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In this work, we investigate various types of ionospheric disturbances observed over Europe after the earthquake in Turkey on 6 February 2023.By combining observations from Doppler sounding systems, ionosondes, and GNSS receivers, we are able to discern different types of disturbances, propagating with different velocities and through different mechanisms. We can detect the co-seismic disturbances produced in the ionosphere close to the epicenter, as well the ionospheric signatures of acoustic waves propagating as a consequence of propagating seismic waves.

The impact of individual meteors on the lower ionosphere (90-150 km height) has been investigated during wintertime meteor showers using measurements of two DPS-4D Digisondes installed at Sopron (47.63°, 16.72°) and at Pruhonice (50°, 14.5°). The optical measurements of meteors have been performed by a zenith camera installed next to the digisonde at Sopron. It provided the opportunity to compare high cadence ionograms measured during meteor showers parallel with the optical data to determine the plasma trails of individual meteors. Campaign measurements with two ionograms/minute have been performed at Sopron station during the Leonid (16-18 November) and Geminid (10-15 December) meteor showers in 2019. Furthermore, skymaps (1/min) detected by the Digisonde at Sopron during the campaign were also investigated.In the 20-25% of the observed meteors faint, short-lived (20-120 sec) Es layers were detected on the ionograms during and after (< 2 min) the optical record, which are typical signal of individual meteor trails on the ionogram based on previous studies. There was no observed Es activity at the same height on the ionograms detected before and after these events. Furthermore, the direction of the echo can be also defined on the ionograms of the DPS-4D Digisonde thanks to the multi-beam observation technique. The direction of the detected Es layers agreed well with the optical observations in most of the cases. The maximum frequency of the observed faint layers (foEs) varied between 1,6 and 4,5 MHz, while their height was between 85 and 136 km. Points on the skymaps were also detected at the time of the faint Es layers in 40 % of the cases. The height and direction of the observed points agreed with these parameters of the plasma traces on the ionograms.Comparing the ionograms with the closest ionosonde observation at Pruhonice station at the same time, we could conclude that the detected faint Es layers were local plasma irregularities, no Es activity at the same height was observed there. This strengthens the hypothesis that the observed trails on the ionograms represents the echo of the optically recorded meteors.

BEVEZETÉS – Az Országos Korányi Pulmonológiai Intézet Dohányzás Leszokást Támogató Módszertani Központja 2013 óta ingyenes segélyvonalat működtet, amelynek az a feladata, hogy a dohányzásról leszokni vágyókat szakmai tanácsokkal lássa el, tájékoztatást adjon a leszokástámogatási lehetőségekről, programokról, az érdeklődőt szükség esetén a megfelelő egészségügyi ellátás keretei közé irányítsa. Meg ha - tározott protokollt követve, a proaktív telefonos beszélgetés hat héten át tart, heti egyszeri alkalommal. A tanulmány az elmúlt hat év tevékenységét ismerteti. MÓDSZER – Retrospektív longitudinális vizsgálat. Az adatokat leíró statisztikai mód szerrel elemeztük. EREDMÉNYEK – A 2015-től 2020-ig terjedő időszakban 24 286 üzenet érkezett a telefonos tanácsadás üzenetrögzítőjére. Az érdeklődők megközelítőleg 55%-ával sikerült beszélgetést kezdeményezni. Az ingyenesen, bárki számára elérhető segítség - nyújtó vonalat leginkább az alacsonyabb iskolai végzettségűek és nehezebb anyagi körülmények között élő emberek veszik igénybe. A segítségkérők nikotinfüggősége erős volt. A program különösen fontos azoknak a dohányzóknak, akik egyébként kevésbé részesülnének szakértői támogatásban. 2015–2020 között a programban résztvevők átlagos absztinencia aránya a pro aktív hívásokat követően 16% volt. A ki - indulási absztinenciaarány 2015-ben 19% volt, ami 2020-ban visszaesett 6%-ra. Ezen időszakban a le szokók arányának átlaga a féléves követésnél 13%, az egyévesnél 9% volt. KÖVETKEZTETÉSEK – Az alacsony leszokási arány egyik lehetséges oka, hogy a telefonos tanácsadási program csak a viselkedés változására tud hangsúlyt fektetni, közvetlen segítséget azonban nem ad a gyógyszeres támogatáshoz. Ezért az egészségügyi dolgozóknak kiemelt szerepük van abban, hogy ösztönözzék a dohányzót a leszokásra, és emellett a nikotinmegvonás kezelésére.

