Pain in the Ash

Living in Perth it’s tempting to think we are so far from anywhere that nothing really affects us from the outside world. Sure, we felt some effect from the GFC and petrol gets more expensive when the price of oil goes up, but when it comes to things of a more natural origin, there’s really not much that comes our way.

The Indian Ocean Tsunami of 2004, while relatively close by in Indonesia, had no impact on the Western Australian coast, the earthquakes in Japan and New Zealand are distant images on our TV’s, and even when most of Europe’s airspace was closed in 2010 due to the Icelandic volcano eruption, down here in sunny Perth life went on as normal.

And so it was on June 4, when once again another volcano erupted in a distant land. Spectacular images showed the huge plume of smoke and ash rising into the Chilean sky from Puyehue, around 7,400 miles away on the other side of the world – literally.

According to Google Maps, the longitude of Puyehue is -72.6 degrees west while Perth Airport is 115.9 degrees east. Adding 72.6 to 115.9 gives a separation of 188.5 degrees, so just 8.5 degrees off being exactly opposite each other on the globe. But here’s the interesting bit – the latitude of Puyehue is -40.6 while the latitude of Perth Airport is -31.9, which is a difference of only 8.7 degrees.

So while Puyehue is almost exactly on the opposite side of the world to Perth, it’s on a very similar latitude. And guess what? When you look at the southern hemisphere on a globe, you’ll see that there’s huge expanses of ocean circling the world with Antarctica to the south and South America, Africa, Australia and New Zealand extending down from the north. And if you draw a straight line directly west on latitude 32 from Perth you end up not in South Africa, but Argentina, which is smack bang next door to Chile.

All of that uninterrupted ocean makes for extremely reliable winds, otherwise known to sailors as the Roaring Forties due to their notorious strength and the fact that they blow through the 40 latitudes. In the northern hemisphere, the land masses of Canada, Alaska, Europe and northern Asia alter the flow of air so that its circulation around the North Pole is nowhere near as steady and reliable as that around the South Pole with its Roaring Forties.

So, a volcano erupts on the 40th latitude and all of that ash and smoke starts to get blown eastwards, is picked up by the Roaring Forties and heads straight towards Australia and New Zealand. Now ordinarily in summer, when large high pressure systems tend to sit in the Great Australian Bight, all of that ash might have skirted to the south of Australia and just hit New Zealand, but in winter, those high pressure anticyclones tend to sit further north, allowing low pressure systems to sweep up from the south, bringing cold air from a long way down.

Which brings us to yesterday, 14 June, when a strong cold front brought heavy rain and showers across WA and, in its wake, air that’s been sucked up from those Roaring Forties latitudes way down south. Only today, 15 June, cold air and something else has been moving north – volcanic ash.

What on June 4 was an event on the other side of the world 7,400 miles away in Chile has now pretty much grounded all flights to and from Perth International Airport in Australia. Flights started to be cancelled from around 13.00 local time with Qantas, Virgin Australia, Jetstar and Tiger Airways suspending all flights. Some international flights were still operating, but any flight taking a southerly route to places like Sydney, Melbourne, Adelaide and the South African Airways flight to Johannesburg were cancelled.

The list below shows the arrivals information for this evening, Wednesday 15 June.

