As is typical, finding the “ideal” radar locations proved to be challenging.  The primary goal was simple enough — a high spot with a good view.  Then we add in the need for power, communications, and access, and it becomes more complicated.

The Turkey River basin, unaltered by glaciers, is rugged and hilly by Iowa standards. Lots of great views, but the ruggedness that makes some of the land difficult to farm, and also means there are a lot of obstructions on the tops of hills, namely tall trees. This image is the “radar’s eye “ view from the St. Olaf site and demonstrates why it was chosen. Credit: Iowa Flood Center

After much planning, looking at satellite images, talking with local cities and groups, it was time to visit the basin for a reality check.  Many sites that had appeared so promising became distant memories, but new possibilities arose with help of local individuals from the City of Decorah, the City of Calmar, local IDNR staff, Northeast Iowa Community College, and others.  We are grateful for their “touring the countryside” time and cooperation.  In the end, two very attractive locations were secured, one in Calmar and one south of St. Olaf.

April 30, 2013, Calmar site: The XPOL installation at Calmar went smoothly enough. It was very windy, but sunny, with mild temperatures. For the follow-up installation of the communications, we dealt with very windy conditions and ice-covered surfaces. Credit: Iowa Flood Center

May 2, 201, St. Olaf Site: The St. Olaf installation was a bit better, 38 degrees F (warm??) , overcast, and very windy, with rain all day. Visiting scholar Jacopo Grazioli, Dan Ceynar, and Radek Goska of the Iowa Flood Center adjust the radar position on the cribbing. Credit: Iowa Flood Center

As many visiting researchers and NASA and scientist are now fully aware, the weather in Iowa is constantly changing, often between extremes. The weather during the installation of the XPOL radars was challenging, ranging mostly from cold, windy, and rainy to windy and icy. Very challenging indeed. Tenacity prevailed, and both new radar locations were successfully installed at the beginning of the month despite the adverse weather conditions.

From May 1 to June 15, NASA and Iowa Flood Center scientists from the University of Iowa will measure rainfall in eastern Iowa with ground instruments and satellites as part of a field campaign called Iowa Flood Studies (IFloodS). They will evaluate the accuracy of flood forecasting models and precipitation measurements from space with data they collect.

Dan Ceynar is a staff engineer at the Iowa Flood Center. He coordinates many of the Iowa Flood Center’s instrumentation networks across Iowa including stream sensors, rain gauges, and XPOL radars. This spring, he has been busy working with NASA and IFC staff to deploy instruments for the IFloodS campaign.

2012 was a year of historic drought in Iowa. IFloodS is all about studying and measuring precipitation. What if drought continued into 2013? In short, what if it didn’t rain?

Turns out my fears were unfounded. The spring of 2013 has turned out to be wet. Very wet. In mid-April, Iowa City got 4.5 inches in a single day, while nearby North Liberty’s rainfall totaled a whopping 8.3 inches that has less than 1% chance of being exceeded in any given year.

May, 2013. Despite a drought in 2012, the NASA NPOL radar near Waterloo has been able to capture information from multiple precipitation events in Iowa this spring. Credit: Witold Krajewski / Iowa Flood Center

OK, so I am no longer worrying that we’ll set up some of the most sophisticated instrumentation in the world for measuring precipitation, only to find ourselves measuring dust.

This last weekend I got the chance to drive around the state and see firsthand what heavy rainfall was doing to Iowa’s streams, rivers, and landscape. I drove north out of Iowa City to the NASA NPOL radar site near Waterloo. As I crossed many streams and rivers in the Cedar River basin, I observed water running high and fast.

May, 2013. Many Iowa streams are bank full this spring after heavy April rain events. Credit Witold Krajewski / Iowa Flood Center

Later on, I drove south to pick up my wife from a horseback outing, and I saw more elevated stream levels and saturated farmland.  Many streams were overflowing the banks.  It reminds me that everything we do at the Iowa Flood Center cannot completely prevent floods and the damage they bring. We can better inform people about impending floods, and we can improve mitigation strategies to lessen the damage. These are all worthwhile activities that I believe in wholeheartedly. But it’s worth remembering, even as we are in the midst of this exciting project, that it’s not the state-of-the-art technology or the groundbreaking studies that matter the most — it’s the people we serve, the citizens of Iowa and citizens of the world, who are living with floods.

Witold Krajewski is the director of the Iowa Flood Center, based at the University of Iowa in Iowa City. He is a professor in the Department of Civil and Environmental Engineering and serves as the Rose & Joseph Summers Chair of Water Resources Engineering. His scientific interests concern measuring, modeling, and forecasting precipitation using radar and satellite remote sensing.