The 15 January 2022 eruption of the Hunga volcano provides a unique opportunity to study the reaction of the ionosphere to large explosive events. In particular, this event allows us to study the global propagation of travelling ionospheric disturbances (TIDs) using various instruments. We focus on detecting the ionospheric disturbances caused by this eruption over Europe, where dense networks of both ionosondes and GNSS receivers are available. This event took place on the day of a geomagnetic storm. We show how data from different instruments and observatories can be combined to distinguish the TIDs produced by the eruption from those caused by concurrent geomagnetic activity. The Lamb wavefront was detected as the strongest disturbance in the ionosphere, travelling between 300 and 340 m/s, consistent with the disturbances in the lower atmosphere. By comparing observations obtained from multiple types of instruments, we also show that TIDs produced by various mechanisms are present simultaneously, with different types of waves affecting different physical quantities. This illustrates the importance of analysing data from multiple independent instruments in order to obtain a full picture of an event like this one, as relying on only a single data source might result in some effects going unobserved.

The Széchenyi István Geophysical Observatory, also known as the Nagycenk Geophysical Observatory (NCK), was established in 1957. It has been the only measurement site in Hungary where observations of various parameters of the atmospheric global electric circuit are made in the framework of organized research under the umbrella of the Hungarian Academy of Sciences (MTA). Measurements of the atmospheric electrical potential gradient (PG) and Schumann resonances (SRs) running quasi-continuously in the observatory for decades provide an invaluable source of information for geophysical research. This paper gives an overview on the history of the observatory and particularly on various atmospheric electricity (AE) measurements on-site to commemorate the efforts and excellence of the people who served atmospheric sciences by dedicating their lives to obtaining high-quality, reliable data and scientific achievements at the highest possible level.

The complex analysis of the largest geomagnetic storms of solar cycle #24 maximum is our main aim in this study. Our focus is on the ionosphere, more precisely on the ionospheric F2-layer. The selected storm intervals are: 11-17 November 2012 (Kpmax=6.33, Dstmin=-108 nT ), 16-23 March 2013 (Kpmax= 6.67, Dstmin=-132 nT ), and 16-25 March 2015 (Kpmax=7.67, Dstmin=-228 nT). Data from 6 digisonde (DPS4D) stations, ground GNSS TEC and Swarm satellite constellation have been used for the investigation.This study is the next step to validate our previous results discussed in Berényi et al. (2018). We analyse the meridional behaviour of the geomagnetic disturbance caused ionospheric storms to understand and interpret the evolution of the caused effects.The storm from 2012 is a no-positive phase (NPP) storm, but the 2013 and 2015 storms show the pattern of the regular positive phase (RPP) storm type (after the categorization by Mendillo and Narvaez, 2010). In all three cases a significant increase in electron density of the F2-layer can be observed at dawn/early morning (around 6:00 UT, 07:00 LT). We compared also the digisonde foF2 parameter with the GNSS TEC data. Besides, we observed the fade-out of the ionospheric layers at night during the geomagnetically disturbed time periods of storm 2012 and 2015. In order to determine whether this fade-out is connected to the L-shell location of the plasmapause we analysed the Swarm observations (for the storm 2015), too.Berényi, K. A., Barta, V., & Kis. (2018). Midlatitude ionospheric F2-layer response to eruptive solar events-caused geomagnetic disturbances over Hungary during the maximum of the solar cycle 24: A case study. Advances in Space Research, 61(5), 1230–1243. https://doi.org/10.1016/j.asr.2017.12.021Mendillo, M., & Narvaez, C. (2010). Ionospheric storms at geophysically-equivalent sites - Part 2: Local time storm patterns for sub-auroral ionospheres. Annales Geophysicae, 28(7), 1449–1462. https://doi.org/10.5194/angeo-28-1449-2010

