global air routes
the economy minister also said the new air routes task force would to help him devise new policies and interventions to improve the north' s air connectivity .
the scientists simulated climate - optimized flight routes for 40, 000 lufthansa flights, which in models succeeded in reducing the overall climate warming effects .
even net - cooling air traffic
was realized on some european routes, stated the report .
suh hh, bahadori t, vallarino j, spengler jd. criteria air pollutants and toxic air pollutants .
increasing global air traffic is commonly regarded as a climate catastrophe, with the aviation industry alone comprising 5 percent of greenhouse gases produced annually .
let' s be honest, we' ve struggled to secure and maintain air routes to key cities and markets. i' m not satisfied with sitting back and saying that because we are small we can' t sustain air routes to places like the us, canada and the middle east as well as hubs around europe .
the following points summarize the role of global circulations in producing long - range transport .
i want us to aggressively pursue new routes that will help us attract tourists and boost our international trade links .
schuessler n, axhausen kw. processing raw data from global positioning systems without additional information .
the new trade plan will try to expand the north' s international presence by the end of next year, while the creation of an air routes task force will help to devise new policies and interventions to improve northern ireland' s air connectivity .
witness the snowbirds’ fitness with this short film from the canada vignettes series. officially known as the royal canadian air force’s 431 air demonstration squadron, the snowbirds are canada’s air show flight demonstration team .
maddison r, mhurchu cn. global positioning system: a new opportunity in physical activity measurement .
global services members have the best award availability, and generally get the best united customer service .
global services members get access to a dedicated phone line with extremely helpful agents. image courtesy of
on the one hand, there is the possibility to close particularly climate - damaging air routes for air transport ,
explained urban weißhaar, a flight route expert at lufthansa systems .
the other possibility is the inclusion of cloud formation in emissions trading .
stormont economy minister simon hamilton is to develop a new international trade plan and air routes task force for northern ireland in a bid to
seize the opportunities presented by the uk exiting the eu
.
“to assist me, i' m establishing a new air routes task force. its job will be to help me to develop a range of policies and interventions that we can utilise to open up new connections .
under the direction of dlr and in cooperation with the german meteorological service (dwd) and the german air traffic control (deutsche flugsicherung), meilinger has analyzed lufthansa flights to assess the possibility of designing air traffic routes that limit climate damage. ideally, they should even contribute to climate protection .
this all depends on the route the plane flies .
with our current routes, we have an overall warming effect ,
meilinger told dw .
stopher p, fitzgerald c, zhang j. search for a global positioning system device to measure person travel .
a particular problem for air traffic is emissions is the high altitude. in addition to co2, production of nitrogen oxide through jet engine exhaust produces ozone, a major cause of global warming .
navidi w, lurmann f. measurement error in air - pollution exposure assessment .
air travel is bad for the climate - but it doesn' t have to be. climate - friendly flight routes and renewable jet fuel could make flying in planes way more environmentally friendly - this would just need to be implemented .
in this monday, june 12, 2017 photo, passengers arrive at the hamad international airport in doha, qatar. an ap videojournalist recounts her struggle to fly back home to dubia after a diplomatic dispute with arab gulf countries saw qatar, a hub of global air travel, cut off from local flight routes. (ap photo / malak harb )
duncan mj, mummery wk, dascombe bj. utility of global positioning system to measure active transport in urban areas .
rodriguez da, brown al, troped pj. portable global positioning units to complement accelerometry - based physical activity monitors .
volker grewe of dlr is in favor of reducing the climate impacts of air travel .
bringing more people to these shores requires better air connections ,
he said .
michael y, mcgregor em, allen j, fickas s. observing outdoor activity using global positioning system - enabled cell phones .
united has 24 global first lounges around the globe, and they’re usually restricted to those with an international first - class ticket. these lounges are sometimes in a different stratosphere than the average united club (though they’re still hardly amazing). typically you need to be booked in united global first to enter, but global services members can enter with an international business - class ticket .
in this monday, june 12, 2017 photo, qatari and other nationals queue at the check in counters of the hamad international airport in doha, qatar. an ap videojournalist recounts her struggle to fly back home to dubia after a diplomatic dispute with arab gulf countries saw qatar, a hub of global air travel, cut off from local flight routes. (ap photo / malak harb )
with global services, your upgrades clear into the higher - priority pn fare class, giving you better odds of riding up front .
conversely, africa sees much lower volumes of air travel. in may, raphael kuuchi from the international air transport association (iata) highlighted the work needed to boost aviation across the continent .
