in two Midwestern Corn Belt streams

    NASA Astrophysics Data System (ADS)

    Kelly, Valerie; Stets, Edward G.; Crawford, Charlie

    2015-06-01

    Long-term changes in nitrate concentration and flux between the middle of the 20th century and the first decade of the 21st century were estimated for the Des Moines River and the Middle Illinois River, two Midwestern Corn Belt streams, using a novel weighted regression approach that is able to detect subtle changes in solute transport behavior over time. The results show that the largest changes in flow-normalized concentration and flux occurred between 1960 and 1980 in both streams, with smaller or negligible changes between 1980 and 2004. Contrasting patterns were observed between (1) nitrate export linked to non-point sources, explicitly runoff of synthetic fertilizer or other surface sources and (2) nitrate export presumably associated with point sources such as urban wastewater or confined livestock feeding facilities, with each of these modes of transport important under different domains of streamflow. Surface runoff was estimated to be consistently most important under high-flow conditions during the spring in both rivers. Nitrate export may also have been considerable in the Des Moines River even under some conditions during the winter when flows are generally lower, suggesting the influence of point sources during this time. Similar results were shown for the Middle Illinois River, which is subject to significant influence of wastewater from the Chicago area, where elevated nitrate concentrations were associated with at the lowest flows during the winter and fall. By modeling concentration directly, this study highlights the complex relationship between concentration and streamflow that has evolved in these two basins over the last 50 years. This approach provides insights about changing conditions that only become observable when stationarity in the relationship between concentration and streamflow is not assumed.

  8. 20th century human pressures drive reductions in deepwater oxygen leading to losses of benthic methane-based food webs

    NASA Astrophysics Data System (ADS)

    Belle, Simon; Millet, Laurent; Verneaux, Valérie; Lami, Andrea; David, Etienne; Murgia, Laurie; Parent, Claire; Musazzi, Simona; Gauthier, Emilie; Bichet, Vincent; Magny, Michel

    2016-04-01

    Freshwater lakes play a key role in the global carbon cycle as sinks (organic carbon sequestration) and sources (greenhouse gas emissions). Understanding the carbon cycle response to environmental changes is becoming a crucial challenge in the context of global warming and the preponderance of human pressures. We reconstructed the long-term (1500 years) evolution of trophic functioning of the benthic food web, based on methanotrophic ancient DNA and chironomid isotope analyses). In addition, human land use is also reconstructed in three different lakes (eastern France, Jura Mountains). Our findings confirm that the benthic food web can be highly dependent on methane-derived carbon (up to 50% of the chironomid biomass) and reveal that the activation of this process can correspond to a natural functioning or be a consequence of anthropic perturbation. The studied lakes also showed a similar temporal evolution over the last century with the disappearance of the profundal aquatic insects (Chironomidae, Diptera), considered as keystone for the whole lake food web (e.g., coupling benthic-pelagic), inducing a potential collapse in the transfer of methane to top consumers. This functional state, also called the dead zone expansion, was caused by the change in human land-use occurring at the beginning of the 20th century. The strong modification of agro-pastoral practices (e.g., fertilization practices, intensive grazing, and sewage effluent) modified the influx of nutrients (by diffuse and/or point-source inputs) and induced a significant increase in the trophic status and organic matter sedimentation to reach unprecedented values. Further studies should be planned to assess dead zone expansion and, according to the regime shift theory, to provide environmental tipping points for sustainable resource management.

