190,059 research outputs found
Dynamic subauroral ionospheric electric fields observed by the Falkland Islands radar during the course of a geomagnetic storm
No full textWe present an analysis of ionospheric electric field data observed during a geomagnetic
storm by the recently deployed HF radar located on the Falkland Islands. On 3 August
2010 at ∼1800 UT evidence of the onset of a geomagnetic storm was observed in ground
magnetometer data in the form of a decrease in the Sym‐H index of ∼100 nT. The
main phase of the storm was observed to last ∼24 hours before a gradual recovery lasting
∼3 days. On 4 August, during the peak magnetic disturbance of the storm, a high velocity
(>1000 m s−1) channel of ionospheric plasma flow, which we interpret as a subauroral
ion drift (SAID), located between 53° and 58° magnetic south and lasting ∼6.5 hours, was
observed by the Falkland Islands radar in the pre‐midnight sector. Coincident flow data
from the DMSP satellites and the magnetically near‐conjugate northern hemisphere
Blackstone HF radar reveal that the SAID was embedded within the broader subauroral
polarization streams (SAPS). DMSP particle data indicate that the SAID location closely
followed the equatorward edge of the auroral electron precipitation boundary, while
remaining generally poleward of the equatorward boundary of the ion precipitation. The
latitude of the SAID varied throughout the interval on similar timescales to variations in
the interplanetary magnetic field and auroral activity, while variations in its velocity were
more closely related to ring current dynamics. These results are consistent with SAID
electric fields being generated by localized charge separation in the partial ring current, but
suggest that their location is more strongly governed by solar wind driving and associated
large‐scale magnetospheric dynamics
Impacts on the deep-sea ecosystem by a severe coastal storm
No full textMajor coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem
Northern hemisphere storm tracks in strong AO anomaly winters
No full textNorthern Hemisphere winter 300 hPa storm tracks/baroclinic waves and their energetics during strong Arctic Oscillation (AO) anomaly events are investigated. It is shown that during strong positive AO anomaly winters, the Atlantic storm track intensifies significantly and shifts northward and far downstream while Pacific storm track extends westward. Baroclinic waves over the Atlantic propagate along central North Atlantic during strong negative AO anomaly winters while during strong positive AO anomaly winters, waves over the Atlantic split into two branches. Distributions of the kinetic energy and energy conversions of different spatial scale over the storm track regions assume different characteristics for different AO phases. Copyright (c) 2008 Royal Meteorological Societyhttp://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000263860700008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Geochemistry & GeophysicsMeteorology & Atmospheric SciencesSCI(E)9ARTICLE3153-159
The Ganzfeld debate continued: A response to Milton and Wiseman (2001)
No full textMost researchers in parapsychological circles and beyond are familiar with the ganzfeld debate, which was revived in a series of articles that appeared in Psychological Bulletin This article is a response to J. Milton and R. Wiseman's (2001) reply to L. Storm and S. Ertel (2001), who took issue with J. Milton and R. Wiseman's (1999a) claim that the evidence for psi in the ganzfeld was not replicable. The authors (Storm & Ertel) argue that in their reply, J. Milton and R. Wiseman (2001) misrepresented the issues raised in R. Hyman and C. Honorton's (1986) joint Communique to their advantage. Milton and Wiseman wrongly took the standards of the Communique as implying low quality of all previous studies and downplayed the accumulated evidence that doubts about the credibility of pre-Communique ganzfeld researchers were unwarranted. They wrongfully belittled statistical significance, an important contributor to empirical evidence, and on mere circumstantial grounds, they ignored the necessity of the bidirectionality test, which is acknowledged as a unique psi indicator. The authors reassess the effect sizes for the various ganzfeld databases and conclude that Milton and Wiseman's critique is essentially out of place. For future ganzfeld and psi research in general, the authors recommend a process-oriented strategy
Magnetospheric convection electric field dynamics and stormtime particle energization: Case study of the magnetic storm of 4 May 1998
No full textInternational audienceIt is shown that narrow channels of high electric field are an effective mechanism for injecting plasma into the inner magnetosphere. Analytical expressions for the electric field cannot produce these channels of intense plasma flow, and thus, result in less entry and adiabatic energization of the plasma sheet into near-Earth space. For the ions, omission of these channels leads to an underprediction of the strength of the stormtime ring current and therefore, an underestimation of the geoeffectiveness of the storm event. For the electrons, omission of these channels leads to the inability to create a seed population of 10-100 keV electrons deep in the inner magnetosphere. These electrons can eventually be accelerated into MeV radiation belt particles. To examine this, the 1-7 May 1998 magnetic storm is studied with a plasma transport model by using three different convection electric field models: Volland-Stern, Weimer, and AMIE. It is found that the AMIE model can produce particle fluxes that are several orders of magnitude higher in the L = 2 ? 4 range of the inner magnetosphere, even for a similar total cross-tail potential difference
Climate Change and the Future Impacts of Storm-Surge Disasters in Developing Countries