the simplified view of the global circulation described above becomes more complex when the effects of continents and oceans are included. global sea - level pressure patterns and surface winds for january and july are shown in figure b. 4. focusing on the northern hemisphere, the janu -
[ 7 ] g. bisignani, “state of the air transport industry”, address to the annual general meeting, international air transport association, vancouver, june 2006, www. iata. org .
in asia, significant air travel is seen in the far east – particularly in china and japan .
rainham d, krewski d, mcdowell i, sawada m, liekens b. development of a wearable global positioning system for place and health research .
elgethun k, fenske ra, yost mg, palcisko gj. time - location analysis for exposure assessment studies of children using a novel global positioning system instrument .
phillips ml, hall ta, esmen na, lynch r, johnson dl. use of global positioning system technology to track subject’s location during environmental exposure sampling .
although not yet ready to be used commercially, such a system offers the potential to track and coordinate aircraft movements in areas not covered by radar. this would allow distances between planes to be lowered, boosting global air traffic capacity and at the same time improving safety .
the dup minister said the north
must become more forward - thinking and outward - looking
as it attempts to become a major player in the global economy .
[ 2 ] air transport association of america (ata), 2007 economic report, www. airlines. org .
the map highlights the sheer volume of global air traffic. both the us and europe become a sea of yellow during daylight hours. you can also see the direction of travel between europe and north america – generally towards europe during the night, and then the reverse during the day .
note that this doesn’t mean those in global services can create an award ticket on any flight at any time, as united often chooses to leave t and r zeroed out. this tends to happen on high - demand routes where giving up free seats would not make business sense. still, it’s a tremendous benefit and more times than not a t fare is available — and r at times as well .
from 2025, other climate effects of air traffic such as cloud formation would also be included in the emissions trading price .
once an air pollutant is released into the atmosphere, chemical, microphysical, and meteorological factors determine how it is distributed. the location of air pollution sources with respect to local, regional, and global air circulation patterns influences how efficiently pollutants are transported and dispersed. the winds transport air both horizontally and vertically. vertical transport is important when considering long - range pollutant transport because pollutants distributed to higher altitudes usually encounter stronger winds that provide rapid transport to distant locations. atmospheric stability, controlled by how temperature varies with height, determines whether vertical transport will be slow or rapid. after emission, pollutants may undergo chemical transformation, be subjected to depletion processes such as particle scavenging and dry or wet deposition, or mix into the atmosphere to become a component of the background concentration. this appendix provides a general description of the atmosphere and a synopsis of air circulation and weather patterns that influence the distribution of air pollutants .
[ 1 ] international air transport association (iata), fact sheet: world industry statistics, www. iata. org .
the busyness of modern airspace poses significant challenges for air traffic controllers. but help could be on the horizon – from space .
as stated earlier, united has a system of fare codes, and the fare code for upgrades for most customers is r. however, for those in global services, upgrades clear into the pn fare code. this means that global services have much better chances of upgrading than everyone else, though pn is not always available — particularly for flights with high demand .
air travel has substantially increased since the creation of the eu' s single aviation market 25 years ago. the number of daily flights has increased from less than 10, 000 in 1992 to around 23, 000 in 2016. in addition passengers now have access to more destinations. today there are around 7, 400 routes compared to less than 2, 700 in 1992 .
meilinger' s research team developed software for climate - optimized flight routes which, once combined with weather forecast data, meant planes could avoid regions with warming clouds. moreover, regions for cooling cloud formation on the flight route could also be targeted .
recent advances in air pollution monitoring and modeling capabilities have made it possible to show that air pollution can be transported long distances and that adverse impacts of emitted pollutants cannot be confined to one country or even one continent. pollutants from traffic, cooking stoves, and factories emitted half a world away can make the air we inhale today more hazardous for our health. the relative importance of this
imported
pollution is likely to increase, as emissions in developing countries grow, and air quality standards in industrial countries are tightened .
it may not be as mysterious as the amex centurion card, but the invite - only united elite status known as global services is still shrouded in a fair amount of secrecy. what is clear is that it takes some serious spending to qualify; according to many sources, that means at least $ 50, 000 in a calendar year to be considered for global services .
an on - air mistake during one of his broadcast was, “western farmers are expecting their biggest crap in years. ” funny .
replacing jet fuel made from fossil fuels with more renewable sources would also be a fundamental step on the road to sustainable air travel .
winer am, paulson se. sacramento, ca: california air resources board; 2010. investigation and characterization of air pollution concentrations and gradients in port - adjacent communities and west and downtown los angeles using a mobile platform. draft final report contract no. 04–348 .
the biggest benefit to global services is the excellent service that is given to those with the status. they receive what can only be described as the royal treatment. below, some examples :
the greatest potential lies in preventing the creation of clouds .