Arrivals Date Airline Flight Origin Terminal STA ETA Status
15/06 SA 280 Johannesburg T1 13:25 13:25 Cancelled
15/06 QF 303 Johannesburg T1 13:25 13:25 Cancelled
15/06 XR 216 West Angelas T3 14:25 15:30 Landed
15/06 SQ 223 Singapore T1 14:40 14:16 Landed
15/06 MH 125 Kuala Lumpur T1 15:00 14:57 Landed
15/06 QR 5322 Kuala Lumpur T1 15:00 14:57 Landed
15/06 AZ 3078 Kuala Lumpur T1 15:00 14:57 Landed
15/06 KL 4107 Kuala Lumpur T1 15:00 14:57 Landed
15/06 TG 481 Bangkok T1 15:35 16:09 Landed
15/06 GA 726 Denpasar T1 16:00 18:10 Landed
15/06 XR 054 Exmouth T3 16:10 16:09 Landed
15/06 XR 250 Cloud Break T3 16:40 13:23 Landed
15/06 XR 146 Esperance T3 16:45 16:35 Landed
15/06 DJ 1486 Broome T3 16:50 16:50 Cancelled
15/06 XR 116 Geraldton T3 17:05 17:19 Landed
15/06 DJ 5116 Geraldton T3 17:05 17:19 Landed
15/06 XR 126 Albany T3 17:20 17:27 Landed
15/06 DJ 5126 Albany T3 17:20 17:27 Landed
15/06 EK 420 Dubai T1 17:25 17:39 Landed
15/06 XR 244 Cloud Break T3 18:00 17:15 Landed
15/06 NZ 175 Auckland T1 18:10 19:25 Landed
15/06 UA 9552 Auckland T1 18:10 19:25 Landed
15/06 US 5338 Auckland T1 18:10 19:25 Landed
15/06 DJ 4160 Denpasar T1 18:25 18:25 Cancelled
15/06 QQ 879 Telfer T3 19:10 19:10 Cancelled
15/06 XR 218 West Angelas T3 19:10 15:15 Landed
15/06 TT 6272 Avalon T3 19:15 19:15 Cancelled
15/06 XR 208 Argyle T3 19:15 17:35 Landed
15/06 XR 222 Barimunya T3 19:20 15:13 Landed
15/06 DJ 1730 Karratha T3 19:30 19:30 Cancelled
15/06 QQ 738 Karratha T3 19:30 19:30 Cancelled
15/06 QZ 8626 Denpasar T1 19:30 19:04 Landed
15/06 QQ 805 Leinster T3 19:50 19:50 Cancelled
15/06 QQ 795 Mount Keith T3 20:00 20:00 Cancelled
15/06 DJ 1846 Port Hedland T3 20:10 20:10 Cancelled
15/06 XR 118 Geraldton T3 20:10 20:10 Cancelled
15/06 DJ 5118 Geraldton T3 20:10 20:10 Cancelled
15/06 XR 238 The Granites T3 20:30 20:30 Cancelled
15/06 DJ 565 Sydney T3 20:45 20:45 Cancelled
15/06 DJ 1882 Newman T3 20:50 20:50 Cancelled
15/06 XR 128 Albany T3 21:05 21:05 Cancelled
15/06 TR 2716 Singapore T1 21:05 21:05 Cancelled
15/06 DJ 5128 Albany T3 21:05 21:05 Cancelled
15/06 XR 148 Esperance T3 21:30 21:30 Cancelled
15/06 DJ 5148 Esperance T3 21:30 21:30 Cancelled
15/06 DJ 1488 Broome T3 22:00 22:00 Cancelled
15/06 DJ 4158 Denpasar T1 22:30 22:30
15/06 CX 171 Hong Kong T1 22:35 22:25
15/06 DJ 697 Melbourne T3 22:45 22:45 Cancelled
15/06 3K 111 Singapore T1 23:10 23:10 Cancelled
15/06 XR 020 Kununurra T3 23:20 23:20 Cancelled
15/06 DJ 5020 Kununurra T3 23:20 23:20 Cancelled
15/06 DJ 571 Sydney T3 23:50 23:50 Cancelled
15/06 SQ 215 Singapore T1 23:55 23:55
15/06 VS 7226 Singapore T1 23:55 23:55
15/06 LH 9785 Singapore T1 23:55 23:55
16/06 DJ 474 Brisbane T3 00:10 00:10 Cancelled
16/06 QF 078 Singapore T1 00:30 10:10 Delayed
16/06 TT 5598 Melbourne T3 00:50 00:50 Cancelled

Air Services Australia has been monitoring the situation, with Qantas and Jeststar looking to resume flights at 06:00 tomorrow morning, 16 June. Virgin Australia are waiting to see what happens.

The forecast weather for the next 24 hours looks like it will push the ash back down to the south and away from Perth. Melbourne, Adelaide and Tasmania, which have been affected by the ash over the last couple of days, are pretty much back to normal, so flights from Perth to these locations should be able to operate, even if the great circle routing over the Bight has to be dropped in favour of a more northerly path to avoid any areas of ash concentration.