The sudden increase of X-radiation and EUV emission following solar flares causes additional ionization and increased absorption of electromagnetic (EM) waves in the sunlit hemisphere of the Earth’s ionosphere. The solar flare impact on the ionosphere above Europe on 05 and 06 December 2006 was investigated using ground-based (ionosonde and VLF) and satellite-based data (Vertical Total Electron Content (VTEC) derived from Global Navigation Satellite Systems (GNSS) observations and VLF measurements from the DEMETER satellite). Based on the geomagnetic indices Kp and Dst, 05 December was a quiet day, while there was a geomagnetic storm on 06 December 2006.The total fade-out of the EM waves emitted by the ionosondes was experienced at all investigated stations during an X9 class flare on 05 December. The variation of the fmin parameter ( representing the minimum frequency of the echo trace observed in the ionogram, and is a rough measure of the “nondeviative” absorption) and its difference between the quiet period and during the flares have been analyzed. A latitude dependent enhancement of fmin (2-9 MHz) and Delta_fmin (relative change of about 150-300 %) was observed at every station at the time of the X9 (on 05 December) and M6 (on 06 December) flares.Furthermore, we analyzed VTEC changes during and after the flare events with respect to the mean VTEC values of reference quiet days. During the X9 solar flare, VTEC increased depending on the latitude (2-3 TECU and 5-20 %). On 06 December, the geomagnetic storm increased ionization (5-10 TECU) representing a „positive” ionospheric storm. However, an additional peak in VTEC related to the M6 flare could not be detected.We have also observed a quantifiable change in transionospheric VLF absorption of signals from ground transmitters detected in low Earth orbit associated with the X9 and M6 flare events on 05 and 06 December in the DEMETER data. Moreover, amplitude and phase of ground-based, subionospherically propagating VLF signals were measured simultaneously during the investigated flares to analyze ionosphere reaction and to evaluate the electron density profile versus altitude. For the X9 and M6 flare events we have also calculated the ionospheric parameters (sharpness, reflection height, etc.) important for the description and modeling of this medium under forced additional ionization.

As a result of the enhanced X-ray and EUV fluxes following large solar flares, the electron density of the ionospheric layers increases. Furthermore, it causes higher absorption or even partial or total fade-out of the emitted radio waves which can be measured with ionosondes and Digisondes by studying the amplitude of the reflected electromagnetic waves [1,2].In the present study, the ionospheric response to large solar flares has been investigated using the ionosonde data measured at the Průhonice (Czech Republic, 49.98° N, 14.55° E) and San Vito (Italy, 40.6° N, 17.8° E) stations in September 2017, the most active solar period of Solar Cycle 24. A novel method [3] to calculate and investigate the absorption of radio waves propagating in the ionosphere is used to determine the absorption during large solar flare events (M and X class). Subsequently, the absorption data are compared with the indicators derived from the fmin method (fmin, the minimum frequency is considered as a qualitative proxy for the “nondeviative” radio wave absorption occurring in the D-layer). Total and partial radio fade-out and increased values (with 2–5 MHz) of the fmin parameter were experienced during and after the intense solar flares (> M3). Furthermore, the signal-to-noise ratio (SNR) measured by the Digisondes was used as well to quantify and characterize the fade-out events and the ionospheric absorption. The combination of these three methods may prove to be an efficient approach to monitor the ionospheric response to solar flares.[1] Sripathi, S., Balachandran, N., Veenadhari, B., Singh, R., and Emperumal, K.: Response of the equatorial and low-latitude ionosphere to an intense X-class solar flare (X7/2B) as observed on 09 August 2011, J. Geophys. Res.-Space, 118, 2648–2659, 2013.[2] Barta, V., Sátori, G., Berényi, K. A., Kis, Á., and Williams, E. (2019). Effects of solar flares on the ionosphere as shown by the dynamics of ionograms recorded in Europe and South Africa. Annales Geophysicae, Vol. 37, No. 4, pp. 747-761[3] Sales, G. S., 2009, HF absorption measurements using routine digisonde data, Conference material, XII. International Digisonde Forum, University of Massachusetts

The sudden increase of X-radiation and EUV emission following solar flares causes additional ionization and increased absorption of electromagnetic (EM) waves in the Earth’s atmosphere. The solar flare impact on the ionosphere above Europe on 05 and 06 December 2006 was investigated using ground-based (ionosonde and VLF) and satellite-based data (Vertical Total Electron Content (VTEC) derived from GNSS observations and VLF measurements from DEMETER satellite). Based on the Kp and Dst indices, 05 December 2006 was a quiet day, while there was a geomagnetic storm on 06 December 2006. The total fade-out of the EM waves emitted by the ionosondes was experienced at all investigated stations during an X9 class flare on 05 December 2006. The variation of the fmin parameter (first echo trace observed on ionograms, it is a rough measure of the “non-deviative” absorption) and its difference between the quiet period and during the flares have been analyzed. A latitude dependent enhancement of fmin (2–9 MHz) and Δfmin (relative change of about 150%–300%) was observed at every station at the time of the X9 (on 05 December) and M6 (on 06 December) flares. Furthermore, we analyzed VTEC changes during and after the flare events with respect to the mean VTEC values of reference quiet days. During the X9 solar flare, VTEC increased depending on the latitude (2–3 TECU and 5%–20%). On 06 December 2006, the geomagnetic storm increased ionization (5–10 TECU) representing a “positive” ionospheric storm. However, an additional peak in VTEC related to the M6 flare could not be detected. We have also observed a quantifiable change in transionospheric VLF absorption of signals from ground transmitters detected in low Earth orbit associated with the X9 and M6 flare events on 05 and 06 December in the DEMETER data. Moreover, amplitude and phase of ground-based, subionospherically propagating VLF signals were measured simultaneously during the investigated flares to analyze ionosphere reaction and to evaluate the electron density profile versus altitude. For the X9 and M6 flare events we have also calculated the ionospheric parameters (sharpness, reflection height) important for the description and modelling of this medium under forced additional ionization.

