A place for PHI?

first_imgDo employers still view Permanent Health Insurance as a useful benefit?Compiled by Simon KentThe way we look at Permanent Health Insurance (PHI) is that it is in theinterest of both the employer and employee to have some form of incomeprotection. It enables workers to have some financial security in the event ofserious illness or disability. We see this as an integral part of our overallapproach to healthcare, so our employees have access to health support advice,an employee careline, free health screening and a private medical insurancescheme. While we do not specifically offer PHI, we self-fund our own prolongedsickness benefit. As far as our employees are concerned, this is the equivalentof PHI and is available to all eligible employees. The main reason why we provide this benefit ourselves, rather than through athird-party PHI scheme, is the belief that if we do it as a self-fund, we cankeep a fairly close tab on who is accessing the fund, where they come from inthe organisation, how we can support them and whether there are any trends inthis provision. If people go sick for any length of time and you have a PHIpolicy through third-party insurance, there is a tendency for you to think ‘outof sight, out of mind’ – particularly when all you pay is an insurance premiumand that premium tends to escalate. If you pay the benefit yourself, there is atendency to maintain contact and therefore have a better success rate atgetting people back to work. While hugely important for the individual, the financial payment is the‘easy’ part. It can be expensive, but it is relatively easy to provide. Themore difficult part is maintaining the relationship when, for a variety ofreasons, people who have been absent for some time feel reluctant to make thefirst move. The longer the period of time with no contact between employer andemployee, the harder it can be to get people back to work. Mandy Devonald-BattHead of HR, SASUKIn the past five years we have hadonly three claims on PHI, so we have a healthy workforce. The only difficultyI’ve experienced has been a reluctance on behalf of the insurers to accept aclaim immediately. I had one experience where an employee wasn’t paid untilfive months after the date payments should have begun, and then the benefitarrived in a lump sum. It put us in a difficult situation, because our contractsays we will pay sick pay until the 26th week of illness, but there’s no actualcommitment for the company to continue paying past that time, because PHIshould have kicked in.If you are considering redundancies and employees receiving PHIare involved, determining who will go can become a moral problem because makingthose people redundant also removes their entitlement to PHI. Derek KempGroup managing director of employment law, Human and Legal ResourcesThere is still a place for PHI.Problems always arise through badly-written contracts and essentially that iseasy to address.Airtours made two errors in its PHI contract (see p13). Itdidn’t make it clear it could terminate someone’s employment. It also tried totell its employees when they would receive their money – but that is the job ofthe insurer. The contract should have said PHI will be paid at the entirediscretion of the insurer. Put the right terms in the contract and explain itto your employees, but leave it to the insurer to run the policy. With thesegolden rules, PHI is a benefit which should be provided more, not less. It isnot very expensive and is something any employer should offer. As an employer, I would like to help someone disabled in anaccident – particularly if they were on company business at the time.Steve HarveyGroup director of people and culture, MicrosoftOur employees’ peace of mind iscritical to us – we don’t want them or their families looking over theirshoulders wondering what would happen to them in the case of any unexpectedhealth emergency. We have maintained our PHI throughout our benefits package, andeven with our upcoming change to flexible benefits, we will still have it as abase benefit. We currently have employees who benefit from permanent healthcover, and it works very well for them. At Microsoft we focus on our employeewell being programme, and we have brought in critical illness cover. I would encourage all companies to reconsider their position,and put the long-term interests of their employees at the top of the agenda.Rod MckenzieHealthcare consultant, IHC The problem some employers have isthat they aren’t doing enough on the occupational health side of things toaddress potential claims before they arise. Insurance companies work to ensureas few claims are made as possible, and that can include practices such as sendingout the insurance company’s own qualified nurse to fill out the claim form.There is increasing importance placed on whether the individualcan capably go back to their job. Schemes which are based on the individual’sown occupation give no scope for the insurer to try and find suitablealternative work for the individual. If you arrange PHI based on anyoccupation, the insurance can support the individual while they adapt to theirnew workplace and the scheme may be better for all concerned. Employers can usually do something positive in terms of howthey deal with health across the workforce. A place for PHI?On 1 May 2003 in Personnel Today Previous Article Next Article Comments are closed. Related posts:No related photos.last_img read more

