Cooperative Institute for Research in Environmental Sciences

Ocean Interactions
Ocean and Atmosphere connecting Scientists, Teachers & Students

Science at Sea ~ Science Summaries

~Brenda's Research Summary

My research is related to how the ocean and atmosphere interact with one another. The atmosphere and ocean interact with one another in many ways. One way is through the exchange of heat and moisture. This form of energy exchange occurs right at the interface between the atmosphere and ocean. The exchange of heat and moisture, referred to as the flux of heat and moisture, occurs when there is a temperature or humidity difference between the atmosphere and the surface of the water. It is a very important process to understand because it helps drive local, regional, and global weather and climate. Scientists have developed models, or algorithms, that simulate how this exchange occurs. The flux algorithms are tested using measurements made with instruments on ships like the Ron Brown. I have been comparing several different flux algorithms to see how well each simulates the fluxes by comparing the fluxes calculated by the algorithms with data collected from past ship cruises.

Ok, so what does this all have to do with my presence on this particular cruise? Well, the fluxes are affected by all sorts of things, like waves on the ocean surface, spray created by high winds, and rain. Rain, when it falls, displaces the air around it and causes a little bit of wind as a result. This can actually change the flux of heat and moisture. However, how this change occurs is not well understood, and is also not included in the flux algorithms. One way we can take a look at how rain is affecting the fluxes is by measuring the rain using a Doppler radar, like the one on the Ron Brown. So while I'm on the ship, I will be operating the radar and gathering data on clouds and any rain that falls on us while we are at sea. When I get back to Boulder, I will then use this data to combined with data gathered by Jeff from the flux measurement system to see how much wind was created by the rain. From that information I can then figure out a way to include it in the flux algorithms to help improve how they calculate the fluxes.

~Jeff's Research Summary

My general area of expertise is air-sea interaction, and my particular focus relies on measurements of the small-scale, turbulent interations between the atmosphere and ocean. Turbulence (which can be simplified to be described as 'mixing') is the most efficient way in which heat, momentum, and mass are exchanged between the two fluids. For example, in order to more thoroughly heat a dish on the stove or in the oven, we know to stir it (mixing).

In science, the 'flux' of a physical quantity (such as heat, mass, or momentum) can be described as the amount of that quantity which passes through an area in a prescribed amount of time. For example, 'heat' is measured in units of Watts, so the 'heat flux' is the number of Watts per meter squared per second. The same is true of a mass flux (grams per meter squared per second) or momentum flux (Newtons per meter squared per second). We can actually measure these things by using sophisticated instruments and careful calculations.

One area of interest to me right now is the measurement and further study of carbon dioxide flux (and other gas fluxes) over the ocean. Carbon dioxide is the most important of the so-called 'greenhouse' gases, which have been linked to possible climate change of the earth. The burning of fossil fuels (gasoline, coal, natural gas, propane, etc) over the past 150 years has caused a build-up of carbon dioxide in our atmosphere. Some scientists hypothesize that humans could be inadvertently warming our planet, but the Earth System is a very complex system and generating decisive results to test the hypothesis is very difficult.

One way in which scientists try to address the hypothesis is to model the amount of carbon dioxide in our atmosphere, and then to run the model way into the future to try to predict any climate change. We know that some of the carbon dioxide in our atmosphere dissolves in the ocean....but we don't know how much or understand the circumstances that cause changes in the amount of carbon dioxide which is exchanged. In order to accurately predict future climate, we must understand how much carbon dioxide dissolves in the ocean and we must understand the physical processes which cause the carbon dioxide to dissolve. By closely examining the processes (such as wind speed, current, waves, bubbles, etc) at the air-sea interface, along with measurements of carbon dioxide fluxes, we may be able to help the climate modellers more accurately make their predictions.