Mt. Whitney Portal Store & Hostel Forums General Mt. Whitney Portal Store Message Board What time is sunrise?

I have a one-day permit for July 19 so this year I thought I would try to be on the summit to see the sunrise. It's a full-moon weekend plus GPS data plus headlamps so I think we'll be fine on the trail (with the only confusing part just above Mirror Lake).
Anyway, my question is what's the time difference for sunrise at the summit compared to the published sunrise for Lone Pine? I'm sure there is some type of earth curvature declination I could figure out but I'm also pretty sure someone here already knows the answer. For example, I'm looking for sunrise at Lone Pine is 6am therefore sunrise at the summit is 5:20 or something like that.

Thanks in advance,

check out: Naval Observatory for sunrise/sunset data anywhere in the country.

JeffH,

The Naval Observatory calculator shows sunrise at 4:50 am Standard Time, so you need to add one hour for Daylight Savings Time on July 19.

I think a more precise calculator can be see at:

http://squ1.org/wiki/Solar_Position_Calculator

This shows sunrise at 5:53 am for Mt. Whitney.

For orientation, the sun will rise over Keynot Peak that morning.

Hope you can catch the sunrise from the top on July 19. Have fun!

Thats a good site to keep in mind. Our group is going up on July 20, and we should be having a good amount of moon light, for our "walk" up.,

Wayne, you would know the answer to this. I have always assumed that the sun/moon rise/set calculators did not give true times, but times based on the location transferred to mean sea level--directly above or below the point of interest. So true only for the earth being replaced by its geoid.

For example, your calculator predicts sunrise at Lone Pine on July 19 for 5:52 PDT. I assume that the sun actually rises for Lone Pine t1 minutes earlier, because it is at ~4000' instead of MSL, corrected by t2 minutes later because of the Inyos. So actual sunrise is 5:52 - t1 +t2, where t2 would be greater than t1.

Similar for Mt. Whitney, but its t1 is larger than Lone Pine's, and its t2 is very small--nonzero not because of the Inyos but the Spring Mountains perhaps.

True or false?

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Jeff, be aware that the moon will be low in the sky (it's summer), so hidden by Mt. Irvine's NE ridge for the first part of your hike. I haven't checked, but I'd guess up to around Trailside Meadow. Of course, it will be brightly illuminating the walls on the north side of the canyon, so will help somewhat.

Bob, you are right. The calculators are based on a theoretical geoid and do not account for the mountains. Therefore, even though the calculator shows a theoretical early rising for the sun "over" Lone Pine, since Lone Pine is more east than Whitney, the reality is that the sun has to rise over 11,000-ft. mountains before being seen in Lone Pine. Since Whitney is so high, observers get an earlier peek at the sun over the peaks compared to Lone Pine. Does this fit with your T1 and T2? I know you the scientist know this a whole lot better than I do. Thanks for any clarification you can give all of us students of Mt. Whitney. Your expertise is most appreciated by a whole bunch of us on this board. Thanks, Bob!