Hidden dangers

first_imgHidden dangersOn 1 May 2003 in Personnel Today Related posts:No related photos. Laundrystaff in hospitals may be at risk from blood-borne viruses from contaminatedinstruments. However, there are measures you can take to keep safe, by EileenSmith Inoculation through the skin with a contaminated sharp instrument is the principlerisk of transmission of blood-borne viruses to healthcare workers (PHLS 2000).1Numerous studies have shown that such injuries occur in a variety ofsettings and are frequently associated with the inappropriate handling anddisposal of sharps (Wilson 2001).2 A recent survey by Godfrey (2001) indicated that two out of five injuredpeople were not the original users of the sharp.3 Downstream injuries arecommon, and May and Brewer (2001) corroborate this evidence.4 Staff at risk The laundry staff employed in a particular NHS Trust hospital were in dangerof contamination by a blood-borne virus by coming into contact with items suchas: – Dirty theatre instruments – Used hypodermic needles – IV cannulae – Blades – Sharp teeth – Splinters of bone Any of these items could have been accidentally or negligently dropped amongthe linen. These ‘sharps’ may cause a percutaneous injury, which is a verydistressing experience for the employee, often compounded by an inability toidentify the donor/source, to facilitate a risk assessment for blood-borneviruses. Despite the availability of vaccination against Hepatitis B, there is stilla risk to employees. According to a report from the RCN in 2001, evidence fromthe US suggests that the probability of a healthcare worker becoming infectedby a contaminated sharp is: – one in three for Hepatitis B, – one in 30 for Hepatitis C – one in 300 for HIV5 Local measures in place Further investigation at the hospital revealed that a variety of measures toreduce the risk of sharps injury had been put into place by the Trust and theHealth and Safety Group, such as protective clothing for laundry staff (asrecommended in the Health Service Guidelines HSG(95)18),6 repeated educationalforums for nurses, doctors and allied healthcare workers, stringent checks oftheatre instruments and a ‘name and shame’ policy. A specific project group wasformed to look at the laundry problem. The primary focus of evaluation of the injury prevention strategies was toimprove the effectiveness of the interventions as described by Feyer andWilliamson (1998).7 However, it was realised that the success of the measures, when put intoplace, depended upon compliance by staff. An examination of the job/task factorsalso revealed that safe working practices interfered with the speed ofperformance and this was the most reported reason for non-compliance(Hoffman-Terry et al 1992).8 So, despite the attempts of the Trust to develop safe systems of work foremployees, some sharp items still appear in the laundry. Legislation Employers have a responsibility to protect employees from such occupationalhealth risks under the Health and Safety at Work Act (1974, ss. 2 and 3).9However, they have a more specific duty to prevent exposure to biologicalagents under the Control of Substances Hazardous to Health Regulations (COSHH1999)10, (Ballard 2000)11. These regulations, which incorporate the Approved Code of Practice on thecontrol of biological agents, would seem to be the most relevant legislation inthe UK relating to sharp injuries, including blood-borne viruses. In the Control of Substances Hazardous to Health Regulations 1999 (COSHH1999), regulation 6 requires that an employee is not exposed to any substancehazardous to health unless there has been a suitable risk assessment made andsteps taken as a result of the risk assessment to protect the employee, whichmeet the requirements of the regulations. With regard to blood-borne viruses,employers are advised to assess: – Which virus may be present – What effects it may have – Where the virus is likely to be present – Ways in which employees may be exposed The chance of exposure, frequency of contact, the protective measures used inthe