condensation trails and fog clouds are formed out of ice crystals in certain weather conditions ,
meilinger explained. climate - optimized flight routes would work by avoiding such weather, hence limiting cloud generation .
cloud formation with climate impact could be priced, like co2 emissions. airlines with climate - friendly routes could gain an advantage by paying less money for pollution certificates - making any additional costs by a small detour very worthwhile. for climate protection, at least .
global circulations during the northern hemisphere summer (figure b. 4b) are quite different from those during winter. low pressure, not high pressure, now dominates the continents, producing the seasonal wind
elgethun k, yost mg, fitzpatrick cte, nyerges tl, fenske ra. comparison of global positioning system (gps) tracking and parent - report diaries to characterize children’s time - location patterns .
united’s global services is one of the more mysterious status levels in the world of loyalty programs; it’s dedicated to high spenders, and unless you’re a member you can’t view the full list of benefits. however, thanks to some sources lucky enough to hold this status, tpg contributor vikram birring is here with a rundown of the best global services perks. read (and dream) on !
with climate - optimized flight routes, however, the negative effects of flying can also be reduced and can
even go in the opposite direction ,
according to stefanie meilinger of the international center for sustainable development at bonn - rhein - sieg university in germany .
people’s time - location patterns are important in air pollution exposure assessment because pollution levels may vary considerably by location. a growing number of studies are using global positioning systems (gps) to track people’s time - location patterns. many portable gps units that archive location are commercially available at a cost that makes their use feasible for epidemiological studies .
lucky enough to check in an airport with a global first check - in area? you can visit a dedicated check - in lounge, and you’ll be taken to the front of the security line .
global sources of local pollution examines the impact of the long - range transport of four key air pollutants (ozone, particulate matter, mercury, and persistent organic pollutants) on air quality and pollutant deposition in the united states. it also explores the environmental impacts of u. s. emissions on other parts of the world. the book recommends that the united states work with the international community to develop an integrated system for determining pollution sources and impacts and to design effective response strategies .
climate - friendly air travel - say what? | environment | all topics from climate change to conservation | dw | 05. 07. 2017
global services (and generally 1k) members have their food orders taken first in premium cabins. this sometimes creates confusion, and at worst jealousy and tension from others in the cabin. however, global services members are the highest - priority united customers, and there are usually only two or three entrée types to order — with limited quantities of each — so giving first dibs on food orders is a small way of saying thanks from united. also, as of january, global services (and 1k) members also get free food from united’s choice menu if sitting in economy, along with a free drink .
here, things get a bit heated. we’re introduced to the royal canadian air force ‘s 32 overseas squadrons and witness canadian airplanes destroy a german munitions train .
[ 6 ] j. heimlich, “outlook: reaching for the skies? ”, air transport association of america, www. airlines. org. january 2007
it is noteworthy that air masses also can be transported long distances without being lifted (i. e. , the air and its pollutants remain in the lower troposphere). this generally occurs in the absence of transient synoptic systems that would contain mechanisms for ascent (e. g. , the wcb). arctic
to reach the goals of the paris climate agreement to limit global warming to well below 2 degrees celsius, every person on earth would be limited to producing an average of only 2 tons of co2 annually over the next 30 years .
integrating air traffic into emissions trading could be another important way to achieve more climate - friendly air travel. one proposal suggest that by 2020, all airlines should pay $ 10 (around 9 euros) per ton of co2 emitted, but that the price of these pollution permits should increase to $ 80 dollars per ton by 2030 .
with a new global agreement to guide governments toward climate protection, personal action is more important than ever. from riding your bike to shopping organic, here are some simple ways you can help save the climate. (15. 12. 2015 )
) were selected based on their potential for tracking people’s time - location patterns in air pollution epidemiological studies. we have used the dg - 100 from globalsat in a previous study
away from the equator. thus, the meridional flow is equatorward at low levels and poleward above. the middle latitudes (30° - 60°) are dominated by transient cyclones (low - pressure areas) and anticyclones (high - pressure areas), especially during the winter. in the long term mean the region is characterized by sinking air near 30° and rising air at its northern boundary (~ 60°), corresponding to the location of the polar front. this region sometimes is denoted the ferrell cell (not depicted in figure b. 3). the polar troposphere (60° - 90°) is dominated by rising air near 60° and sinking air over the poles, sometimes denoted the polar cell .
global services members are invited to board before all other united customers, with the possible exception of those in the military. this may not be a real advantage, however, as there tends to be plenty of space in the overhead bins of first / business class, where global services members tend to travel. plus, united boarding procedure tends to take about 45 minutes, so it could end up being unnecessary extra time for some — while for others it could be a head start on drinking on board .
