ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the American Water Resources Association 25 (1989), S. 0 
    ISSN: 1752-1688
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: : In a study to measure the efficacy of chioramines at inactivating Giardia cysts, the ability of cysts to excyst was measured after exposure to different concentrations of chloramines, for different times, and at different temperatures and pH. The chloramines were generated by mixing ammonium sulfate and sodium hypochlorate in water to approximate a 7:1 chlorine:ammonia ratio by weight. Times of 40, 80, 180, and 270 minutes; temperatures of 3, 10, and 18°C; target chioramine concentrations of 0.4, 1.4, 2.0, and 2.6 mg/L; and pH of 7.0 and 8.5 were the actual values tested. The combinations of these variables that were able to inactivate 〉99.8 percent of the cysts were a minimum chloramine concentration of 2.26 mg/L applied for 270 minutes at a water temperature of 10°C; and at 18°C, averaged minimum chloramine concentrations of 2.14 and 1.55 mg/L applied for 180 and 270 minutes, respectively. The minimum CT values corresponding to these combinations capable of 〉99.8 percent cyst inactivation, are 610 at 10°C and 385 at 18°C. Temperature was noted to exert a major effect on the ability of chloramines to inactivate cysts. Modifications of the methods used to generate chloramines may have an effect on the capacity of this disinfectant to inactivate cysts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2019
    Electronic ISSN: 2041-1723
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General , Physics
    Published by Springer Nature
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2018-08-01
    Description: Convective surface winds in the contiguous United States are classified as severe at 50 kt (58 mi h−1, or 26 m s−1), whether measured or estimated. In 2006, NCDC (now NCEI) Storm Data, from which analyzed data are directly derived, began explicit categorization of such reports as measured gusts (MGs) or estimated gusts (EGs). Because of the documented tendency of human observers to overestimate winds, the quality and reliability of EGs (especially in comparison with MGs) has been challenged, mostly for nonconvective winds and controlled-testing situations, but only speculatively for bulk convective data. For the 10-yr period of 2006–15, 150 423 filtered convective-wind gust magnitudes are compared and analyzed, including 15 183 MGs and 135 240 EGs, both nationally and by state. Nonmeteorological artifacts include marked geographic discontinuities and pronounced “spikes” of an order of magnitude in which EG values (in both miles per hour and knots) end in the digits 0 or 5. Sources such as NWS employees, storm chasers, and the general public overestimate EGs, whereas trained spotters are relatively accurate. Analysis of the ratio of EG to MG and their sources also reveals an apparent warning-verification-influence bias in the climatological distribution of wind gusts imparted by EG reliance in the Southeast. Results from prior wind-tunnel testing of human subjects are applied to 1) illustrate the difference between measured and perceived winds for the database and 2) show the impact on the severe-wind dataset if EGs were bias-corrected for the human overestimation factor.
    Print ISSN: 1558-8424
    Electronic ISSN: 1558-8432
    Topics: Geography , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2018-02-01
    Description: During the 2014–15 academic year, the National Oceanic and Atmospheric Administration (NOAA) National Weather Service Storm Prediction Center (SPC) and the University of Oklahoma (OU) School of Meteorology jointly created the first SPC-led course at OU focused on connecting traditional theory taught in the academic curriculum with operational meteorology. This class, “Applications of Meteorological Theory to Severe-Thunderstorm Forecasting,” began in 2015. From 2015 through 2017, this spring–semester course has engaged 56 students in theoretical skills and related hands-on weather analysis and forecasting applications, taught by over a dozen meteorologists from the SPC, the NOAA National Severe Storms Laboratory, and the NOAA National Weather Service Forecast Offices. Following introductory material, which addresses many theoretical principles relevant to operational meteorology, numerous presentations and hands-on activities focused on instructors’ areas of expertise are provided to students. Topics include the following: storm-induced perturbation pressure gradients and their enhancement to supercells, tornadogenesis, tropical cyclone tornadoes, severe wind forecasting, surface and upper-air analyses and their interpretation, and forecast decision-making. This collaborative approach has strengthened bonds between meteorologists in operations, research, and academia, while introducing OU meteorology students to the vast array of severe thunderstorm forecast challenges, state-of-the-art operational and research tools, communication of high-impact weather information, and teamwork skills. The methods of collaborative instruction and experiential education have been found to strengthen both operational–academic relationships and students’ appreciation of the intricacies of severe thunderstorm forecasting, as detailed in this article.
