To see the other types of publications on this topic, follow the link: Graupner.
Journal articles on the topic 'Graupner'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Graupner.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Lawson, C. "Exploring Bach's contemporaries: Fasch and Graupner." Early Music 43, no. 1 (January 14, 2015): 179–82. http://dx.doi.org/10.1093/em/cau143.
Full text
2
O'Loughlin, Niall, Keith Puddy, Victoria Soames, Roger Heaton, Julius Drake, and Duke String Quartet. "The Early Clarinet Family: Anonymous, Handel, Graupner, Beethoven, Danzi." Musical Times 134, no. 1805 (July 1993): 410. http://dx.doi.org/10.2307/1003111.
Full text
3
Talle, Andrew. "Nürnberg, Darmstadt, Köthen - Neuerkenntnisse zur Bach-Überlieferung in der ersten Hälfte des 18. Jahrhunderts." Bach-Jahrbuch 89 (March 12, 2018): 143–72. http://dx.doi.org/10.13141/bjb.v20031785.
Full textAbstract:
Der Artikel widmet sich der Identifizierung und näheren Beschreibung dreier Schreiber: LS=Lorenz Sichart (1694-1771; Sighard, Sichert), Anonymus Darmstadt=Christoph Graupner d. J. (1715-1760) und Anonymus 5= Bernhard Christian Kayser (1705-1758).
Erwähnte Artikel:
Rudolf Bunge: Johann Sebastian Bachs Kapelle zu Cöthen und deren nachgelassene Instrumente. BJ 1905, S. 14-47
Alfred Dürr: Heinrich Nicolaus Gerber als Schüler Bachs. BJ 1978, S. 7-18
4
Clark, Christina A. "Sexuality Human Rights: A Global Overview. Edited by H. Graupner & P. Tahmindjis." Journal of Sex Research 44, no. 3 (July 23, 2007): 303–4. http://dx.doi.org/10.1080/00224490701444088.
Full text
5
Eichberg, Hartwig. "Unechtes unter Johann Sebastian Bachs Klavierwerken." Bach-Jahrbuch 61 (March 22, 2018): 7–49. http://dx.doi.org/10.13141/bjb.v19752001.
Full textAbstract:
Eine Reihe von Stücken Unter Bachs verstreuten Capriccios, Variationen, Sonaten und Suiten, die in NBA V/10 hätten aufgenommen werden sollen, kann als nicht authentisch aus Bachs Œuvre und damit aus der der NBA ausgeschieden werden. Alle diese Stücke sind ohne Authentifizierung überliefert und zeigen stilistische Merkmale, die nicht zu Bachs Autorschaft passen: BWV 834, 835 (J. P. Kirnberger), 838 (C. Graupner), 839, 844/8443 (BWV 844a vermutlich eine Komposition von W. F. Bach; BWV 844a eine spätere Version, wahrscheinlich aus dem Kreis von J. C. Kittel), 845, 964, 968 (BWV 964 und 968 nicht-authentische Transkriptionen aus den Soloviolinsonaten von J. S. Bach, vermutlich von W. F. Bach), 969 und 990. Darüber hinaus wird gezeigt, dass Bach drei weitere Kompositionen, die in andere NBA-Bände passen würden, fälschlicherweise zugeschrieben wurden: BWV 943, 960 und 923a (eine fehlerhafte Version von BWV 923, wahrscheinlich aus dem Kreis von Kittel). In einem Anhang wird die Authentizität der B-Dur-Suite (BWV 821) diskutiert, deren Autorschaft noch unklar und die daher für die Veröffentlichung in einem Ergänzungsband des NBA vorgesehen ist. (Übertragung des englischen Resümees am Ende des Bandes)
6
FRAMPTON, ANDREW. "CHRISTOPH GRAUPNER (1683–1760), JOHANN DAVID HEINICHEN (1683–1729), GEORG PHILIPP TELEMANN (1681–1767) ICH HEBE MEINE AUGEN AUF: TELEMANN, HEINICHEN & GRAUPNER IN LEIPZIG Veronika Winter (soprano) / Alex Potter (countertenor) / Hans Jörg Mammel (tenor) / Markus Flaig (bass) / L'arpa festante / Rien Voskullen (director) Carus 83.337, 2015: one disc, 78 minutes." Eighteenth Century Music 13, no. 2 (August 16, 2016): 326–28. http://dx.doi.org/10.1017/s1478570616000166.
Full text
7
Cammarota, Robert M. "On the Performance of "Quia respexit ... omnes generationes" from J. S. Bach's Magnificat." Journal of Musicology 18, no. 3 (2001): 458–89. http://dx.doi.org/10.1525/jm.2001.18.3.458.
Full textAbstract:
The modern-day custom of performing the 'omnes generationes' section from J. S. Bach's Magnificat twice as fast as the aria "Quia respexit" has its origins in Robert Franz's vocal and orchestral editions of 1864, the details of which were discussed in his Mittheilungen of 1863. Up until that time, 'omnes generationes' was inextricably connected to "Quia respexit" and formed part of the third movement of Bach's Magnificat. Moreover, when Bach revised the score in 1733, he added adagio to the beginning of "Quia respexit . . . omnes generationes," establishing the tempo for the whole movement. In this study I show that Bach's setting of this verse is in keeping with Leipzig tradition (as evidenced by the settings of Schelle, G. M. Hoffmann, Telemann, Kuhnau, and Graupner) and with early 18thcentury compositional practice; that he interpreted the verse based on Luther's 1532 exegesis on the Magnificat; that the verse must be understood theologically, as a unit; that the change in musical texture at the words 'omnes generationes' is a rhetorical device, not "dramatic effect"; and, finally, that there is no change in tempo at the words 'omnes generationes' either in Bach's setting or in any other from this period. An understanding of the early 18th-century Magnificat tradition out of which Bach's setting derives, with the knowledge of the reception of Bach's Magnificat in the mid 19th century, should help us restore Bach's tempo adagio for the movement.
8
Krum, Jonathan G., and Scott A. Ensign. "Evidence that a Linear Megaplasmid Encodes Enzymes of Aliphatic Alkene and Epoxide Metabolism and Coenzyme M (2-Mercaptoethanesulfonate) Biosynthesis in XanthobacterStrain Py2." Journal of Bacteriology 183, no. 7 (April 1, 2001): 2172–77. http://dx.doi.org/10.1128/jb.183.7.2172-2177.2001.
Full textAbstract:
ABSTRACT The bacterial metabolism of propylene proceeds by epoxidation to epoxypropane followed by a sequence of three reactions resulting in epoxide ring opening and carboxylation to form acetoacetate. Coenzyme M (2-mercaptoethanesulfonic acid) (CoM) plays a central role in epoxide carboxylation by serving as the nucleophile for epoxide ring opening and the carrier of the C3 unit that is ultimately carboxylated to acetoacetate, releasing CoM. In the present work, a 320-kb linear megaplasmid has been identified in the gram-negative bacterium Xanthobacter strain Py2, which contains the genes encoding the key enzymes of propylene oxidation and epoxide carboxylation. Repeated subculturing of Xanthobacter strain Py2 under nonselective conditions, i.e., with glucose or acetate as the carbon source in the absence of propylene, resulted in the loss of the propylene-positive phenotype. The propylene-negative phenotype correlated with the loss of the 320-kb linear megaplasmid, loss of induction and expression of alkene monooxgenase and epoxide carboxylation enzyme activities, and the loss of CoM biosynthetic capability. Sequence analysis of a hypothetical protein (XecG), encoded by a gene located downstream of the genes for the four enzymes of epoxide carboxylation, revealed a high degree of sequence identity with proteins of as-yet unassigned functions in the methanogenic archaeaMethanobacterium thermoautotrophicum andMethanococcus jannaschii and in Bacillus subtilis. The M. jannaschii homolog of XecG, MJ0255, is located next to a gene, MJ0256, that has been shown to encode a key enzyme of CoM biosynthesis (M. Graupner, H. Xu, and R. H. White, J. Bacteriol. 182: 4862–4867, 2000). We propose that the propylene-positive phenotype of Xanthobacter strain Py2 is dependent on the selective maintenance of a linear megaplasmid containing the genes for the key enzymes of alkene oxidation, epoxide carboxylation, and CoM biosynthesis.
9
Willmes, Bernd. "Werner H. Schmidt, Vielfalt und Einheit alttestamentlichen Glaubens. Band 1: Studien zur Hermeneutik und Methodik, Pentateuch und Prophetie. Hrsg. von Axel Graupner, Holger Delkurt und Alexander B.Ernst, Neukirchen-Vluyn (Neukirchener Verlag) 1995, 256 S., 68.- DM; ISBN 3-7887-1546-4." Biblische Zeitschrift 44, no. 1 (April 5, 2000): 125–28. http://dx.doi.org/10.1163/25890468-04401017.