  9. Coral-based history of lead and lead isotopes of the surface Indian Ocean since the mid-20th century

    NASA Astrophysics Data System (ADS)

    Lee, Jong-Mi; Boyle, Edward A.; Suci Nurhati, Intan; Pfeiffer, Miriam; Meltzner, Aron J.; Suwargadi, Bambang

    2014-07-01

    Anthropogenic lead (Pb) from industrial activities has greatly altered the distribution of Pb in the present-day oceans, but no continuous temporal Pb evolution record is available for the Indian Ocean despite rapidly emerging industries around the region. Here, we present the coral-inferred annual history of Pb concentration and isotope ratios in the surface Indian Ocean since the mid-20th century (1945-2010). We analyzed Pb in corals from the Chagos Archipelago, western Sumatra and Strait of Singapore - which represent the central Indian Ocean via nearshore sites. Overall, coral Pb/Ca increased in the mid-1970s at all the sites. However, coral Pb isotope ratios evolve distinctively at each site, suggesting Pb contamination arises from different sources in each case. The major source of Pb in the Chagos coral appears to be India's Pb emission from leaded gasoline combustion and coal burning, whereas Pb in western Sumatra seems to be largely affected by Indonesia's gasoline Pb emission with additional Pb inputs from other sources. Pb in the Strait of Singapore has complex sources and its isotopic composition does not reflect Pb from leaded gasoline combustion. Higher 206Pb/207Pb and 208Pb/207Pb ratios found at this site may reflect the contribution of Pb from coals and ores from southern China, Indonesia, and Australia, and local Pb sources in the Strait of Singapore. It is also possible that the Pb isotope ratios of Singapore seawater were elevated through isotope exchange with natural fluvial particles considering its delta setting.

  10. 19th-20th century rainfall patterns reconstructed from sediment provenance in a Santa Barbara Basin box core

    NASA Astrophysics Data System (ADS)

    Napier, T.; Hendy, I. L.; Schimmelmann, A.

    2013-12-01

    Rainfall patterns in Southern California directly affect the availability of water resources and induce hazards in this highly populated and water stressed region. Extreme weather consists of heavy rainfall events in winter associated with atmospheric rivers, and drought conditions when winter rains do not arrive. Water availability has a significant societal impact in Southern California. Here we reconstruct 19th-20th century precipitation history of river catchments draining into Santa Barbara Basin (SBB) through a combination of high-resolution elemental and mineralogical analyses. The deep center of the SBB features suboxic bottom waters and high sedimentation rates resulting in minimal bioturbation of annual sedimentation, which enables high-resolution paleoclimate research. Scanning XRF analysis at a 200 μm resolution of box core SPR0901-04BC from SBB was used to determine annual changes in sediment composition. Samples at 1 cm resolution from the same box core were analyzed for a more extensive suite of elements by ICP-MS, while mineralogy in each sample was determined from whole rock and clay fraction (<2 μm) analysis using X-ray defraction. Elements associated with siliciclastic sediment increase in relative abundance during wet years when significant river runoff events (floods) occurred. The relative proportions of these elements differ between flood events, possibly reflecting differences in temporal and/or spatial rainfall patterns that vary the response of each river catchment draining into SBB. Watershed sediment from the Santa Ynez Mountain streams and Ventura and Santa Clara River catchments derives mostly from Cenozoic sedimentary units, except the Santa Clara River catchment, which contains metamorphic and igneous units. As river runoff is responsible for a significant portion of the terrigenous input into SBB, and is primarily the result of precipitation events, characteristic mineralogy and elemental signatures are a direct recorder of

  11. Northern Hemisphere extratropical winter cyclones variability over the 20th Century derived from ERA-20C Reanalysis

    NASA Astrophysics Data System (ADS)

    Varino, Filipa; Philippe, Arbogast; Bruno, Joly; Gwendal, Rivière; Marie-Laure, Fandeur; Henry, Bovy; Jean-Baptiste, Granier; Mitchell-Wallace, Kirsten