No full textAs the climate changes during the 21st century, larger cyclonic storm surges and growing populations may collide in disasters of unprecedented size. As conditions worsen, variations in coastal morphology will magnify the effects in some areas, while largely insulating others. In this paper, we explore the implications for 84 developing countries and 577 of their cyclone-vulnerable coastal cities with populations greater than 100,000. Combining the most recent scientific and demographic information, we estimate the future impact of climate change on storm surges that will strike coastal populations, economies and ecosystems. We focus on the distribution of heightened impacts, because we believe that greater knowledge of their probable variation will be useful for local and national planners, as well as international donors. Our results suggest gross inequality in the heightened impact of future disasters, with the most severe effects limited to a small number of countries and a small cluster of large cities.climate change; developing countries; disasters; coastal cities; storm surges; coastal populations; economic activity
The Ganzfeld debate continued: A response to Milton and Wiseman (2001)
No full textMost researchers in parapsychological circles and beyond are familiar with the ganzfeld debate, which was revived in a series of articles that appeared in Psychological Bulletin This article is a response to J. Milton and R. Wiseman's (2001) reply to L. Storm and S. Ertel (2001), who took issue with J. Milton and R. Wiseman's (1999a) claim that the evidence for psi in the ganzfeld was not replicable. The authors (Storm & Ertel) argue that in their reply, J. Milton and R. Wiseman (2001) misrepresented the issues raised in R. Hyman and C. Honorton's (1986) joint Communique to their advantage. Milton and Wiseman wrongly took the standards of the Communique as implying low quality of all previous studies and downplayed the accumulated evidence that doubts about the credibility of pre-Communique ganzfeld researchers were unwarranted. They wrongfully belittled statistical significance, an important contributor to empirical evidence, and on mere circumstantial grounds, they ignored the necessity of the bidirectionality test, which is acknowledged as a unique psi indicator. The authors reassess the effect sizes for the various ganzfeld databases and conclude that Milton and Wiseman's critique is essentially out of place. For future ganzfeld and psi research in general, the authors recommend a process-oriented strategy
Coastal Storm Activity along the Eastern North Island of New Zealand - East Cape to Wellington
No full textCoastal storm activity for the eastern North Island, between East Cape and Wellington, has been quantified from a meteorological perspective through the use of cyclone tracks and extreme winds and from an oceanographic perspective by using hindcast wave information. It has culminated in the production of a high quality, digital coastal storm database for the eastern North Island. Together, this information provides a new understanding of coastal storm behaviour for the eastern North Island. A regional database of historical coastal storms along the eastern North Island between 1930 and 2005 (75 years) is now available in digital format. Coastal storms were identified as bouts of strong winds (greater than or equal to 10.5 m/s) from long-term local wind records from 1962 to 2005, and prior to this period, coastal storms were qualitatively recognised as any event leading to coastal shipping disruptions/delays, large wave conditions along the coast, episodes of coastal erosion and strong onshore wind periods. This digital database consists of five informative components that include storm meteorology, storm oceanography, impacts and damages, storm photo’s and images, and data sources. It has identified a set of five storm types for the eastern North Island consisting of Trough/Ridges, East Coast Lows, Subtropical Lows, Tasman Sea Lows, and Cyclone-Anticyclone pair. The two dominant types are Trough/Ridge and East Coast Low, with the Trough pattern involving weather systems primarily from the southern ocean, whilst East Coast Lows involve large cyclones off the coast that can be distantly generated (from the Tasman Sea or subtropics) or locally generated around NZ from southern ocean troughs. The most intense coastal storms off the eastern North Island are East Coast Lows involving cyclones from the subtropics. These storm events reveal blocking-type anticyclones east of the Chatham Islands play a vital role in coastal storm activity by steering cyclones southward towards NZ and then blocking any eastward movements so that cyclones become slow-moving off the east coast. These factors increase the intensity of pressure gradients directly over eastern NZ. The Gisborne region, for the 1962-1991 period (30 years), had an annual average of three coastal storms and displays peak activity in September. These storms are overwhelming from the south and southeast. A longer dataset of local winds at Wellington, spanning 1962-2005 (44 years), produced an annual average frequency of 9 coastal storms per year. The monthly distribution revealed peak storm activity in June and heightened activity between May and August. Both short-lived, high intensity storms (winds greater than or equal to 14.5 m/s for at least 12 hours) and long-lived, lower intensity storms (winds greater than or equal to 10.5m/s for at least 24 hours) were identified for the Wellington region. Approximately 70% of these coastal storms persisted for up to two days duration and are predominately from the south and southwest. Furthermore, the more exposed nature and steep terrain surrounding Wellington means a greater likelihood of higher intensity coastal