Full text
10
Takahashi, Tsutomu, Yoshihiro Nagao, and Yuzuru Kushiyama. "Possible High Ice Particle Production during Graupel–Graupel Collisions." Journal of the Atmospheric Sciences 52, no. 24 (December 1995): 4523–27. http://dx.doi.org/10.1175/1520-0469(1995)052<4523:phippd>2.0.co;2.
Full text
11
Sukovich, Ellen M., David E. Kingsmill, and Sandra E. Yuter. "Variability of Graupel and Snow Observed in Tropical Oceanic Convection by Aircraft during TRMM KWAJEX." Journal of Applied Meteorology and Climatology 48, no. 2 (February 1, 2009): 185–98. http://dx.doi.org/10.1175/2008jamc1940.1.
Full textAbstract:
Abstract Empirical characterization of graupel and snow in precipitating tropical convective clouds is important for refining satellite precipitation retrieval algorithms and cloud-resolving and radiative transfer models. Microphysics data for this analysis were collected by the University of North Dakota (UND) Citation and the National Aeronautics and Space Agency (NASA) DC-8 aircraft during the Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX) in the western tropical Pacific Ocean. An ice particle identification algorithm was applied to two-dimensional optical array probe data for the purpose of identifying ice particle ensembles dominated by graupel or snow particles. These ensembles were accumulated along 1-km flight segments at temperatures below 0°C. A third category, mixed graupel/snow, has characteristics between those of the predominately graupel and snow ensembles and can be used either in combination with the other two categories or separately. Snow particle ensembles compose 80% of UND Citation and 98% of NASA DC-8 ensemble data. For the UND Citation, graupel ensembles compose ∼5% of the total with mixed graupel/snow ensembles composing ∼15%. There were no graupel ensembles in the NASA DC-8 data, which were collected primarily at temperatures <−35°C. Particles too small to classify (<150-μm maximum dimension) compose 56% of UND Citation and 64% of NASA DC-8 particle images. Nearly all these “tiny” particles occur coincident with particles >∼150 μm. Combining data from both aircraft, snow and mixed graupel/snow ensembles were evident over the full range of subfreezing temperatures (from 0° to −65°C) sampled by the aircraft. In contrast, graupel ensembles were present primarily at temperatures >−10°C. Accurate graupel identification was further supported by all graupel ensembles observed either coincident with or within a 10-km horizontal distance of radar-identified convective precipitation structures.
12
Adams-Selin, Rebecca D., Susan C. van den Heever, and Richard H. Johnson. "Sensitivity of Bow-Echo Simulation to Microphysical Parameterizations." Weather and Forecasting 28, no. 5 (October 1, 2013): 1188–209. http://dx.doi.org/10.1175/waf-d-12-00108.1.
Full textAbstract:
Abstract The sensitivity of a case study bow-echo simulation to eight different microphysical schemes in the Weather Research and Forecasting model was tested, with a focus on graupel parameter characteristics. The graupel parameter in one scheme was modified to have a larger mean size and faster fall speed to represent hail (“hail like”). The goal of the study was to measure the sensitivity of five parameters that are important to operational forecasters to graupel properties: timing of bowing development, system speed, wind gusts, system areal coverage, and accumulated precipitation. The time each system initiated bowing varied by as much as 105 min. Simulations containing graupel with smaller mean size and slower fall speed (“graupel like”) bowed earlier due to increased microphysical cooling and stronger cold pools. These same systems had reduced precipitation efficiency, producing a peak storm-total accumulation of 36 mm, compared to a hail-like peak value of 237 mm, and observed a peak value of 53 mm. Faster-falling hail-like hydrometeors reached the surface with minimal melting, producing the largest accumulations. Graupel-like systems had 10-m wind gusts 73% stronger compared to hail-like systems, due to stronger low-level downdrafts. Systems with a smaller mean graupel size were 19% faster, also due to increased microphysical cooling. The size of the convective region varied by 150%, although this was partially due to scheme differences other than the graupel parameter. The significant differences in bow-echo characteristics produced by graupel property variations in convective-resolving models emphasize careful microphysical parameterization design. These sensitivities have forecasting implications, as graupel characteristics vary depending on the ambient environment and other factors. Detailed observations of graupel properties are recommended.
13
Abe, Osamu. "Shear strength and angle of repose of snow layers including graupel." Annals of Glaciology 38 (2004): 305–8. http://dx.doi.org/10.3189/172756404781815149.
Full textAbstract:
AbstractSnow avalanches with failure layers including graupel are sometimes observed in Japan. A snow layer including graupel may be formed close to the melting point (0°C) after passage of a cold front with cumulus clouds. Graupel particles have a large diameter and a spherical shape, so they have a relatively small contact area per unit volume and may form weak layers within the snowpack. In this paper, characteristics of snow layers that include graupel are described by angle of repose, shear frame index (SFI), grain-size distribution, density and temperature. The mean value of the angle of repose was found to be 45°, independent of the grain-size. This suggests that a graupel layer near 0°C will not be formed on a slope exceeding 45°. SFI data for three different graupel layers were measured over 1–3 days for each layer, and were correlated with density. An exponential relationship between shear strength and density was found. The results indicate that the SFI of graupel layers is approximately one-third that of dry new snow with the same density.
14
Milbrandt, Jason A., and Hugh Morrison. "Prediction of Graupel Density in a Bulk Microphysics Scheme." Journal of the Atmospheric Sciences 70, no. 2 (February 1, 2013): 410–29. http://dx.doi.org/10.1175/jas-d-12-0204.1.
Full textAbstract:
Abstract A method to predict the bulk density of graupel ρg has been added to the two-moment Milbrandt–Yau bulk microphysics scheme. The simulation of graupel using the modified scheme is illustrated through idealized simulations of a mesoscale convective system using a 2D kinematic model with a prescribed flow field and different peak updraft speeds. To examine the relative impact of the various approaches to represent rimed ice, simulations were run for various graupel-only and graupel-plus-hail configurations. Because of the direct feedback of ρg to terminal fall speeds, the modified scheme produces a much different spatial distribution of graupel, with more mass concentrated in the convective region resulting in changes to the surface precipitation at all locations. With a strong updraft, the model can now produce solid precipitation at the surface in the convective region without a separate hail category. It is shown that a single rimed-ice category is capable of representing a realistically wide range of graupel characteristics in various atmospheric conditions without the need for a priori parameter settings. Sensitivity tests were conducted to examine various aspects of the scheme that affect the simulated ρg. Specific parameterizations pertaining to other hydrometeor categories now have a direct impact on the simulation of graupel, including the assumed aerosol distribution for droplet nucleation, which affects the drop sizes of both cloud and rain, and the mass–size relation for snow, which affects its density and hence the embryo density of graupel converted from snow due to riming.
15
Lighezzolo, R. A., R. G. Pereyra, and E. E. Avila. "Measurements of electric charge separated during the formation of rime by the accretion of supercooled droplets." Atmospheric Chemistry and Physics Discussions 9, no. 6 (November 3, 2009): 23349–70. http://dx.doi.org/10.5194/acpd-9-23349-2009.
Full textAbstract:
Abstract. In these experiments, the electric charge carried by single particles ejected from the surface of a graupel particle growing by riming was measured. Simulated graupel pellets were grown by accretion of supercooled water drops, at temperatures ranging from −2 to −10°C in a wind tunnel at air velocities between 5 and 10 m s−1, with the goal of studying the charging of graupel pellets under conditions of secondary ice crystal production (Hallett-Mossop mechanism). The graupel, and induction rings upstream and downstream of the graupel, were connected to electrometers and analyzing circuits of sufficient sensitivity and speed to measure, correlate and display individual charging events. The results suggest that fewer than 1% of the ejected particles carry a measurable electric charge (>2 fC). Further, it was observed that the graupel pellets acquire a positive charge and the average charge of a single splinter ejected is −14 fC. This mechanism of ejection of charged particles seems adequate to account for a positive charge of around 1 pC that individual precipitation particles of mm-size could acquire in the lower part of the cloud, which in turn could contribute to the lower positive charge region of thunderstorms.
16
Lighezzolo, R. A., R. G. Pereyra, and E. E. Avila. "Measurements of electric charge separated during the formation of rime by the accretion of supercooled droplets." Atmospheric Chemistry and Physics 10, no. 4 (February 15, 2010): 1661–69. http://dx.doi.org/10.5194/acp-10-1661-2010.