    2017-04-01

    Strom-track variability and trends over the 20th Century using long-term reanalyses is a subject of interest among the scientific community. However the homogeneity of these datasets throughout the time is questioned and results less conclusive or unreliable for early periods of the century. In this study we intend to better understand the climatology of extra-tropical cyclones during the last century using a vorticity-based tracking algorithm applied to the new-released long-term ERA-20C reanalysis from ECMWF since the beginning of the century. The main originality of our study relies on the physical interpretation of the detected cyclone trends in terms of changes in the large-scale circulation. It provides confidence in the results despite the heterogeneous assimilated observations throughout the analysed period. The variability of moderate-to-deep extra-tropical winter cyclones in ERA-20C show three distinct periods. Two at the beginning and at the end of the century (1900-1935 and 1980-2010) present no significant trends in the Northern Hemisphere and one in between (1935 - 1980) is marked by a significant increase in frequency of these cyclones. During this latter period, polar regions underwent a significant cooling that increased the mid-latitude meridional temperature gradient over the whole troposphere and consequently the baroclinicity. As a result, extra-tropical cyclones intensified. In contrast, the first and third periods are characterized by warmer polar temperatures. However, as the stronger warming is confined to the lower troposphere, the mid-latitude meridional temperature gradients and the baroclinicity do not uniformly increase in the whole troposphere. This may explain why the recent rapid increase in polar temperatures has not affected the behaviour of extratropical cyclones very much.

  12. Long-term changes in nitrate conditions over the 20th century in two Midwestern Corn Belt streams

    USGS Publications Warehouse

    Kelly, Valerie J.; Stets, Edward G.; Crawford, Charles G.

    2015-01-01

    Long-term changes in nitrate concentration and flux between the middle of the 20th century and the first decade of the 21st century were estimated for the Des Moines River and the Middle Illinois River, two Midwestern Corn Belt streams, using a novel weighted regression approach that is able to detect subtle changes in solute transport behavior over time. The results show that the largest changes in flow-normalized concentration and flux occurred between 1960 and 1980 in both streams, with smaller or negligible changes between 1980 and 2004. Contrasting patterns were observed between (1) nitrate export linked to non-point sources, explicitly runoff of synthetic fertilizer or other surface sources and (2) nitrate export presumably associated with point sources such as urban wastewater or confined livestock feeding facilities, with each of these modes of transport important under different domains of streamflow. Surface runoff was estimated to be consistently most important under high-flow conditions during the spring in both rivers. Nitrate export may also have been considerable in the Des Moines River even under some conditions during the winter when flows are generally lower, suggesting the influence of point sources during this time. Similar results were shown for the Middle Illinois River, which is subject to significant influence of wastewater from the Chicago area, where elevated nitrate concentrations were associated with at the lowest flows during the winter and fall. By modeling concentration directly, this study highlights the complex relationship between concentration and streamflow that has evolved in these two basins over the last 50 years. This approach provides insights about changing conditions that only become observable when stationarity in the relationship between concentration and streamflow is not assumed.

  13. Exponential decline of aftershocks of the M7.9 1868 great Kau earthquake, Hawaii, through the 20th century

    USGS Publications Warehouse

    Klein, F.W.; Wright, Tim

    2008-01-01

    The remarkable catalog of Hawaiian earthquakes going back to the 1820s is based on missionary diaries, newspaper accounts, and instrumental records and spans the great M7.9 Kau earthquake of April 1868 and its aftershock sequence. The earthquake record since 1868 defines a smooth curve complete to M5.2 of the declining rate into the 21st century, after five short volcanic swarms are removed. A single aftershock curve fits the earthquake record, even with numerous M6 and 7 main shocks and eruptions. The timing of some moderate earthquakes may be controlled by magmatic stresses, but their overall long-term rate reflects one of aftershocks of the Kau earthquake. The 1868 earthquake is, therefore, the largest and most controlling stress event in the 19th and 20th centuries. We fit both the modified Omori (power law) and stretched exponential (SE) functions to the earthquakes. We found that the modified Omori law is a good fit to the M ??? 5.2 earthquake rate for the first 10 years or so and the more rapidly declining SE function fits better thereafter, as supported by three statistical tests. The switch to exponential decay suggests that a possible change in aftershock physics may occur from rate and state fault friction, with no change in the stress rate, to viscoelastic stress relaxation. The 61-year exponential decay constant is at the upper end of the range of geodetic relaxation times seen after other global earthquakes. Modeling deformation in Hawaii is beyond the scope of this paper, but a simple interpretation of the decay suggests an effective viscosity of 1019 to 1020 Pa s pertains in the volcanic spreading of Hawaii's flanks. The rapid decline in earthquake rate poses questions for seismic hazard estimates in an area that is cited as one of the most hazardous in the United States.

