Camp Blanding Lightning Mapping Array

A seven station, short base-line Lightning Mapping Array was installed at the Camp Blanding International Center for Lightning Research and Testing (ICLRT) during April 2011. This network will support science investigations of Terrestrial Gamma-Ray Flashes (TGFs) and lightning initiation using rocket triggered lightning at the ICLRT. The network operations and data processing will be carried out through a close collaboration between several organizations, including the NASA Marshall Space Flight Center, University of Alabama in Huntsville, University of Florida, and New Mexico Tech. The deployment was sponsored by the Defense Advanced Research Projects Agency (DARPA). The network does not have real-time data dissemination. Description, status and plans will be discussed

Atmospheric Optics

This collection, created and maintained by Harald Edens, contains photographs of many different atmospheric optical phenomena. Those phenomena include ice crystal halos, light scattering, and atmospheric refraction, among others. The pictures of each phenomenon are accompanied by a brief explanation of what causes it. Prints of the pictures can be purchased from the web site

Media 1: Probable photographic detection of the natural seventh-order rainbow

Originally published in Applied Optics on 01 February 2015 (ao-54-4-B93

Media 3: Probable photographic detection of the natural seventh-order rainbow

Originally published in Applied Optics on 01 February 2015 (ao-54-4-B93

Examining the Statistical Relationships between Volcanic Seismic, Infrasound, and Electrical Signals: A Case Study of Sakurajima Volcano, 2015

Sakurajima volcano in Japan is known for frequent eruptions containing prolific volcanic lightning. Previous studies from eruptions at Redoubt have shown preliminary correlations between seismic, infrasound, and radio frequency signals. This study uses field data collected at Sakurajima from 28 May–7 June 2015 and multivariable statistical modeling to quantify these relationships. We build regression equations to examine each of the following parameters of electrical activity: (1) the presence of electrical activity, (2) the presence of the radio frequency signal called continual radio frequency impulses (CRF), (3) the presence of lightning, (4) the overall duration of electrical activity, and (5) the total number of radio frequency sources located by a lightning mapping array. We model these response variables against: (1) seismic energy, (2) infrasound energy, (3) seismic duration, (4) infrasound duration, and (5) the volcano acoustic seismic ratio. Our final regression equations show that each parameter of electrical activity is best defined by a separate set of response parameters, but overall events with greater explosivity correlate with higher amounts of electrical activity. Specifically, (1) the probability of CRF occurring, and the overall number of located radio frequency sources are likely related to deeper fragmentation depths; (2) the probability of electrical activity occurring at all, and specifically the probability of lightning being generated are correlated with high infrasound energies indicating that the gas thrust phase of plume formation plays an important role in charge generation; and (3) the longer an eruption (as determined by the duration of the infrasound signal) the longer we can expect to see radio frequency signals generated

Examining the Statistical Relationships between Volcanic Seismic, Infrasound, and Electrical Signals: A Case Study of Sakurajima Volcano, 2015

Sakurajima volcano in Japan is known for frequent eruptions containing prolific volcanic lightning. Previous studies from eruptions at Redoubt have shown preliminary correlations between seismic, infrasound, and radio frequency signals. This study uses field data collected at Sakurajima from 28 May–7 June 2015 and multivariable statistical modeling to quantify these relationships. We build regression equations to examine each of the following parameters of electrical activity: (1) the presence of electrical activity, (2) the presence of the radio frequency signal called continual radio frequency impulses (CRF), (3) the presence of lightning, (4) the overall duration of electrical activity, and (5) the total number of radio frequency sources located by a lightning mapping array. We model these response variables against: (1) seismic energy, (2) infrasound energy, (3) seismic duration, (4) infrasound duration, and (5) the volcano acoustic seismic ratio. Our final regression equations show that each parameter of electrical activity is best defined by a separate set of response parameters, but overall events with greater explosivity correlate with higher amounts of electrical activity. Specifically, (1) the probability of CRF occurring, and the overall number of located radio frequency sources are likely related to deeper fragmentation depths; (2) the probability of electrical activity occurring at all, and specifically the probability of lightning being generated are correlated with high infrasound energies indicating that the gas thrust phase of plume formation plays an important role in charge generation; and (3) the longer an eruption (as determined by the duration of the infrasound signal) the longer we can expect to see radio frequency signals generated

Volcanic Lightning as an Indicator of Ash Parameters: A Case Study of Sakurajima Volcano, Japan, May-June 2015