Full textAbstract:
Abstract. In these experiments, the electric charge carried by single particles ejected from the surface of a graupel particle growing by riming was measured. Simulated graupel pellets were grown by accretion of supercooled water drops, at temperatures ranging from −2 to −10 °C in a wind tunnel at air velocities between 5 and 10 m s−1, with the goal of studying the charging of graupel pellets under conditions of secondary ice crystal production (Hallett-Mossop mechanism). The graupel, and induction rings upstream and downstream of the graupel, were connected to electrometers and analyzing circuits of sufficient sensitivity and speed to measure, correlate and display individual charging events. The results suggest that fewer than 1% of the ejected particles carry a measurable electric charge (>2 fC). Further, it was observed that the graupel pellets acquire a positive charge and the average charge of a single splinter ejected is −14 fC. This mechanism of ejection of charged particles seems adequate to account for a positive charge of around 1 pC that individual precipitation particles of mm-size could acquire in the lower part of the cloud, which in turn could contribute to the lower positive charge region of thunderstorms.
17
Pereyra, Rodolfo G., Eldo E. Avila, Nesvit E. Castellano, and Clive P. R. Saunders. "A laboratory study of graupel charging." Journal of Geophysical Research: Atmospheres 105, no. D16 (August 1, 2000): 20803–12. http://dx.doi.org/10.1029/2000jd900244.
Full text
18
Takahashi, Tsuneya, and Norihiko Fukuta. "Observations of the Embryos of Graupel." Journal of the Atmospheric Sciences 45, no. 21 (November 1988): 3288–97. http://dx.doi.org/10.1175/1520-0469(1988)045<3288:ooteog>2.0.co;2.
Full text
19
Mecikalski, Retha Matthee, Anthony L. Bain, and Lawrence D. Carey. "Radar and Lightning Observations of Deep Moist Convection across Northern Alabama during DC3: 21 May 2012." Monthly Weather Review 143, no. 7 (July 1, 2015): 2774–94. http://dx.doi.org/10.1175/mwr-d-14-00250.1.
Full textAbstract:
Abstract The Deep Convective Clouds and Chemistry (DC3) experiment seeks to understand the kinematic and microphysical controls on the lightning behavior of deep moist convection. This study utilized multiple dual-polarization Doppler radars across northern Alabama to quantify microphysical and kinematic properties and processes that often serve as precursors to lightning, such as the graupel echo volume, graupel mass, and convective updraft volume. The focus here was on one multicellular complex that occurred on 21 May 2012 in northern Alabama during DC3. The graupel echo volume and the graupel mass in the charging region correlated well with the total lightning flash rate (FR), and even better than the updraft volumes and maximum updraft velocities. The flash length scales (LS) and flash areas were generally anticorrelated to the FR, while it was correlated to the nonprecipitation ice volume. More specifically, the presence of smaller flashes was associated with a stronger lower positive charge region caused by larger graupel volumes, stronger updraft volumes, and stronger maximum updraft velocities while larger flashes occurred during lower FRs and were associated with a weakened lower positive charge region in combination with a stronger upper positive charge region, weaker updraft velocities, a smaller graupel volume and mass, and an increase in nonprecipitation ice volume.
20
Oue, Mariko, Matthew R. Kumjian, Yinghui Lu, Zhiyuan Jiang, Eugene E. Clothiaux, Johannes Verlinde, and Kultegin Aydin. "X-Band Polarimetric and Ka-Band Doppler Spectral Radar Observations of a Graupel-Producing Arctic Mixed-Phase Cloud." Journal of Applied Meteorology and Climatology 54, no. 6 (June 2015): 1335–51. http://dx.doi.org/10.1175/jamc-d-14-0315.1.
Full textAbstract:
AbstractCharacteristics of graupel in an Arctic deep mixed-phase cloud on 7 December 2013 were identified with observations from an X-band scanning polarimetric radar and a Ka-band zenith-pointing radar in conjunction with scattering calculations. The cloud system produced generating cells and strongly sheared precipitation fall streaks. The X-band radar hemispheric RHI observables revealed spatial sorting of polarimetric signatures: decreasing (with increasing range) differential propagation phase shift φDP, negative specific differential phase KDP collocated with negative differential reflectivity ZDR in the upper half of the fall streak, and increasing or near-constant φDP with positive ZDR at the bottom edge of the fall streak. The negative KDP and ZDR, indicating prolate particles with vertically oriented maximum dimensions, were consistent with small, slow-falling conical graupel coexisting with low concentrations of more isometric graupel. The observed negative KDP values were best matched by scattering calculations for small, dense conical graupel with 30°–40° cone angles. The positive KDP and ZDR and the Doppler spectra indicate that large isometric graupel coexisted with a second population of slower-falling rimed platelike particles in the lower half of the fall streak. Through the core of the fall streak, φDP decreased in range while ZDR was slightly positive, indicating that the prolate conical graupel dominated φDP while the isometric larger graupel dominated reflectivity (and thus ZDR). These results demonstrate the capability of polarimetric observables and Doppler spectra to distinguish different growth stages of rimed particles, allowing for the improvement of hydrometeor classification methods.
21
Adams-Selin, Rebecca D., Susan C. van den Heever, and Richard H. Johnson. "Impact of Graupel Parameterization Schemes on Idealized Bow Echo Simulations." Monthly Weather Review 141, no. 4 (April 1, 2013): 1241–62. http://dx.doi.org/10.1175/mwr-d-12-00064.1.
Full textAbstract:
Abstract The effect of changes in microphysical cooling rates on bow echo development and longevity are examined through changes to graupel parameterization in the Advanced Research Weather Research and Forecasting Model (ARW-WRF). Multiple simulations are performed that test the sensitivity to different graupel size distributions as well as the complete removal of graupel. It is found that size distributions with larger and denser, but fewer, graupel hydrometeors result in a weaker cold pool due to reduced microphysical cooling rates. This yields weaker midlevel (3–6 km) buoyancy and pressure perturbations, a later onset of more elevated rear inflow, and a weaker convective updraft. The convective updraft is also slower to tilt rearward, and thus bowing occurs later. Graupel size distributions with more numerous, smaller, and lighter hydrometeors result in larger microphysical cooling rates, stronger cold pools, more intense midlevel buoyancy and pressure gradients, and earlier onset of surface-based rear inflow; these systems develop bowing segments earlier. A sensitivity test with fast-falling but small graupel hydrometeors revealed that small mean size and slow fall speed both contribute to the strong cooling rates. Simulations entirely without graupel are initially weaker, because of limited contributions from cooling by melting of the slowly falling snow. However, over the next hour increased rates of melting snow result in an increasingly more intense system with new bowing. Results of the study indicate that the development of a bow echo is highly sensitive to microphysical processes, which presents a challenge to the prediction of these severe weather phenomena.
22
Barszcz, Agnieszka, Jason A. Milbrandt, and Julie M. Thériault. "Improving the Explicit Prediction of Freezing Rain in a Kilometer-Scale Numerical Weather Prediction Model." Weather and Forecasting 33, no. 3 (May 17, 2018): 767–82. http://dx.doi.org/10.1175/waf-d-17-0136.1.
Full textAbstract:
Abstract A freezing rain event, in which the Meteorological Centre of Canada’s 2.5-km numerical weather prediction system significantly underpredicted the quantity of freezing rain, is examined. The prediction system models precipitation types explicitly, directly from the Milbrandt–Yau microphysics scheme. It was determined that the freezing rain underprediction for this case was due primarily to excessive refreezing of rain, originating from melting snow and graupel, in and under the temperature inversion of the advancing warm front ultimately depleting the supply of rain reaching the surface. The refreezing was caused from excessive collisional freezing between rain and graupel. Sensitivity experiments were conducted to examine the effects of a temperature threshold for collisional freezing and on varying the values of the collection efficiencies between rain and ice-phase hydrometeors. It was shown that by reducing the rain–graupel collection efficiency and by imposing a temperature threshold of −5°C, above which collisional freezing is not permitted, excessive rain–graupel collection and graupel formation can be controlled in the microphysics scheme, leading to an improved simulation of freezing rain at the surface.
23
Schulze, Hans-Joachim. "Bemerkungen zu einigen Kantatentexten Johann Sebastian Bachs." Bach-Jahrbuch 46 (March 1, 2018): 168–70. http://dx.doi.org/10.13141/bjb.v19591535.