work, where information is available, whether or not the blood or bodyfluids come from an infected individual (Ballard 2000). In addition to this, The Management of Health and Safety at Work Regulations(HSE 1999) provide for risk assessment, effective planning, organisation,control, monitoring and review of the preventive and protective measures.Employers must also provide employees with health and safety training.12 Unfortunately, the risk, although somewhat reduced by the above strategies,still remains, and the cost both to the employee (physical and mental) andemployer – including the financial costs of an injury, treatment and possiblelegal processes (RCN 2001)5 – are too great to ignore. Viewed together, these conclusions highlight the need for complementarymeasures to be found. In the report, The influence of employee/job task andorganisational factors on adherence to universal precautions among nurses,which appears in the International Journal of Industrial Ergonomics, it says itis possible to use available engineering technology to reduce direct exposureto harm in certain circumstances.13 Mechanical measures The project group reached the general consensus that mechanical/engineeringmeasures might be the answer to creating a safer working environment at theTrust. However, so far, technology has not been successfully applied to theproblem in this country – even in the US, where legislative costs are high, asolution has not been found either. There are an estimated 10 million healthcare workers in the US experiencingbetween 600,000 and 800,000 needle-stick injuries per year (GAO 2000).14 In anattempt to reduce this number, new legislation will mandate the use of saferdevices (Needlestick Safety and Prevention Act 2000)15, but this solution maynot be a catchall. A local initiative was developed at the hospital to find other ways ofpreventing needle-stick injuries in the laundry. This included a visit to alocal airport, where an offer had been made to test the ability of their x-rayscanning equipment to pick up small sharp items such as hypodermic needles,concealed in the laundry, with a view to obtaining similar equipment for thehospital. Disappointingly, the test was not successful, however, it did providethe impetus to explore further means of detecting sharps in the laundry. The methods used by other establishments to monitor for sharps were alsoinvestigated, but networking with other hospital laundries in the countryproved that the problem was widespread and solutions to date were inadequate.However, contact with a local prison revealed that a hand-held metal detectorserved their purpose. The manufacturer of this machine facilitated the loan ofa superior hand-held machine to trial. Unfortunately, this was not successfuleither as it involved increased handling of the linen. Discussion with a colleague revealed that food manufacturers use metaldetection to screen pre-packed food before it leaves the factory. A localproducer explained that a machine incorporating a metal detector housed in anarch above a conveyor belt on which cartons of food passed along, is used as aquality-control method. This company kindly provided a list of manufacturers ofsimilar machines used by various industries. A telephone trawl of a selection of those manufacturers revealed that themajority believed the task of detecting tiny metal items concealed in laundrywas, to date, insurmountable. The aperture under the detector needs to be relatively small to affordgreater sensitivity – even more so to detect tiny items such as suture needles– so they did not anticipate being able to build a machine of the proportionrequired to screen dirty laundry. However, one company, Cintex, which manufactures needle search metaldetectors for clothing and footwear industries, expressed an interest in thedilemma. The combined objective was to determine a method of inspecting the laundryfor metal contaminants and, in particular, sharp instruments, to eliminate themfrom the laundry chain before they caused harm. Cintex responded to thisproblem