Satellite observations of lightning-induced hard X-ray flux enhancements in the conjugate region

Preliminary examination of October-December 2002 SONG (SOlar Neutron and Gamma rays) data aboard the Russian CORONAS-F (Complex Orbital Near-Earth Observations of the Activity of the Sun) low-altitude satellite has revealed many X-ray enhanced emissions (30–500 keV) in the slot region (<i>L</i> ~ 2–3) between the Earth's radiation belts. In one case, CORONAS-F data were analyzed when the intense hard X-ray emissions were seen westward of the South Atlantic Anomaly in a rather wide <i>L</i> shell range from 1.7 to 2.6. Enhanced fluxes observed on day 316 (12 November) were most likely associated with a Major Severe Weather Outbreak in Eastern USA, producing extensive lightning flashes, as was documented by simultaneous optical observations from space. We propose that whistler mode signals from these lightning discharges cause precipitation of energetic electrons from terrestrial trapped radiation belts, which, in turn, produce atmospheric X-rays in the Southern Hemisphere

Are We Missing Important Areas in Pelagic Marine Conservation? Redefining Conservation Hotspots in the Ocean

The protection of biodiversity is one of the most important goals in terrestrial and marine conservation. Marine conservation approaches have traditionally followed the example of terrestrial initiatives. However, patterns, processes, habitats, and threats differ greatly between the 2 systems - and even within the marine environment. As a result, there is still a lack of congruence as to how to best identify and prioritize conservation approaches moving from the static terrestrial and nearshore realm into a more fluid, 3-dimensional pelagic realm. To address this problem, we investigate how the conservation science literature has been used to inform and guide management strategies in the marine system from coastal to pelagic environments. As cumulative impacts on the health of the oceans continue to increase, conservation priorities have shifted to include highly dynamic areas of the pelagic marine system. By evaluating whether priorities match science with current place-based management approaches (i.e. marine protected areas, MPAs), we identify important gaps that must be considered in current conservation schemes. Effective pelagic MPA design requires monitoring and evaluation across multiple physical, biological, and human dimensions. Because many threatened and exploited marine species move through an ephemeral and ever-changing environment, our results highlight the need to move beyond traditional, 2-dimensional approaches to marine conservation, and into dynamic management approaches that incorporate metrics of biodiversity as well as oceanographic features known to promote multilevel, trophic productivity

Mitigating the Expansion of Harmful Algal Blooms Across the Freshwater-to-Marine Continuum

Anthropogenic nutrient overenrichment, coupled with rising temperatures, and an increasing frequency of extreme hydrologic events (storms and droughts) are accelerating eutrophication and promoting the expansion of harmful algal blooms (HABs) across the freshwater-to-marine continuum. All HABs - with a focus here on cyanobacterial blooms - pose serious consequences for water supplies, fisheries, recreational uses, tourism, and property values. As nutrient loads grow in watersheds, they begin to compound the effects of legacy stores. This has led to a paradigm shift in our understanding of how nutrients control eutrophication and blooms. Phosphorus (P) reductions have been traditionally prescribed exclusively for freshwater systems, while nitrogen (N) reductions were mainly stressed for brackish and coastal waters. However, because most systems are hydrologically interconnected, single nutrient (e.g., P only) reductions upstream may not necessarily reduce HAB impacts downstream. Reducing both N and P inputs is the only viable nutrient management solution for long-term control of HABs along the continuum. This article highlights where paired physical, chemical, or biological controls may improve beneficial uses in the short term, and offers management strategies that should be enacted across watershed scales to combat the global expansion of HABs across geographically broad freshwater-to-marine continua

MeV magnetosheath ions energized at the bow shock

A causal relationship between midlatitude magnetosheath energetic ions and bow shock magnetic geometry was previously established for ion energy up to 200 keV e−1 for the May 4, 1998, storm event. This study demonstrates that magnetosheath ions with energies above 200 keV up to 1 MeV simply extend the ion spectrum to form a power law tail. Results of cross-correlation analysis suggest that these ions also come directly from the quasi-parallel bow shock, not the magnetosphere. This is confirmed by a comparison of energetic ion fluxes simultaneously measured in the magnetosheath and at the quasi-parallel bow shock when both regions are likely connected by the magnetic field lines. We suggest that ions are accelerated at the quasi-parallel bow shock to energies as high as 1 MeV and subsequently transported into the magnetosheath during this event

Multiscaling of galactic cosmic ray flux

Multiscaling analysis of differential flux dissipation rate of galactic cosmic rays (Carbon nuclei) is performed in the energy ranges: 56.3-73.4 Mev/nucleon and 183.1-198.7 MeV/nucleon, using the data collected by ACE/CRIS spacecraft instrument for 2000 year. The analysis reveals strong (turbulence-like) intermittency of the flux dissipation rate for the short-term intervals: 1-30 hours. It is also found that type of the intermittency can be different in different energy ranges

Identification of harmful cyanobacteria in the Sacramento-San Joaquin Delta and Clear Lake, California by DNA barcoding.

Accurate identification of cyanobacteria using traditional morphological taxonomy is challenging due to the magnitude of phenotypic plasticity among natural algal assemblages. In this study, molecular approach was utilized to facilitate the accurate identification of cyanobacteria in the Sacramento-San Joaquin Delta and in Clear Lake in Northern California where recurring blooms have been observed over the past decades. Algal samples were collected from both water bodies in 2011 and the samples containing diverse cyanobacteria as identified by morphological taxonomy were chosen for the molecular analysis. The 16S ribosomal RNA genes (16S rDNA) and the adjacent internal transcribed spacer (ITS) regions were amplified by PCR from the mixed algal samples using cyanobacteria generic primers. The obtained sequences were analyzed by similarity search (BLASTN) and phylogenetic analysis (16S rDNA) to differentiate species sharing significantly similar sequences. A total of 185 plasmid clones were obtained of which 77 were successfully identified to the species level: Aphanizomenon flos-aquae, Dolichospermum lemmermannii (taxonomic synonym: Anabaena lemmermannii), Limnoraphis robusta (taxonomic synonym: Lyngbya hieronymusii f. robusta) and Microcystis aeruginosa. To date, Dolichospermum and Limnoraphis found in Clear Lake have only been identified to the genus lavel by microscopy. During the course of this study, morphological identification and DNA barcoding confirmed A. flos-aquae as the predominant cyanobacterium in the Sacramento-San Joaquin Delta indicating a shift from M. aeruginosa that have dominated the blooms in the past decade. Lastly, the species-specific identification of Limnoraphis robusta in Clear Lake is another significant finding as this cyanobacterium has, thus far, only been reported in Lake Atitlan blooms in Guatemala