wind speeds in the troposphere generally increase with altitude. thus, the vertical motion experienced by air parcels is vitally important since pollutants that are transported from near the surface to higher altitudes usually will be horizontally transported the most rapidly. areas of rising air tend to be smaller and shorter lived than areas of subsidence, which generally cover larger areas and persist longer .
this book will be useful to international, federal, state, and local policy makers responsible for understanding and managing air pollution and its impacts on human health and well - being .
the european space agency’s proba - v is primarily designed to monitor vegetation growth. however, the mini - satellite (it’s smaller than a cubic metre) can also monitor air traffic movements .
wallace l, nelson w, ziegenfus r, et al. the los angeles team study: personal exposures, indoor - outdoor air concentrations, and breath concentrations of 25 volatile organic compounds .
one of the newest benefits is that if a global services member has a purchased business - class ticket, and a companion is in economy class, the companion will be bumped into business class (pn code) — so long as the member has the proper upgrade in his / her account and there’s availability within 24 - 72 hours of the flight. this is a great perk, as many global services passengers’ premium tickets are paid for by employers in the first place — and who wants to leave their companion in economy while they travel in luxury ?
this is the first of 2 nfb films about planes released in 1944. as opposed to its train - busting counterpart below, this deliciously retro 15 - minute doc focuses on the civil aviation side of things, giving an account of the development of air transport during wwii and, according to the synopsis, “highlighting the contribution of air transport to world unity. ” (ah planes. )
as its name implies the cold conveyor belt is located completely within the cold sector of the cyclone (figure b. 6). the low - level air flows toward the west along the north (cold side) of the surface warm frontal position. during part of this route, the wcb is overhead. as cold air approaches the center of the cyclone the air begins to ascend into the middle troposphere while making a clockwise loop, eventually reversing direction and combining with the wcb in the upper troposphere. the role of the cold conveyor belt in transporting pollutants aloft has received relatively little attention .
some 100, 000 flights take off and land every day across the world. if you’re struggling to visualize this incredible volume of daily air traffic, this animated map might help put it into perspective .
the jet streams are important distributors of air pollutants for two reasons. they create major areas of air exchange between the troposphere and stratosphere. and the strong winds of the jet stream can rapidly transport pollutants. for example, if one assumes an average wind speed of 35 m s – 1 (~ 70 kt) at 40° latitude, an eastward - moving air parcel will circumnavigate the globe in only 10 days. the stratosphere, which extends to ~ 50 km, has regions of strong winds, but virtually no turbulent mixing except for occasional overshooting thunderstorms, certain types of lightning, and occasional thin clouds .
tager i, hammond sk, balmes j, et al. sacramento, ca: california air resources board; 2006. fresno asthmatic children’s environment study (faces). final report contract no. 99–322 .
shows the percentage of gps data falling within 10 - m and 20 - m buffers of the corresponding doqq routes under mobile conditions. we did not show 5 - m buffer results because usually a road was more than 10 m wide and the reported accuracy of the gps devices ranged from 2–5 m according to the product specifications. all the devices performed well while in a passenger vehicle on the i - 5 and i - 405 freeways, with > 75% (the 1st run) and > 88% (the 2nd run) of points within 10 - m of the corresponding doqq route except wbt - 201 in the 1st run. gps performance during walking did not differ much between the uci route and the la route in the 1st run but higher accuracy was observed on the uci route in the 2nd run. despite dense high buildings surrounding the la bus route, the performance of the gps devices was only slightly better on the uci bus route than on the la bus route. in downtown la, somewhat better gps performance was observed for traveling by bus and car than by walking, possibly because the driving or bus routes were further away from adjacent high buildings than sidewalk walking routes .
sometimes, the p code (a business - class fare) is available, but pn is not. within 24 hours, a nice global services agent may bump you into business class even though the pn upgrade code is not available. this is not guaranteed, but it’s a wonderful benefit when it happens .
though air travel is more popular than ever, the vast majority of people in the world have never been on a plane. as that dynamic slowly changes, the environment stands to suffer. is flying less the only solution ?
the international airline industry provides service to virtually every corner of the globe, and has been an integral part of the creation of a global economy. the airline industry itself is a major economic force, both in terms of its own operations and its impacts on related industries such as aircraft manufacturing and tourism, to name but two. few other industries generate the amount and intensity of attention given to airlines, not only among its participants but from government policy makers, the media, and almost anyone who has an anecdote about a particular air travel experience .
global services members, on the other hand, have their own phone line, and hold times tend to be nonexistent. also, the agents are based in the united states and are extremely helpful. they’re known to do anything in their power to help the passenger. if only this was the case for all united customers !
