272:

273: function summarytxt(e){

274:     var layer = e.target;

275:     // pcco2=layer.feature.properties.co2pc;

276:

277:     if (layer.feature.properties.co2pc<emissions){

278:            ratio=emissions/layer.feature.properties.co2pc;

279:            stringplus="This flight produces (per passenger) the same amount of greenhouse gases as "+ratio.toFixed(1)+" average resident of "+layer.feature.properties.name +" did in 2017.";

280:     } else {

281:            ratio=layer.feature.properties.co2pc/emissions;

282:            stringplus="This average resident of "+layer.feature.properties.name +" produced the same amount of greenhouse gases in 2017 as "+ratio.toFixed(1) +" of these flights (per passenger)";

283:     }

284:

285:     hoverstring="<span id='hovername'>"+layer.feature.properties.name+":</span> "+layer.feature.properties.co2pc+" tonnes CO₂ per capita<br>"+stringplus;

286:

345:

346: //constants for equation

347: shDC=50;

348: lhDC=125;

349: ash=3.87871E-05;

350: alh=0.000134576;

351: bsh=2.9866;

352: csh=1263.42;

353: blh=6.1798;

354: clh=3446.20;

355: Ssh=158.44;

356: Slh=280.39;

357: Plf=0.77;

358: passF=0.951;

359: ecosh=0.96;

360: ecolh=0.8;

361: bussh=1.26;

362: buslh=1.54;

363: fcsh=2.4;

364: fclh=2.4;

365: EF=3.150;

366: pp=0.51;

367: Mnonco2=2;

389:    eraseErrorMsg();

390:

391:    origin=airportdata[fromindex];

392:    destination=airportdata[toindex];

393:

394:    origincoord=[origin.Lat,origin.Long];

395:    destcoord=[destination.Lat,destination.Long];

396:

397:    greatcircledist=getDistance(origincoord,destcoord)/1000; //units of km

398:

399:    if (greatcircledist<1500){

400:            CW=ecosh;

401:            dist2=greatcircledist+shDC;

402:            flightdist= (dist2);

403:            emissions2=((ash*flightdist**2+bsh*flightdist+csh)/(Ssh*Plf))*passF*CW*(EF*Mnonco2+pp)*2/1000;

404:

405:    } else {

406:            CW=ecolh;

407:            dist2=greatcircledist+lhDC;

408:            flightdist= (dist2);

409:            emissions2=((alh*flightdist**2+blh*flightdist+clh)/(Slh*Plf))*passF*CW*(EF*Mnonco2+pp)*2/1000;

410:

421:

422:    // emissions = flightdist*175*2.7/1000000;  //unit is tonnes

423:    // emissions3=greatcircledist*0.62*co2fact/1000*2;  //miles * co2factor * roundtrip

424:

425:    emissions=emissions2;

426:    // console.log(emissions,emissions3);

427:    // console.log(emissions2/(flightdist*1.609)*1000);

428:    

429:    threshold=emissions;

430:

431:    drawSubset();

432:    drawGreatCircle();

433:    globaltxt();

434:

435:    emissionsstring="The round-trip flight from <span id='stringorig'>"+origin.City+"</span> to <span id='stringdest'>"+destination.City +"</span> is <span id='stringdist'>"+parseInt(flightdist*2/1.609).toLocaleString()+" miles</span> and produces <span id='stringemiss'>"+ emissions.toFixed(1)+" tonnes</span> of CO₂ equivalent emissions <b><i>for each passenger</i></b>. In 2017, <span id='stringnum'>"+numCountries+" countries</span> in the world have lower annual per capita emissions than this flight, accounting for <span id='stringpct'>"+pctpop+"</span> of the world's population."

436:    $("#emissions").html(emissionsstring);

437: }

438:

439: function getDistance(origin, destination) {

440:     // return distance in meters

441:     var lon1 = toRadian(origin[1]),

442:         lat1 = toRadian(origin[0]),

443:         lon2 = toRadian(destination[1]),

444:         lat2 = toRadian(destination[0]);

445:

446:     var deltaLat = lat2 - lat1;

447:     var deltaLon = lon2 - lon1;

448:

449:     var a = Math.pow(Math.sin(deltaLat/2), 2) + Math.cos(lat1) * Math.cos(lat2) * Math.pow(Math.sin(deltaLon/2), 2);

450:     var c = 2 * Math.asin(Math.sqrt(a));

451:     var EARTH_RADIUS = 6371;

452:     return c * EARTH_RADIUS * 1000;