  14. Early 20th-century research at the interfaces of genetics, development, and evolution: reflections on progress and dead ends.

    PubMed

    Deichmann, Ute

    2011-09-01

    Three early 20th-century attempts at unifying separate areas of biology, in particular development, genetics, physiology, and evolution, are compared in regard to their success and fruitfulness for further research: Jacques Loeb's reductionist project of unifying approaches by physico-chemical explanations; Richard Goldschmidt's anti-reductionist attempts to unify by integration; and Sewall Wright's combination of reductionist research and vision of hierarchical genetic systems. Loeb's program, demanding that all aspects of biology, including evolution, be studied by the methods of the experimental sciences, proved highly successful and indispensible for higher level investigations, even though evolutionary change and properties of biological systems up to now cannot be fully explained on the molecular level alone. Goldschmidt has been appraised as pioneer of physiological and developmental genetics and of a new evolutionary synthesis which transcended neo-Darwinism. However, this study concludes that his anti-reductionist attempts to integrate genetics, development and evolution have to be regarded as failures or dead ends. His grand speculations were based on the one hand on concepts and experimental systems that were too vague in order to stimulate further research, and on the other on experiments which in their core parts turned out not to be reproducible. In contrast, Sewall Wright, apart from being one of the architects of the neo-Darwinian synthesis of the 1930s, opened up new paths of testable quantitative developmental genetic investigations. He placed his research within a framework of logical reasoning, which resulted in the farsighted speculation that examinations of biological systems should be related to the regulation of hierarchical genetic subsystems, possibly providing a mechanism for development and evolution. I argue that his suggestion of basing the study of systems on clearly defined properties of the components has proved superior to

  15. The 20th century whole-basin trophic history of an inter-drumlin lake in an agricultural catchment.

    PubMed

    Jordan, Philip; Rippey, Brian; Anderson, N John

    2002-10-07

    Eight 1-m sediment cores were extracted from across the basin of Friary Lough, a 5.4-ha eutrophic lake in a wholly grassland agricultural catchment in Co. Tyrone, Northern Ireland. Sedimentary TP, diatom inferred TP, Ca, Na, Fe, Mn, loss-on-ignition (LOI), dry weight and density were determined in the core profiles. Core dating and correlation gave a 210Pb, 137Cs and 241Am chronology from 1906 to 1995 and enabled a whole-basin estimate of chemical and sediment accumulation rate over the 20th Century. The major changes for all parameters occurred after c. 1946. Sediment accumulation rate was most influenced by organic matter accumulations, probably of planktonic origin, and increasing after c. 1946. Inorganic sediment accumulation rate was found to be largely unchanging through the century at 10 t km(-2) yr(-1) when expressed as catchment exports. All chemical accumulation rate changes occurred after c. 1946. Total phosphorus accumulation rate, however, was found to be the only chemical to be increasing throughout the epilimnion and hypolimnion areas of the sedimentary basin at an average of 22.5 mg m(-2) yr(-1) between 1946 and 1995. The other chemical parameters showed increasing accumulation rates after c. 1946 in the epilimnion part of the basin only. Interpreted in terms of whole-basin sedimentation and catchment export processes over time, it is suggested that diffuse TP inputs are independent of sediment inputs. This corresponds to hydrochemical models that suggest soluble P as the primary fraction that is lost from grassland catchments. The increase in sedimentary TP accumulation rate, and DI-TP concentration, are also explained with regard to current models that suggest increases in runoff P concentrations from elevated soil P concentrations. Increases in eplimnion chemical and sediment accumulation rate after c. 1