according to data provided by germany' s federal environment agency (uba), germany subsidizes air flights to the tune of 12 billion euros per year - mainly by exempting ticket prices from sales tax and jet fuel from energy tax .
the list goes on, but the reason why global services members are treated so well is because they are united’s highest - revenue customers. if you (and / or your employer) spend enough on airfare to earn this exclusive status, you’ll enjoy the best customer service, upgrade priority and other perks the airline has to offer .
as the crow flies provides a rare insider’s glimpse into the royal canadian air cadets’ intensive seven - week flight training camp. filmmaker tess girard sat down with one of the female subjects to discuss life before, during and after the film .
this seems to be the most fascinating of all the benefits. if a global services member has an extremely tight connection, an agent will be waiting at the front of the plane to accompany the passenger and baggage into a waiting mercedes - benz, which will drive them directly to the waiting plane. this is the definition of vip services .
i love airplanes. when i was a young and innocent 20 - something, i took a job as a flight attendant with air creebec, a native - owned airline that services cree communities in northern quebec and ontario. it was grand .
[ 3 ] air transport association of america (ata), statement on the state of the airline industry, statement for the record of the sub - committee on aviation, transportation and infrastructure committee, us house of representatives, june 2004 .
suddenly, the air route between the two cities that typically saw dozens of daily flights had none. and as i finished up my reporting on the crisis, i suddenly had a new challenge in trying to figure out how to get home .
figure b. 2 cross - section of mean potential temperature (k) from 30° n to the north pole. note that the isentropes slope upward toward the pole. air parcels move along isentropic surfaces when no heat energy is added or subtracted .
it often is important to determine the source of air pollution at a specific location or where pollution from a given source will be located in the future. the basic concept is simple if one has an accurate four - dimensional (x, y, z, t) representation of temperature and wind. one simply uses the data to advect air parcels backward or forward over increments of time. accurately applying this concept is very difficult because of the myriad types and scales of processes that affect transport .
european air connectivity in international air transport is equally dependent on foreign and eu airlines. when flying to or from the eu, all air carriers are granted the same rights. this may not always be the case for eu airlines when operating outside of the eu. in the absence of international rules, eu airlines may be subject to practices affecting competition. in the long run this could also affect the eu' s connectivity, impacting the union' s competitiveness and limiting the choices of travellers. the commission is therefore proposing a new tool to ensure that eu airlines can compete on the basis of equal opportunities and connectivity can be safeguarded. it will allow the eu to take appropriate action, should certain practices put the eu’s connectivity at risk .
over the course of two weeks, the international civil aviation organization (icao) will be struggling with a big question: how can aviation' s co2 emissions be reduced - even as air travel continues to grow worldwide? (26. 09. 2016 )
an important characteristic of free tropospheric air movement is that air parcels experiencing no exchange of heat energy conserve their potential temperature and thus move along surfaces of constant potential temperature (isentropic surfaces). exceptions are regions of cloud cover where radiative processes and water vapor phase changes can be major sources or sinks of heat. in addition, air parcels in the surface boundary layer undergo temperature changes due to exchanges of radiation with earth’s surface. isentropic surfaces slope upward toward the north, with isentropic values increasing vertically (figure b. 2). as a result poleward moving air conserving its potential temperature tends to ascend, while equatorward - moving air tends to sink. this concept has applications for pollution transport into the arctic (stohl et al. , 2006; law and stohl, 2007). specifically, pollution - laden parcels beginning at low altitudes and heading north that conserve their potential temperature will ascend to the middle troposphere. conversely, for low - level parcels to remain near the surface during northward excursions, they either must be very cold initially or undergo considerable loss of heat due to passing over ice - covered surfaces, especially during the long polar winter seasons. northern eurasia is sufficiently cold that its pollutants can be transported quasi - horizontally to the arctic, making it a major source of arctic pollution during winter .
another priority is to enhance the efficiency of european skies by reducing its fragmentation, which is responsible for eur 3 billion of extra costs a year and 50 million tonnes of co 2, and by minimising air traffic disruption. today the commission is therefore inviting member states and aviation stakeholders to consider a number of good practices to ensure air service continuity in the event of industrial action. these practices do not question the fundamental right to strike, but rather aim to improve service continuity and minimise disruption to the european network for airlines and passengers. between 2005 and 2016, more than 243, 000 flights were cancelled due to industrial action in air traffic management, affecting around 27 million passengers. the good practices put forward by the commission draw on a number of existing practices across the eu member states .
retired air vice - marshal thomas a. lawrence, leader of the 1927 - 28 aerial survey expedition to ungava bay and the hudson strait reminisces on the early days of canadian aviation (in general) and the challenges of flying under arctic conditions (in particular) .
