When you want to see the stars, find someplace dark
A gorgeous image released by NASA’s Earth Observatory this week. it features the recent snowfall atop our island’s summits. I suggest you go to the link above, download the 6k x 6k version, then just zoom in and enjoy the detail! (Sorry the full image is bigger than the WordPress size limit to post here)
Calls from the summit facility are not exactly what I want to see on my phone display on Christmas Eve. Heather was very apologetic about calling, but she had no choice, the Keck 2 dome would not rotate.
It was just before sunrise that we drove up the mountain from Waikoloa, the sun rising over the shoulder of Mauna Kea, casting long crepuscular rays into the sky. It is a beautiful Christmas morning, a clear sky, the snow capped summits of two volcanoes looming overhead. Heading to work on this morning is a bit surreal, while at the same time seeming a bit more festive for the snow.
We did make it up.
It was simply gorgeous at the summit, sunny and clear with no sign of the winds that had raged across the summit all week. The evidence of those winds was all to apparent, they had left a landscape of sculpted drifts. While the actual snowfall had not been that much, maybe a foot, the drifts were impressive.
I am currently sitting at Hale Pōhaku on the side of the mauna waiting for the snowplows to get us access. We are all looking at the webcams and the drifts of snow in front of our facility wondering if we will make it up today.
It does not look like it was a huge amount of snow, rather the high winds re-sculpted the snow into drifts against the buildings and the road cuts. The result is some impressive snow drifts. The snowplow crews are reportedly making slow progress.
In the meantime all we have are the webcam images…
It is currently snowing with freezing fog at the summit. The morning ranger report noted that there are blizzard conditions on the summit and that the road was impassable. The road is closed to all vehicles (not just the public) and the snow removal crews will not attempt to clear the road today. I am scheduled to go up tomorrow, I do have a few things I would like to get done, this may not happen.
All day the storm atop our mountain continued. As we watched in the cameras the snow fell heavily, often so thick nearby structures disappeared into the white. Unlike yesterday the winds have eased, the snow quickly accumulates where it falls instead of drifting against the structures. As we watch through the day things began to vanish, railings and guardrails buried in the snow.
Observing is, of course, cancelled.
While most states have yet to see any snow this winter, Hawaiʻi is not one of them. A light dusting of snow graced the summit of Mauna Kea this morning.
Interestingly recent forecasts have revisited the possibility of a La Niña event forming in the central Pacific this fall. If this does come to pass Hawaiʻi may be looking at a wetter than usual winter with the potential of significant snowfall on Mauna Kea. While this can wreak havoc with observatory operations, it can also be quite pretty.
Getting rain or snow on the primary mirrors is bad.
The problem… You can have both rain and snow occur with low humidity. Moist air above the telescope can produce rain or snow which falls into drier air at the summit level. This can catch the operators by surprise, a situation we have observed on a number of occasions.
To help detect this you can deploy a precipitation sensor, something some of the neighboring telescopes have done. The engineers over at CFHT were kind enough to show me the units they had installed during their remote operation project.
Not that the project was finished there… The new sensor does not come with any sort of network interface. Rather surprising given that just about everything else Vaisala sells has either a serial interface or an ethernet interface. This sensor has just a couple simple outputs… A logic level indication of precipitation, an analog output representing roughly how much, and a frequency output representing the same thing. I needed to interface this unit to the network. As I have installed a terminal server in the rack below the weather mast, at the minimum I needed a serial port.
While I was at it there are a couple other little devices I want to install on the weather mast. These need a network interface as well. May as well put together another little PIC controller and assemble it all together in one neat little package. a few evenings of coding and I had my solution, an interface that allowed remote computer control and status read-back. How many microcontrollers do I have performing little tasks at the summit now? Quite a few.
A light dusting of snow on the summit today, currently snowing. The forecast is for clearing into the new year.
