SEAMANSHIP

Passage Maker - - Contents - Bye, Bye, Birdie: So­lar Storms Robert Reeder

Up un­til now in this col­umn we have only con­sid­ered the po­ten­tial loss of GPS satel­lites dur­ing a voy­age. How­ever, our GPS satel­lites are in no way uniquely vul­ner­a­ble, nor are we uniquely de­pen­dent on them for nav­i­ga­tion. We also use satel­lites for com­mu­ni­ca­tions and weather pre­dic­tion; hence, we need to be self-suf­fi­cient and able to carry on with­out these ca­pa­bil­ties as well. So far we have dis­cussed the largescale loss of satel­lites in fairly ab­stract terms, but for this ar­ti­cle we are go­ing to cre­ate a very spe­cific hy­po­thet­i­cal sce­nario.

PRE­LUDE

The fol­low­ing sce­nario is based as closely as pos­si­ble on the 1859 Car­ring­ton Event, a pow­er­ful so­lar storm. We will fo­cus only on the im­me­di­ate ef­fects such an event would have on a small cruis­ing boat at sea, in­clud­ing how it would af­fect the satel­lite and ra­dio re­sources com­monly used by cruis­ers. For those un­fa­mil­iar with the his­tory of this event, here is a sum­mary: In early Septem­ber 1859, a so­lar coro­nal mass ejec­tion hit the earth, caus­ing spec­tac­u­lar au­ro­ras world­wide and also caus­ing tele­graph sys­tems (the only large elec­tri­cal sys­tems that ex­isted at the time) to fail cat­a­stroph­i­cally. The Car­ring­ton Event re­mains the largest so­lar storm to af­fect the earth since hu­mans have used elec­tric­ity in a wide­spread fash­ion. A storm of sim­i­lar mag­ni­tude also oc­curred in 2012, but it nar­rowly missed Earth. NASA pre­dicts that the prob­a­bil­ity of Earth be­ing hit square on by a coro­nal mass ejec­tion of this size over the next decade is about 12%.

For our sce­nario, we’re go­ing to sup­pose we are a cruis­ing trawler mak­ing a rhumb-line pas­sage of 240° True from San Fran­cisco to Kahu­lui Har­bor on Maui, a trip of more than 2,000 miles. For ar­gu­ment’s sake we’ll as­sume that the main en­gine is a sim­ple diesel that op­er­ates in the ab­sence of elec­tric­ity; oth­er­wise we’d be with­out propul­sion and adrift.

Let’s say that the first night af­ter we left San Fran­cisco we ob­served a very weak aurora. While it was vis­i­ble only be­cause the night was moon­less and we were off­shore and away from the city lights, it was still a bit sur­pris­ing to see an aurora this far south. Then, dur­ing our daily noon sights, we no­ticed that there was an un­usu­ally large num­ber of sunspots. This, it turns out, was just the open­ing act of the sun’s per­for­mance.

Now our sin­gle-side­band (SSB) ra­dio ap­pears to be lim­ited to line of sight, which is very con­sis­tent with the au­ro­ras. Of all of our equip­ment, our SSB ra­dio is by far the most vul­ner­a­ble to space weather, and we would ex­pect sky­wave ra­dio sig­nals to be dis­rupted or elim­i­nated by a so­lar storm of this mag­ni­tude. Our satel­lite re­sources, such as GPS and Irid­ium phone, seem rel­a­tively un­af­fected at this point. We might ac­tu­ally be ex­pe­ri­enc­ing some small degra­da­tion in GPS ac­cu­racy, but in open ocean we have noth­ing to com­pare that with, other than dead reckoning and ce­les­tial. So as far as we can ob­serve our GPS is fine.

Now, on the fourth day un­der­way, we’re at the half­way point, some­where around 30° North and 140° West, lit­er­ally a thou­sand miles from any­where, av­er­ag­ing 10 knots in fol­low­ing seas.

Dur­ing our morn­ing Irid­ium satel­lite down­load we get our usual weath­er­fax maps and a cou­ple of rou­tine emails. There is a trop­i­cal storm, Brigid, west of Aca­pulco and head­ing west­ward gen­er­ally to­ward Hawaii. It is still more than 600 miles away and should pass well south of us.

But we have one ad­di­tional mes­sage from our weather ser­vice provider, marked “Ur­gent Space Weather Warn­ing.” Is this an old mes­sage that came late, telling us about the au­ro­ras from the other day? No, this is new.