the arctic lower troposphere is isolated from the rest of the atmosphere by its very cold air, i. e. , the arctic front. however, the front is not zonally symmetric, and can extend to 40°n over eurasia during january. thus, northern eurasia is the major source of arctic pollution during winter. air from further south can be transported to the arctic, but only in the middle and upper troposphere. during summer, the transport is from the north atlantic ocean, across the high arctic, and toward the north pacific .
the kinematic method utilizes the three dimensional wind components at an initial location to advect air parcels over an interval of time. once at the new location and time the wind components at that location and time are used to advect the parcel. the process continues for the desired time period. as with isentropic trajectories the wind data are from numerical meteorological models whose grid spacing typically varies from ~ 50 to 150 km for global data, down to a few km for regional models. the models typically contain approximately 50 levels in the vertical, often with closer spacing near the surface and near tropopause level. an example of 10 - day backward trajectories is shown in figure b. 9 .
since the deregulation of us airlines in 1978, the pressure on governments to reduce their involvement in the economics of airline competition has spread to most of the rest of the world. the us experience with airline deregulation is perceived to be a success by other countries, as the overall benefits to the vast majority of air travelers have been clearly demonstrated. while us domestic air travel grew at rates significantly greater than prior to deregulation, average real fares declined since deregulation and today remain at less than half of 1978 levels [ 2 ]. several successful new entrant and low - fare airlines had a great impact both on airline pricing practices and on the public’s expectations of low - priced air travel. and, despite worries at the time of deregulation that competitive cost pressures might lead to reduced maintenance standards, there is no statistical evidence that airline safety deteriorated .
the recent growth of low - fare air travel options combined with a reduced willingness on the part of business travelers to pay the higher air fares charged by network carriers played a major role in contributing to the poor financial performance of traditional network airlines, both in the us and in many other countries. in the us, low - fare airlines (also known as low cost carriers or “lccs”) exhibited slow but steady growth since deregulation, but low - fare carriers accounted for less than 7% of us domestic air passengers in 1991. as shown in figure 3, lccs grew more rapidly in the us since the mid - 1990s, to the point that they carried 25% of all us domestic traffic as a group in 2005 [ 4 ]. the largest low - fare airlines in the us industry include southwest, jetblue, airtran, and frontier .
as the pbl collapses with the onset of evening, pollutants that were transported aloft by turbulence remain, forming a residual layer (stull, 1988) that is decoupled from the surface and thereby experiences stronger wind speeds than air within the pbl (angevine et al. 1996). most turbulence in the free troposphere (above the pbl) is produced by an optimum combination of temperature lapse rate and the degree to which the prevailing winds vary with height (wind shear). although the forcing mechanisms differ, the effect is the same—turbulence in the free atmosphere thoroughly mixes the air .
global flow patterns in the middle and upper troposphere (figure b. 5) are simpler than those near the surface. prominent features are easterly flow in the deep tropics, clockwise flow around the semipermanent high - pressure regions in the subtropics, and circumpolar cyclonic flow. the prevailing westerlies, which contain north to south undulations cover a major portion of the northern hemisphere. the westerlies are stronger during winter than summer .
stability that suppresses vertical motion. layers containing temperature inversions (a negative lapse rate) are very stable, greatly inhibiting vertical transport and promoting the accumulation of pollutants. inversions in the troposphere can occur when the surface is colder than the overlying air and in subsiding air, which occurs in regions of high pressure. the stratosphere is a permanently stable region, with a near zero lapse rate between 11 and 20 km and increasingly negative (stable) rates above. as a result of this stability pollutants injected into the stratosphere tend to remain there for much longer periods than in the troposphere .
weisel cp, zhang j, turpin bj, et al. boston, ma: health effects institute; 2005. relationships of indoor, outdoor, and personal air (riopa). part i. collection methods and descriptive analyses. research report no. 1041 - 5505; pp. 1–107 .
this one’s about another canadair plane, the challenger. a totally new type of aircraft, this super - executive jet was faster, cheaper to fly, and more comfortable than any other business jet out there. would it make it off the drawing board and into the air? watch and see .
i learned to appreciate the thrill and immediacy of small aircrafts (king air 100s, dhc - 3 otters) but more importantly, to trust maintenance and flight crews to keep us safe and sound despite the mayhem that comes with flying propeller airplanes (we flew mostly dhc - 8 - 100s) into northern canada’s winter wonderland .