The Danube is the second-longest river in Europe that is subjected to various man-made alterations, including those related to hydro-power plants. We surveyed and analyzed the presence and abundance of macrophytes in the main channel from 2582 river kilometers (rkm) to 171 rkm. We also assessed selected habitat parameters in the sampled river stretches. Sixty-eight different plant species were recorded along the entire course. Among neophytes, we found Elodea nuttallii, E. canadensis, Vallisneriaspiralis and Azolla filiculoides. Based on similarity analysis, we distinguished 15 plant communities, most of which were defined as associations, which were classified into 5 alliances and represented three vegetation classes, namely vegetation of rooted hydrophytes Potamogetonetea, the vegetation of pleustophytes Lemnetea and vegetation of marshes Phragmitetea. The number and abundance of plant species, as well as plant communities recorded in single stretches, varied along the course. Canonical correspondence analysis (CCA) revealed that environmental parameters explained 21% of plant species composition. CCA runs with neophytes explained 41% of the variance, and current velocity, water transparency, species number and bank structure were significant variables. The present study revealed that the free-running sections of the river are poor in number and abundance of plant species, whereas impounded reaches mainly show an opposite result.

WOS:000610265200001 The purpose of the present study is to investigate simultaneously pre-earthquake ionospheric and atmospheric disturbances by the application of different methodologies, with the ultimate aim to detect their possible link with the impending seismic event. Three large earthquakes in Mexico are selected (8.2 Mw, 7.1 Mw and 6.6 Mw during 8 and 19 September 2017 and 21 January 2016 respectively), while ionospheric variations during the entire year 2017 prior to 37 earthquakes are also examined. In particular, Total Electron Content (TEC) retrieved from Global Navigation Satellite System (GNSS) networks and Atmospheric Chemical Potential (ACP) variations extracted from an atmospheric model are analyzed by performing statistical and spectral analysis on TEC measurements with the aid of Global Ionospheric Maps (GIMs), Ionospheric Precursor Mask (IPM) methodology and time series and regional maps of ACP. It is found that both large and short scale ionospheric anomalies occurring from few hours to a few days prior to the seismic events may be linked to the forthcoming events and most of them are nearly concurrent with atmospheric anomalies happening during the same day. This analysis also highlights that even in low-latitude areas it is possible to discern pre-earthquake ionospheric disturbances possibly linked with the imminent seismic events.