Full textAbstract:
Erwähnter Artikel: Friedrich Noack: Johann Seb. Bachs und Christoph Graupners Kompositionen zur Bewerbung um das Thomaskantorat in Leipzig 1722-23. BJ 1913, S. 145-162
Vergleiche auch: Elisabeth Noack: Georg Christian Lehms, ein Textdichter Johann Sebastian Bachs. BJ 1970, S. 7-18
24
Liu, J., H. D. Luo, W. Z. Tan, and L. Hu. "First Report of a Leaf Spot on Conyza sumatrensis Caused by Phoma macrostoma in China." Plant Disease 96, no. 1 (January 2012): 148. http://dx.doi.org/10.1094/pdis-03-11-0228.
Full textAbstract:
Conyza sumatrensis (Asteraceae), an annual or biennial plant, is native to North and South America. It is an invasive, noxious weed that is widespread in southern and southeastern China. It invades farm land and causes great losses to dry land crops, including wheat, corn, and beans. It also reduces biological diversity by crowding out native plants in the infested areas (3,4). During a search for fungal pathogens that could serve as potential biological control agents of C. sumatrensis, a leaf spot disease was observed in 2010 in Chongqing, China. An isolate (SMBC22) of a highly virulent fungus was obtained from diseased leaves. Pathogenicity tests were performed by placing 6-mm-diameter mycelial disks of 7-day-old potato dextrose agar (PDA) cultures of SMBC22 on leaves of 15 healthy greenhouse-grown plants of C. sumatrensis; the same number of control plants was treated with sterile PDA disks. Treated plants were covered with plastic bags for 24 h and maintained in a growth chamber with daily average temperatures of 24 to 26°C, continuous light (3,100 lux), and high relative humidity (>90%). Lesions similar to those observed in the field were first obvious on the SMBC22-inoculated leaves 3 days after inoculation. Symptoms became severe 7 to 9 days after inoculation. Control plants remained healthy. The fungus was reisolated from inoculated and diseased leaves and it was morphologically the same as SMBC22. The pathogenicity test was conducted three times. A survey of 10 southern and southeastern Chinese provinces revealed that the disease was widespread and it attacked leaves and stems of seedlings and mature plants of C. sumatrensis. Lesions on leaves were initially small, circular, and water soaked. The typical lesion was ovoid or fusiform, dark brown, and surrounded by a yellow halo. The spots coalesced to form large lesions and plants were often completely blighted. Fungal colonies of SMBC22 on PDA plates were initially white and turned dark gray. Colonies were circular with smooth edges with obvious rings of pycnidia on the surface. Aerial hyphae were short and dense. Pycnidia, black and immersed or semi-immersed in the medium, were visible after 12 days of incubation. Pycnidia were 72 to 140 μm in diameter. Conidia were produced in the pycnidia and were hyaline, unicellular, ellipsoidal, and 4.4 to 6.1 × 1.6 to 2.2 μm. To confirm identification of the fungus, genomic DNA was extracted from mycelia of a 7-day-old culture on PDA at 25°C (2). The internal transcribed spacer (ITS) gene of rDNA was amplified using primers ITS4/ITS5. The gene sequence was 524 bp long and registered in NCBI GenBank (No. HQ645974). BLAST analysis showed that the current sequence had 99% homology to an isolate of Phoma macrostoma (DQ 404792) from Cirsium arvense (Canada thistle) in Canada and reported to cause chlorotic symptoms on that host plant (1). To our knowledge, this is the first report of P. macrostoma causing disease on C. sumatrensis in China. P. macrostoma, thought of as a biocontrol agent of broadleaf weeds in Canada, has been patented in the United States. The current isolate of P. macrostoma is considered as a potential biocontrol agent of C. sumatrensis. References: (1) P. R. Graupner et al. J. Nat. Prod. 66:1558, 2004. (2) S. Takamatsu et al. Mycoscience 42:135, 2001. (3) W. Z. Tan et al. Page 177 in: Manual of Emergency Control Technology Invasive Pests in China. G. L. Zhang, ed. Science Press, Beijing, 2010. (4) C. Wang et al. J. Wuhan Bot. Res. 28:90, 2010.
25
Bringi, V. N., P. C. Kennedy, G. J. Huang, C. Kleinkort, M. Thurai, and B. M. Notaroš. "Dual-Polarized Radar and Surface Observations of a Winter Graupel Shower with Negative Zdr Column." Journal of Applied Meteorology and Climatology 56, no. 2 (February 2017): 455–70. http://dx.doi.org/10.1175/jamc-d-16-0197.1.
Full textAbstract:
AbstractComprehensive analysis of an unusual graupel-shower event recorded by an S-band polarimetric radar and two optical-imaging surface instruments is presented. The primary radar characteristic was negative differential reflectivity Zdr values along a vertical column. During the afternoon hours of 16 February 2015, a sequence of three showers that were composed primarily of small (8–15-mm diameter) graupel affected the ground instrumentation site that was established for the Multi-Angle Snowflake Camera and Radar (MASCRAD) experiment in the high plains of Colorado. While these showers passed the instrumentation site, the CSU–CHILL radar conducted high-time-resolution (~2.5-min cycle time) range–height indicator (RHI) scans from a range of 13 km. The RHI data show that the negative Zdr values extended vertically through much of the reflectivity cores, implying that the reflectivity-weighted mean axis ratios of the graupel particles in this event remained somewhat prolate throughout their lifetime. To be specific, the cores of the convective showers only extended to heights of ~3.5 km AGL and had fractionally negative (from ~−0.3 to −0.7 dB) Zdr levels in those cores. Particle-image data obtained by the MASC system and by a collocated 2D video disdrometer measured the diameters, shapes, and fall speeds of the graupel particles as they reached the surface. The graupel particles were found to be primarily of the lump type with a slightly prolate mean shape (especially for the larger-diameter particles). Microwave backscatter calculations confirm that the graupel-particle shape and orientation characteristics are consistent with the observed slightly, but consistently, negative Zdr values.
26
Jouan, Caroline, and Jason A. Milbrandt. "The Importance of the Ice-Phase Microphysics Parameterization for Simulating the Effects of Changes to CCN Concentrations in Deep Convection." Journal of the Atmospheric Sciences 76, no. 6 (June 1, 2019): 1727–52. http://dx.doi.org/10.1175/jas-d-18-0168.1.
Full textAbstract:
Abstract Simulations of a well-observed squall line that occurred during the Midlatitude Continental Convective Clouds Experiment (MC3E) were conducted using a mesoscale model with a horizontal grid spacing of 1 km to examine the importance of parameterized ice-phase processes to changes in concentrations of activated cloud condensation nuclei (CCN) in a detailed two-moment bulk microphysics scheme. Numerical experiments showed that the simulated squall-line structure was sensitive to changes in activated CCN concentration not only from the direct impacts on cloud droplet sizes and autoconversion rates, but also because of changes in the growth rates and spatial distribution of ice-phase condensate. A microphysical budget analysis highlighted the importance of graupel in rain production and the sensitivity of graupel growth rates on changes to CCN concentrations. Sensitivity tests on the level of detail in the representation of graupel, specifically the treatment of its bulk density and the number of prognostic moments, indicated that changes in the reflectivity and precipitation structure of the simulated storm due to changes in CCN were sensitive to the graupel parameterization. The results suggest that the proper representation of graupel and possibly other ice-phase categories in microphysics schemes may be crucial for correctly simulating the effects of changes to CCN concentrations for continental deep convective systems.
27
Wang, Pao K., and Alexander Kubicek. "Flow fields of graupel falling in air." Atmospheric Research 124 (April 2013): 158–69. http://dx.doi.org/10.1016/j.atmosres.2013.01.003.
Full text
28
Dodson, J. Brant, Patrick C. Taylor, and Mark Branson. "Microphysical variability of Amazonian deep convective cores observed by CloudSat and simulated by a multi-scale modeling framework." Atmospheric Chemistry and Physics 18, no. 9 (May 8, 2018): 6493–510. http://dx.doi.org/10.5194/acp-18-6493-2018.
Full textAbstract:
Abstract. Recently launched cloud observing satellites provide information about the vertical structure of deep convection and its microphysical characteristics. In this study, CloudSat reflectivity data is stratified by cloud type, and the contoured frequency by altitude diagrams reveal a double-arc structure in deep convective cores (DCCs) above 8 km. This suggests two distinct hydrometeor modes (snow versus hail/graupel) controlling variability in reflectivity profiles. The day–night contrast in the double arcs is about four times larger than the wet–dry season contrast. Using QuickBeam, the vertical reflectivity structure of DCCs is analyzed in two versions of the Superparameterized Community Atmospheric Model (SP-CAM) with single-moment (no graupel) and double-moment (with graupel) microphysics. Double-moment microphysics shows better agreement with observed reflectivity profiles; however, neither model variant captures the double-arc structure. Ultimately, the results show that simulating realistic DCC vertical structure and its variability requires accurate representation of ice microphysics, in particular the hail/graupel modes, though this alone is insufficient.
