TSE 2015 finds landfall only on two north Atlantic island locations. The first, to the south-east of the centerline of the path of totality, on the Faroe Islands (latitude 62° N) where the Sun will fall into total eclipse for a maximum duration of off-centerline totality of 2m 25s on the western side of the tiny island of Mykines. The second, as the centerline of the path of totality traverses Svalbard/Spitzbergen (latitude ~ 79° N) giving rise to a nearly equal maximum on-the-ground duration of on-centerline totality 2m 26s from the island's north coast.  Both island locations, while wonderful locations to visit and explore, are very likely contra-indicated as eclipse viewing sites in mid-March due to the strong prevalence of clouds and precipitation (e.g., see here and here) with high probabilities of obscuration with the Sun at low elevation angles above the local horizons. Some eclipse chasers will undoubtedly make the attempt, and we wish them great luck – but the virtually-assured solution for TSE 2015 observers is to take to the skies above the prevailing weather. 

The point of greatest eclipse, 250 km north of the Faroe Islands in the Norwegian Sea between Iceland and Norway, is where the Moon's shadow is very nearly simultaneously moving most slowly across the Earth and the duration of totality is at a maximum anywhere along the path of totality (2m 47s).  Further north, after passing over Svalbard/Spitzbergen, the Moon's shadow streaks northward to the geographic North Pole where at 10:17 UT with (from sea-level) the horizon bifurcating the fully-eclipsed Sun as it very slowly rises and the Pole is plunged into a prolonged total eclipse induced twilight for 1m 55s. 




The ideal location on Earth for eclipse-chasers to observe TSE 2015 would be at (or very close to) at the point of greatest eclipse, if the twin, daunting, concerns of weather (high probability of cloud cover) and lack-of-accessibility (in the frigid waters off the east coast of Iceland) could be overcome.  With a now planned TSE 2015 eclipse observation flight, "EFLIGHT 2015 64N" these dual obstacles are removed, and this rare opportunity is now enabled for high-flying umbraphiles.


Viewing a total solar eclipse, and the sweep of the Moon's umbral shadow as it races across (and above) the Earth, as seen from such a lofty height as enabled by our EFLIGHT aircraft, is magnificent beyond description.  As seen from 37,000 feet above the surface of the Earth, the apparent horizon is 377 km (234 miles) away and depressed by 3.4° compared to sea level.  Looking along the apex of the lunar umbral cone toward the eclipsed Sun at mid-totality, or along its outer periphery as the shadow sweeps over the aircraft coincident with the instants of second or third contacts, the curvature and grandure of the umbral shadow boundary (i.e., the "shadow ellipse") is stunningly apparent. At near-polar latitudes in mid-March, the high reflectivity of the polar ice and/or cloud tops far below accentuates the stark contrast between the eclipse-darkened regions within umbral shadow, and those illuminated by the Sun beyond the shadow's edge. Being above more than 3/4 of the Earth's atmosphere the corona of the Sun is presented with contrast and clarity in the rarefied air incomparable to ground-based venues at the bottom of a bubbling pool of atmospheric turbulence.  (See below, shadow and corona photos taken from our predecessor TSE 2008 flight; similarly executed over the Arctic Ocean).

DEPLOYMENT/RELOCATION FLEXIBILITY To Find the BEST Spot(s) in the Area of Operations for Observing	CLOUD OBSCURATION AVOIDANCE High Latitude Stratosphere Stratosphere: 99.99% -- Virtually Assured
TOTALITY PROLONGATION FOR MAXIMUM ECLIPSE (Flight #1) Aircraft Speed Extends the Duration of Totality	SKY TRANSPARENCY Significantly Improved -- Low Particulate Scattering
SKY DARKNESS Much Higher Contrast Coronal Visibility and to Larger Distance	IMPROVED ASTRONOMICAL SEEING "r_naugh" Decreases with Increasing Altitude
REDUCED ATMOSPHERIC TURBIDITY Vorticity & Sheer Decline in Power Above Tropopause	PANCHROMATIC VISIBILITY IR and UV "Windows" Open Up or are Extended
UNPARALLELED HORIZON  REACH & OBSERVATION VISTA Apparent horizon 377 km distant, depressed 3.4° (at 37,000 ft)	ESTHETIC, ETHEREAL EXPERIENCE There is nothing quite like it...

