New Zealand’s Incredible Clouds!

Shooting clouds over Mt. Cook (Aoraki)
             Shooting clouds over Mt. Cook (Aoraki)

For the past couple of months, I’ve been working on NSF research with Dr. Brian Billings that I’m very excited to share with you! Thousands of images of incredible New Zealand clouds Brian and I captured are now being used in our cloud stereo photogrammetry research. This work is tied with the DEEPWAVE Mission (several research centers are involved, including NCAR‘s Earth Observing Lab, Naval Research Lab-NRL, and New Zealand’s NIWA). 

DEEPWAVE aims to better understand the dynamics of internal atmospheric gravity waves; how moisture (that condenses into clouds) affects the grav-waves and how the waves affect the atmosphere and climate over a longer time frame (they have a big effect on the atmosphere’s momentum budget).  

The cloud stereo photogrammetry case I chose to focus on (June 13th shooting clouds over the ocean from Kumara Junction) will allow me to study coastal interactions and a possible barrier jet parallel to the West shore of the South Island.  This day provided stunning images that easily became my favorite of them all, as they capture the cumuliform clouds changing above AND the ocean waves moving below! Photos to come…

“Stratus”: Arahura Valley, New Zealand

THE PROCESS:  I shot with one camera (we cleverly call “Stratus”), while Brian shot with the other (“Cumulus”) at least 250 m away.  We first set the cameras on tripods so that we could see one another in the camera view at that distance, then turned each camera 90 degrees in order to capture images parallel to one another.  We tilted the cameras to view as much of the sky as possible. Using synchronized timers, we captured images on a set interval of every 5 or 10 seconds.

After each shoot, we saved our images on DVDs and even created time-lapse videos of the beautiful clouds using ImageJ! The main focus with our stereo photogrammetry is to measure the clouds and changes in them, so I’m now using a MATLAB Camera Calibration Toolbox and GPS measurements to perform calculations.  Using the triangulation measurements and algorithm results, I can determine how high clouds are and even their distance from mountains or other features to better understand and analyze conditions surrounding each day!

Good criteria for shooting:

  1. Clouds between clear and  overcast (with at least some breaks so it’s “scattered enough”); This way, we still have a clear view of the cloud base and cloud tops
  2. Would be nice to overlap with field/flight operations (if weather allows)—to capture images that correspond with NSF/NCAR HIAPER GV (research aircraft) flights and dropsondes AND Hokitika weather balloon launches (to represent upstream conditions for the flight)
  3. Smaller scale atmospheric features resulting from large-scale system—ex. fog forming under a ridge to look at how its form changes over time
  4. Strong cross-mountain winds–the mountains get in the way of the air flow, creating a disturbance that may cause gravity waves to form
  5. If there’s Easterly wind flow, we may see leeside weather phenomena (ex. gravity waves—lenticular “UFO” clouds) because of our location on the West side of mountains.  This would make us on the leeside of the mountain flow where all the action is!

It was quite an adventure scouting out the best locations for what we’re researching.  Many days ran long and late, but I loved it and have learned from it all.  All the while, I was  fortunate to do field work for NCAR on the DEEPWAVE mission and learn from incredible scientists!  I’m now working on stereo photogrammetric analyses for my Senior Thesis.  I presented preliminary results at the August AMS Mountain Meteorology Conference in San Diego and will be presenting more about the June 13th case at the American Geophysical Union (AGU) Fall Meeting in San Francisco (December) and the 2015 American Meteorological Society (AMS) Meeting in Phoenix (January)! 

Check out our field mission here, and find details on our first flight here!  @TashianaOsborne for live updates.

Truly,

Tash

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First DEEPWAVE Flight

I’m a bit behind on updates in all the excitement going on with DEEPWAVE, plus exploring beautiful New Zealand, but here’s more about our first flight mission and some links to stay involved!

Friday, June 6th, 2014: Hokitika, South Island, New Zealand

Click to view missions!
HIAPER GV Flight Path (4 dropsondes to release-all in the ocean)
Click for more mission plots!
Skew-T plot from 06 UTC Hokitika upsonde. We use these to tell us about the conditions at different levels of the atmosphere!

Today was our first Intensive Observing Period (IOP)! We’ve been watching the weather and tracking Energy Flux (EF) and wind over South Island, NZ. There’s a chance conditions will allow for internal gravity waves over us, so NSF/NCAR’s HIAPER GV research aircraft took off from Christchurch at 6 pm. They’re recording in-flight data and releasing dropsondes from 41,000 ft while we launch upsondes (weather balloons + radiosondes to collect data) from Hokitika!

Click for recent plots
Ceilometer Backscatter plotting above 4*10-9 m-1 sr-1 up to just after 4 pm local time. All the deep red reaching the ground (0 m on the vertical axis) is the rain we had today!

We launched two more upsondes here in Hokitika; one at 06 UTC and another at 09 UTC. The first used a 300 g balloon filled with 43 ft3 Helium, and the second filled with 39 ft3 He, rather than the 200 g balloons (bigger balloons because they reach higher altitudes before bursting = more data for us to use!)

I’m now tracking the 09 UTC upsonde and relaying its upper-air data to the HIAPER GV and the Operation Center in Christchurch. GV just let us know that the first two dropsondes were fastfalls, meaning their parachute didn’t deploy when released.  The exciting news is that gravity waves are now being tracked over the ocean southeast of South Island!  Next dropsonde is set for around 2230 local time.

20140606_195336
Relaying info to HIAPER and Ops Center!

Until then, I’m corresponding with HIAPER GV at least until the 09 UTC balloon reaches 150 mb. HIAPER is set to land back in Christchurch around 3 am and has the two dropsondes to release before then.

06 UTC launch with Jordan Miller
06 UTC launch with Jordan Miller

An overall exciting day for DEEPWAVE New Zealand and my first IOP experience!  (To say I was enthusiastic about today is an understatement–just ask our Project Supervisor Bill Brown, or Brian Billings who kindly brought me dinner while I was glued to the HIAPER GV chat and incoming data…)  

I’m very much looking forward to the days ahead with DEEPWAVE!  View the detailed summary of IOP #1 and future missions here.  If you’d like to stay updated on our experiment, check out our Field Catalog!

Truly,

Tash

 

 

 

Hokitika Downpour

 

Radar from today at 9:05 pm local time (Hokitika, New Zealand). See the rain shadow?! All of the rain’s coming from the windward side of the mountains over to the leeward side. Light Westerly winds, 10 mph at max.

NZ Met Service radar from today at 9:05 pm. See the rain shadow?! Rain’s coming from the windward side (west) of the mountains over to the dry leeward side. Light Westerly winds, 10 mph max.

 

Friday, June 6th, 2014 Hokitika, South Island, New Zealand

We’ve had rain, rain, and more rain that began two nights ago. We recorded a high rainfall rate at one point of 67 mm/hr (2.65 in/hr) mid-afternoon yesterday, but there may have been even higher rates overnight.  It looks like there may be some dry periods in Hokitika tomorrow morning through mid-afternoon, but we’ll get soaked again Sunday–maybe even more than the last couple days!