Climate Change

Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate. NMC participates in research to improve the next generation of climate models by looking at the analysis and modeling of rotating stratified flows. NMC is also involved in modeling ocean currents and how ocean circulation models are used to understand the climate.

NMC research in climate change is also closely tied to our Plant Biology initiative. We investigate carbon dynamics, energy and nutrient exchange, and climate feedbacks within the global climate system based on molecular-to-cellular-to-plant-to-ecosystem science and modeling.  The latest climate research at NMC includes:

Coherent Structures and Mixing in Rotating and Stratified Flows

Susan Kurien, NMC Affiliate Researcher, LANL Staff Scientist

This research aims to quantify the emergent length scales of coherent flow structures in rotating and stratified flows and relate those to the characteristic length scales over which mixing occurs. The coherent structures range from tall and columnar to flat and pancake-like, with characteristic vertical and horizontal sizes vary depending on the relative strengths of the rotation and stratification. The efficiency with which such flows mix a scalar, such as heat or mass density, into the flow will vary across the structures formed. This variation will be analyzed using statistical analysis of a series of large scale simulations with varying parameters of interest. The connection between intrinsic scale and mixing scales will be deduced as a function of the global parameters.

Energy Pathways and Scale Interactions in the Ocean

Hussein Aluie, NMC Affiliate Researcher, University of Rochester

The project would enable us to quantify the power (in Watts) being injected/extracted in different flow structures as well as identify the sources/sinks of such energy. This would constitute a fundamental intellectual advance in physical oceanography using a novel approach in fluid dynamics and nonlinear multiscale physics. The benefits to the science of climate prediction and uncertainty reduction can be very significant. The work would potentially unravel the scale-physics at play in the ocean, offer a priori constraints on parameter tuning of ocean parameterization schemes, and help in the development of a new class of parameterizations that are a function of geographic location and grid resolution, currently a major DOE thrust in ocean modeling and scientific computing.

Analysis and Modeling of Rotating Stratified Flows

Susan Kurien, NMC Affiliate Researcher, LANL Staff Scientist
Annick Pouquet, National Center for Atmospheric Research
Leslie Smith, University of Wisconsin  
 

The next generation of climate models will have access to ever more resolved simulations but will still need proper parameterization of the small scales. This project connects experts in applied mathematics and geophysics with massive high-performance computational resources from the DOE Office of Science INCITE program to approach the problem of parameterization comprehensively using theoretical and mathematical development, coupled with detailed numerical experiments. This approach is expected to result in a deeper understanding of the multiscale physics of geophysical flows and lead to practical parameterizations of unresolvable processes in models. Funding for this project comes from the National Science Foundation.

Global Surface Drifters and Sub-mesoscale Processes

Milena Veneziani, NMC Affiliate Researcher, LANL Staff Scientist
Christopher Edwards, University of California, Santa Cruz
Annalisa Griffa, University of Miami
 

Global Surface Drifters are buoys placed on the ocean that take observations of currents, sea surface temperature, atmospheric pressure, winds and salinity. Studies of the data from these satellite-tracked buoys revealed the presence of small-scale eddies possibly associated with the formation of barrier layers in ocean currents. This project focuses on the distribution and polarity of sub-mesoscale processes in the open ocean, and in particular in the subtropical South Atlantic Ocean. Funding for this project comes from the National Science Foundation.

The Role of Basin Modes in Pacing Pacific Decadal Variability

Wilbert Weijer, NMC Affiliate Researcher, LANL Staff Scientist
Keith McElroy, NMC Affiliate Researcher, NM Institute of Mining and Technology
Ernesto Munoz, National Center for Atmospheric Research
Francois Primeau, University of California, Irvine
Niklas Schneider, University of Hawaii, Manoa
 
This research explores the role of ocean circulation in climate variability. Changes in the Earth's climate system are governed by changes in external forcing (such as human activity, volcanic eruptions or solar insolation), as well as internal climate variability (such as El Nino). Understanding climate variability is important to distinguish anthropogenic changes from natural climate cycles. Of special importance is low-frequency climate variability which takes place on decadal or multidecadal time scales. The dynamics behind these modes of variability are uncertain, but most hypotheses agree that the memory resides in the ocean. One hypothesis is that these modes are caused by internal ocean oscillations called basin modes. These modes consist of basin scale planetary Rossby waves that propagate westward across ocean basins on the timescale of decades. Baroclinic Rossby basin modes are large-scale oscillations of the ocean with periods of up to a decade, thus of interest for understanding climate variability. This project, through ocean modeling, will enhance our understanding of Pacific Decadal Variability by identifying the role of low-frequency Rossby wave basin modes. By improving our understanding of low-frequency variability in the Pacific ocean this project has the potential of greatly enhancing the ability to predict climate and to better manage fisheries. Funding for this project comes from the National Science Foundation.

 

See the report: Normal Modes of the World Ocean

Global Energy Observatory

Rajan Gupta, NMC Affiliate Researcher, LANL Staff Scientist

The Global Energy Observatory (GEO) is a set of free interactive databases and tools built collaboratively through open source data. The goal of GEO is to promote an understanding, on a global scale, of the dynamics of change in energy systems, quantify emissions and their impacts, and accelerate the transition to carbon-neutral, environmentally benign energy systems while providing affordable energy to all. By providing easy to use and visualize data, models and analysis tools we aim to engage the public and the experts. Data in GEO can be edited from anywhere in the world. 

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