storms compared to the Gisborne region. Strong cyclonic systems in the southwest Pacific cluster in the central Tasman Sea and east of the Chatham Islands in all seasons and are most frequent in winter. It is during winter that a clear frequency maximum is spotted over North Cape and appears to be related to the presence of slow-moving cyclones rather than high counts of discrete systems. Strong cyclones tend to form in the western Tasman Sea, in the subtropics near 22-23S, and near North Cape. This local formation off North Cape could be related to the Tasman front and North Cape eddy which create warm sea surface temperature anomalies. The complete life cycle of all strong cyclones shows formation, intensification and maturity in the western-central Tasman Sea, and therefore, a large proportion of these cyclones approaching NZ are weakening systems. However, local generation and intensification near North Cape and the Chatham Islands ensures strong cyclones continue to influence eastern NZ, and further indicates weakened Tasman Sea cyclones can drive coastal storm events through interactions with ridges and high pressure systems. Strong cyclones are most frequent around NZ in August when an average of 4-5 systems per month occurs. Extreme onshore winds off the eastern coast of NZ consist principally of winds from the southwest and south with a single high latitude frequency maximum near the dateline. These winds are generated from southern ocean cyclonic activity and their northward-extending troughs that pass over NZ, and their spread onto eastern NZ means they likely represent intense coastal storm events. Southeast, east and northeast winds rarely reach up to and beyond 20 m.s-1 over the seas to the east of NZ and generally cluster north of 40-45S indicating both subtropical and higher midlatitude source mechanisms. Extreme southeast winds are generated by the eastern flanks of large anticyclones that occupy the western Tasman Sea or large anticyclones south of the Chatham Islands. The principal frequency maximum of east and northeast winds is remote from NZ appearing near 165°W, and represent distant generation areas for large swell events (rather than coastal storm activity). These winds that occur over northern NZ are associated with a Tasman Sea or subtropical cyclone off North Cape in combination with a large anticyclone or ridge over/or east of the South Island. In contrast, the distant core for eastward of NZ are generated off the backs of large anticyclones with a trough or cyclone on its northern flank. The deep-water wave climate off the eastern North Island is dominated by waves from the south. Between 9 and 13 large wave events occur each year between East Cape and Wellington and are most likely in the months of May, June and July. In contrast, large storm waves from the southeast, east and northeast have annual average frequencies of 1-3 events. The Gisborne coast was found to be the most exposed with large deep-water waves (greater than or equal to 3m) coming from the northeast through to the southwest. However, waves from the south and southwest are the largest and most persistent. The meteorology creating these waves are southern ocean troughs whilst the less frequent waves from the easterly quarter involve low pressure systems east or northeast of NZ. The different proxies for studying coastal storms all have shortfalls and arrive at different levels of coastal storm activity. It is suggested here that an optimal mix of these proxies can be used to identify damaging coastal storms along the eastern North Island
moves-rwth/carl-storm: 14.26
No full text<h2>What's Changed</h2>
<ul>
<li>Interval operations by @sjunges in https://github.com/moves-rwth/carl-storm/pull/14</li>
<li>Omit use of deprecated std::is_literal_type in a STATIC_ASSERT by @tquatmann in https://github.com/moves-rwth/carl-storm/pull/16</li>
<li>Require CMake 3.15 and removed bindings by @volkm in https://github.com/moves-rwth/carl-storm/pull/13</li>
<li>Towards c++20 support by @tquatmann in https://github.com/moves-rwth/carl-storm/pull/19</li>
<li>Fixed cmake export by @volkm in https://github.com/moves-rwth/carl-storm/pull/20</li>
</ul>
<h2>New Contributors</h2>
<ul>
<li>@tquatmann made their first contribution in https://github.com/moves-rwth/carl-storm/pull/16</li>
</ul>
<p><strong>Full Changelog</strong>: https://github.com/moves-rwth/carl-storm/compare/14.25...14.26</p>
C-14 and Be-10 in dust deposited during the storm of 16-17 April 2006 in Beijing
No full textThe concentrations of Be-10 and C-14 and values of delta C-13 in samples collected during a major dust storm in Beijing on 16-17 April 2006 were studied. The Be-10 concentrations ranged from 1.69 x 10(8) to 2.07 x 10(8) atom/g, C-14 ages for black carbon (BC) ranged from 3001 to 5181 yr BP and for total inorganic carbon (TIC) from 8464 to 9119 yr BP, and delta C-13 values for BC ranged from -23.15% to -23.80% and for TIC from -5.39% to -5.98%. A comparison of BC content and delta C-13 value between the dust, surface soil in the dust source region, and aerosols in Beijing indicated that BC in the dust deposited in Beijing is significantly incorporated by aerosol BC during the dust transportation. Based on the C-14 ages of BC, the proportion of fossil-fuel-derived BC was 0.35-0.49 of the total. In contrast to BC, the TIC deposited in Beijing can be firmly related to the source area and delta C-13 was not significantly modified during its transportation. According to the C-14 ages of TIC, the proportion of the secondary carbonate in the dust was from 0.63 to 0.70. The results confirm that C-14 of TIC is another useful tracer to indicate the source region of dust besides the content and delta C-13 value of TIC from the arid and semi-arid regions of China.Geochemistry & GeophysicsSCI(E)0ARTICLE2-31790-18005
- …
