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a GasEX III blog: After a handful of extraordinarily calm and sunny days, we’ve left our study site and begun the journey back to terra firma. Our destination: Montevideo, Uruguay. We were scheduled to arrive in port on April 10th, but the other night we encountered a low pressure system that pounded us like nothing before. We’re currently stopped dead, bow into the wind, and bravely facing the waves. Winds have been force 9 on the Beaufort scale, reaching over 41 knots, and the waves have been eye height with the bridge crew – ironically, great conditions for collecting more flux samples! Right now, feelings amongst the crew are mixed. We are all very happy to have successfully completed our research mission, but we’re excited to head home. And we are, of course, very tired. The movie room last night was crowded as ever, a sure sign that all of us are trying to get some R&R after an intense sampling campaign. Conversations have been along the lines of, “Imagine the first nice meal we’re going to have once we reach port...” and “Can’t wait to trade my small bunk for a nice, big, cozy bed.” And everyone’s talking about having a good, cold beer again! (I’ve been missing wine, myself.) So here we are in our last days at sea, packing boxes and writing cruise reports in the intense rolling during the storm. In my case, I’ll wait to pack in port with the next crew, who’ll be participating in a research cruise from Montevideo to Barbados. If all goes as planned, April 16th I’ll be back home in Colorado and can start processing (cautiously) the data we’ve been collecting. Already we’ve produced some preliminary results, but they need more analysis before going public. In particular, we need to do quality control on the flux measurements and remove bad data points (like when the wind was blowing from the back of the ship or when the ship was maneuvering...). When that’s done, we should know a lot more about gas transfer under high wind conditions in the Southern Ocean. To conclude this last post, I’d like to say that I’ve had many memorable moments on this cruise and have enjoyed sharing them through the blog! To quote the book Ships of Discovery and Exploration by Lincoln P. Paine: “How the wind roars through the sailing ship’s ringing! How magnificent is its sound!” Another author Villiers wrote: “Though it brings us only work – hard, dangerous, tremendous, Herculean work of a kind people ashore can never know – we yet can feel the glory of the roar of the wind.”
Week 5: Giant petrels, dolphins, and snow! I always look forward to receiving emails from my landlubber friends (thanks, Greg, for teaching me this new word) who are following the blog and asking me questions about life at sea. Am I seeing amazing sunsets? What about marine animals? Have I seen any icebergs? Unfortunately, colorful sunsets are quite rare in the Great Southern Ocean, mainly because this is a storm path where low pressure systems traveling eastward bring cloudy weather and precipitation. Last night it was cold enough that we got snow! I was amazed to see snow over the ocean for the first time in my life. These stormy weather systems also create the high winds -- the “Furious Fifties” -- which are the reason for conducting our gas exchange experiments here. The highest winds we’ve encountered have reached 35 knots (about 40 mph). So far, our flux instruments have been running continuously. However, every once in a while, an unexpected hardware problem occurs. When the problem is up in the mast, you can’t just go up and repair it; you have to wait until the weather calms. A few days ago, I was able to climb the jackstaff – the vertical pole at the front of the ship -- to repair one of our sensors. It was kind of exiting...like climbing a tree about to topple over at any moment. To conduct measurements of fluxes and near-surface meteorology, we use a variety of high frequency sensors. The “heart” of the flux system is composed of a sonic anemometer and a motion pack mounted on the jackstaff. The anemometer measures the three directions and speeds of the wind, and the motion pack records the ship’s movements. By combining both signals, we are able to correct for the motion of the ship and obtain a measurement of the wind as if it were taken from a fixed platform. The rest of the flux menagerie includes:
Most of these instruments are located at the front of the ship, ahead of the engine and air-conditioner exhausts. Finally, from the corrected wind velocities and with the other sensor measurements, we calculate all the desired fluxes between the atmosphere and ocean: momentum, sensible heat, latent (moist) heat, ozone, DMS and CO2 fluxes. Voila! Enjoy the pictures! And, thanks to the Field Operation Officer Liz for the nice close-up pictures of the birds and for providing their names.