    Print ISSN: 0003-0007
    Electronic ISSN: 1520-0477
    Topics: Geography , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2020-09-09
    Description: The cyclone-relative location and variability in the number of tornadoes among tropical cyclones (TCs) are not completely understood. A key understudied factor that may improve our understanding is ambient (i.e., synoptic-scale) deep-tropospheric (i.e., 850–200-hPa) vertical wind shear (VWS), which impacts both the symmetry and strength of deep convection in TCs. This study conducts a climatological analysis of VWS impacts upon tornadoes in TCs from 1995 to 2018, using observed TC and tornado data together with radiosondes. TC tornadoes were classified by objectively defined VWS categories, derived from reanalyses, to quantify the sensitivity of tornado frequency, location, and their environments to VWS. The analysis shows that stronger VWS is associated with enhanced rates of tornado production—especially more damaging ones. Tornadoes also become localized to the downshear half of the TC as VWS strengthens, with tornado location in strongly sheared TCs transitioning from the downshear-left quadrant in the TC inner core to the downshear-right quadrant in the TC outer region. Analysis of radiosondes shows that the downshear-right quadrant in strongly sheared TCs is most frequently associated with sufficiently strong near-surface speed shear and veering aloft, and lower-tropospheric thermodynamic instability for tornadoes. These supportive kinematic environments may be due to the constructive superposition of the ambient and TC winds, and the VWS-induced downshear enhancement of the TC circulation among other factors. Together, this work provides a basis for improving forecasts of TC tornado frequency and location.
    Print ISSN: 0882-8156
    Electronic ISSN: 1520-0434
    Topics: Geography , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2020-09-24
    Description: As lightning-detection records lengthen and the efficiency of severe weather reporting increases, more accurate climatologies of convective hazards can be constructed. In this study we aggregate flashes from the NLDN and ATDnet lightning-detection networks with severe weather reports from ESWD and SPC Storm Data on a common grid of 0.25° and 1-hour steps. Each year approximately 75–200 thunderstorm hours occur over the southwestern, central and eastern United States, with a peak over Florida (200–250 hours). The activity over the majority of Europe ranges 15–100 hours, with peaks over Italy and mountains (Pyrenees, Alps, Carpathians, Dinaric Alps; 100–150 hours). The highest convective activity over continental Europe occurs during summer and over the Mediterranean during autumn. The United States peak for tornadoes and large hail reports is in spring, preceding the maximum of lightning and severe wind reports by 1–2 months. Convective hazards occur typically in the late afternoon, with the exception of the Midwest and Great Plains, where mesoscale convective systems shift peak lightning threat to the night. The severe wind threat is delayed by 1–2 hours compared to hail and tornadoes. The fraction of nocturnal lightning over land ranges 15%–30% with lowest values observed over Florida and mountains (∼10%). Wintertime lightning shares the highest fraction of severe weather. Compared to Europe, extreme events are considerably more frequent over the United States, with maximum activity over the Great Plains. However, the threat over Europe should not be underestimated, as severe weather outbreaks with damaging winds, very large hail and significant tornadoes occasionally occur over densely populated areas.