Below is the latest bulletin from the Volcanic Ash Advisory Centre (VAAC) in Darwin:

Darwin VAAC
IDD60156
VOLCANIC ASH ADVISORIES FROM DARWIN VAAC – LAST 7 DAYS
DARWIN VAAC 13:51 UTC, 15/06/2011
——————————————————————–

Received FVAU0190 at 11:52 UTC, 15/06/11 from ADRM
VA ADVISORY
DTG: 20110615/1151Z
VAAC: Darwin

VOLCANO: Cordon Caulle 1507-141
PSN: S4031 W07212
AREA: Chile C
SUMMIT ELEV: 1798M

ADVISORY NR: 2011/35
INFO SOURCE: MTSAT, MODIS, NOAA, AIREP
AVIATION COLOUR CODE: RED
ERUPTION DETAILS: HIGH LEVEL ERUPTION, ASH MOVING EAST

OBS VA DTG: 15/1200Z
OBS VA CLD:
FL100/FL270 S5410 E07825 – S6630 E07455 – S6600 E15955 –
S4740 E15955 – S5005 E15025 – S5045 E14845 – S5150 E14600 –
S5325 E14105 – S5410 E07825 MOV E 70KT
FL150/FL350 S1845 E08205 – S4040 E08535 – S5410 E07835 –
S5325 E14120 – S4700 E13545 – S3815 E12755 – S3125 E11645 –
S2945 E10455 – S2030 E10000 – S1845 E08205 MOV E 40KT
FL240/FL380 S3250 E16000 – S3455 E15215 – S4050 E14920 –
S4705 E13550 – S5320 E14115 – S4740 E16000 – S3250 E16000 MOV E 40KT

FCST VA CLD +6HR: 15/1800Z
FL100/FL270 S5400 E08045 – S6640 E07455 – S6600 E15955 –
S4755 E15955 – S5000 E15040 – S5045 E14845 – S5150 E14600 –
S5330 E14110 – S5400 E08045
FL150/FL350 S1840 E08200 – S4055 E08850 – S5405 E08100 –
S5330 E14110 – S5145 E14555 – S5010 E14400 – S3920 E13155 –
S3355 E12145 – S3130 E10815 – S2030 E10000 – S1840 E08200
FL240/FL380 S3250 E15955 – S3445 E15255 – S5010 E14415 –
S5150 E14605 – S4745 E16000 – S3250 E15955
FCST VA CLD +12HR: 16/0000Z
FL100/FL270 S5400 E08225 – S6640 E07455 – S6610 E15955 –
S4745 E15955 – S5025 E15035 – S5110 E14845 – S5150 E14605 –
S5340 E14120 – S5400 E08225
FL150/FL350 S1840 E08200 – S4055 E09255 – S5350 E08235 –
S5325 E14110 – S5055 E14845 – S4125 E13635 – S3525 E12430 –
S3355 E11010 – S2030 E10155 – S1840 E08200
FL240/FL380
FCST VA CLD +18HR: 16/0600Z
FL100/FL270 S5410 E08455 – S6630 E07500 – S6610 E15950 –
S4740 E16005 – S5025 E15050 – S5100 E14830 – S5155 E14600 –
S5330 E14110 – S5410 E08455
FL150/FL350 S1845 E08200 – S4055 E09505 – S5405 E08505 –
S5325 E14100 – S5000 E15025 – S4120 E13900 – S3605 E12755 –
S3610 E11300 – S2035 E10500 – S1845 E08200
FL240/FL380

RMK: VAA LIMITED TO VAAC DARWIN AREA. FOR W OF E075 SEE TOULOUSE
VAA FVXX01. FOR E OF E160 SEE WELLINGTON VAA FVPS01. VA NEAR
ANTARCTICA LOWERED DUE AIREP Graphic at [lower case]
http://www.bom.gov.au/info/vaac/advisories.shtml
NXT ADVISORY: NO LATER THAN 20110615/1800Z

All of which translates into the map shown here:

http://www.bom.gov.au/products/IDD65290.shtml

So, here we are, all the way down here in our out of the way city, being affected by events on the other side of the world . . . quite amazing really.

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