Laprise, a professor of climate physics at l’Université du Québec à Montréal, and Caron, a graduate student, spend their days working with a computer software program that represents the atmosphere. The software, called the Canadian Regional Climate Model, consists of mathematical modules that simulate the atmospheric processes that create hurricanes. By modelling the last 30 years of hurricane activity, and then testing their model against records of maximum wind speeds, pathways and locations of known hurricanes during that same time period, Laprise and Caron verify the accuracy of their software tool.
“If we can reproduce what we saw in the last 30 years, then we feel confident that if we simulate the climate of the future — let’s say in the next 30 years — we have some confidence in our simulations,” says Laprise, also the director of the ESCER Centre for the Study and Simulation of Climate at Regional Scale.
Laprise’s research group is the only one in Canada specializing in regional climate modelling, he says. Other predictions of how global warming will affect the Earth are based on global climate models. But the resolution of those models is too low to show regional patterns with any accuracy.
As the world’s focus on the effects of climate change intensifies, so does the need to predict more regionalized consequences. That’s why Laprise's high-resolution regional climate model will be critical in advising Canadians about what to expect as ocean temperatures warm and atmospheric winds change — two key factors that influence the duration, intensity and frequency of hurricanes. With that knowledge, decision-makers can help people prepare for severe storms, such as Hurricane Juan, which caused more than $200 million in damage when it landed in Nova Scotia in 2003.
Climate scientists know that increased greenhouse gas emissions that warm the atmosphere will affect hurricanes, but they still don’t know whether there will be more or fewer of them, how severe they will be or if their pathways will change.
“There’s some reason to believe there will be an increase in intensity, but beyond that we don’t know very much,” says Caron.
By understanding the physical processes that shape hurricanes, Laprise and Caron will improve the formulation of their model. Their clients at Ouranos, a consortium of 250 scientists and professionals focused on climate change and adaptation, and the Meteorological Service of Canada could potentially use that software to predict hurricane patterns over the next 90 years.
To date, using the regional climate model to analyze the last 30 years of activity has generated annual numbers of storms similar to actual observations in typical hurricane areas. The model also managed to generate images that closely resemble satellite photos of the real hurricanes, says Caron. “Preliminary results are encouraging.”