Natural and artificial lakes are able to change the climate of their surroundings. These modifications are collectively known as lake effects and range from microscale to synoptic scale. The presence of the lake can cause negative effect on the local thunderstorm activity in summertime decreasing the convection and precipitation over lakes due to the greater stability created by the lower atmosphere and the colder surfaces of the lake [1, 2]. However, it also can have a positive impact on thundercloud generation when the temperature difference between air in 850 mb height and near earth's surface is more than 13 C causing instability in the atmosphere [3]. The main objective of the present study is to investigate the impact of Lake Fertő (Neusiedler See, located in Hungary and Austria) on local thunderstorm activity by applying statistical analysis on meteorological and lightning data and event studies. Data of the Blitzortung lightning location network, local meteorological data (temperature, precipitation) measured at stations around the lake, water temperature measured at Fertőrákos and temperature measured at 850 mb in Vienna station were used for the analysis. The local thunderstorm activity was investigated during summertime (May - September) in 2015, 2016 and 2017. Lightning distribution maps above and around the lake for the investigated period have been determined based on the Blitzortung data. According to the lightning distribution maps we can not observe any positive impact of the lake on the lightning activity when water temperature was higher than the air temperature around the lake. Furthermore, we can not conclude that there is a clear negative effect of the lake on the lightning activity based on the lightning distribution maps when the air temperature is higher than the water temperature. Nevertheless, there are some months when it seems a clear border between the lightning activity measured above the lake and at the coast (e. g. in June and July 2015, June 2016). The negative effect also seems to appear in some cases of the investigated local individual thunderstorms, namely the thunderstorm activity is larger above the surrounding surface than directly above the lake. This seems to strengthen the hypothesis that "Deep convection is not often formed in summer above the lakes, and existing storms dissipate significantly when moving above the lakes due to the greater stability created by the lower atmosphere and the colder surfaces of the lake" [1]. [1] Lyons, W. A., Some effects of Lake Michigan upon sqall lines and summertime convention. Proc. 9th Conf. Great Lakes Research, Great Lakes Res. Div. Publ. No. 15, University of Michigan, 259–273, 1966[2] Scott, R. W., & Huff, F. A. . Impacts of the Great Lakes on Regional Climate Conditions. Journal of Great Lakes Research, 22(4), 845–863., 1996[3] Wilson, J. W. : Effect of Lake Ontario on precipitation. Mon. Wea. Rev. 105, 207–214., 1977

The most intense external force affecting the ionosphere from above is related to large solar flare events, therefore it is of particular importance to study their impact on the ionosphere. During solar flares, the suddenly increased radiation causes increased ionization and enhanced absorption of radio waves leading to partial or even total radio fade-out lasting for hours in some cases (e. g. [1] [2]). The ionospheric response to large solar flares have been investigated using the ionosonde data measured at Pruhonice (PQ052, 50°, 14.5°) in September 2017, the most active solar period of Solar Cycle 24. A novel method [3] to calculate and investigate the absorption of radio waves propagating in the ionosphere is used to determine the absorption during large solar flare events (M and X class). Subsequently, the absorption data are compared with the indicators derived from the fmin method (fmin, the minimum frequency is considered as a qualitative proxy for the “nondeviative” radio wave absorption occurring in the D-layer). Total and partial radio fade-out and increased values (with 2-5 MHz) of the fmin parameter were experienced during and after the intense solar flares (> M3). The combination of these two methods may prove to be an efficient approach to monitor the ionospheric response to solar flares. [1] Sripathi, S., Balachandran, N., Veenadhari, B., Singh, R., and Emperumal, K.: Response of the equatorial and low-latitude ionosphere to an intense X-class solar flare (X7/2B) as observed on 09 August 2011, J. Geophys. Res.-Space, 118, 2648–2659, 2013.[2] Barta, V., Sátori, G., Berényi, K. A., Kis, Á., and Williams, E. (2019). Effects of solar flares on the ionosphere as shown by the dynamics of ionograms recorded in Europe and South Africa. Annales Geophysicae, Vol. 37, No. 4, pp. 747-761[3] Sales, G. S., 2009, HF absorption measurements using routine digisonde data, Conference material, XII. International Digisonde Forum, University of Massachusetts

The impact of meteor showers and individual meteors on the ionosphere has been investigated during wintertime meteor showers using synchronised measurements of two DPS-4D Digisondes installed at Pruhonice (50°, 14.5°) and at Sopron (47.63°, 16.72°). Rather short distance between Pruhonice and Sopron allow us to perform special joint campaigns of vertical and oblique sounding under the high sampling rate to detect fine structures within ionospheric plasma. High cadence campaigns have been performed to observe behavior of sporadic E layer (Es) during the Leonids, Geminids and Quadrantids meteor showers in 2018 and 2019. The time resolution of the ionograms have been set to approximately 0.5 - 2 ionograms per minute. We used vertical and oblique reflections to investigate the fine structure and the movement of Es layer. Based on the first results the oblique sounding is a good technique to detect the Es activity between two stations, however there were periods (typically 10 to 40 minutes of duration) when the Es was observed using oblique trace but there was no observation of Es layer in vertical ionograms. Furthermore, double Es structures have been detected more times for tens of minutes during the observation nights. Beside the regular behavior of Es we concentrated on observation of intervals of increased plasma frequency in the Es region presumably directly induced by the meteors. In the framework of GINOP-2.3.2-15-2016-00003 (“Kozmikus hatások és kockázatok") an optical camera has been installed at the MTA Széchenyi István Geophysical Observatory (Sopron) in September 2019 with the cooperation of the Konkoly Observatory to monitor the meteors. Therefore, we were able to compare the ionograms measured during meteor showers with the optical data to determine the plasma trails of individual meteors. In the 20-25% of the observed meteors a faint Es layers were detected on the ionograms during and after (< 1 min) the optical record. The direction of the detected plasma traces determined by the SAO Explorer was in good agreement with the direction of the optically observed meteors in most of the cases. Consequently, the plasma trace of individual meteors could be detected on the high time resolution ionograms.

