Modelling activities; chemistry-climate model and obserations

The last report was already the 9th of September where I then indicated that not much had happened since my return from Greenland in July. However, we have now Brian Seok from the Institute of Arctic and Alpine Research (INSTAAR) at Colorado University, Boulder, visiting me to work together on the use of a column model version of a chemistry-climate model to help interpret all observations at Summit. For Brian, who has a more experimental background, this is a great opportunity to get introduced in the "challenges" of modelling the complex behaviour of chemical compounds in the harsch environment over- and within the Greenland icesheet. Before we can start focussing more on a comparison of the observed and simulated exchange of reactive compounds such as ozone and nitrogen (di)oxides we first need to know that the model is doing a reasonable job on simulating the local meteorology at the site. This is because the chemical processes all strongly depend on many meteorological parameters such as temperature, wind speed and radiation. In the figure you can find one result of the very nice comparison that Brian has been doing last 2 months; it shows a comparison of the measured and simulated net radiation at the surface showing that the model is reasonably well simulating this important parameter that controls the snowpack temperature but also the so-called "photolysis" of chemical compounds like ozone and nitrogen dioxide.

In the near future we will show more results and hope that Brian will soon be able to write a nice publication about these very interesting findings,

Laurens

Time for an update

I have already been back now for about 2 months and have been busy with many other activities but in some month we will have one of the team members from Colorado University, Brian Seok, visiting Wageningen for about half a year. He will get started with the modelling of some of the processes we observe at Summit and so hope to give some more updates on the progress on this in the upcoming months,

Laurens

Back in Kangerlussuaq

It is nine in the morning after an early start to fly back to Kangerlussuaq. Last days I have not given more updates on the work and live at Summit also since it has been quite stormy and because the system that I was supposed to use for additional measurements needs to be fixed. Hopefully, I can get some of the spare parts we need here in the warehouse in Kangerlussuaq. Today I flew in in my private jet; it was the Hercules but because of the high temperatures, making the snow at Summit really heavy they needed the JATO system to take off. These are kind of rockets that give the airplane the extra push to take off at this high altitude with the heavy conditions (so the C-130 being a jet for a short moment). I was also the only passenger going out and so could sit at the flight deck with the pilots having a great view especially flying in to Kanger passing by the mountain ridges quite close. By the way, it was also an expensive flight; they told me that using this JATO system costs about 180.000$! Consequently, they hardly use it and the crew was really happy that they took off without any problems, Maybe later some more updates on the data interpretation of this campaign Laurens

Inspector Clousseau at Summit

4th of July at Summit; all people have the whole weekend off except of us. We went today to the flux site also to find out why some of our instruments have failed. Yesterday afternoon we started another experiment with the "elevator" intented to measure the ozone concentrations at 5 different heights in a cycle of about 5 minutes. Yesterday it was working fine and logging in on the computer from the Big House, it seemed to run without a problem. However, then waking up this morning I found out that the temperature of the engine to move the elevator was 40C; a "little" too high. Coming to the site my suspicion was immediately confirmed; the wire to move the elevator has snapped but how did this happen? Putting all the evidence together, seeing ice formation at the opening of the engine box where the wire goes in and checking the detailed height information file it seemed easy to put the storyline together; elevator moving up, getting stuck, engine warms up, melting snow at the top of box, nighttime cooling results in ice formation, blocks cable, breaks, elevator moving down fast, and at the end ending at the surface; or....?
The next days we have to find out what went wrong and, especially, how we can solve this to get more of these useful measurements the upcoming weeks when one of the Phd students will operate the system.
By the way, you can see from the movie (and read my lips to interpret what I am saying; the wind is too strong to hear it); the conditions are not that optimal for a nice independence day BBQ and I also have to get shaved! Laurens

Another day at Summit

One more week to go; I like it here but also look forward to go back to NL next week; I heard that it is now there about 30C whereas here it is about -10C during the day, the "sense" temperature strongly dependent on the wind speed. Last night the wind picked up making it a little noisy in the tent. Since my watch is not working properly, waking up I guessed it was about 8 in the morning; time to go the site. However, then making it to the "Big house" for breakfast my watch turned out to indicate the right time, 3.30. At some lower latitude, the darkness would clearly indicate that there are some hours to sleep.
So with the winds we have had some accumulation of snow at the site due to snow drift but also had some snowfall. This implies that we soon have to put some of the lowest instruments higher up at the tower. This is also an issue for the different buildings they have here at the site. At one of the pictures below you can see the "Big house" put on poles to have it always above the snow whereas on the left hand side you see the last compartment of the "Greenhouse" where most of the staff sleeps. It got stuck into the snow so deep that they are now already for about 2 weeks moving it completely to a higher point so that it will be not burried into the snow pack for the next years,

Laurens

Summit golf course

Today, sunday, is for most people here a resting day. We actually had to work a little doing some of the daily maintenance on the measurements systems and these sundays are also used to give a guided tour at the flux site to the people that have a day off. All these people help a lot us collecting all the data and it is nice to give some insights what we are doing with all those instruments a little remote from where all the activity is. It was good to have a relaxed day; yesterday I was assigned the task being the mouse of the "big house" which implies that you are helping for one day with all the housekeeping (on a rotation basis) including preparing lunches/diner and, especially, doing a lot of dishwash although I was so lucky that at the moment there are only about 21 people here. In about 2 weeks from now there will be 50 people (including students) here. That's a lot of dishwash.

Today we played some nice golf here at the Summit golfcourse; some people read books, others are computering the whole day, or do skiiing. We decided to play some golf; was real fun!

Laurens

Measurements at Summit

So far I didn't mention that much about the kind of measurements we are doing here at Summit despite the fact that this is the main reason why I am here for about 3 weeks. So, I am here as a Co-PI of an US National Science Foundation project on long term measurements of reactive trace gas exchange between snow and the atmosphere. Despite the fact that I am supposed to contribute to this project doing the modelling work we (me, Detlev Helmig, the late Richard Honrath and other colleagues) felt it was essential to also have me here helping collecting data. I have done this before in the tropical forests of Manaus and it turned out that such a contribution as modeller to the experiments is valuable and highly appreciated for numerous reasons.
Anyhow, we use different systems to measure the fluxes (flow) of reactive gases such as ozone, reactive nitrogen and organic nitrogen between the atmosphere and the snow pack. For example, we measure the concentrations of these gases in and above the snowpack and with different parameters such as wind speed and temperature we can then estimate the flux between the snow and the atmosphere and inside the snow pack.

The actual measurements are not done in the towers themselves but through measuring the air that is pumped all the way through tubes from inlets at the towers to the instruments that are put in a container burried deep into the snow pack. The construction is quite impressive and it has taken a big effort to get this put at this site. It takes about two stairs to make it all the way down into the container (see picture, the door is deep down there).

The container is full with instruments, cilinders (with gases to calibrate the instruments) and computers to monitor and control all these complex instruments. The other picture shows all the tubing behind the instruments. Through all these lines the air with the gases is fed to the instruments,


Laurens