29
Lasher-Trapp, Sonia, David C. Leon, Paul J. DeMott, Cecille M. Villanueva-Birriel, Alexandria V. Johnson, Daniel H. Moser, Colin S. Tully, and Wei Wu. "A Multisensor Investigation of Rime Splintering in Tropical Maritime Cumuli." Journal of the Atmospheric Sciences 73, no. 6 (June 1, 2016): 2547–64. http://dx.doi.org/10.1175/jas-d-15-0285.1.
Full textAbstract:
Abstract Three flights from the Ice in Clouds Experiment–Tropical (ICE-T) field campaign examined the onset of ice near the ascending cloud tops of tropical maritime cumuli as they cooled from 0° to −14°C. Careful quantitative analysis of ice number concentrations included manual scrutiny of particle images and corrections for possible particle-shattering artifacts. The novel use of the Wyoming Cloud Radar documented the stage of cloud development and tops relative to the aircraft sampling, complemented the manual estimates of graupel concentrations, and provided new clear evidence of graupel movement through the rime-splintering zone. Measurements of ice-nucleating particles (INPs) provided an estimate of primary initiated ice. The data portray a dynamically complex picture of hydrometeor transport contributing to, and likely resulting from, the rime-splintering process. Hundreds per liter of supercooled raindrops ascended within the updrafts as the cloud tops reached 0°C and contributed in part to the 0.1 L−1 graupel detected soon after the cloud tops cooled to −5°C. Rime splintering could thus be initiated upon first ascent of the cloud top through that zone and arguably contributed to the 1 L−1 or more graupel observed above it. Graupel ascending/descending into, or balanced within, the rime-splintering zone were found. In wider, less isolated clouds with dying updrafts and tops near −14°C, ice particle concentrations sometimes reached 100 L−1. Future 3D numerical modeling will be required to evaluate if rime splintering alone can explain the difference of three to four orders of magnitude in the observed INPs and the graupel observed at −5°C and colder.
30
Yano, Jun-Ichi, and Vaughan T. J. Phillips. "Explosive Ice Multiplication Induced by Multiplicative-Noise Fluctuation of Mechanical Breakup in Ice–Ice Collisions." Journal of the Atmospheric Sciences 73, no. 12 (November 10, 2016): 4685–97. http://dx.doi.org/10.1175/jas-d-16-0051.1.
Full textAbstract:
Abstract The number of ice fragments generated by breakup of large graupel in collisions with small graupel fluctuates randomly owing to fluctuations in relative sizes and densities of colliding graupel particles and the stochastic nature of fracture propagation. This paper investigates the impact of the stochasticity of breakup on ice multiplication. When both the rate of generation of primary ice and the initial number concentration of ice crystals are low, the system most likely loses all the initial ice and graupel owing to a lack of sustaining sources. Even randomness does not change this mean evolution of the system in its phase space. However, a fluctuation of ice breakup number gives a small but finite chance that substantial ice crystal fragments are generated by breakup of large graupel. That, in turn, generates more large graupel. This multiplicative process due to fluctuations potentially leads to a small but finite chance of explosive growth of ice number. A rigorous stochastic analysis demonstrates this point quantitatively. The randomness considered here belongs to a particular category called “multiplicative” noise, because the noise amplitude is proportional to a given physical state. To contrast the multiplicative-noise nature of ice breakup with a standard “additive” noise process, fluctuation of the primary ice generation rate is also considered as an example of the latter. These processes are examined by taking the Fokker–Planck equation that explicitly describes the evolution of the probability distribution with time. As an important conclusion, stability in the phase space of the cloud microphysical system of breakup in ice–ice collisions is substantially altered by the multiplicative noise.
31
Takahashi, Tsutomu, Soichiro Sugimoto, Tetsuya Kawano, and Kenji Suzuki. "Riming Electrification in Hokuriku Winter Clouds and Comparison with Laboratory Observations." Journal of the Atmospheric Sciences 74, no. 2 (January 24, 2017): 431–47. http://dx.doi.org/10.1175/jas-d-16-0154.1.
Full textAbstract:
Abstract Riming electrification is the main charge separation mechanism of thunderstorms, occurring mainly during graupel particle–ice crystal collisions. Laboratory experiments have found that charge separation polarity and magnitude depend critically on cloud water content and temperature. Several groups have mapped this dependence, but there are substantial differences between their results. These conflicting laboratory-derived riming electrification topographies can be tested by comparing them to field observations. Here, direct and simultaneous sonde-based measurement of both precipitation particle type and charge (videosonde) and cloud water content [hydrometeor videosonde (HYVIS)] in lightning-active Hokuriku winter clouds at Kashiwazaki, Niigata Prefecture, Japan, are reported. With decreasing height, summed graupel charge transitioned from negative to positive at a mean temperature of −11°C, and the mean peak cloud water content in the positive graupel domain was 0.4 g m−3. Thus, in cloud regions of relatively high temperature (≥−11°C) and low cloud water content (CWC; ≤0.4 g m−3), graupel particles were mainly positively charged. This result can be compared with those of laboratory riming experiments; for example, in this temperature/cloud water content domain, graupel electrification has been reported to be positive by Takahashi, largely negative in early reports using the Manchester cloud chamber, positive in later reports using the Cordoba and Manchester modified cloud chambers, and partially positive in a more recent report using the Cordoba cloud chamber.
32
Kouketsu, Takeharu, Hiroshi Uyeda, Tadayasu Ohigashi, Mariko Oue, Hiroto Takeuchi, Taro Shinoda, Kazuhisa Tsuboki, Mamoru Kubo, and Ken-ichiro Muramoto. "A Hydrometeor Classification Method for X-Band Polarimetric Radar: Construction and Validation Focusing on Solid Hydrometeors under Moist Environments." Journal of Atmospheric and Oceanic Technology 32, no. 11 (November 2015): 2052–74. http://dx.doi.org/10.1175/jtech-d-14-00124.1.
Full textAbstract:
AbstractA fuzzy-logic-based hydrometeor classification (HC) method for X-band polarimetric radar (X-pol), which is suitable for observation of solid hydrometeors under moist environments producing little or no hail, is constructed and validated. This HC method identifies the most likely hydrometeor at each radar sampling volume from eight categories: 1) drizzle, 2) rain, 3) wet snow aggregates, 4) dry snow aggregates, 5) ice crystals, 6) dry graupel, 7) wet graupel, and 8) rain–hail mixture. Membership functions are defined on the basis of previous studies. The HC method uses radar reflectivity Zh, differential reflectivity Zdr, specific differential phase Kdp, and correlation coefficient ρhv as its main inputs, and temperature with some consideration of relative humidity as supplemental information. The method is validated against ground and in situ observations of solid hydrometeors (dry graupel, dry snow aggregates, and ice crystals) under a moist environment. Observational data from a ground-based imaging system are used to validate the HC method for dry graupel and dry snow aggregates. For dry snow aggregates and ice crystals, the HC method is validated using simultaneous observations from a balloonborne instrument [hydrometeor videosonde (HYVIS)] and an X-pol range–height indicator directed toward the HYVIS. The HC method distinguishes effectively between dry graupel, dry snow aggregates, and ice crystals, and is therefore valid for HC under moist environments.
33
Van Weverberg, Kwinten, Andrew M. Vogelmann, Hugh Morrison, and Jason A. Milbrandt. "Sensitivity of Idealized Squall-Line Simulations to the Level of Complexity Used in Two-Moment Bulk Microphysics Schemes." Monthly Weather Review 140, no. 6 (June 1, 2012): 1883–907. http://dx.doi.org/10.1175/mwr-d-11-00120.1.
Full textAbstract:
Abstract This paper investigates the level of complexity that is needed within bulk microphysics schemes to represent the essential features associated with deep convection. To do so, the sensitivity of surface precipitation is evaluated in two-dimensional idealized squall-line simulations with respect to the level of complexity in the bulk microphysics schemes of H. Morrison et al. and of J. A. Milbrandt and M. K. Yau. Factors examined include the number of predicted moments for each of the precipitating hydrometeors, the number and nature of ice categories, and the conversion term formulations. First, it is shown that simulations of surface precipitation and cold pools are not only a two-moment representation of rain, as suggested by previous research, but also by two-moment representations for all precipitating hydrometeors. Cold pools weakened when both rain and graupel number concentrations were predicted, because size sorting led to larger graupel particles that melted into larger raindrops and caused less evaporative cooling. Second, surface precipitation was found to be less sensitive to the nature of the rimed ice species (hail or graupel). Production of hail in experiments including both graupel and hail strongly depends on an unphysical threshold that converts small hail back to graupel, indicating the need for a more physical treatment of the graupel-to-hail conversion. Third, it was shown that the differences in precipitation extremes between the two-moment microphysics schemes are mainly related to the treatment of drop breakup. It was also shown that, although the H. Morrison et al. scheme is dominated by deposition growth and low precipitation efficiency, the J. A. Milbrandt and M. K. Yau scheme is dominated by riming processes and high precipitation efficiency.