however, for those in global services, an award ticket can be created if there are seats available in the t and / or r buckets (though some reports state that r isn’t always guaranteed to work). to see what seats are available in what buckets, log in to your united account and turn on expert mode. then, when you search for tickets based on price, you can see all the fare buckets and the number of seats in each bucket .
turbulence is the prime example of microscale circulations. turbulence is important in pollution transport because it can thoroughly mix the air and its pollutants. a well - mixed layer is characterized by vertically uniform concentrations of pollutants, water vapor, and potential temperature. the depth of the mixed layer is denoted the planetary boundary layer (pbl) .
the dry air intrusion (di) of a middle - latitude cyclone originates in the upper troposphere and lower stratosphere (figure b. 6). it is located on the poleward side of the cyclone and descends into the middle to lower troposphere. the di is characterized by subsidence and often by regions of much lower tropopause height (tropopause folds) that are related to the jet stream aloft. thus, the di can transport upper tropospheric or stratospheric air into the middle or lower troposphere. some authors have described a cold, dry post - cold - frontal airstream in the middle to lower troposphere beneath the di and behind the surface cold front (cooper et al. , 2001) .
in terms of aircraft productivity, the legacy carriers also made big gains, stemming in large part from the shift of larger and longer - range aircraft to international routes. domestically, they tried to replicate the productivity strategies of lccs, by eliminating fixed connecting banks at many hubs and moving to “continuous” or “rolling” banks that shortened aircraft ground times. still, despite all of their efforts to improve aircraft productivity, the legacy carriers have not been able to match the utilization rates (block hours per day of aircraft operation) that lccs have been achieving (figure 6). for example, southwest and jet blue continue to hold a clear advantage in this measure of productivity [ 5 ]
this next film tackles a vastly more sombre topic: the deeds of canadian pilots who served in the air force bomber command in britain during wwii. told they would be targeting factories and military targets, the airmen were actually ordered to drop their payloads on civilians in an attempt to annihilate the enemy. sensitive souls be warned: viewer discretion is advised .
figure b. 8 cross section perpendicular to a squall line (adapted from houze et al. , 1989). large hollow arrows identify the ascending front to rear inflow (left) and core updraft transporting air to the cloud top and forward anvil (right). black arrows represent the rear inflow jet supporting the cold pool generation directly below the core updraft .
in summary, deep convection is a very efficient transporter of boundary layer air to the free troposphere (dickerson et al. , 1987; park et al. , 2001). cotton et al. (1995) estimated an annual flux of 4. 95 × 10 1 9 kg of boundary layer air by cloud systems (including extratropical cyclones), which represents a venting of the entire boundary layer about 90 times a year. calculations for the central united states suggest that nearly 50 percent of boundary layer co is transported to the free troposphere by deep convection during summer (thompson et al. , 1994), while a typical middle latitude squall line was found to transport of 9. 9 × 10 3 tons of co out of
on a global scale and especially in the united states, the airline industry has been in a financial crisis for much of this new century. the problems that began with the economic downturn at the beginning of 2001 reached almost catastrophic proportions after the terror attacks of september 11, 2001. in the united states alone, the industry posted cumulative net losses of over $ 40 billion from 2001 to 2005, and only in 2006 was it able to return to the black with a total net profit of just over $ 3 billion [ 2 ] .
also, global services members can guarantee upgrades at time of booking if the pn fare code is available at that time. finally, complimentary upgrades also book into the pn fare code at 120 hours before the flight; one non - gs companion on the same reservation is eligible for upgrade into pn as well. the exception is waitlisting, which puts gs members at the top of the waitlist and clear as soon as pn availability opens up, though our own zach honig wrote about a recent “surprise and delight” program that has been implemented for elites recently .
mountain and valley circulations also are diurnally varying mesoscale thermal circulations. in this case the horizontal temperature gradient is due to altitude differences. during the day, the mountains act as an elevated heat source, causing air and its pollutants to rise up the side of the sloping terrain. under summertime fair weather conditions three times the volume of the valley can be lofted into the free troposphere each day (henne et al. , 2004). if conditions are favorable, the ascent can lead to thunderstorm development along the mountain tops. at higher altitudes away from the mountains the air sinks into the surrounding valleys. at night the horizontal temperature gradient reverses, producing downslope flow into the nearby valley that is assisted by gravity. this can lead to an accumulation of pollutants in the valley .
doha' s brand - new hamad international airport, which cost over $ 15 billion to build, was quiet on friday afternoon when i set out to return home. but the line at the oman air counters moved slowly. staff there said most catching flights were those trying to go to dubai. typically, business travelers and those working in the region routinely shuttle between cities with relative ease .
