Dynamics and Multiscale Interactions

Leads: Alexander Voronovich and Gilbert Compo

When climate and weather stray from their typical range, extremes such as heatwaves and cold spells, floods and droughts, can have adverse consequences on society. It is a central priority at NOAA to understand and predict these departures from normal. As an example, consider the Boulder, Colorado Floods of 2013. These historic rains cost lives, destroyed buildings and infrastructure, and still have lasting effects. This type of event often brings numerous questions, such as whether it could have been predicted a week, a month, or a season in advance? Or, could its impacts have been better anticipated with more complete knowledge of the complex interplay between ocean, atmosphere, and land?

PSL's Dynamics and Multiscale Interactions Team is working to understand and predict variations and trends in weather, water, and climate, with an emphasis on extremes. To address these issues, theoretical, observational, and modeling approaches are used. Theoretical approaches are guided by the idea that the complex interactions of the atmosphere and ocean can be significantly simplified by separating out unpredictable interactions and focusing on those that are predictable. Storms, weather patterns, seasonal irregularities such as El Niño, floods and droughts, and decades-long climate variations, all can be better understood and even predicted with this focus. We also use these approaches to better understand extremes by characterizing the complete distribution from which the extremes are drawn.

We also use global models of the atmosphere and ocean to understand the connections between variations in weather, water, and climate extremes and changes in atmospheric composition, such as greenhouse gases or aerosols from volcanoes, or changes in sea surface temperature, such as those associated with El Niño. While useful, such models still have room for considerable improvement, such as in representing observed weather patterns or the exchange of heat and moisture between the ocean, land, and the atmosphere. To make progress in these areas, we develop global historical weather data sets, and a variety of innovative measurements. For example, we are determining how Global Navigation Satellite Systems, Sirius radio, satellite TV, and sound waves can each be used as low-cost measurements of the atmosphere, land and ocean surface.

Current Research Activities

DEVELOPING and expanding the Linear Inverse Modeling framework for sea surface temperature forecasts.
STUDYING and applying the Stochastically-Generated Skewed distribution, a new theoretical framework to characterize extreme values.
INVESTIGATING how existing man-made electromagnetic signals, such as GPS, reflected from the ocean and terrain provide information about ocean surface wind speed, soil moisture, or snow accumulation – filling gaps in existing observing systems.
INVESTIGATING the use of satellite TV, Sirius radio, or cell phone signals for remote sensing of the atmosphere.
EXPLORING how novel use of sound waves can provide detailed information about the small-scale, fast variations of temperature, wind, and the heat/momentum fluxes which are needed in boundary-layer meteorology.
DEVELOPING the longest possible observation-based reconstructions of global weather & climate, currently back to 1836. The 20th Century Reanalysis dataset can put modern extremes in a historical perspective & characterize historical risks of extremes.
ESTABLISHING the critical impact of tropical ocean warming & cooling patterns on both global & regional climate changes, & determining that climate models currently do not capture these details.
CREATING a framework to better understand how the interplay of different oceanic, atmospheric, and coupled processes drive different ENSO patterns, as part of the ENSO Diversity working group.
APPLYING new analysis techniques to current and historical wind-profiler data in order to study tropospheric turbulence, turbulent structures, boundary layers, and precipitation.