Prediction of lightning flash density with the WRF model

The Lightning Potential Index (LPI) is a measure of the potential for charge generation and separation that leads to lightning flashes in convective thunderstorms. It is calculated from model simulated updraft and microphysical fields. It was designed to predict the potential of lightning occurrence in operational weather forecasting models, but could possibly be used to improve short-range forecasts of heavy rain. The index is modified here to be model grid-scale transparent between 1 and 4 km (the approximate upper limit of explicit microphysical weather forecasts). Two case studies show that the modification appears to work quite well, and that LPI can be calculated on both an extremely high resolution research-grid (i.e., 1.33 km) and high resolution (i.e., 4 km) operationally compatible forecast grid. Analytical expressions are presented to use the LPI to predict the hourly lightning flash density

Análisis judeo-cristiano de la crisis de COVID-19 y su gestión

The present coronavirus crisis caused major worldwide disruption. Numerous experts admit now that the crisis management was far from optimal from the very beginning. In the paper, we first digest the available information on the crisis and its management. We then list factors that led to the chosen way of crisis management. Afterwards, we question whether religious leaders could have gained enough information for them not to have supported lockdowns etc. back in March, 2020. In our opinion, they could have if they would have addressed trustworthy experts with a list of reasonable professional questions. We then analyze the question if hypothetical coercive measures are justified in the case when they are effective in decreasing the overall mortality but cause the death of several people. Our conclusion is that such measures are not justified ethically, and implementing emergency powers is justified only in the case of war. Finally, we formulate several important problems highlighted by COVID-19 to be discussed in the future.La actual crisis del coronavirus ha causado una gran perturbación a nivel mundial. Numerosos expertos admiten ahora que la gestión de crisis estuvo lejos de ser óptima desde el principio. En el documento, primero resumimos la información disponible sobre la crisis y su gestión. A continuación, enumeramos los factores que llevaron a la forma elegida de gestión de crisis. Posteriormente, cuestionamos si los líderes religiosos podrían haber obtenido suficiente información para no haber apoyado los bloqueos, etc. en marzo de 2020. En nuestra opinión, podrían haberlo hecho si se hubieran dirigido a expertos confiables con una lista de preguntas profesionales razonables. Luego analizamos la cuestión de si las medidas coercitivas hipotéticas están justificadas en el caso de que sean efectivas para disminuir la mortalidad general pero causen la muerte de varias personas. Nuestra conclusión es que tales medidas no están justificadas éticamente, y la implementación de poderes de emergencia solo está justificada en caso de guerra. Finalmente, formulamos varios problemas importantes destacados por COVID-19 para ser discutidos en el futuro. Palabras clave: salud pública; ateísmo; responsabilidad del sacerdocio; Toma de decisiones; elecció

Quantized representation of some nonlinear integrable evolution equations on the soliton sector

The Hirota algorithm for solving several integrable nonlinear evolution equations is suggestive of a simple quantized representation of these equations and their soliton solutions over a Fock space of bosons or of fermions. The classical nonlinear wave equation becomes a nonlinear equation for an operator. The solution of this equation is constructed through the operator analog of the Hirota transformation. The classical N-solitons solution is the expectation value of the solution operator in an N-particle state in the Fock space.Comment: 12 page

The spatio-temporal distribution of lightning over Israel and the neighboring area and its relation to regional synoptic systems

The spatio-temporal distribution of lightning flashes over Israel and the neighboring area and its relation to the regional synoptic systems has been studied, based on data obtained from the Israel Lightning Location System (ILLS) operated by the Israel Electric Corporation (IEC). The system detects cloud-to-ground lightning discharges in a range of ~500 km around central Israel (32.5° N, 35° E). The study period was defined for annual activity from August through July, for 5 seasons in the period 2004–2010. <br><br> The spatial distribution of lightning flash density indicates the highest concentration over the Mediterranean Sea, attributed to the contribution of moisture as well as sensible and latent heat fluxes from the sea surface. Other centers of high density appear along the coastal plain, orographic barriers, especially in northern Israel, and downwind from the metropolitan area of Tel Aviv, Israel. The intra-annual distribution shows an absence of lightning during the summer months (JJA) due to the persistent subsidence over the region. The vast majority of lightning activity occurs during 7 months, October to April. Although over 65 % of the rainfall in Israel is obtained during the winter months (DJF), only 35 % of lightning flashes occur in these months. October is the richest month, with 40 % of total annual flashes. This is attributed both to tropical intrusions, i.e., Red Sea Troughs (RST), which are characterized by intense static instability and convection, and to Cyprus Lows (CLs) arriving from the west. <br><br> Based on daily study of the spatial distribution of lightning, three patterns have been defined; "land", "maritime" and "hybrid". CLs cause high flash density over the Mediterranean Sea, whereas some of the RST days are typified by flashes over land. The pattern defined "hybrid" is a combination of the other 2 patterns. On CL days, only the maritime pattern was noted, whereas in RST days all 3 patterns were found, including the maritime pattern. It is suggested that atmospheric processes associated with RST produce the land pattern. Hence, the occurrence of a maritime pattern in days identified as RST reflects an "apparent RST". The hybrid pattern was associated with an RST located east of Israel. This synoptic type produced the typical flash maximum over the land, but the upper-level trough together with the onshore winds it induced over the eastern coast of the Mediterranean resulted in lightning activity over the sea as well, similar to that of CLs. <br><br> It is suggested that the spatial distribution patterns of lightning may better identify the synoptic system responsible, a CL, an "active RST" or an "apparent RST". The electrical activity thus serves as a "fingerprint" for the synoptic situation responsible for its generation

