Science on a Plane

Temperature profile flying in to MSP around 2120 UTC on April 25, 2016.  Image credit: Bill Mitchell (CC-BY).
Temperature profile flying in to MSP around 2120 UTC on April 25, 2016. Image credit: Bill Mitchell (CC-BY).

One of my favorite things to do on an airplane, when I can, is to take a temperature profile during the descent. Until recently, this could generally only be done on long international flights, when they had little screens which showed the altitude and temperature along with other flight data. However, I found on my latest trip that sometimes now even domestic flights have this information in a nice tabular form.

To take a temperature profile, when the captain makes the announcement that the descent is beginning, get out your notebook and set your screen to the flight information, where hopefully it tells you altitude (m) and temperature (°C). Record the altitude and temperature as frequently as they are updated on the way down, though you might set a minimum altitude change (20 m) to avoid lots of identical points if the plane levels off for a while. When you land, be sure to include the time, date, and location of arrival.

When you get a chance, transfer the data to a CSV (comma-separated value) file, including the column headers like in the example below.


Alt (m),Temp (C)
10325,-52
10138,-51
9992,-48
...
250,17

You can then use your favorite plotting program (I like R with ggplot) to plot up the data. I’ve included my R script for plotting at the bottom of the page. Just adjust the filename for infile, and it should do the rest for you.

At the top of the page is the profile I took on my way in to Minneapolis on the afternoon of April 25th. There were storms in the area, and we see a clear inversion layer (warmer air above than below) about 1 km up, with a smaller inversion at 1.6 km. From the linear regression, the average lapse rate was -6.44 °C/km, a bit lower than the typical value of 7 °C/km.

On the way in to Los Angeles the morning of April 25th, no strong inversion layer was present and temperature increased to the ground.

Temperature profile descending into Los Angeles on the morning of April 25, 2016.  Image credit: Bill Mitchell (CC-BY).
Temperature profile descending into Los Angeles on the morning of April 25, 2016. Image credit: Bill Mitchell (CC-BY).

This is a pretty easy way to do a little bit of science while you’re on the plane, and to practice the your plotting skills when you’re on the ground. For comparison, the University of Wyoming has records of weather balloon profiles from around the world. You can plot them yourself from the “Text: List” data, or use the “GIF: to 10mb” option to have it plotted for you.

Here is the code, although the long lines have been wrapped and will need to be rejoined before use.


# Script for plotting Alt/Temp profile
# File in format Alt (m),Temp (C)

infile <- "20160425_MSP_profile.csv" # Name of CSV file for plotting

library(ggplot2) # Needed for plotting
library(tools) # Needed for removing file extension to automate output filename

mydata <- read.csv(infile) # Import data
mydata[,1] <- mydata[,1]/1000 # convert m to km
mystats <- lm(mydata[,2]~mydata[,1]) # Run linear regression to get lapse rate
myslope <- mystats$coefficients[2] # Slope of regression
myint <- mystats$coefficients[1] # Intercept of regression

p <- ggplot(mydata, aes(x=mydata[,2], y=mydata[,1])) + stat_smooth(method="lm", color="blue") + geom_point() + labs(x="Temp (C)",y="Altitude (km)") + annotate("text", x=-30, y=1, label=sprintf("y=%.2fx + %.2f",myslope,myint)) + theme_classic() # Create plot

png(file=paste(file_path_sans_ext(infile),"png",sep="."), width=800, height=800) # Set output image info
print(p) # Plot it!
dev.off() # Done plotting

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Big Ben Gigapan

Processing the Big Ben gigapan.  Screenshot by Bill Mitchell.
Processing the Big Ben gigapan. Screenshot by Bill Mitchell.

This post is the first in a series of three on the gigapans I took on Heard Island. (Part 2, Part 3)

My first gigapan on Heard Island, this one of Big Ben, came unexpectedly. As I was out hiking one afternoon, my hiking partner, Arliss, noticed that we had a clear view of the summit of Big Ben. Clearings like this can be relatively short and infrequent, so we took a few pictures immediately. We headed back to base camp just east of Atlas Cove, arriving under an hour before sunset. The mountain was still visible, so I moved quickly to set everything up and get the gigapan taken before the light faded.

From camp, Big Ben is situated to the southeast, rising up beyond the flat sandy plain of the nullarbor. In this view, the moraines and glaciers begin about 2 km from the camera. To the right of the image is the eastern slope of Mt. Drygalski. The edge of the Azorella Peninsula lava flow is in the bottom left corner.