in the us airline industry, approximately 100 certificated passenger airlines operate over 11 million flight departures per year, and carry over one - third of the world’s total air traffic – us airlines enplaned 745 million passengers in 2006. us airlines reported over $ 160 billion in total revenues, with approximately 545, 000 employees and over 8, 000 aircraft operating 31, 000 flights per day [ 2 ]. the economic impacts of the airline industry range from its direct effects on airline employment, company profitability and net worth to the less direct but very important effects on the aircraft manufacturing industry, airports, and tourism industries, not to mention the economic impact on virtually every other industry that the ability to travel by air generates. commercial aviation contributes 8 percent of the us gross domestic product, according to recent estimates [ 3 ] .
options on other airlines had me traveling over 10 hours. that was too much. but i got lucky when a last - minute cancellation got me on an oman air flight to muscat, the capital of the sultanate. that flight and another to dubai cost 1, 805 dirhams ($ 490). it still was a lot, but i was happy to get a ticket. the airline has since increased the frequency of its flights to doha .
low - pressure areas are important regions of strong horizontal and vertical pollution transport. locations of cyclone initiation (cyclogenesis) and their subsequent storm tracks are important in determining the routes of long - range pollution transport. once a cyclone begins to form it is “steered” by upper tropospheric flow patterns, generally toward the east. important areas of cyclogenesis are located over eastern asia and the western pacific ocean, as well as the east coast of north america. cyclones forming in these areas are important mechanisms for transporting pollutants from the east coasts of both asia and north america (merrill and moody, 1996; cooper et al. , 2002a, b; stohl et al. , 2002). another preferred region of cyclogenesis is downwind of major mountain ranges such as the rocky mountains or the alps. it is noteworthy that europe and western asia are not major regions of cyclone formation or transit .
without mountain and valley circulations mountain ranges could block the horizontal transport of pollutants. if the daytime upslope flow is sufficiently strong, the polluted air can rise up and over the mountains and be transported away from its source by the stronger winds aloft. mexico city is a prime example of where terrain - induced circulations strongly affect pollution concentrations (fast et al. , 2007; lei et al. , 2007; de foy et al. , 2008) .
boundary layer turbulence appears to be the major source of vertical transport in parts of asia. dickerson et al. (2007) found that the warm - sector pbl air ahead of a cold front was highly polluted while in the free troposphere, concentrations of trace gases and aerosols were less but still well above background. they concluded that dry convection appears to dominate vertical transport, with warm conveyor belts first coming into play as the cyclonic systems move off the coast .
synoptic circulation features have sizes of ~ 1, 000 - 2, 000 km and lifetimes of several days to a week. transient middle - latitude cyclones (lows) and anticyclones (highs) are prime examples of these circulations. anticyclones generally are regions of tranquil weather with sinking air that leads to relatively cloud - free skies and stable conditions that suppress mixing and tend to trap pollutants. their light winds also reduce horizontal transport. anticyclones with little forward motion allow these stagnating conditions to persist over days or even weeks .
more generally, the long - range intercontinental transport of pollutants can be considered a two - step process. first, the pollutants must be transported vertically out of the boundary layer where winds are relatively light and into the free troposphere where winds are stronger, especially near the jet stream. once in the free troposphere the pollutants are transported quasi - horizontally by larger wind systems such as the prevailing westerlies. the strength of the winds determines how rapidly the transport will occur, and there can be considerable mixing with stratospheric air above the troposphere .
the airline industry is in the midst of a dramatic restructuring that involves even more fundamental changes than those experienced following its deregulation in 1978. yet, nearly three decades after deregulation – and after multiple cycles of financial successes and failures – the industry remains fragile. competitive pressure from low - cost carriers, the loss of consumer confidence in the air transportation system’s reliability and operating performance, and the transparency of pricing facilitated by the internet and online travel distribution channels have all contributed to a precipitous decline in average fares and a significant impact on airline revenues.
global air routes is a 14-minute 1944 canadian documentary film produced by the national film board of canada , directed and edited by stuart legg . the film is part of the the world in action series . legg directed a number of documentaries for both the world in action and earlier canada carries on series . many of the documentaries were created as morale-boosting propaganda films during the second world war . 
global air routes is a 14-minute 1944 canadian documentary film produced by the national film board of canada, directed and edited by stuart legg. the film is part of the the world in action series. legg directed a number of documentaries for both the world in action and earlier canada carries on series. many of the documentaries were created as morale-boosting propaganda films during the second world war.
global air routes is a 14-minute 1944 canadian documentary film produced by the national film board of canada, directed and edited by stuart legg. the film is part of the the world in action series. legg directed a number of documentaries for both the world in action and earlier canada carries on series. many of the documentaries were created as morale-boosting propaganda films during the second world war.