34
Franklin, Charmaine N., Greg J. Holland, and Peter T. May. "Sensitivity of Tropical Cyclone Rainbands to Ice-Phase Microphysics." Monthly Weather Review 133, no. 8 (August 1, 2005): 2473–93. http://dx.doi.org/10.1175/mwr2989.1.
Full textAbstract:
Abstract A high-resolution tropical cyclone model with explicit cloud microphysics has been used to investigate the dynamics and energetics of tropical cyclone rainbands. As a first step, the model rainbands have been qualitatively compared with observed rainband characteristics. The model-generated rainbands show many of the mesoscale and convective-scale features of observed tropical cyclone rainbands. Sensitivity studies of numerically simulated tropical cyclone convection to ice-phase microphysical parameters showed that the model was most sensitive to changes in the graupel fall speed parameters. Increasing the fall speeds saw graupel being confined to the convective regions and producing higher rain rates in the inner core of the storm. A greater region of stratiform precipitation was produced when the efficiency for the collection of snow and cloud ice by graupel was reduced and when the mean size of graupel was reduced. Both of these simulations resulted in a higher concentration of snow being transported into the stratiform region. Although the precipitation structure changed across the simulations, the surface rainfall rate and the fundamental dynamical variables showed little sensitivity to the parameter variations.
35
Bao, J. W., S. A. Michelson, and E. D. Grell. "Microphysical Process Comparison of Three Microphysics Parameterization Schemes in the WRF Model for an Idealized Squall-Line Case Study." Monthly Weather Review 147, no. 9 (August 7, 2019): 3093–120. http://dx.doi.org/10.1175/mwr-d-18-0249.1.
Full textAbstract:
Abstract Three bulk microphysics schemes with different complexities in the Weather Research and Forecasting Model are compared in terms of the individual microphysical process terms of the hydrometeor mass and number mixing ratio tendency equations in an idealized 2D squall-line case. Through evaluation of these process terms and of hydrometeor size distributions, it is shown that the differences in the simulated population characteristics of snow, graupel, and rainwater are the prominent factors contributing to the differences in the development of the simulated squall lines using these schemes. In this particular case, the gust front propagation speed produced by the Thompson scheme is faster than in the other two schemes during the first 2 h of the simulation because it has a larger dominant graupel size. After 2 h into the simulation, the initially less intense squall lines in the runs using the WSM6 and Morrison schemes start to catch up in intensity and development to the run using the Thompson scheme. Because the dominant size of graupel particles in the runs using the WSM6 and Morrison schemes is smaller, these particles take more time to fall below the freezing level and enhance the rainwater production and its evaporative cooling. In the run using the Thompson scheme, the graupel production slows down at later times while the snow particle growth increases, leading to more snow falling below the freezing level to melt and surpass graupel particle melting in the production of rainwater.
36
Satoh, Masaki, and Yuya Matsuda. "Statistics on High-Cloud Areas and Their Sensitivities to Cloud Microphysics Using Single-Cloud Experiments." Journal of the Atmospheric Sciences 66, no. 9 (September 1, 2009): 2659–77. http://dx.doi.org/10.1175/2009jas2948.1.
Full textAbstract:
Abstract Statistics on high-altitude cloud areas associated with deep cumulus clouds and their sensitivities to cloud microphysics are studied in the framework of single-cloud experiments with an explicit cloud system–resolving model. A comprehensive six-category single-moment bulk cloud microphysics scheme is used to investigate parameter dependency. High-cloud areas are defined by the threshold values of the outgoing longwave radiation, and probability distribution functions of high-cloud areas are obtained. First, resolution dependencies on grid sizes of approximately 3.5, 7, and 14 km are examined. It is found that although quantitative differences are confirmed, diurnal variations in high-cloud covers are similarly captured by all three experiments conducted. The main focus of the sensitivity experiments of cloud microphysics is on the fall speed and number concentration, or mean radius, of ice particles. The results clearly show that the sum of snow and cloud ice amounts is closely related to high-cloud covers. Among the number of experiments conducted, one interesting result is that the intercept parameters of snow and graupel have opposite effects on high-cloud covers. As the intercept parameter of graupel increases, the graupel amount increases because of an increase in the accretion rate of cloud water by graupel, which results in a decrease in the amount of snow and hence a decrease in high-cloud covers. This implies that a greater production of graupel leads to an increase in precipitation efficiency.
37
Jin, Han-Gyul, Hyunho Lee, and Jong-Jin Baik. "A New Parameterization of the Accretion of Cloud Water by Graupel and Its Evaluation through Cloud and Precipitation Simulations." Journal of the Atmospheric Sciences 76, no. 2 (January 21, 2019): 381–400. http://dx.doi.org/10.1175/jas-d-18-0245.1.
Full textAbstract:
Abstract A new parameterization of the accretion of cloud water by graupel for use in bulk microphysics schemes is derived by analytically integrating the stochastic collection equation (SCE). In this parameterization, the collection efficiency between graupel particles and cloud droplets is expressed in a functional form using the data obtained from a particle trajectory model by a previous study. The new accretion parameterization is evaluated through box model simulations in comparison with a bin-based direct SCE solver and two previously developed accretion parameterizations that employ the continuous collection equation and a simplified SCE, respectively. Changes in cloud water and graupel mass contents via the accretion process predicted by the new parameterization are closest to those predicted by the direct SCE solver. Furthermore, the new parameterization predicts a decrease in the cloud droplet number concentration that is smaller than the decreases predicted by the other accretion parameterizations, consistent with the direct SCE solver. The new and the other accretion parameterizations are implemented into a cloud-resolving model. Idealized deep convective cloud simulations show that among the accretion parameterizations, the new parameterization predicts the largest rate of accretion by graupel and the smallest rate of accretion by snow, which overall enhances rainfall through the largest rate of melting of graupel. Real-case simulations for a precipitation event over the southern Korean Peninsula show that among the examined accretion parameterizations, the new parameterization simulates precipitation closest to observations. Compared to the other accretion parameterizations, the new parameterization decreases the fractions of light and moderate precipitation amounts and increases the fraction of heavy precipitation amount.
38
Kong, Rong, Ming Xue, Alexandre O. Fierro, Youngsun Jung, Chengsi Liu, Edward R. Mansell, and Donald R. MacGorman. "Assimilation of GOES-R Geostationary Lightning Mapper Flash Extent Density Data in GSI EnKF for the Analysis and Short-Term Forecast of a Mesoscale Convective System." Monthly Weather Review 148, no. 5 (April 28, 2020): 2111–33. http://dx.doi.org/10.1175/mwr-d-19-0192.1.
Full textAbstract:
Abstract The recently launched Geostationary Operational Environmental Satellite “R-series” (GOES-R) satellites carry the Geostationary Lightning Mapper (GLM) that measures from space the total lightning rate in convective storms at high spatial and temporal frequencies. This study assimilates, for the first time, real GLM total lightning data in an ensemble Kalman filter (EnKF) framework. The lightning flash extent density (FED) products at 10-km pixel resolution are assimilated. The capabilities to assimilate GLM FED data are first implemented into the GSI-based EnKF data assimilation (DA) system and tested with a mesoscale convective system (MCS). FED observation operators based on graupel mass or graupel volume are used. The operators are first tuned through sensitivity experiments to determine an optimal multiplying factor to the operator, before being used in FED DA experiments FEDM and FEDV that use the graupel-mass or graupel-volume-based operator, respectively. Their results are compared to a control experiment (CTRL) that does not assimilate any FED data. Overall, both DA experiments outperform CTRL in terms of the analyses and short-term forecasts of FED and composite/3D reflectivity. The assimilation of FED is primarily effective in regions of deep moist convection, which helps improve short-term forecasts of convective threats, including heavy precipitation and lightning. Direct adjustments to graupel mass via observation operator as well as adjustments to other model state variables through flow-dependent ensemble cross covariance within EnKF are shown to work together to generate model-consistent analyses and overall improved forecasts.