Glacial features dominate the landscape, including a prominent moraine now covered in vegetation (lower right). Coming toward the camera are the Schmidt and Baudissin glaciers. I think this view covers from the Allison and Vahsel glaciers (at right) to the Ealey glacier (at left).

On the Nullarbor, there are a few king penguins and elephant seals, primarily to the left of center.

Big Ben itself has a range of rock types, including basanites, alkali basalts, and trachybasalts, overlying limestones and volcanic/glacial deposits.[1-4]

[1] Quilty, P. G.; Wheller, G. (2000) Heard Island and The McDonald Islands: a Window into the Kerguelen Plateau. Papers and Proceedings of the Royal Society of Tasmania. 133 (2), 1–12.

[2] Barling, J.; Goldstein, S. L. (1990) Extreme isotopic variations in Heard Island lavas and the nature of mantle reservoirs. Nature 348:59–62, doi 10.1038/348059a0.

[3] Barling, J.; Goldstein, S. L.; Nicholls, I. A. (1994) Geochemistry of Heard Island (Southern Indian Ocean): Characterization of an Enriched Mantle Component and Implications for Enrichment of the Sub-Indian Ocean Mantle. Journal of Petrology 35:1017–1053, doi 10.1093/petrology/35.4.1017.

[4] Stephenson, J.; Barling, J.; Wheller, G.; Clarke, I. “The geology and volcanic geomorphology of Heard Island”, in Heard Island: Southern Ocean Sentinel (Eds K. Green and E. Woehler) Surrey Beatey & Sons, 2006, p. 10–27.

Back to Shore

Carlos and Bill on the prow of the Braveheart, between Heard Island and western Australia.  Image credit: Braveheart crew, used with permission.
Carlos and Bill on the prow of the Braveheart, between Heard Island and western Australia. Image credit: Braveheart crew, used with permission.

After a 10-11 day voyage, our expedition team has arrived in port. It’s good to be back on land again, though I will very much miss the company and atmosphere aboard the ship. The crew aboard the Braveheart were amazing, the food was delicious, and it was kind of fun to unplug (mostly) from the internet and civilization for a while.

Heading Home

Yellow-nosed albatross flying alongside the Braveheart.  Image credit: Bill Mitchell (CC-BY).
Yellow-nosed albatross flying alongside the Braveheart. Image credit: Bill Mitchell (CC-BY).

As may have been apparent from the silence here, we have left Heard Island and the good satellite connection we had there. Aboard the Braveheart, we have had only sparse email access on a special pared-down email account. Today, however, with good weather conditions and a very gentle sea state, we have been able to use the satellite internet terminal again.

Presently we are roughly 200 miles WSW of Fremantle, Australia, and expect to enter the harbor on Friday. The sun is beginning to set, and there is a beautiful warm light on the sea and the ship.

On board, we have been going through photographs and paring down the unusable ones, processing the good ones, exchanging images with each other, and writing descriptions of those which are of particular note or are of unusual things. Our science team have been processing samples and preparing them for shipment. Daily cloud observations and occasional 10-minute bird counts are still being performed.

Heard Island was a magnificent place to visit, and I am very glad to have had the opportunity to go. I managed to take three gigapan pictures, including one of Big Ben. I wish there had been more gigapans, but time and weather windows were quite limited and limiting. When I have a bigger, more reliable connection I’ll write more about the gigapan project results (and upload the gigapans).

There are still a few days of travel ahead, plus a flurry of activity in Fremantle. It’ll be a struggle to get photos processed and documented, enter a little data about the scientific samples, and get a couple presentations written before getting home. Even then, I will still need to write up some of the results of my scientific projects on the island.

To the End of the Earth

The end of the Earth.  Image credit: NASA (public domain), modified by Bill Mitchell (CC-BY).
The end of the Earth. Image credit: NASA (public domain), modified by Bill Mitchell (CC-BY).

This post written March 6, 2016.

When I was in elementary school, we learned that the opposite point on the globe from the Twin Cities was in the southern Indian Ocean, far from any land. I thought to myself: it would be interesting to go to the opposite point on Earth [ed: the scientific term is antipode], but given that it’s in the middle of a vast ocean with nothing of note nearby, I’ll never see that spot.

Yet, now I am going there, the antipode of the Twin Cities, passing it on the way from Heard Island to Australia. This is as far away from home as it is possible to be without going to space. I have reached the end of the Earth, literally.

You can see that end of the Earth in the image above, taken by astronauts on the space shuttle while they were over (roughly) the antipode of the Twin Cities, at roughly the time I was thinking it would be interesting to go there.