Week 4: Red Sky at Night - video post
a GasEX III blog: When it’s not about our science sensors, it’s about the sea! And with the sea, everything depends on the ship’s course. If we go with the waves, it can be gentle; but if the waves come sideways at the ship, it can be a roller of a ride. Just a couple days ago toolboxes were flying and people in rolling chairs were sliding all over the lab. Needless to say, it’s not always easy to focus in front of a computer and write during such conditions. So here’s a little more about life aboard the Ronald H. Brown. The ship is the largest vessel in the NOAA fleet. For this experiment, the ship is home to about 24 crew members and 31 scientists, almost maximum capacity. Food service seating capacity is just 30 people. So one of the golden rules on the ship is “Eat it and beat it.” It’s definitely not a restaurant! Still, our trio of cooks is doing a great job providing food for everyone. The only big difference between a ship meal and a meal at home is the serving schedule. Breakfast is from 7am to 8am, lunch from 11am to 12pm, and dinner from 4:30pm to 5:30pm. Meals are somewhat close to each other, but this allows our three kitchen stewards to have some time to relax. I’ve known cooks Herb and Richie since I first voyaged on the RHB in 2005. Since that time, Herb likes to call me “Frenchy”... don’t ask why. He is an amazing man and a talented ping pong player. Speaking of which, the ping pong table has usually been a great distraction during research cruises and is usually set up in the main science lab; but since this cruise is fully loaded, the table has yet to emerge from the storage room. To burn some calories after meals and/or snacks, we instead use “the house of pain,” as Herb likes to call it—aka the gym. It’s a great place to test your reflexes and balance, what with the continual motion of the ship (see Chris’ post on the SO GASEX blog). One funny thing I like to do when we are cruising with the waves is to use the rowing machine. You feel a bit like you’re rowing the boat by yourself. Afterwards, we get to enjoy showers in pretty luxurious bunks. The room onboard a ship is small but sufficient for a good night’s sleep. I’m sharing my room with Alejandro Cifuentes and Chris Buonassissi, both from the University of Connecticut. After more than a week at sea now, my life on the ship can be summarized as follows:
Do you know ozone? Thursday, March 6, we arrived at our study site, located approximately at 50°S and 38°W. So what am I doing out here in the middle of the Southern Ocean? I’m part of the air-sea interaction team from NOAA's Earth System Research Lab at Boulder, and my job, for the next month, is to operate a flux system - a system that contains various sensors to measure momentum, sensible heat, latent heat, ozone and carbon dioxide turbulent fluxes between the atmosphere and ocean. All these atmospheric measurements will help us understand the different processes involved in the air-sea gas exchange in this high wind region. While a lot can be said for why we study carbon dioxide, I'd like to talk a little about ozone, a different greenhouse gas, and one that plays a part in urban smog problems. The interesting thing about ozone is that it can be either supportive of or harmful to life. In the stratosphere, the ozone layer protects living organisms from dangerous ultraviolet radiation; but, in the troposphere, it becomes an air pollutant that can cause health problems. It's important that we have a good understanding of the global ozone atmospheric budget. How much ozone is deposited from the air into the ocean is a very significant part of the total budget and, so far, direct observations from ships are quite rare. That's why this research cruise is such a great opportunity to take ozone flux measurements!
Cruising for Carbon It has been three days now since we left Punta Arenas, Chile, where the winds are so strong that all along the main street the trees are bent in one direction. The town, populated by about 120,000 habitants, is located in the Strait of Magellan, which connects the Pacific and Atlantic Oceans. They say it’s the most austral city in the world, but this is not exactly true since Ushuaia, Argentina is even more southern. After five days in port loading everything needed for our research cruise plus one day of delay, we departed Punta Arenas at 1900 on Friday, February 29. We’re currently on our way to our study site, located around 50S and 40W, near South Georgia Island. (Click here to follow our track).The first day at sea was a bit bumpy, but the last two days have been sunny and calm. All the scientists seem to have their sea legs, but I wouldn’t be surprised if all of that changed once we get farther out into the windy seas. So why go to the Southern Ocean? Well, the cruise experiment is called GasEx, which stands for Gas Exchange. While on the ship, we’ll sample gases like carbon dioxide (CO2), ozone (O3) and Dimethyl Sulfide (DMS).We know that the ocean acts like a big CO2 sink, but just how much and how fast it absorbs CO2 is the essential question. And, understanding precisely how a greenhouse gas like CO2 moves through the environment is essential to understanding and predicting global warming. My research team, in collaboration with other teams from Lamont-Doherty Earth Observatory, the University of Connecticut, and the University of Hawaii, are going to measure momentum, sensible heat, latent (moist) heat, ozone, DMS, and CO2 fluxes between the atmosphere and ocean. With these measurements, we can provide all field researchers, modelers, and remote-sensing specialists with the best possible meteorological reference data for improving carbon cycle science. |
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