This buoy in Laguna La Salada is outfitted with automatic sensors that take measurements in the lake every five minutes, and then it transmits them to shore in near-real time. Photo by Lisa Borre.
As I walked along the shore of the serene Laguna La Salada at the northern fringe of the Patagonia region of Argentina, I struggled to imagine the severity of the storm that wrecked havoc on this small lake and the rest of Buenos Aires province just six months before.
The Southern Hemisphere spring was in full bloom on that early November day. I desperately sought shade from the bright mid-day sun, but there was little to be found in the park-like setting. The bright blue sky and glass-calm water made it feel like this is what every day is like here in the Pampas grasslands south of Bahia Blanca.
I was attending my third “all hands” meeting of the Global Lake Ecological Observatory Network (GLEON). We were enjoying a traditional asado, an Argentinian barbeque, at the shallow, saline lake – a real treat at the end of a busy week.
While beef and sausages cooked over an open fire, some of us watched a demonstration of a miniature, unmanned boat map the bottom of the lake. Alejandro Vitale, the engineer who created the automated vessel from a remotely operated toy boat rigged with a depth sounder, showed how he could steer the boat using pre-programmed GPS coordinates on his laptop. A real boat towing a water skier steered carefully around the automated vessel, and a kayaker paddled by nonchalantly, more concerned about getting in a workout than participating in science.
A yellow buoy in the distance silently measured parameters such as water temperature, salinity, dissolved oxygen, suspended sediments, and wind speed and direction, sending the information in near real-time to a computer onshore. We were getting a glimpse at the cutting edge of lake science, where researchers use sensors and other automated tools to collect high frequency data, in addition to more traditional field observations and measurements.
Another Meeting, Another Extreme Weather Event
For the third year in a row, an extreme weather event was a hot topic of discussion among locals hosting the international meeting of lake scientists.
The first instance was at the GLEON 13 meeting on Lake Sunapee, in the foothills of the White Mountains of New Hampshire in the U.S. The October 2011 meeting was held at a time when the entire New England region was recovering from the lashing of tropical storms Irene and Lee. Scientists studying nine lakes affected by the storms later compared their high frequency data. Their published findings were the topic of a post I wrote about the impacts of extreme weather events on lakes a year ago.
The second extreme weather event was discussed at the GLEON 14 meeting in Mulranny, County Mayo, Ireland, in 2012. During a field trip to Lough Feeagh and the Burrishoole Catchment, near Newport, we heard about an intense storm in 2009. This well-documented storm will be the topic of a future post about the ecological effects of these episodic weather events.
I learned about the third extreme event while talking with undergraduate students from the Universidad Nacional del Sur at the GLEON 15 meeting. They explained that over a five-day period in late March and early April, an intense low pressure system formed over northwestern Argentina, and when it combined with a cold front to the south, the system created strong winds and heavy rains that lasted for more than five days. It was an extreme version of a typical weather event known as sudestada in Argentina.
“It rained 392 millimeters (over 15 inches) in a 24-hour period on April 2nd, with most of the rain falling in just four hours,” said Ana Calissano during a poster session at the Instituto Argentino de Oceanografia (IADO) in Bahia Blanca. It was the highest rainfall ever measured by the Astronomic Observatory of La Plata University and double the historical average for the month.
Along with classmates, Alan Bahnmüeller, Azul Gilabert, Noelia Nieva, and Maxi Arena, Calissano pointed to pictures of the destruction in La Plata, the provincial capital, and added, “78 people died and 70,000 homes were destroyed with flooding.” Economic losses exceeded $1.7 billion.
Bahnmüeller told me a story about a friend of his who was about 1 kilometer (a half-mile) from his home when the worst of the storm hit. Water was ankle deep when he started running for home and chest high by the time he reached his house, where he discovered that all was lost.
By my count, that’s three record-breaking extreme weather events on three different continents in three different years.
And it’s just a small sample of the extreme weather events – both extended droughts and severe storms – that are sadly becoming more frequent, including most recently the super typhoon that struck the Philippines and the late-season tornadoes that tore through the Midwestern U.S. earlier this month.
Study of Lakes in Argentina
For their class project, the young Argentinian scientists worked as a team to study the response of four small lakes to the storm in Buenos Aires Province, including Laguna La Salada.
Like the other studies of extreme weather events in North America and Europe, they were able to examine high frequency data collected from sensors mounted on buoys in all four lakes. The “smart” buoys collected data every five minutes, and all but one – torn from its mooring due to high winds – survived the storm.
On all four lakes, the water level was raised about 10 centimeters (4 inches), salinity decreased, and lake temperature decreased 2 degrees Celsius (3.5 degrees Fahrenheit) during the storm. “Even though the lakes were more than 700 kilometers (about 450 miles) apart, they exhibited similar responses to the storm,” said Calissano.
The implications of their study are much larger than even these enthusiastic students might appreciate. Not only is their research relevant for understanding the response of lakes, but by studying lakes, scientists can gain insights about the effects of storms on the surrounding landscape as well.
Only a small portion of the world’s lakes are being monitored with automated sensors. The fact that they captured data from the storm and presented their study at a meeting of scientists who are already collaborating as part of a global network is the key. It creates opportunities for comparative studies – to connect the dots among research on lakes around the world – with a group that is already doing just that.
With intense storms becoming more frequent in a changing global climate, understanding the impacts of these extreme events is critical for climate change preparedness and adaptation.
The student team’s professor, M. Cintia Piccolo, is a member of the GLEON steering committee and organized the meeting that brought me to learn about Laguna La Salada and the April 2nd storm. She is very pleased with what her students were able to learn by piecing together data from the buoys with other available information from the Argentine National Meteorological Service.
Students make up about 30 percent of the membership of the global network. In addition to using high-tech devices to study lakes, training early career scientists to use an interdisciplinary, team-based approach to research is a high priority within the network. “We are transforming the way lake science is conducted,” said Piccolo. “Having these students using high frequency data to collaborate globally is a great learning experience.” It’s also great for the future of lake science.
Lisa Borre is a lake conservationist, freelance writer, and avid sailor. With her husband, she co-founded LakeNet, a world lakes network, and co-wrote a sailing guide called “The Black Sea” based on their voyage around the sea in 2010. A native of the Great Lakes region, she served as coordinator of the Lake Champlain Basin Program in the 1990s. She is now an active member of the Global Lake Ecological Observatory Network.