Pictures from the Field

Standing just outside the tents at Atlas Cove, Heard Island, on a clear evening.  Note that there is no incandescence from lava on Mawson Peak.  Image credit: Adam Brown.
Standing just outside the tents at Atlas Cove, Heard Island, on a clear evening. Note that there is no incandescence from lava on Mawson Peak. Image credit: Adam Brown.

A few days have gone by, and they have been busy! We’ve been fortunate in that when the weather has been poor, the radio propagation has been good. A fair bit of windy, drizzly weather has been present this week, and we have managed to make more than 50,000 contacts with stations all around the world.

Unfortunately, the weather has meant I haven’t had the opportunity to take more gigapans. I am prepared for wet weather, and this morning I went a few hundred meters across the lake which had formed in front of camp (ankle deep) to Wharf Point, the point inside Atlas Cove. There on the cobbles lining the beach I did a stationary count of the birds in the hummocks nearby, on the water, and along the beach. It took about 10 minutes, and I managed to get the list recorded in a weatherproof notebook for upload later. Getting out of the tent and away from things for a while was a welcome change.

Inside the operating tent are many tables with radio equipment.  We have six stations set up, two of which are outside the frame to the left.  The galley is just barely showing on the right, and I'm standing in the front door.  The sleeping tent is through a little hallway.  From left to right, by leftmost extent of the head, we have Adam, Dave Lloyd, Jim, Vadym, Ken, Arliss, and Hans-Peter.  Image credit: Bill Mitchell (CC-BY)
Inside the operating tent are many tables with radio equipment. We have six stations set up, two of which are outside the frame to the left. The galley is just barely showing on the right, and I’m standing in the front door. The sleeping tent is through a little hallway. From left to right, by leftmost extent of the head, we have Adam, Dave Lloyd, Jim, Vadym, Ken, Arliss, and Hans-Peter. Image credit: Bill Mitchell (CC-BY).
The sleeping tent, which sleeps 14.  Although there are windows, they are kept shuttered all day.  It's a good place to sleep, but not particularly warm.  Image credit: Bill Mitchell (CC-BY).
The sleeping tent, which sleeps 14. Although there are windows, they are kept shuttered all day. It’s a good place to sleep, but not particularly warm. Image credit: Bill Mitchell (CC-BY).

One thing which has been abundantly clear on this expedition is that if you want to do something that depends on the weather, be prepared to do it. The weather can shift very rapidly (especially if it’s permissive weather), so “I’ll just wait until later” often won’t cut it. If you see Big Ben and want a photograph of it, get your camera and shoot. There may not be another chance. This evening I didn’t immediately take a picture when there was a clear, starry sky. I at least saw the starry sky, but did not get the photograph. With only a bit more than a week to go, I hope I can still get that picture.

In the afternoon a few days ago, the weather cleared enough to get a view of Mawson Peak atop Big Ben. I quickly grabbed the camera, put on the telephoto lens, and got a few pictures of the summit. Indeed, there was a small plume indicating (at minimum) hydrothermal activity or venting, but possibly a small active lava flow.

Mawson Peak with a small plume indicating volcanic activity.  Image credit: Bill Mitchell (CC-BY).
Mawson Peak with a small plume indicating volcanic activity. Image credit: Bill Mitchell (CC-BY).

Heard Island’s mood changes with the weather, and the effect that has on the landscape can be quite striking. The picture at the top of this post and the one immediately below are taken in pretty similar places looking in similar directions. What a difference the weather makes!

Antenna Lake, Atlas Cove, Heard Island.  Rain fell fast enough to flood much of the low-lying volcanic sand plain near our camp.  We were glad not to have camped there, and the antennas still worked.  It looks quite other-worldly, with the dark, broken lava flows and fog concealing the mountain.  Image credit: Bill Mitchell (CC-BY).
Antenna Lake, Atlas Cove, Heard Island. Rain fell fast enough to flood much of the low-lying volcanic sand plain near our camp. We were glad not to have camped there, and the antennas still worked. It looks quite other-worldly, with the dark, broken lava flows and fog concealing the mountain. Image credit: Bill Mitchell (CC-BY).
Camp seen on a rainy, dreary day typical of Heard Island.  Image credit: Bill Mitchell (CC-BY).
Camp seen on a rainy, dreary day typical of Heard Island. Image credit: Bill Mitchell (CC-BY).

Finally, the king penguins make tracks as they walk around on the wet sandy ground.

King penguin tracks in the sand of the nullarbor, Heard Island.  Each track is roughly 8 cm in length.  Image credit: Bill Mitchell (CC-BY).
King penguin tracks in the sand of the nullarbor, Heard Island. Each track is roughly 8 cm in length. Image credit: Bill Mitchell (CC-BY).