by involving its research and development specialists in a project tofind potential solutions. Numerous visits by the company representative resulted in an attempt tomodify one of the existing needle search machines – a metal detector sitedaround a conveyor belt. A problem lay in the size of the aperture required topass the laundry under the detector. However, using new advancements in itselectronics and software, Cintex manufactured a larger aperture detector, whilestill maintaining excellent sensitivity. This machine was installed into the laundry for a trial period and provedsuccessful in monitoring dirty linen. It was subsequently purchased, whichresulted in a reduction in the number of staff required to handle the dirtylaundry. Two workers have been trained to use the machine and have been provided withprotective gloves for placing linen on the conveyor and removing suspect itemsidentified by the machine. Their knowledge of the dangers of blood-borneviruses was updated, their Hepatitis B status checked and the procedurefollowing a needle-stick injury was re-enforced. Research is ongoing to extend the machine’s use to wet laundry, which wouldprovide more comprehensive monitoring. Conclusion Following the installation of the machine, other uses are coming to light,such as screening newly-stitched theatre swabs for needle remnants. There isstill a long way to go to perfect the system in the laundry, but this machineprovides a broader, more multi-faceted intervention strategy that does not relyso heavily on the individual worker’s behaviour and ability to follow safepractices in all situations. Instead, the new equipment complements education,active prompts and reminders. At the very least, it is a step in the rightdirection to fulfil the Trust’s responsibilities in protecting employees fromharm. Eileen Smith RGN, BSc (Hon’s) Health Studies, BSc (Hon’s) CommunityNursing/Occupational Health, C&G FETC 7307, ENB 998, is a specialist practitioner,OH department, Sunderland Royal Hospital References 1. Public Health Laboratory Service (1993), Unlinked anonymous monitoring ofHIV prevalence in England and Wales: 1990-92, CDR Review, 3(1): R1-11 2. Wilson, J (2001), Safe Sharps Management in the Health Care Environment,Cory Bros, London 3. Godfrey, K (2001), Sharp Practice, Nursing Times, 97 (2): 22-24 4. May, D, Brewer, S (2001), Sharps injury: prevention and management,Nursing Standard, 15 (32): 45-52 5. Royal College of Nursing (2001), Be sharp – be safe, avoiding the risksof sharps injury, RCN London 6. Health Service Guidelines (1995), Hospital Laundry Arrangements for Usedand Infected Linen, NHS Executive, Crown 7. Feyer, AM and Williamson, A, (1998), Occupational Injury, Risk Preventionand Intervention, Taylor and Francis, London 8. Hoffman, Terry M, Rhodes, LV and Reed, JF (1992), Impact of humanimmunodeficiency virus on medical and surgical residents, Archives of InternalMedicine, 152, 1788-1796 9. Health and Safety at Work Act (1974) 10. Health and Safety Commission (1999), General COSHH AcoP (Control ofSubstances Hazardous to Health), Carcinogens Acop (Control of biologicalagents), Control of Substances Hazardous to Health Regulations 1999, HSE Books,Suffolk 11. Ballard, J (2000), HIV and viral hepatitis at work. An introduction tothe relevant health and safety law, Occupational Health Review, May/June 27-32 12. Health and Safety Executive (1999), Management of Health and Safety atWork Regulations, London, The Stationery Office 13. DeJoy, DM, Murphy, LR and Gershon, RM (1995), The influence ofemployee/job task and organisational factors on adherence to universalprecautions among nurses, International Journal of Industrial Ergonomics, 16,43-55 14. General Accounting Office (2000), Occupational Safety: selected cost andbenefit implications of needle-stick prevention devices for hospitals,GAO-01-6R, United States General Accounting Office, Washington DC 20548 15. Needle-stick safety and prevention Act section (2000), 2 (7), US Senate Comments are closed. Previous Article Next Articlelast_img read more


