Dr Christopher Chapman

I am a senior lecturer in oceanography based in the School of Science at UNSW-Canberra. My research spans a broad range of topics, from physical and biological oceanography, to meteorology and remote sensing and even ecology, but focuses on disentangling how our oceans influence weather, climate, and marine ecosystems. I use observations, field campaigns (including on board the RV Investigator, Australia's premier blue-water research vessel) and numerical modelling to tackle a wide range of problems.

Scholarships of AUD$35,000 are available for PhD students who achieved H1/High Distinction in their undergraduate program and/or have completed a Masters by Research. If you are interested, please contact me at christopher.c.chapman AT unsw.edu.au

My current research priorities are:

• The role of the oceans in extreme events

Extreme weather events, such as floods; tropical cyclones; and heatwaves, can have devesting impacts on society and ecosystems. While an extreme weather system over land may not, at first glance, seem to have a strong relationship with ocean conditions hundreds or even thousands of kilometers away, scientists have shown that the ocean can strongly impact how these events unfold over days and weeks. For example, tropical cyclones draw their destructive energy from warm tropical oceans, and the state of the sub-surface ocean can profoundly influence how the storm intensifies. My research focuses on how we can improve understanding and prediction of these extreme events by exploiting knowledge of the ocean in the Australian and Indo-Pacific context. Using theory, numerical modelling, and observations (including new platforms such as animal borne sensors and cutting-edge satellite systems), we are shedding new light on how the ocean influences impactful weather events. 

• Small scale interaction between the tropical ocean and atmosphere

Tropical and sub-tropical marine environments are exceedingly complex. In these regions the marine atmosphere and surface ocean strongly interact: sometimes the ocean drives the atmosphere, sometimes it's the atmosphere that leads. These interactions result in intense, yet small scale motions on both sides of the air-sea interface that have important impacts on the climate system, on ecosystems, and for Defence operations. For example, clouds in the tropical atmosphere can act as a "pump", bringing dry air from the top of the marine boundary layer to the ocean surface, which in turn influences the exchange of heat and momentum across the air-sea interface. Using in-situ observations and very high resolution atmosphere and ocean models, we are working to better understand, model and predict these air-sea interactions and the small-scale motions that they produce.

• The ocean's influence on marine ecosystems, plankton, and predators

Marine ecosystems respond to changes in the ocean environment. Sometimes these responses are beneficial - such as when ocean "upwelling" brings nutrient rich water to the surface, allowing plankton to grow. Sometimes these responses are destructive: for example, in 2015-2016 a massive marine heatwave in the Tasman Sea resulted in extensive die back of giant kelp in Tasmania, a shift in coastal plankton communities, and even changes in where and how little penguins foraged for food. However, integrating physical and ecological information is hard, and requires multi-disciplinary approach. I work with ecologists, biologists and oceanographers to unravel how the physical and biological ocean interact. Our work has focused on plankton at the base of the oceanic food-web, and predators, such as penguins, seals, tuna and turtles closer to the top. We collaborate strongly with fisheries agencies and marine park managers to see our research translated into real conservation impacts. 

• Large scale drivers of local scale extremes: the "outside-in" approach

Whenever an extreme event, such as a flood or heatwave, occurs there is often a rush to attribute the event to a larger-scale climate driver, such as El-Niño. Doing so can be tricky - at a local or regional scale, weather is driven by a combination of local scale dynamics and broader scale climate drivers. As this approach starts at the local scale and then zooms out to the broad-scale, we call this the "inside-out" methodology. In recent years, using a powerful data mining technique called Archetype Analysis, we have developed an alternative "outside-in" approach. Archetype Analysis allows us to directly, and unambiguously, identify broad-scale "extreme" states. We have shown conclusively that this approach works for all manner of extremes, from drought and floods, to marine and terrestrial heatwaves. Our current work includes expanding the method to compound or multi-variate extremes (such as hot-and-humid heatwaves), understanding the climate drivers of crop-failure or electricity price spikes, and using the method to characterize long-range weather forecasts.