May 3, 2013. The D3R radar, which measures precipitation at similar frequencies as the radar on the GPM Core satellite, measured rain, snow, and sleet at the Traer site in Iowa. Credit: Walt Petersen / NASA

In fact, the snowfall portion of the storm turned out to be a record event for Iowa in May. The fact that D3R and NPOL co-scanned the event is important because you have a longer wavelength, high power reference radar (NPOL) with dual-polarization (both vertical and horizontal scans), and hence enhanced capability to discern specifics on precipitation shapes, sizes and numbers, scanning coincident with a radar (D3R) that carries the same higher frequencies that the DPR radar will carry on the GPM Core Satellite.

The higher frequencies of the D3R are more sensitive, but will often attenuate, or dissipate, faster in the mixture of precipitation we sampled. So, you can test how well you can correct for that attenuation and retrieve the complex precipitation structure from the D3R, which is our proxy for the space-borne radar, against your reference platform, the NPOL. At the same time, we learn a great deal about the precipitation physics when we look at things with 3 different frequencies and in dual-polarization modes.

Map of field locations of IFloodS instruments. The NPOL and D3R radars are located dead center and a ray of disdrometers and rain gauges stretches southeast toward Iowa City in the bottom right. Other rain sensors are distributed throughout the Turkey River basin in the north east and the south fork of the Iowa river west of Traer. Credit: Iowa Flood Center

Moreover, we did this over a “reference” 100 km-long ray of disdrometers, vertically pointing micro rain radars, and rain gauges – all in all, what will probably amount to a great deal of information to interpret.

From May 1 to June 15, NASA and Iowa Flood Center scientists from the University of Iowa will measure rainfall in eastern Iowa with ground instruments and satellites as part of a field campaign called Iowa Flood Studies (IFloodS). They will evaluate the accuracy of flood forecasting models and precipitation measurements from space with data they collect. Walt Petersen, a scientist based at NASA’s Wallops Flight Facility, is the Ground Validation Scientist for the Global Precipitation Measurement (GPM) mission.

We had some funny things happen with the antenna last night. Wind stopped it a few times in big gusts; it is a big 28-foot “sail” after all, and then we had some miscommunication between the antenna controller and the software that controls scanning. The radar scientist on duty, Dr. Timothy Lang, came up with a good work-around. His solution was to run constant “PPI volumes,” which basically do a full 360 degree sweep at several elevation angles. This enabled us to keep collecting good data and to do it at our sub-3 minute cycle time. We set that time as the outside limit on how frequently we wanted to fully sample the rainfall field around us.

We got the antenna situation repaired this morning, and I was able to go back into alternate rain scan vs. range-height scanning mode with the D3R, so that we sample both the rain field and the structure of the precipitation with height at very high resolution along our ray of disdrometers and rain gauges that stretch in a line toward Iowa City.

May 2, 2013. A radar image similar to what you’d see in a weather report. Precipitation appears in colors ranging from light rain (blue to green) to heavier precipitation (yellow to red). Credit: NPOL radar / NASA

One thing that is really impressive is the change in precipitation type, and the rapid drop in the height of the freezing level we are seeing as one moves west of the radar. This is illustrated nicely in the dual-polarimetric data that the radar collects. The first image (above) shows an example of the radar reflectivity field that we saw around 15:15 UTC (or 10:15 local time). This variable is typically what your TV Meteorologist shows you on the evening newscast. Notice the band of higher reflectivity just to the west of the radar that indicates heavier rain.

Now the second image (below) shows a variable called the “correlation coefficient” or, RHOHV. This variable takes the signal at both the horizontal and vertical polarizations and computes their correlation at each range sample along all the rays. It is a sensitive measure of the degree to which you have a mixture of liquid and frozen precipitation particles in a given sample volume.

May 2, 2013. This radar image combines two measurements to show what the mixture of liquid and ice is in the precipitation. Bright pink is liquid rain. Yellow to red shows that snow and ice are mixed with the rain. The line of this rain-snow mix stretches from the southwest (bottom left) to the northeast (top right) of the NPOL radar. Credit: NPOL radar / NASA

Raindrops are usually very highly correlated and values will typically exceed 0.98 or so. However, when you get a mixture of snow and rain, the correlation drops rapidly. You can see this rapid drop in correlation to the west of the radar along the narrow line yellowish to orange colors (embedded in the solid pinkish colors of high RHOHV) that extend in a line from southwest of the radar up to the northeast of the radar. That is where the infamous rain-snow line is located in Central Iowa. We await the arrival of that line over NPOL—though it is only progressing eastward very slowly.