PREPA­RA­TION

06:00 UTC is 20:00 lo­cal time in Hawaii, about an hour af­ter sun­set. Hawaii will be on the night side of the planet for the first 11 hours or so of the storm, and due to a lat­i­tude of only 20° North, the dis­tance from either of the mag­netic poles is close to ideal to min­i­mize the ef­fects of this so­lar

event. For our boat and our des­ti­na­tion port, things are much bet­ter than they could be for an event like this, and much bet­ter than they will be in other places.

Be­fore sunrise we take a ce­les­tial fix on Jupiter and the stars Betel­geuse and Schedar, com­pare it to our GPS po­si­tion, and lay out our dead reckoning track from these. We will con­tinue plot­ting our GPS po­si­tion hourly for as long as we can.

The sun rises on a beau­ti­ful day in the Pa­cific tradewinds, the weather is clear with fol­low­ing seas, and other than the spar­sity of ra­dio traf­fic on our SSB, ev­ery­thing is pretty rou­tine. We still have about 14 hours be­fore the coro­nal mass ejec­tion (CME) ar­rives. Much like a hur­ri­cane, a CME al­lows us am­ple time to pre­pare to the best of our abil­ity. Un­like a hur­ri­cane, how­ever, avoid­ing the so­lar storm en­tirely is not a pos­si­bil­ity.

We spend the day in prepa­ra­tion and take in­ven­tory, look­ing at both the best­case and the worst-case sce­nar­ios. Our first ac­tion­able pri­or­ity will be stow­ing as much of our small elec­tron­ics as we can in any­thing that might pass for a Fara­day cage. Any­thing from a covered wire-mesh garbage can to a seal­able metal cof­fee can or the oven will do the trick. We dis­con­nect as much of our elec­tri­cal equip­ment as pos­si­ble, pump our hold­ing tank, top off our potable tanks with the wa­ter­maker, and move diesel to our day-tanks.

This is one of those rare times that you would want to use a com­puter printer if you have one. Up un­til now, we haven’t been es­pe­cially con­cerned about the afore­men­tioned Trop­i­cal Storm Brigid, which was more than 600 miles away from us last time we checked. But the pos­si­bil­ity of be­ing adrift out here in its path gives us a re­newed aware­ness of its sig­nif­i­cance. With our Irid­ium phone we down­load and print the lat­est storm tracks and sur­face anal­y­sis maps, as well as plot the rel­e­vant in­for­ma­tion from these on our Pi­lot Chart. As­sum­ing we still have propul­sion af­ter the CME, we’ll only have about four days to Maui, so we also print the 24-hour, 48-hour, and 96-hour weath­er­fax sur­face fore­cast maps, as this may be the best ex­ter­nal weather in­for­ma­tion we’ll have avail­able.

Ver­i­fy­ing our aneroid barom­e­ter with the sur­face anal­y­sis charts and our elec­tronic barom­e­ter is also crit­i­cal, as it may be the only di­rect weather in­for­ma­tion we have other than our eyes for the rest of the trip. Sim­i­larly, ver­i­fy­ing our mag­netic steer­ing com­pass is a ne­ces­sity as well.

Any other nav­i­ga­tion and weather re­source we will need for the re­main­der of our ocean pas­sage and our ap­proach to Kahu­lui, such as ex­cerpts from the U.S. Coast Pi­lots and tide ta­bles, should also be printed in case our hard drive be­comes in­op­er­a­ble or inac­ces­si­ble. En­larg­ing and print­ing the por­tion of the Pi­lot Chart that in­cludes our route may prove ben­e­fi­cial. Im­por­tant files should be trans­ferred onto a flash drive and se­cured in one of the makeshift Fara­day cages.

Plot­ting our track on the Pi­lot Chart, it is ap­par­ent that our rhumb-line route crosses the great-cir­cle track from Los An­ge­les to Honolulu that is pre­ferred by con­tainer ships and other com­mer­cial traf­fic. Thus, we will need to make sure to re­store or re­place our run­ning lights af­ter the CME ar­rives.