International audience; In 1999, the first sprites were observed above European thunderstorms using sensitive cameras. Since then, Eurosprite campaigns have been conducted to observe sprites and other transient luminous events (TLEs), expanding into a network covering large parts of Europe and coastal areas. In 2009 through 2013, the number of optical observations of TLEs reached a peak of 2000 per year. Because of this unprecedented number of European observations, it was possible to construct a climatology of 8394 TLEs observed above 1018 thunderstorm systems and study for the first time their distribution and seasonal cycle above Europe and parts of the Mediterranean Sea. The number of TLEs per thunderstorm was found to follow a power law, with less than 10 TLEs for 801 thunderstorms and up to 195 TLEs above the most prolific one. The majority of TLEs were classified as sprites, 641 elves, 280 halos, 70 upward lightning, 2 blue jets and 1 gigantic jet. The climatology shows intense TLE activity during summer over continental areas and in late autumn over coastal areas and sea. The two seasons peak, respectively, in August and November, separated by March and April with almost no TLEs, and a relative minimum around September. The observed TLE activity, i.e. mostly sprites, is shown to be largely consistent with lightning activity, with a 1/1000 of observed TLE-to-lightning ratio in regions with most observations. The overall behaviour is consistent among individual years, making the observed seasonal cycle a robust general feature of TLE activity above Europe

Systematic analysis of ionosopheric parameters measured at mid- and low-latitudes was performed to study the ionospheric response to solar flares. The lowest recorded ionosonde echo, the mimimum frequency (fmin, a qualitative proxy for the nondeviative radio wave absorption occurring in the D-layer), furthermore the dfmin parameter (difference between the value of the fmin and the mean fmin for reference days) have been investigated. The time series of the fmin and dfmin parameters recorded at meridionally-distributed ionosonde stations in Europe and South Africa were analyzed during eight X and M class solar flares during solar cycle 23. The solar zenith angles of the observation sites at the time of the selected flares have been also taken into account. Total and partial radio fade-out was experienced at every ionospheric stations during intense solar flares (> M6). The duration of the total radio fade-out varied between 15 and 150 min and it was highly dependent on the solar zenith angle of the ionospheric stations. Furthermore, a solar zenith angle-dependent enhancement of the fmin (2–9 MHz) and dfmin (1–8 MHz) parameters was observed at almost every stations. The fmin and dfmin parameters show an increasing trend with the enhancement of the X-ray flux. Based on the results, the dfmin parameter is a good qualitative measure for the relative variation of the nondeviative absorption especially in the case of the less intense solar flares which do not cause total radio fade-out in the ionosphere (class&thinsp

A new series of beta amino acids, which act as CXCR3 antagonists, has been identified. The formerly optimized N,N-disubstituted benzylamine derivatives with carboxylic acid function on the N-atom was used as starting point and compounds with carboxyl function not attached to the N-atom were investigated. Affinity, metabolic stability in human and mouse liver microsomes and Caco-2 permeability were optimized. Compounds with double-digit nanomolar CXCR3 affinity, favourable microsomal stability and Caco-2 permeability have been identified.

Schumann resonances (SR) are the electromagnetic oscillations of the spherical cavity bounded by the electrically conductive Earth and the conductive but dissipative lower ionosphere (Schumann in Z Naturforsch A 7:6627–6628, 1952). Energetic emissions from the Sun can exert a varied influence on the various parameters of the Earth’s SR: modal frequencies, amplitudes and dissipation parameters. The SR response at multiple receiving stations is considered for two extraordinary solar events from Solar Cycle 23: the Bastille Day event (July 14, 2000) and the Halloween event (October/November 2003). Distinct differences are noted in the ionospheric depths of penetration for X-radiation and solar protons with correspondingly distinct signs of the frequency response. The preferential impact of the protons in the magnetically unshielded polar regions leads to a marked anisotropic frequency response in the two magnetic field components. The general immunity of SR amplitudes to these extreme external perturbations serves to remind us that the amplitude parameter is largely controlled by lightning activity within the Earth–ionosphere cavity.