Dave Wolff is a radar scientist at NASA Wallops. He is monitoring the radar data inside the science trailer on site at Traer, Iowa. Credit: Walt Petersen / NASA

Dave Wolff (above), my companion Radar Scientist this week, and also from NASA Wallops, has done a great job of getting some of our NPOL imagery online in real time, so that is a big help to the field operations. It seems that most of the equipment and networking is working- a testament to the hard work several of these folks are putting in.

I must say though, right now I am most anxiously awaiting a hot cup of coffee which one of our Radar Engineers has graciously offered to grab for me on his lunch run.

From May 1 to June 15, NASA and Iowa Flood Center scientists from the University of Iowa will measure rainfall in eastern Iowa with ground instruments and satellites as part of a field campaign called Iowa Flood Studies (IFloodS). They will evaluate the accuracy of flood forecasting models and precipitation measurements from space with data they collect. Walt Petersen, a scientist based at NASA’s Wallops Flight Facility, is the Ground Validation Scientist for the Global Precipitation Measurement (GPM) mission.

May 1, 2013. Clouds along the “fine-line”, a boundary that means a change in wind, temperature and/or humidity is occurring. Credit: Walt Petersen / NASA

At any rate, we watched one of these boundaries for quite some time yesterday with the radar. It passed NPOL in the afternoon (below) and I went out to take a quick picture of the clouds along it (above; which were unimpressive…..alas).  However, southwest of Des Moines there were a few severe storms that developed along the same line; just didn’t happen in our area.

NPOL radar view of the “fine-line.” Clouds and rain are shown in blue. The NPOL position is labeled in white and the line of green sites show where the ground instruments are located. Credit: NASA

Today (currently) we are awaiting a major storm system that is sitting just to our west and northwest and producing rain mixed with snow in the northwest corner of Iowa — the same system that was producing snow in Colorado early this morning. It looks to be wet and cold here for the next few days after the storm arrives. If and when we get the rain/snow mix, we will focus very hard on coordinated scanning with the D3R as this will be a very unique opportunity for us to collect data in a mixed-phase event with three different radar frequencies at dual-polarization. Since this situation happens more often in the mid-latitudes, and GPM will extend our rain and snowfall measurement capability into the mid-latitudes, this could be a great case for looking at the famous “rain-snow line” transition and how our GPM radar and radiometer algorithms will work in this situation.

From May 1 to June 15, NASA and Iowa Flood Center scientists from the University of Iowa will measure rainfall in eastern Iowa with ground instruments and satellites as part of a field campaign called Iowa Flood Studies (IFloodS). They will evaluate the accuracy of flood forecasting models and precipitation measurements from space with data they collect. Walt Petersen, a scientist based at NASA’s Wallops Flight Facility, is the Ground Validation Scientist for the Global Precipitation Measurement (GPM) mission.

Patrick Gatlin (NASA/MSFC) and Merhala Thurai (Colorado State Univ.) perform calibration tests on a NASA two-dimensional video disdrometer (2DVD) being used to measure the size, shape and fall speed of raindrops for the IFloodS campaign. Credit: NASA

Shaped like a giant pizza box, the disdrometer has a medium sized square opening in the center. Along two adjacent sides at 90 degrees from each other are two video camera systems that record the raindrops as they fall. With a front view and side view of the droplets, scientists can determine their size and shape, and get an idea of how many of differing sizes are falling.

Hamburger shaped raindrop viewed by the disdrometer software from the front (left) and side (right). Credit: Patrick Gatlin / NASA

“A common misconception is that raindrops are shaped like a tear-drop, but actually they are shaped more like a hamburger bun similar to the 5 mm sized raindrop shown here,” Gatlin says. During IFloodS, millions of raindrops will be measured by these type of rainfall sensors. Scientists will examine all these raindrops in order to provide better estimates of rainfall from weather radars probing the atmosphere from the ground up and those looking down on Earth from space, like the eventual GPM Core satellite.

Apr. 8, 2013. NASA and Iowa Flood Center staff set up about 20 disdrometers throughout the field area in April. Credit: Aneta Goska / Iowa Flood Center

From May 1 to June 15, NASA and Iowa Flood Center scientists from the University of Iowa will measure rainfall in eastern Iowa with ground instruments and satellites as part of a field campaign called Iowa Flood Studies (IFloodS). They will evaluate the accuracy of flood forecasting models and precipitation measurements from space with data they collect.