We must also de­cide whether to keep our en­gines run­ning as the CME passes through or to shut them down and try to restart them af­ter­ward. If our en­gines are de­pen­dent on elec­tronic sys­tems in order to op­er­ate, shut­ting down is prob­a­bly best, and we need to be pre­pared for them to never start again. At the other ex­treme, a very sim­ple diesel en­gine with a pneu­matic or other me­chan­i­cal-only start may not be af­fected by the CME at all. As with au­to­mo­biles, for any kind of elec­tro­mag­netic pulse, older en­gines are bet­ter than new and diesel is bet­ter than gaso­line. For cruis­ing boats, sails are bet­ter than any of them, if you hap­pen to have them or are able to jury-rig one.

In our case we’ll sim­ply as­sume that our en­gine is an older diesel. Given the fact that we’ll be on the night side of the earth when the CME hits, we’ll take a chance and keep our en­gine run­ning and en­gaged but dis­con­nect any elec­tri­cal loads from it. We’ll power down our radar and dis­con­nect the coax­ial, but real­is­ti­cally we will have to write it off as a loss and hope for the best.

Fi­nally, we make a nice meal from our per­ish­ables be­cause any­thing we can’t keep cold will have to be thrown away. Noth­ing much to do now but re­lax, con­tinue mo­tor­ing into the sun­set, and wait.

LUCK FA­VORS THE WELL PRE­PARED

In the evening twi­light we break out the sex­tant and shoot the stars Alkaid, Antares, and Deneb, and draw the fix

on our plot­ting sheet. We take a small chance and re­move a cheap hand­held GPS re­ceiver from one of the Fara­day cages to get a last com­par­i­son with our ce­les­tial. The re­ceiver boots up fine but has no satel­lite sig­nal. Whether this means that the satel­lites have al­ready been dam­aged or that they’ve sim­ply been taken off­line to pro­tect their elec­tron­ics, we have no way of know­ing. Re­gard­less, we put the GPS re­ceiver back in the Fara­day cage.

As the sky dark­ens we see a faint green glow to the north; if we weren’t look­ing for it we likely wouldn’t no­tice it. It re­mains there, like a faintly lu­mi­nous cloud, for the bet­ter part of an hour. Then sud­denly the sky erupts in greens and reds, sparkling emerald cur­tains dance in the night above us. Static elec­tric­ity builds quickly on metal sur­faces, es­pe­cially the rails and lifelines, giv­ing oc­ca­sional mild shocks. To our re­lief, the old en­gine rum­bles on undis­turbed.

The aurora con­tin­ues through­out the night, some­times strong and dra­matic, some­times re­treat­ing to a green glow­ing cloud in the north­ern sky, but never fad­ing com­pletely. The bright­est stars are vis­i­ble through it, and the hori­zon is suf­fi­ciently il­lu­mi­nated to al­low ce­les­tial nav­i­ga­tion sights through the night, as de­sired. Our wrist­watch seems un­af­fected by the so­lar storm. Our small bat­tery-pow­ered backup run­ning lights are sim­i­larly un­af­fected, so we mount and il­lu­mi­nate those for safety. Our first night, pre­sum­ably the worst of the so­lar storm, is oth­er­wise un­event­ful.

We have no up­dates on Trop­i­cal Storm Brigid. How­ever, as we mon­i­tor and log our barom­e­ter hourly, we see no pre­cip­i­tous drops in baro­met­ric pres­sure. Watch­ing the skies for tell­tale signs of an ap­proach­ing low has sim­i­larly yielded noth­ing; the ubiq­ui­tous pop­corn cu­mu­lus of the tradewinds march steadily west­ward, with no cir­rus clouds any­where in sight. Either Brigid has passed far to the south of us or more likely it sim­ply dis­si­pated as eastern Pa­cific trop­i­cal cy­clones of­ten do.

Our cur­rent ETA into Kahu­lui has us ar­riv­ing a lit­tle af­ter mid­night seven days later. Given the like­li­hood of ex­ten­sive power out­ages on the is­lands, in­clud­ing lighted aids to nav­i­ga­tion, we de­cide to slow our­selves a bit both to con­serve fuel and to en­sure that we make land­fall on Mt. Haleakala soon af­ter sunrise so that we can ap­proach Kahu­lui Har­bor in day­light.

For­tu­nately, Maui’s elec­tri­cal grid is small and much of it is wind-pow­ered, so crit­i­cal loads will likely be re­stored there much more quickly than on the main­land. Even more for­tu­nately, elec­tric­ity is not re­quired to make a Mai Tai. Good watch!

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