first_img Comments are closed. Previous Article Next Article Thisweek’s guruAuroraleft Guru green around the gillsNewsthat the 500 passengers aboard P&O liner the Aurora had been struck down bya powerful norovirus came as no surprise to Guru.Afternews of the virus – which causes nausea, chronic diarrhoea and vomiting –‘leaked’, the Aurora was refused permission to dock in Greece. It then causedSpanish authorities to close its border with Gibraltar when the ship dockedthere. Gurucould have told passengers what to expect. After the HR Director’s Forum washeld aboard the vessel last year, he felt green for several days. He told MrsGuru he believed he was struck down by a powerful illness. She agreed – she’dseen his bar bill.Wordsof wisdom from HR professionRoryMcCaffer, HR officer at the Crown Prosecution Service, sent Guru this list ofwise sayings that he feels could benefit the workplace:–If you’re too open-minded, your brains will fall out–Don’t worry about what people think; they don’t do it very often–Artificial intelligence is no match for natural stupidity–Not one shred of evidence supports the notion that life is serious–It is easier to get forgiveness than permission–For every action, there is an equal and opposite government programme–If you look like your passport picture, you need the holiday–Men are from earth. Women are from earth. Deal with it–There is always one more imbecile than you counted on–Experience is a wonderful thing. It enables you to recognise a mistake when youmake it again–If you must choose between two evils, pick the one you’ve never tried before.Doinga few lines clears the passagesAtschool, Guru was constantly in trouble, and the age-old punishment of ‘lines’was often meted out.Thesedays, lines have been deemed a waste of time, with expensive holidays and theodd bit of counselling becoming all the rage when it comes to discipliningerrant kids.However,after a particularly fraught day, Guru realised that maybe he should have paidmore attention to his punishments as lines clearly play a significant part inbusiness life. Takethe other day. Guru was waiting for an important pack-age to arrive, but ofcourse, the fate of the post was on the line, and the Royal Mail and CWUcouldn’t seem to agree.Instead,Guru headed out to give the keynote speech at Personnel Today’s HR DirectorsClub breakfast, but, lo and behold, there were leaves on the line. Guru wasgoing nowhere. They lined up some chap called Waterstone to read out a fewlines. Guru supposes he would do in an emergency.Whatwas there left for Guru to do except drown his sorrows at the local wateringhole? Sittingat the bar next to a gorgeous lady, Guru felt a desperate need for somethingclever to say. But could he come up with a decent line or two? Of course not. Thepoint of all this linear meandering is this: if line managers want to get thebest out of people and prepare them for all eventualities, they should perhapsset up a blackboard in the office. They could then randomly force staff towrite lines, thus focusing their thoughts and helping them improve the bottomline.Thusback on line, this new focus might even put them in line for a promotion,clearing the passages to power. Maybe Guru needs to take a good look in themirror and take up a new line of business. Don’tmix business with pleasureChinesecouples no longer have to seek permission from their employers before marrying.A new law introduced to celebrate the 54th anniversary of Communist rule meanscouples no longer need the consent of their ‘work unit’.WuChangzhen, a professor at the China University of Political Science and Law,pointed to one of the many injustices that couples had faced. “Some peopledidn’t have a good relationship with their managers, so when they wanted to getpermission for marriage, they were refused.”Asfar as ‘having a good relationship with your manager’ goes, Guru recommends youtread carefully. If you want to get married, relationships with the boss areprobably best avoided. GuruOn 11 Nov 2003 in Personnel Today Related posts:No related photos.last_img read more