From May 1 to June 15, he is leading the Iowa Flood Studies, or IFloodS campaign in eastern Iowa. He and his team, as well as their partners at the Iowa Flood Center at the University of Iowa are measuring rainfall with ground instruments, ground radar, and satellites, and then evaluating flood forecasting models. Over the next few weeks, Walt and others on the ground will be sending us their notes from the field.

4/29/2013, NPOL Radar Site near Traer, Iowa

Apr 29, 2013. The NASA Polerametric (NPOL) precipitation radar (center) scans for rainfall in both the horizontal and vertical planes to measure precipitation throughout the whole volume of the air column. The smaller D3R radar is to the far left. Credit NASA

This morning, my first full day around the area of Waterloo, Iowa. Quite appropriately, we were greeted by severe thunderstorms with some ping pong ball-sized hail in the area. Luckily for my rental car,  and even more luckily for the NPOL and D3R antennas, that hail stayed north of the radar site (large hail, rental cars, and/or radar antennas not being the best mix). I thought it an appropriate welcoming to the experiment. I drove out to the radar for the first time this morning in my little Nissan rental car. I’ll be curious to see how it does on the gravel/dirt road after it rains a few inches.

Apr. 25, 2013. A team of NASA staff and Iowa Flood Center and University of Iowa students assist with the NPOL setup in eastern Iowa. Credit: Aneta Goska, Iowa Flood Center.

Things are impressive out here. The NPOL and D3R guys did a very nice job of getting the NPOL and D3R set up. We are still in the midst of tweaking small things prior to getting down to serious data collection. For example, we need to make certain that the NPOL is well-calibrated (doing that now), and then we need to test the timing of our scan sequences to make sure we are making the requirement that we sample the rain field in a 360 degree circle once every 3 minutes or less. The objective is to make rapid maps of rainfall (out to a range of say, 150 km, from the NPOL) at high time and space resolution, and then in between making those rain maps, do coordinated scanning of the precipitation in the vertical plane with the D3R radar or over other river basins of interest. The rapidly collected rain maps serve as a reference for doing our comparisons to satellite products and to test products for hydrologic modeling of runoff (e.g., flood forecasting).

Apr. 29, 2013. The science trailer where data from the radars is collected. From left to right, Walt Petersen, Dave Wolff, and Delbert Willie. Credit: NASA

The coordinated scanning with the D3R is done for a slightly different reason. These scans are collected along a line that has many raingauges and disdrometers located at different points so that we can connect the dots between the rainfall we are measuring near the ground (for example, rainfall rates and raindrop sizes, numbers and shapes) to the physics happening in the column of the atmosphere above those points (e.g., how the rain is made). We care about this from the perspective of testing algorithms designed to retrieve precipitation estimates from space using the GPM DPR radar (which has similar frequencies to the D3R) which will fly on the GPM Core satellite.

Hi there! Today I have another story to share with you! It’s about the tracking of the temperature evolution of the firn aquifer temperature by using two thermistor strings that we set up in the two holes made by Jay (see Jay’s post on drilling for details).

By tracking temperatures over a year, we will observe the firn heating mechanisms in the summer with the melt from the surface of the ice followed by water infiltration in the firn. In the winter, we will get a sense of the refreezing processes from the cold surface air, which cools the upper part of the firn and we will observe the persistence of the firn aquifer over the years.

To achieve this, we installed two thermistor strings with two different lengths: 30 and 60 meters. The shorter string has 60 sensors on it, sampling every half-meter. The longer one will only get a temperature reading every 2.5 meters but it will record deeper temperatures. Both strings are set to collect data every hour for an entire year, assuming the batteries last that long (hopefully!) The temperature chain is called a thermistor string because each sensor is a thermistor, a type of resistor sensitive to temperature changes. After measuring a resistance change, calibration curves allow us to retrieve temperature changes.

The thermistor-string story started in Utah, when we received the equipment late from the manufacturers, giving us only 5 days to work on it before leaving for Greenland. We realized that integrating the whole system together with the satellite uplink would take most of our last prep days.

It was definitely too late to ship the thermistor equipment with the rest of our gear, so Rick and I traveled with it in our checked luggage! I ended up with a 50 lbs of spool coiled with about 60 meters of cable in a suitcase. Rick had a black pelican case as his checked bag, with the second thermistor string, datalogger, ARGOS antenna and other pieces of hardware. We learned how to travel light, bringing minimal clothing, and wearing the cold-weather clothes in the airplane so we were able to meet the airline luggage restrictions – it definitely made for fun travels!