39
Roberto, N., E. Adirosi, L. Baldini, D. Casella, S. Dietrich, P. Gatlin, G. Panegrossi, M. Petracca, P. Sanò, and A. Tokay. "Multi-sensor analysis of convective activity in central Italy during the HyMeX SOP 1.1." Atmospheric Measurement Techniques 9, no. 2 (February 17, 2016): 535–52. http://dx.doi.org/10.5194/amt-9-535-2016.
Full textAbstract:
Abstract. A multi-sensor analysis of convective precipitation events that occurred in central Italy in autumn 2012 during the HyMeX (Hydrological cycle in the Mediterranean experiment) Special Observation Period (SOP) 1.1 is presented. Various microphysical properties of liquid and solid hydrometeors are examined to assess their relationship with lightning activity. The instrumentation used consisted of a C-band dual-polarization weather radar, a 2-D video disdrometer, and the LINET lightning network. Results of T-matrix simulation for graupel were used to (i) tune a fuzzy logic hydrometeor classification algorithm based on Liu and Chandrasekar (2000) for the detection of graupel from C-band dual-polarization radar measurements and (ii) to retrieve graupel ice water content. Graupel mass from radar measurements was related to lightning activity. Three significant case studies were analyzed and linear relations between the total mass of graupel and number of LINET strokes were found with different slopes depending on the nature of the convective event (such as updraft strength and freezing level height) and the radar observational geometry. A high coefficient of determination (R2 = 0.856) and a slope in agreement with satellite measurements and model results for one of the case studies (15 October 2012) were found. Results confirm that one of the key features in the electrical charging of convective clouds is the ice content, although it is not the only one. Parameters of the gamma raindrop size distribution measured by a 2-D video disdrometer revealed the transition from a convective to a stratiform regime. The raindrop size spectra measured by a 2-D video disdrometer were used to partition rain into stratiform and convective classes. These results are further analyzed in relation to radar measurements and to the number of strokes. Lightning activity was not always recorded when the precipitation regime was classified as convective rain. High statistical scores were found for relationships relating lightning activity to graupel aloft.
40
Harimaya, Toshio. "The Relationship between Graupel Formation and Meteorological Conditions." Journal of the Meteorological Society of Japan. Ser. II 66, no. 4 (1988): 599–606. http://dx.doi.org/10.2151/jmsj1965.66.4_599.
Full text
41
Khain, A., M. Pinsky, M. Shapiro, and A. Pokrovsky. "Collision Rate of Small Graupel and Water Drops." Journal of the Atmospheric Sciences 58, no. 17 (September 2001): 2571–95. http://dx.doi.org/10.1175/1520-0469(2001)058<2571:crosga>2.0.co;2.
Full text
42
Chueh, Chih-Che, Pao K. Wang, and Tempei Hashino. "Numerical Study of Motion of Falling Conical Graupel." Atmospheric Research 199 (January 2018): 82–92. http://dx.doi.org/10.1016/j.atmosres.2017.09.008.
Full text
43
Lang, Stephen E., Wei-Kuo Tao, Jiun-Dar Chern, Di Wu, and Xiaowen Li. "Benefits of a Fourth Ice Class in the Simulated Radar Reflectivities of Convective Systems Using a Bulk Microphysics Scheme." Journal of the Atmospheric Sciences 71, no. 10 (September 22, 2014): 3583–612. http://dx.doi.org/10.1175/jas-d-13-0330.1.
Full textAbstract:
Abstract Current cloud microphysical schemes used in cloud and mesoscale models range from simple one-moment to multimoment, multiclass to explicit bin schemes. This study details the benefits of adding a fourth ice class (frozen drops/hail) to an already improved single-moment three-class ice (cloud ice, snow, graupel) bulk microphysics scheme developed for the Goddard Cumulus Ensemble model. Besides the addition and modification of several hail processes from a bulk three-class hail scheme, further modifications were made to the three-ice processes, including allowing greater ice supersaturation and mitigating spurious evaporation/sublimation in the saturation adjustment scheme, allowing graupel/hail to transition to snow via vapor growth and hail to transition to graupel via riming, wet graupel to become hail, and the inclusion of a rain evaporation correction and vapor diffusivity factor. The improved three-ice snow/graupel size-mapping schemes were adjusted to be more stable at higher mixing ratios and to increase the aggregation effect for snow. A snow density mapping was also added. The new scheme was applied to an intense continental squall line and a moderate, loosely organized continental case using three different hail intercepts. Peak simulated reflectivities agree well with radar for both the intense and moderate cases and were superior to earlier three-ice versions when using a moderate and large intercept for hail, respectively. Simulated reflectivity distributions versus height were also improved versus radar in both cases compared to earlier three-ice versions. The bin-based rain evaporation correction affected the squall line more but overall the agreement among the reflectivity distributions was unchanged. The new scheme also improved the simulated surface rain-rate histograms.
44
Morrison, Hugh, Jason A. Milbrandt, George H. Bryan, Kyoko Ikeda, Sarah A. Tessendorf, and Gregory Thompson. "Parameterization of Cloud Microphysics Based on the Prediction of Bulk Ice Particle Properties. Part II: Case Study Comparisons with Observations and Other Schemes." Journal of the Atmospheric Sciences 72, no. 1 (January 1, 2015): 312–39. http://dx.doi.org/10.1175/jas-d-14-0066.1.
Full textAbstract:
Abstract A new microphysics scheme has been developed based on the prediction of bulk particle properties for a single ice-phase category, in contrast to the traditional approach of separating ice into various predefined species (e.g., cloud ice, snow, and graupel). In this paper, the new predicted particle properties (P3) scheme, described in Part I of this series, is tested in three-dimensional simulations using the Weather Research and Forecasting (WRF) Model for two contrasting well-observed cases: a midlatitude squall line and winter orographic precipitation. Results are also compared with simulations using other schemes in WRF. Simulations with P3 can produce a wide variety of particle characteristics despite having only one free ice-phase category. For the squall line, it produces dense, fast-falling, hail-like ice near convective updraft cores and lower-density, slower-falling ice elsewhere. Sensitivity tests show that this is critical for simulating high precipitation rates observed along the leading edge of the storm. In contrast, schemes that represent rimed ice as graupel, with lower fall speeds than hail, produce lower peak precipitation rates and wider, less distinct, and less realistic regions of high convective reflectivity. For the orographic precipitation case, P3 produces areas of relatively fast-falling ice with characteristics of rimed snow and low- to medium-density graupel on the windward slope. This leads to less precipitation on leeward slopes and more on windward slopes compared to the other schemes that produce large amounts of snow relative to graupel (with generally the opposite for schemes with significant graupel relative to snow). Overall, the new scheme produces reasonable results for a reduced computational cost.
45
Jost, Alexander, Miklós Szakáll, Karoline Diehl, Subir Kumar Mitra, Anna Hundertmark, Birte Salome Klug, and Stephan Borrmann. "The Effect of Turbulence on the Accretional Growth of Graupel." Journal of the Atmospheric Sciences 76, no. 10 (September 13, 2019): 3047–61. http://dx.doi.org/10.1175/jas-d-18-0200.1.
Full textAbstract:
Abstract Wind tunnel experiments were carried out to investigate the influence of turbulence on the collection kernel of graupel. The collection kernel defines the growth rate of a graupel accreting supercooled droplets as it falls through a cloud. The ambient conditions were similar to those occurring typically in the mixed-phase zone of convective clouds, that is, at temperatures between −7° and −16°C and with liquid water contents from 0.5 to 1.3 g m−3. Tethered spherical collectors with radii between 220 and 340 μm were exposed in a flow carrying supercooled droplets with a mean volume radius of 10 μm. The vertical root-mean-square fluctuation velocity, the dissipation rate, and the Taylor-microscale Reynolds number of the turbulent flow were determined as urms = 0.13 m s−1, ε = 0.13 m2 s−3, and Rλ = 48, respectively. The collection kernels of tethered graupel grown under laminar and turbulent conditions revealed no measurable difference, indicating that turbulence has no effect on the growth of graupel in the investigated size range. A comparison of laminar collection kernels to theoretically calculated values from a continuous growth model showed that graupel growth is strongly dominated by the fast increase of the radius due to the accretion of rime ice with low density. It is assumed that, compared to a water drop growing by collision and coalescence, this causes a fast increase in the swept volume overcompensating all other effects such as the self-induced stochastic movements due to surface roughness and latent heat release, as well as the possible influence of the flow’s small-scale turbulence.