    Print ISSN: 0894-8755
    Electronic ISSN: 1520-0442
    Topics: Geography , Geosciences , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2012-07-01
    Description: The accuracy, reliability, and skill of several objective supercell identification methods are evaluated using 113 simulations from an idealized cloud model with 1-km horizontal grid spacing. Horizontal cross sections of vorticity and radar reflectivity at both mid- and low levels were analyzed for the presence of a supercell, every 5 min of simulation time, to develop a “truth” database. Supercells were identified using well-known characteristics such as hook echoes, inflow notches, bounded weak-echo regions (BWERs), and the presence of significant vertical vorticity. The three objective supercell identification techniques compared were the Pearson correlation (PC) using an analysis window centered on the midlevel storm updraft; a modified Pearson correlation (MPC), which calculates the PC at every point in the horizontal using a small 3 km × 3 km analysis window; and updraft helicity (UH). Results show that the UH method integrated from 2 to 5 km AGL, and using a threshold value of 180 m2 s−2, was equally as accurate as the MPC technique—averaged from 2 to 5 km AGL and using a minimum updraft threshold of 7 m s−1 with a detection threshold of 0.3—in discriminating between supercells and nonsupercells for 1-km horizontal grid spacing simulations. At courser resolutions, the UH technique performed best, while the MPC technique produced the largest threat scores for higher-resolution simulations. In addition, requiring that the supercell detection thresholds last at least 20 min reduced the number of false alarms.
    Print ISSN: 0027-0644
    Electronic ISSN: 1520-0493
    Topics: Geography , Geosciences , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2014-10-24
    Description: This manuscript documents the tornado in the Rockwell Pass area of Sequoia National Park, California, that occurred on 7 July 2004. Since the elevation of the tornado’s ground circulation was approximately 3705 m (~12 156 ft) MSL, this is the highest-elevation tornado documented in the United States. The investigation of the storm’s convective mode was performed mostly inferentially on the basis of an analysis of the radar imagery from Edwards Air Force Base (which was in clear-air mode on this day), objectively produced soundings and/or CAPE estimates from two mesoscale models, an objectively produced proximity sounding and hodograph, and analyses of satellite imagery. The nearest Weather Surveillance Radar-1988 Doppler (WSR-88D) in Hanford, California, could not be used to observe this storm because of terrain blockage by the Sierra Nevada, and the nearest sounding sites were too distant and in a different meteorological environment on this day. The near-storm environment may have been favorable briefly for a supercell in the upper portion of the Kern River Canyon. The limitations of the radar data precluded the authors from making a definitive conclusion on the convective mode of the storm but do not rule out the possibility that the storm briefly might have been a supercell. There was insufficient evidence, however, to support the notion that the tornado itself was mesocyclone induced. High LCL heights in the proximity sounding also suggest that the tornado was formed by processes not associated with a mesocyclone (popularly known as a “landspout”), but do not allow us to dismiss the possibility that the tornado was mesocyclone induced.
    Print ISSN: 0027-0644
    Electronic ISSN: 1520-0493
    Topics: Geography , Geosciences , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2012-12-01
    Description: A gridded, hourly, three-dimensional environmental mesoanalysis database at the Storm Prediction Center (SPC), based on objectively analyzed surface observations blended with the Rapid Update Cycle (RUC) model-analysis fields and described in Parts I and II of this series, is applied to a 2003–11 subset of the SPC tropical cyclone (TC) tornado records. Distributions of environmental convective parameters, derived from SPC hourly mesoanalysis fields that have been related to supercells and tornadoes in the midlatitudes, are evaluated for their pertinence to TC tornado occurrence. The main factor differentiating TC from non-TC tornado environments is much greater deep-tropospheric moisture, associated with reduced lapse rates, lower CAPE, and smaller and more compressed distributions of parameters derived from CAPE and vertical shear. For weak and strong TC tornado categories (EF0–EF1 and EF2–EF3 on the enhanced Fujita scale, respectively), little distinction is evident across most parameters. Radar reflectivity and velocity data also are examined for the same subset of TC tornadoes, in order to determine parent convective modes (e.g., discrete, linear, clustered, supercellular vs nonsupercellular), and the association of those modes with several mesoanalysis parameters. Supercellular TC tornadoes are accompanied by somewhat greater vertical shear than those occurring from other modes. Tornadoes accompanying nonsupercellular radar echoes tend to occur closer to the TC center, where CAPE and shear tend to weaken relative to the outer TC envelope, though there is considerable overlap of their respective radial distributions and environmental parameter spaces.
    Print ISSN: 0882-8156
    Electronic ISSN: 1520-0434
    Topics: Geography , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2009-08-01
    Print ISSN: 0882-8156
    Electronic ISSN: 1520-0434
    Topics: Geography , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...