At the Kulusuk Hotel, in southeast Greenland, we finished integrating the thermistor string, mostly by picking the right data-transmission rate to the satellite in regards to our battery consumption estimates. Having the ARGOS satellite uplink will let us receive temperature data via email every day from the field site and tell us almost in real time what the temperatures are in the two holes.

In the field, shortly after drilling each hole (to avoid water refreezing due to cold air down the hole), we lowered the thermistor string down and backfilled the hole with surface snow. Then, we used the Felics drill to make a 4-meter hole to anchor the long pole that holds the ARGOS antenna.

Lowering the second thermistor string down the 30-meter hole.

On that day, the 20-knot katabic winds were blowing a lot of snow, so we used a mountain tent as a snow-proof environment to work with the electronics before dropping off the case in its hole. To give you a taste of the wind speed: Rick was charging one of the thermistor-string battery and the wind was so strong that it blew the small 1kw generator off…. crazy! When the winds finally died down, we buried the case in a 2-meter deep snow pit, because we wanted to prevent the case from being exposed to surface densification and melt during the summer.

Digging a deep snow pit for the thermistor case.

Last check on the electronics, to make sure all the wires are tightened before closing the box — next opening in one year!

That is it! The box is down the hole.

After backfilling the snow pit, the only evidence at the surface of the temperature strings is the top of the pole with the ARGOS antenna and a red flag!

We are hoping to recover the case with the datalogger next year, but we are not sure if the ARGOS antenna will still be sticking out, because this sector of the ice sheet is getting a lot of snow accumulation in the winter. We will use a metal detector to find the metal pipes left near the case.

Because this is likely my last post for this expedition’s blog, I would like to thank the all team for this great adventure and everybody that was supporting this exciting research. Until next time!

Watching dogsleds go by in Kulusuk.

Well, I am back in Greenbelt, Maryland, typing with warm fingers in a climate-controlled office with high-speed Internet and drinking fountain just down the hall. After fieldwork, I am always thankful for things I generally take for granted, like being able to charge my laptop by simply plugging it into an outlet. There is no longer a need fill a generator with gas and then start it just to charge batteries. Aw, the comforts of home!  (We all had safe trips back to the US and have returned to our home institutions last week.)

For the last blog post of the season, I decided to pull together a few of my favorite photos from our trip to give you a sampling of the great fun we get to have while doing this kind of research. The most fun I had during this trip was on our final day in Kulusuk: we were invited to the Kulusuk School to with the children in the upper grades (who speak some English) about our work. I regret that we do not have any pictures of this event, but we were giving our presentation and letting the students run our small ice core drill, thus neglecting picture taking. The school in Kulusuk has about 70 students and includes all grades. The building has lots of windows and is very bright inside — it is one of the prettiest schools I have been in, with lots of open space, a small kitchen, library and a gym. I especially liked the entrance to the school, which was equipped with plenty of coat hangers and boot racks for the students to shed their cold weather gear as soon as they come inside. Though we were there talking about science, the school in Kulusuk is known for their art. We were hosted by the art teacher, Anne-Mette Holm, and after our talk got to attend one of her classes where the students were making wooden sculptures. We also got to see other student projects including weaving, toy making and furniture making. Quite a portfolio!  The students’ art has traveled the world, being shown at different expeditions across the Arctic. (Check out pages 11 -15 of this document for some examples of the children’s art work under Anne-Mette’s tutelage.)

While our visit to the school was definitely the top highlight of the trip here are a few others highlights in pictures.

The northern lights (Aurora) never got old and were out almost every night.

The view out the window from our dinner table in Kulusuk at sunset.

Sunset in Kulusuk.

Seeing mountains from our campsite on the ice sheet, a nice change from the typical flat white ice sheet.

Watching Clem dig a really big hole for the thermistor control boxes.

Seeing the transition between the flat ice sheet and the fast flowing outlet glaciers.

Catching a ride in the airport luggage carts.