Superposed epoch analysis (SEA) was used to study possibly statistically significant variations of the critical frequency (foEs) and virtual height (h’Es) of the sporadic E layer (Es) related to thunderstorm activity generated in the troposphere. The reference time for the SEA was the time of lightning strokes measured by the World Wide Lightning Location Network at the ionosonde station of Rome (41.9 $$^\circ $$ N, 12.5 $$^\circ $$ E) during the year 2009. The results obtained reveal that: (a) a statistically significant decrease of foEs after the time of lightnings has been found for time windows of $$\pm $$ 100 h; (b) the effects of thunderstorms on the ionosphere is larger when the thunderstorm approaches from the opposite direction to the mean neutral stratosphere–mesosphere wind flow; (c). a statistically significant decrease of foEs related to thunderstorms during nighttime was observed. No significant changes in foEs and hEs over the seasonal time scale as well as in the latter parameter in the three (a–c) cases related to thunderstorms.

Possible thunderstorm – sporadic E (Es) layer coupling effects are investigated during two measurement periods, one in 2013 and one in 2014. The analysis was based on ionospheric observations obtained from a Digisonde at Pruhonice, the Czech Republic, an ionosonde at Nagycenk, Hungary, and a 3.59 MHz five-point continuous HF Doppler system located in the western part of the Czech Republic. The latter is capable of detecting ionospheric wave-like variations caused by neutral atmospheric waves generated by thunderstorms. The present study searches for possible impacts on Es layers caused by the presence of two active thunderstorms: one passing across the Czech Republic on June 20, 2013 (19:00–01:00 LT), and one through Hungary on July 30, 2014 (11:00-01:00 LT). During these two time periods, presence and parameters of Es layer were inferred from ionograms, recorded every minute at Pruhonice and every two minutes at Nagycenk, whereas concurrent lightning activity was monitored by the LINET detection network. In addition, transient luminous events (TLEs) were also observed during both nights from Sopron, Hungary and from Nýdek, the Czech Republic. A noticeable fact was the reduction and disappearance of the ongoing Es layer activity during part of the time in both of the traversing thunderstorms. The analysis indicated that the critical frequency foEs dropped below ionosonde detection levels in both cases, possibly because of thunderstorm activity effects. This option, however, needs more case studies in order to be further substantiated.

Meteorological processes (cold fronts, mesoscale convective complexes, thunderstorms) in the troposphere can generate upward propagating waves in the neutral atmosphere affecting the behaviour of the ionosphere. One type of these waves are the internal atmospheric gravity waves (AGWs) which are often generated by thunderstorms. Davis & Johnson (2005) found in low pressure systems that a localized intensification of the sporadic E layer (Es) can be attributed to lightnings. To confirm this result, we have performed two different statistical analysis using the time series of the critical frequency (foEs), the virtual height of the sporadic E layer (h'Es), and meteorological observations (lightnings, Infrared maps) over the ionospheric station of Rome (41.9° N, 12.5° E). In the first statistical analysis, we separated the days of 2009 into two groups: stormy days and fair-weather days, then we studied the occurrence and the properties of the Es separately for the two different groups. No significant differences have been found. In the second case, a superposed epoch analysis (SEA) was used to study the behaviour of the critical frequency and virtual height 100 hours before and after the lightnings. The SEA shows a statistically significant decrease in the critical frequency after the time of the lightnings, which indicates a sudden decrease in the electron density of the sporadic E layer associated with lightnings. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

This paper gives a resume of the papers written in English which (a) describe some of the recording instruments in use at the Nagycenk Observatory (NCK) since the International Geophysical Year (IGY 1957–1958) and up to the present time, (b) summarise the most important and different types of observations associated with thunderstorms which have been made there, and (c) discuss their various geophysical interpretations. The paper describes the main results which have been obtained in four areas of thunderstorm associated atmospheric and geospace science within the context of Earth system science. These relate to the following parameters of atmospheric electricity: the vertical electric potential gradient just above the Earth’s surface and the air–Earth current as well as the point discharge current, Schumann resonance (SR) signals of the Earth-ionosphere cavity at 8, 14 and 20 Hz, transient luminous events (TLEs), and some aspects of the behaviour of the ionosphere. Deductions from these data sets are concerned with the global lightning activity and the conductivity of the air, with diurnal, seasonal, annual and long-term variations of the SR amplitudes and resonant frequencies in terms of migrating thunderstorm centres, with transient SR excitations and with sprites and other TLEs, and with ionospheric disturbances. The paper closes with some thoughts on future research directions based on the observations at NCK and Sopron and the results achieved since the IGY.