46
Van Weverberg, Kwinten. "Impact of Environmental Instability on Convective Precipitation Uncertainty Associated with the Nature of the Rimed Ice Species in a Bulk Microphysics Scheme." Monthly Weather Review 141, no. 8 (July 25, 2013): 2841–49. http://dx.doi.org/10.1175/mwr-d-13-00036.1.
Full textAbstract:
Abstract Despite a number of studies dedicated to the sensitivity of deep convection simulations to the properties of the rimed ice species in microphysics schemes, no consensus has been achieved on the nature of the impact. Considering the need for improved quantitative precipitation forecasts, it is crucial that the cloud modeling community better understands the reasons for these differing conclusions and knows the relevance of these sensitivities for the numerical weather prediction. This study examines the role of environmental conditions and storm type on the sensitivity of precipitation simulations to the nature of the rimed ice species (graupel or hail). Idealized 3D simulations of supercells/multicells and squall lines have been performed in varying thermodynamic environments. It has been shown that for simulation periods of sufficient length (>2 h), graupel-containing and hail-containing storms produce domain-averaged surface precipitation that is more similar than many earlier studies suggest. While graupel is lofted to higher altitudes and has a longer residence time aloft than hail, these simulations suggest that most of this graupel eventually reaches the surface and the surface precipitation rates of hail- and graupel-containing storms converge. However, environmental conditions play an important role in the magnitude of this sensitivity. Storms in large-CAPE environments (typical of storms in the U.S. Midwest) are more sensitive than their low-CAPE counterparts (typical of storms in Europe) to the nature of the rimed ice species in terms of domain-average surface precipitation. Supercells/multicells are more sensitive than squall lines to the nature of the rimed ice species in terms of spatial precipitation distribution and peak precipitation, disregarding of the amount of CAPE.
47
Jensen, Anders A., Jerry Y. Harrington, and Hugh Morrison. "Impacts of Ice Particle Shape and Density Evolution on the Distribution of Orographic Precipitation." Journal of the Atmospheric Sciences 75, no. 9 (August 20, 2018): 3095–114. http://dx.doi.org/10.1175/jas-d-17-0400.1.
Full textAbstract:
Abstract An IMPROVE-2 orographic precipitation case is simulated using the Ice-Spheroids Habit Model with Aspect-Ratio Evolution (ISHMAEL) microphysics. In ISHMAEL, the evolution of ice particle properties such as mass, shape, size, density, and fall speed are predicted. These ice particle properties along with the ice size distributions from ISHMAEL and model-derived spatial distribution of accumulated precipitation are compared to observations. ISHMAEL predicts planar and columnar particles at spatial locations that agree with observations. Sensitivity simulations are used to explore the impact of predicting ice particle shape evolution on orographic cloud properties and precipitation compared to the traditional approach of representing snow and graupel using separate categories with conversion from snow to graupel during riming. High biases in both IWCs aloft and surface precipitation accumulation occur in the Umpqua River valley using separate snow and graupel categories because snow that does not convert to graupel is advected over the Coast Range and precipitates out in the valley. Improvements in IWCs aloft and surface precipitation using ISHMAEL occur from both predicting various vapor-grown habits and predicting the impact of partial riming on ice particle properties. Compared to traditional microphysics schemes, ISHMAEL also produces less spatial variability in accumulated precipitation.
48
Roberto, N., E. Adirosi, L. Baldini, D. Casella, S. Dietrich, P. Gatlin, G. Panegrossi, M. Petracca, P. Sanò, and A. Tokay. "Multi-sensor analysis of convective activity in Central Italy during the HyMeX SOP 1.1." Atmospheric Measurement Techniques Discussions 8, no. 9 (September 7, 2015): 9241–87. http://dx.doi.org/10.5194/amtd-8-9241-2015.
Full textAbstract:
Abstract. A multi-sensor analysis of convective precipitation events that occurred in central Italy, in autumn 2012 during the HyMeX (Hydrological cycle in the Mediterranean eXperiment) Special Observation Period (SOP) 1.1 is presented. Various microphysical properties of liquid and solid hydrometeors were examined to assess their relationship with lightning activity. The instrumentation used consisted of a C-band dual-polarization weather radar, a 2-D video disdrometer, and a lightning network. A fuzzy logic based hydrometeor classification algorithm was tuned and optimized for the detection of graupel from C-band dual-polarization radar measurements. Graupel ice water content was then retrieved and related to lightning activity. A linear correlation was found between the total mass of graupel above the 0° isothermal and the number of strokes detected by the lightning network in agreement with model outputs, which confirms the importance of ice in the electrical charging of convective clouds, although differences were noticed among events. Parameters of the gamma raindrop size distribution measured by a 2-D video disdrometer, revealed the transition from convective to stratiform regime during the event and where related. However, lightning activity was not always recorded when the precipitation regime was classified as convective. More robust relationships were found relating lightning activity to graupel.
49
Lin, Yanluan, and Brian A. Colle. "The 4–5 December 2001 IMPROVE-2 Event: Observed Microphysics and Comparisons with the Weather Research and Forecasting Model." Monthly Weather Review 137, no. 4 (April 1, 2009): 1372–92. http://dx.doi.org/10.1175/2008mwr2653.1.
Full textAbstract:
Abstract This paper highlights the observed and simulated microphysical evolution of a moderate orographic rainfall event over the central Oregon Cascade Range during 4–5 December 2001 of the Second Improvement of Microphysical Parameterization through Observational Verification Experiment (IMPROVE-2). Airborne in situ measurements illustrate the spatial variations in ice crystal distributions and amounts over the windward Cascades and within some convective cells. The in situ microphysical observations, ground radars, and surface observations are compared with four bulk microphysical parameterizations (BMPs) within the Weather Research and Forecasting (WRF) model. Those WRF BMP schemes that overpredict surface precipitation along the Cascade windward slopes are shown to have too rapid graupel (rimed snow) fallout. Most BMP schemes overpredict snow in the maximum snow depositional growth region aloft, which results in excessive precipitation spillover into the immediate lee of the Cascades. Meanwhile, there is underprediction to the east of the Cascades in all BMP schemes. Those BMPs that produce more graupel than snow generate nearly twice as much precipitation over the Oregon Coast Range as the other BMPs given the cellular convection in this region. Sensitivity runs suggest that the graupel accretion of snow generates too much graupel within select WRF BMPs. Those BMPs that generate more graupel than snow have shorter cloud residence times and larger removal of available water vapor. Snow depositional growth may be overestimated by 2 times within the BMPs when a capacitance for spherical particles is used rather than for snow aggregates. Snow mass–diameter relationships also have a large impact on the snow and cloud liquid water generation. The positive definite advection scheme for moisture and hydrometeors in the WRF reduces the surface precipitation by 20%–30% over the Coast Range and improves water conservation, especially where there are convective cells.
50
Mansell, Edward R., and Conrad L. Ziegler. "Aerosol Effects on Simulated Storm Electrification and Precipitation in a Two-Moment Bulk Microphysics Model." Journal of the Atmospheric Sciences 70, no. 7 (July 1, 2013): 2032–50. http://dx.doi.org/10.1175/jas-d-12-0264.1.
Full textAbstract:
Abstract The effects of cloud condensation nuclei (CCN) concentrations are found to strongly affect the microphysical and electrical evolution of a numerically simulated small multicell storm. The simulations reproduce the well-known effects of updraft invigoration and delay of precipitation formation as increasing CCN from low to intermediate concentrations causes droplet sizes to decrease. Peak updrafts increased from 16 m s−1 at the lowest CCN to a maximum of 21–22 m s−1 at moderate CCN, where condensation latent heating is maximized. The transition from low to high CCN first maximizes warm-rain production before switching over to the ice process as the dominant precipitation mechanism. Average graupel density stays fairly high and constant at lower CCN, but then drops monotonically at higher CCN concentration, although high CCN also foster the appearance of small regions of larger, high-density graupel with high simulated radar reflectivity. Graupel production increases monotonically as CCN concentration rises from 50 to about 2000 cm−3. The lightning response is relatively weak until the Hallett–Mossop rime-splintering ice multiplication becomes more active at CCN > 700 cm−3. At very high CCN concentrations (>2000 cm−3), graupel production decreases slowly, but lightning activity drops dramatically when the parameterization of Hallett–Mossop rime-splintering ice multiplication is based on the number of large cloud droplets collected by graupel. Conversely, lightning activity remains steady at extremely high CCN concentration when the Hallett–Mossop parameterization is based simply on the rate of rime mass accumulation. The results lend support to the aerosol hypothesis as applied to lightning production, whereby greater CCN concentration tends to lead to greater lightning activity, but with a large sensitivity to ice multiplication.