Volcanic lightning is an emerging field of study for monitoring explosive, ashproducing eruptions. Volcanic ash is hazardous to aviation as well as local communities. Using volcanic lightning to monitor ongoing ash emissions, however, requires a better understanding of how volcanic lightning develops, and whether or not lightning can be used as an indicator for specific ash characteristics. Volcanic lightning is common at Sakurajima Volcano, Japan. During the summer of 2015 we deployed a 9 station Lightning Mapping Array (LMA), developed by New Mexico Institute of Mining and Technology, within 20 km of Sakurajima Volcano to detect the very high-frequency electromagnetic radiation generated by volcanic lightning. Of the eruptions analyzed so far the two main types of electrical signals recorded were near vent-lightning and continuous radio frequencies (CRF). In addition to the LMA data we collected samples of actively falling ash during a tenday observation period from May 29th-June 7th 2015. Eruptive events were also recorded on a Trillium broadband three-component seismometer. Ash samples were characterized in terms of componentry, plagioclase microlite number density, laser diffraction particle size analysis, and particle morphology using a PharmaVision 830. The ash parameters were compared with maximum vertical seismic amplitudes and the electrical discharge statistics of the respective explosive events. We have begun to determine the relationships that exist between quantifiable ash characteristics and volcanic electrification, especially the occurrence of CRF. We have found that CRF occurred during events where ash samples were composed of greater than 60% glass with less than 10% lithics. CRF was also present during eruptions whose samples have have high mean roundness but maintain a distribution tail of acicular grains. Finally, CRF occurred in more explosive events as defined by higher seismic amplitudes (\u3e7um). We infer from these relationships that CRF is generated in highly explosive events by a combination of initial and secondary fragmentation of the ash as it is generated and travels up the conduit

Über die Wärmeleitfähigkeit von Sonnenblumenkernen

Bei zunehmender Feuchtigkeit W der Sonnenblumenkerne von 6 auf 17,8 % nehmen Schüttdichte, Dichte und Wärmekapazität derselben nach dem linearen Gesetz zu. Die Zunahme von W auf 11 % führt zu einer Steigerung des Abkühlungstempos, des Wärmeleitfähigkeitskoeffizienten und zur Verringerung des thermischen Widerstands. Eine weitere Zunahme von W hat keinen Einfluß auf die Veränderung der Kenngrößen. Der Temperaturleitfähigkeitskoeffizient der Körner nimmt zuerst bei Zunahme von W auf 11 % zu und bei weiterer Zunahme von W ab

Volcanic Lightning as an Indicator of Ash Parameters: A Case Study of Sakurajima Volcano, Japan, May-June 2015

Volcanic lightning is an emerging field of study for monitoring explosive, ashproducing eruptions. Volcanic ash is hazardous to aviation as well as local communities. Using volcanic lightning to monitor ongoing ash emissions, however, requires a better understanding of how volcanic lightning develops, and whether or not lightning can be used as an indicator for specific ash characteristics. Volcanic lightning is common at Sakurajima Volcano, Japan. During the summer of 2015 we deployed a 9 station Lightning Mapping Array (LMA), developed by New Mexico Institute of Mining and Technology, within 20 km of Sakurajima Volcano to detect the very high-frequency electromagnetic radiation generated by volcanic lightning. Of the eruptions analyzed so far the two main types of electrical signals recorded were near vent-lightning and continuous radio frequencies (CRF). In addition to the LMA data we collected samples of actively falling ash during a tenday observation period from May 29th-June 7th 2015. Eruptive events were also recorded on a Trillium broadband three-component seismometer. Ash samples were characterized in terms of componentry, plagioclase microlite number density, laser diffraction particle size analysis, and particle morphology using a PharmaVision 830. The ash parameters were compared with maximum vertical seismic amplitudes and the electrical discharge statistics of the respective explosive events. We have begun to determine the relationships that exist between quantifiable ash characteristics and volcanic electrification, especially the occurrence of CRF. We have found that CRF occurred during events where ash samples were composed of greater than 60% glass with less than 10% lithics. CRF was also present during eruptions whose samples have have high mean roundness but maintain a distribution tail of acicular grains. Finally, CRF occurred in more explosive events as defined by higher seismic amplitudes (\u3e7um). We infer from these relationships that CRF is generated in highly explosive events by a combination of initial and secondary fragmentation of the ash as it is generated and travels up the conduit