N,N-Disubstituted benzylamine derivatives have been identified as CXCR3 antagonists. Compounds were optimized to improve affinity and selectivity, to increase metabolic stability in human and mouse liver microsomes, to increase Caco-2 permeability. Optimization was supported by monitoring physico-chemical properties using both experimental and computational means. Several compounds with double-digit nanomolar CXCR3 affinity, favorable selectivity, microsomal stability, Caco-2 permeability and human hepatocyte clearance have been identified.

This study reports observations of energetic ions upstream of the Earth's quasi-parallel bow shock by Cluster at times when interspacecraft separation distances were large. We analyze two individual upstream ion events during high solar wind velocity conditions to compare the spatial evolution of partial energetic ion densities in front of the Earth's bow shock along the magnetic field line. Using a bow shock model, we determine the distance of SC1 and SC3 to the bow shock surface parallel to the magnetic field. The CIS-HIA instrument on board Cluster provides partial energetic ion densities in four energy channels between 10 and 32 keV. Using the differences of the partial energetic ion densities observed on SC1 and SC3, and the distances of the spacecraft to the bow shock, we determine the spatial gradient of partial energetic ion densities at various distances from the bow shock. We show, for the first time, that the e-folding distance and the diffusion coefficient of the diffuse ions become unusually small when these ions interact with high-intensity waves generated by a strong field-aligned beam.

The UNESCO Biosphere Reserve Lobau (Austria), established in 1977 within the city limits of Vienna, is part of the Danube National Park and one of the ecologically richest parts of the Danube River Corridor. Hardly noticed by diverging stakeholder interests the smaller aquatic habitats in the floodplain area are acutely threatened by wetland ageing and terrestrialisation processes. In 2007 an aquatic plant survey was carried out in the water bodies of the active floodplain on the left bank of the Danube main river channel as well as in the semi-separated water bodies of the Lobau. Results clearly show the impact of through-flow on aquatic plant species composition and abundance, as these metrics are significantly higher in the semiseparated location. Suitable water regime for all sensitive aquatic plants is an essential prerequisite for sustaining aquatic macrophyte diversity in the Lobau Biosphere Reserve, and could provide an ecohydrological basis for rehabilitation activities in other regulated river floodplains located in cultivated landscapes.

The Global atmospheric Electric Circuit (GEC) is a fundamental coupling network of the climate system connecting electrically disturbed weather regions with fair weather regions across the planet. The GEC sustains the fair weather electric field (or potential gradient, PG) which is present globally and can be measured routinely at the surface using durable instrumentation such as modern electric field mills, which are now widely deployed internationally. In contrast to lightning or magnetic fields, fair weather PG cannot be measured remotely. Despite the existence of many PG datasets (both contemporary and historical), few attempts have been made to coordinate and integrate these fragmented surface measurements within a global framework. Such a synthesis is important elvinin order to fully study major influences on the GEC such as climate variations and space weather effects, as well as more local atmospheric electrical processes such as cloud electrification, lightning initiation, and dust and aerosol charging. The GloCAEM (Global Coordination of Atmospheric Electricity Measurements) project has brought together experts in atmospheric electricity to make the first steps towards an effective global network for atmospheric electricity monitoring, which will provide data in near real time. Data from all sites are available in identically-formatted files, at both one second and one minute temporal resolution, along with meteorological data (wherever available) for ease of interpretation of electrical measurements. This work describes the details of the GloCAEM database and presents what is likely to be the largest single analysis of PG data performed from multiple datasets at geographically distinct locations. Analysis of the diurnal variation in PG from all 17 GloCAEM sites demonstrates that the majority of sites show two daily maxima, characteristic of local influences on the PG, such as the sunrise effect. Data analysis methods to minimise such effects are presented and recommendations provided on the most suitable GloCAEM sites for the study of various scientific phenomena. The use of the dataset for a further understanding of the GEC is also demonstrated, in particular for more detailed characterization of day-to-day global circuit variability. Such coordinated effort enables deeper insight into PG phenomenology which goes beyond single-location PG measurements, providing a simple measurement of global thunderstorm variability on a day-to-day timescale. The creation of the GloCAEM database is likely to enable much more effective study of atmospheric electricity variables than has ever been possible before, which will improve our understanding of the role of atmospheric electricity in the complex processes underlying weather and climate.