Watch: Gil Dezer on guerrilla marketing and working with Donald Trump

first_img Dezer developmentgil dezerThe ClosingVideo Share via Shortlink Share on FacebookShare on TwitterShare on LinkedinShare via Email Share via Shortlink Tags For this month’s The Closing, The Real Deal sat down with Gil Dezer, the head of Dezer Development and one of the most active real estate players in South Florida. The family-run firm, which was started in 1970 by Dezer’s father, Michael, is behind flashy projects such as the Porsche Design Tower and Residences by Armani/Casa.The elder Dezer influenced his son’s approach to real estate, according to the developer, teaching him “[h]ow to negotiate, how to be patient, know when you’re winning, know when you’re losing.”Dezer was also candid about his approach to management and his partnership with Donald Trump, saying that “not for a minute” did he regret having such a close relationship with the former president. He also brushed off the idea of getting into politics himself.“I don’t think I’d be in it directly,” he said. “It’s like being on your condo board. You do all the work and nobody says thank you for it.”Watch the interview above.last_img read more

Retention of phytoplankton by an eddy

first_imgA patch of high phytoplankton biomass, approximately 109 m2 in area, remained apparently stationary off King George Island, South Shetland Islands, over a period of at least 11 days. The patch was centred on an eddy at the apex of a tight meander formed by water passing round the eastern end of King George Island and being turned back immediately by the strong northeastern flow of water within the Bransfield Strait. Chlorophyll a biomass approached 1 g m2 and was concentrated within the top 50–75 m of water. The community consisted mainly of diatoms, which were growing actively. Growth in situ might have been sufficient to generate the observed high biomass from the general concentration of phytoplankton observed locally but only if all production had been retained within the patch. However, elevated biomass downcurrent of the patch suggested that physical retention was only about 50% efficient. It is concluded that the patch was derived from a pulse of high biomass which had been transported into the area and partially retained by the horizontal recirculation of water within the eddy. Dominant diatom species, Odontella weissflogii, Proboscia ‘alata’, Chaetoceros curvisetum and Thalassiosira tumida, were also predominant in a phytoplankton maximum off Brabant Island, upcurrent of the study site. This may have provided the seed population for the patch off King George Island. Vertical migration may have prevented krill accumulation within the eddy and it is concluded that some shallow eddies may partially insulate phytoplankton communities from heavy grazing pressure.last_img read more

Seafloor spreading in the Weddell Sea and southwest Atlantic since the Late Cretaceous

first_imgGeosat radar altimetry defines a pattern of closely spaced curvilinear gravity anomalies in the northern Weddell Sea and adjacent parts of the southwest Atlantic. These anomalies are caused by a fracture zone pattern resulting from seafloor spreading, mainly on the southern flank of a ridge system which now exists only to the east of the South Sandwich Trench. Flowlines derived from these anomalies are combined with isochrons resulting from an interpretation of all available magnetic anomaly profiles in the region, to produce a new tectonic summary chart. This chart reveals major changes in spreading direction during (i) the Cretaceous magnetic superchron, (ii) the latest Cretaceous/Paleocene (∼ 65 Ma) and (iii) the mid-Eocene (∼ 50 Ma). The latter two changes enclose a period of very slow spreading, and define a kink in the flowlines which is discernable throughout most of the Weddell Sea. Preliminary modelling indicates that trends from the western Weddell Sea to near the South Atlantic triple junction can be explained by the separation of just two plates. There is some disagreement between the observed flowlines and those predicted by rotations published for the South Atlantic and Southwest Indian Ridge, but abrupt changes in spreading direction and a slowing of rates are observed on all three branches of the South America-Africa-Antarctica plate system between the times of anomalies C31 and C21. This suggests that the lack of closure results from errors in the calculated rotations, and that the seafloor of the Weddell Sea and southwest Atlantic was created as a direct consequence of South America-Antarctica plate motion. The data do not support the existence of a Late Cretaceous Malvinas Plate within the Weddell Sea, although microplates in the northernmost Weddell Sea do appear to have formed briefly as a result of interactions between the former spreading ridge and a subduction zone located at the South Scotia Ridge.last_img read more

Trench-proximal volcanism following ridge crest-trench collision along the Antarctic Peninsula

first_imgOn the basis of multichannel seismic reflection, magnetics and bathymetry data, a Pleistocene-Holocene (<0.1Ma) volcanic seamount has been identified at a location very close to the shelf edge off the west coast of the Antarctic Peninsula. The seamount overlies the subducted trace of a transform fracture zone which divides segments of the margin along which collision took place 3.1 and 6.0 Ma ago. New trace element and isotopic data from dredged samples demonstrate that the seamount appears to be predominantly formed of relatively primitive undersaturated alkali basalt. The basalts have geochemical signatures that are indistinguishable from ocean island basalts and some continental alkali basalts, (e.g. Th/Ta 1.0–1.5, Rb/Nb<0.5, 87Sr/86Sr 0.70265–0.7028, 143Nd/144Nd approximately 0.5129) and are totally lacking in any evidence for interaction with subduction-enriched mantle. Geochemical similarities with other, more trench distal, postsubduction alkalic basalts along the Antarctic Peninsula are striking, strongly implying that all the postsubduction basalts were derived from a chemically similar asthenospheric source region. The basalts were most likely to have been generated as a result of the formation of a slab window beneath the Antarctic Peninsula following ridge crest-trench collision. Subduction component-free subslab asthenosphere upwelled into the incipient void left by the continued sinking of the leading plate following collision, and decompressional melting resulted. This type of trench-proximal volcanism following ridge crest-trench collision differs from that in other locations where calc-alkaline volcanism persisted or ophiolite obduction occurred.last_img read more