Ground-based observations of the relations between lightning charge-moment-change and the physical and optical properties of column sprites

Optical observations of 66 sprites, using a calibrated commercial CCD camera, were conducted in 2009-2010 and 2010-2011 winter seasons as part of the ILAN (Imaging of Lightning And Nocturnal flashes) campaign in the vicinity of Israel and the eastern Mediterranean. We looked for correlations between the properties of parent lightning (specifically, the charge moment change; CMC) to the properties of column sprites, such as the measured radiance, the length and the number of column elements in each sprite event. The brightness of sprites positively correlates with the CMC (0.7) and so does the length of sprite elements (0.83). These results are in agreement with previous studies, and support the QE model of sprite generation. © 2013 Elsevier Ltd

Limitations to Frechet's Metric Embedding Method

Frechet's classical isometric embedding argument has evolved to become a major tool in the study of metric spaces. An important example of a Frechet embedding is Bourgain's embedding. The authors have recently shown that for every e>0 any n-point metric space contains a subset of size at least n^(1-e) which embeds into l_2 with distortion O(\log(2/e) /e). The embedding we used is non-Frechet, and the purpose of this note is to show that this is not coincidental. Specifically, for every e>0, we construct arbitrarily large n-point metric spaces, such that the distortion of any Frechet embedding into l_p on subsets of size at least n^{1/2 + e} is \Omega((\log n)^{1/p}).Comment: 10 pages, 1 figur

Cosmic ray measurements in the atmosphere at several latitudes in October, 2014

Cosmic ray fluxes in the atmosphere were recorded during balloon flights in October 2014 in northern Murmansk region, Apatity (Russia; 67o33’N, 33o24’E), in Antarctica (observatory Mirny; 66o33’S, 93o00’E), in Moscow (Russia; 55o45’N, 37o37’E), in Reading (United King-dom; 51o27’N, 0o 58’W), in Mitzpe-Ramon (Israel; 30o36’N, 34o48’E) and in Zaragoza (Spain; 41o9’N, 0o54’W). Two type of cosmic ray detectors were used, namely, (1) the standard ra-diosonde and its modification constructed at the Lebedev Physical Institute (Moscow, Russia) and (2) the device manufactured at the Reading University (Reading, United Kingdom). We compare and analyze obtained data and focus on the estimation of the cosmic ray latitudinal effect in the atmosphere

Descanse en paz: enfoque judeocristiano sobre el final de la vida y los tratamientos paliativos.

The concept of "dying of old age" almost does not exist today: it is always death from some illness. The religious world became captive to the concept that we must do everything to prolong metabolism for every additional moment. In most cases, a person is separated from the world while in an alienated environment, connected to transfusions and machines. While we deny euthanasia in an absolute and unconditional manner, our practical suggestion is encouraging palliative medicine. This type of care is focused on providing relief from the symptoms and stress of the illness rather than attempting to cure. We wish to instill the understanding that natural death from old age is a gift from God, not a punishment.El concepto de "morir de vejez" casi no existe hoy en día; siempre es una muerte por alguna enfermedad. El mundo religioso ha quedado atrapado en la noción de que debemos hacer todo lo posible para prolongar el metabolismo en cada momento adicional. En la mayoría de los casos, una persona está separada del mundo en un entorno alienado, conectada a transfusiones y máquinas. Aunque negamos la eutanasia de manera absoluta e incondicional, nuestra sugerencia práctica es fomentar la medicina paliativa. Este tipo de atención se centra en brindar alivio a los síntomas y el estrés de la enfermedad en lugar de intentar curarla. Deseamos inculcar la comprensión de que la muerte natural por vejez es un regalo de Dios, no un castigo