So those were some of the highlights of the field work and now it is time to work with the data we gathered. In the week we have been back, we have already started to analyze our data. We see that, as expected, the densities in the firn (aged snow) above the aquifer are higher than expected and that there is more water than originally predicted. We still need more data to fully understand what this water trapped in the Greenland ice sheet means for sea level rise. We need many years of data to understand how and if the aquifer is changing with time… but remember this was an exploratory mission. When we set out, we were not even sure if our drills would even work. There was a chance they would have just frozen in place and we would not have gotten any data. This was a high-risk mission due to the weather in the region and all the new things we were trying. We came back with all the data we set out to get and, quite frankly, I am surprised. We had a large team that helped with this project including the field team, logistics support, airport support, the NASA and NSF support teams and all of you for your well wishes and interest in our research. Thanks to all! Until next time, stay cool

We were on Greenland’s ice sheet for only a week, but despite the short deployment, we had to accomplish two main science objectives. The first was drilling two deep cores into the firn (aged snow) and ice (30- and 65-m deep, respectively), to insert temperature probes that will record temperature evolution at various depths. Secondly, we wanted to drill shallower cores (7 to 15 m) to record the snow’s density vertical profile using a neutron density probe – and this is what this post is going to be about: the shallow drilling that we did and the measurements we took in these holes to monitor the snow and ice layering and their properties.

To drill the shallower cores, we used the same solar-powered drill as in 2010 and 2011 in Antarctica during the Satellite Era Accumulation Traverse. It is composed of four parts, which I’ll describe from top to bottom. The first segment contains the motor to rotate the other parts. The second and third parts are barrels — one for the snow and ice chips, and the other to store the one-meter long drilled core. The fourth part, the cutters, is screwed into the latter barrel. Cutters are critical since they are the sharp elements that cut the snow, firn, and ice. Since snow and ice having different properties, the cutters for snow and ice are different. For instance, if we use the ice cutters at a smaller angle, we will drill at less depth during each barrel rotation. Where we drilled, part of the winter snow melts during the summer and when it refreezes, it forms a thick ice layer every year. The snow that did not melt will slowly evolve to firn, and, eventually, ice. Because of the different, we thus had to switch cutters during our drilling: otherwise, we would have not been able to drill through the past summer ice layers.

Ice cutters screwed at the bottom of the barrel, which rotates into the ice to extract an ice core.

Lora showing how to extract the first meter of the snow core.

Jay drilled cores through the water contained within the firn (the aquifer). We used our smaller drill, since we did not want to enter in contact with the aquifer. Therefore, each of our cores was shallower than the water layer’s top and each was drilled in about an hour.

Once we had drilled the hole, we observed the layering of the snow and ice cover using a video camera. Thanks to the camera’s flashlight, we were able to identify the thick 2012 summer ice layer (about 3 m below the surface) that formed after a massive surface melt event, as well as the previous summer ice layers. Our team used this sensor to monitor a water-filled hole for the first time. We were all really excited to see the inner upper part of the ice sheet!

Lora holding the video camera that she will send down in the hole to monitor the snow and ice layering.

Rick and Clem enjoying the first view of the firn’s internal stratigraphy

We also used this useful device to check the position of the temperature probes and to ensure that the entire line of temperature sensors was straight inside the hole. The first time we inserted the camera into the water in the hole, we were amazed to discover the amount of air bubbles released by the firn, which propagated toward the water/air interface. The aquifer is composed of ice, water, and air. These elements are present several meters below the surface, which means they’re under pressure. Once we drilled the cores, the pressurized air bubbles in the vicinity of the hole migrated toward the hole and then moved upwards to the water/air interface.

Our last scientific activity was to monitor density with 1-cm vertical resolution using the neutron density probe. We moved the probe along the borehole at a speed of about 5 cm per minute. This sounds like a time-consuming measurement, but measuring density manually is significantly more labor intensive since one must saw the core into segments and then measure each segment’s length, diameter, and weight.

To be more comfortable during the drilling and while recording our scientific data, we always paid particular attention to staying behind our wind break.

Lora and Ludo drilling behind a windbreak during a windy day, with a lot of blowing snow near the ground.

A windbreak is composed of a simple plastic tarp supported by bamboo sticks and held by bungee cords. While we were in Kulusuk preparing our departure to the field, Jay told us several times that bamboo sticks would be critical pieces of equipment while we worked on the ice and that they had to be in mint condition to offer the best resistance to wind. So we spent more than a day in Kulusuk fixing and reinforcing bamboo sticks, using wires and tape. And I am glad we did it!

Working in the warehouse to improve the bamboo sticks that we’ll use in the field as wind breaks.

Once we had collected all the data needed from a hole, we packed our equipment, removed the precious windbreak and the bamboo sticks, and either headed toward a new site few hundreds meters away, or went to the cook tent for diner. That’s how our busy days in the field went!