The influence of acclimation and substratum on the metabolism of the Antarctic amphipods Waldeckia obesa (Chevreux 1905) and Bovallia gigantea (Pfeffer 1888)

first_imgRespiration rates in the Antarctic amphipods Waldeckia obesa (Chevreux 1905) and Bovallia gigantea (Pfeffer 1888) were measured in relation to the presence or absence of a substratum to attach to, and the amount of time spent in a respirometer. During the first 4 h after placing animals in respirometers oxygen consumption in W. obesa was reduced by factors between 1.2 and 3.6 times by the presence of a nylon mesh net substratum. Oxygen consumption over the first 12 h after being placed in respirometers was reduced by factors of between 1.1 and 3.9 times for B. gigantea by the presence of pieces of corrugated plastic pipe. The effects on oxygen consumption of acclimating animals to respirometers were only assessed for W. obesa. Rates during the first 12 h after placing animals in chambers were 3.6 times higher than rates between 12 and 30 h after the start of trials. Standard metabolic rates were measured in W. obesa in the presence of a mesh substratum and following a 12 h acclimation period after 60 days of starvation. Under these conditions oxygen consumption was 2.5 μl O2 h−1 for a specimen of 0.113 g dry mass. This was 3–5 times lower than routine metabolic rates previously reported for W. obesa and 2.4–18 times lower than routine rates for other Antarctic gammaridean amphipods.last_img read more

Tidal modulation of the gravity-wave momentum flux in the Antarctic mesosphere

first_imgAirglow imager and dynasonde/IDI radar wind measurements at Halley Station, Antarctica (76degreesS, 27degreesW) have been used to estimate the diurnal variation of the vertical fluxes of horizontal momentum carried by high-frequency atmospheric gravity waves. The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from the sodium airglow imager data collected during four consecutive nights of near total darkness during July of 2000. These were combined with wind-velocity variances from coincident radar measurements to estimate the upper limit of the vertical flux of horizontal momentum during three-hour intervals throughout the period. The resulting momentum flux showed a marked semi-diurnal oscillation in the zonal and meridional components. Calculations of the momentum flux through the Na airglow show variations in period and phase consistent with the observations, implying that tidal propagation and modulated gravity-wave forcing may both affect observed wind variations.last_img read more

Spatial structure of ionospheric convection velocities in regions of open and closed magnetic field topology

first_imgWe present a spatial structure function analysis of ionospheric velocity, measured by the Halley Super Dual Auroral Radar Network (SuperDARN) radar over five years. We show evidence for scale-free velocity fluctuations for separations from 45 km to ∼1000 km. For larger separations a deviation from scale-free structure is seen that we interpret as the influence of the global convection pattern. We find evidence for scale-free structure in regions of both open and closed field line topology, though with different power-law exponents. The measured power-law exponents poleward and equatorward of the open-closed field line boundary are 0.31 and 0.39 respectively. We propose that the scale-free spatial structure of ionospheric velocity fluctuations on open magnetic field lines is a reflection of the spatial structure of the solar wind and the scale-free spatial structure of ionospheric velocity fluctuations on closed magnetic field lines is dictated by the internal dynamics of the magnetosphere-ionosphere system.last_img read more

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