At this altitude and latitude, aerosol scattering of sunlight by airborne particulate is usually extremely low, giving rise to an exceptionally dark sky during totality, enabling eclipse viewing with significantly enhanced image contrasts. Moreover, the airmass along the line-of-sight to the Sun is significantly reduced (by ~ 75%), resulting in exceptional sky transparency, greatly reduced atmospheric turbidity, and better astronomical "seeing". 

{At 64° N east of Iceland, the possibility of high-altitude volcanic ash originating in Iceland while statistically small is non-zero.  Thus, for further (but intrinsically very-low) risk we mitigation we are looking to design our EFLIGHT 2015 64N plan with sufficient flexibility to reach higher latitudes (with somewhat reduced maximum duration of totality) where such particulate are very unlikely to be transported given normal polar wind circulation patterns.  Details TBD}.



The detailed definition EFLIGHT 2015 64N flight plan is actively being developed to optimize the observing opportunity while minimizing to near-zero risks that are otherwise high-probability at ground-based locations. The nominal (baseline) flight plan is built around an eclipse-viewing "totality run" (TR) constrained by celestial mechanics, aircraft operational considerations, and a need to maintain in situ flexibility to implement contingency alternatives.  For baseline planning and logistical purposes we build from: (1) a flight altitude for eclipse-viewing of 37,000 feet AMSL, with (2) a ground speed of 470 nm/hr and (3) no wind (so ground speed = air speed, and heading = course).  Detailed pre-eclipse flight planning, and in-flight execution, will incorporate and allow for the full range of possible flight levels, air speeds, and wind-vectors that may be encountered in flight to re-optimize the totality runs in situ as may be necessary or desired. 

We define the baseline totality run such that the aircraft is centrally located at the apex of the lunar umbral shadow (but corrected for the irregular lunar-limb profile) at the topocentric instants of "maximum eclipse" at the chosen intercept point.  We also define the baseline totality run so that the aircraft velocity vector at mid-eclipse places the Sun "straight out" the right-side windows of the aircraft passenger cabin to provide optimum out-the-window viewing and utilization.  This orientation also provides an optimal orientation to prolong the duration of totality to a theoretical maximum anywhere along the path of totality by using the aircraft's speed to (partially) keep pace with the lunar shadow.  With these constraints, we compute, and tabulate below, three key time correlated waypoints for the totality runs that define the lunar shadow intercept and crossing by the aircraft designated C2 (eclipse contact II), MAX (corresponding to the UTC instant of maximum eclipse), and C3 (eclipse contact III).  MAX, in both UTC and lat/long will depend upon the aircraft altitude AMSL.  C2 and C3 will also depend upon the aircraft ground speed and track (i.e., airspeed and winds aloft). 

The (earlier) start of the pre-totality leg of the totality run is be defined by a pre-totality time-correlated waypoint TBD (but probably about 9) minutes before C2. The aircraft is initially positioned on the MAX-eclipse intercept track at the requisite course/heading, distance, and flight-time from the intercept point allowing for airspeed adjustment in the run up to the C2 time-correlated waypoint to compensate for deviations due to actual (vs. predicted) winds aloft (holding the MAX intercept time-correlated waypoint invariant).  After C3 the aircraft will remain on the MAX-to-C3 heading for TBD (but appx 5) minutes to allow viewing of the recession of the Moon's shadow before returning home.

Flight #1 – EFLIGHT 2015 64N   Totality Duration: 3m 49.1s    Mid-UT: 09h 45m 37.75s  (C2-9m) C2 MAX C3 U.T. 09h 34m 41.2s 09h 43m 41.2s 09h 45m 38.6s 09h 47m 30.3s Aircraft Lat. 63° 11' 54.94" 64° 02' 18.10" N 64° 13' 04.0" N 64° 23' 14.71" N Aircraft Lon. 08° 24' 14.83" 06° 34' 07.25 W 06° 09' 18.0"W 05° 45' 22.53" W Ast./App. Sun Alt. 17.8° / 21.1° 18.6° /  22.0° 18.8° / 22.2° 18.9° / 22.3° Sun Azimuth 130.2° 134.5° 135.4° 136.4° Limb Profile Offset N/A -1.9s  N/A -1.8s Heading/Distance* 43.38°, 70.5 nm 45.03°, 15.33 nm 45.40°, 14.59 nm  *provided for info only -- navigation by time-correlated waypoints