Low clouds over Fox Glacier,
Westland National Park, New Zealand |
Group Members
| John Cassano |
 Meteorology and climate of polar regions using regional climate models and numerical weather prediction models, in-situ and remotely sensed observations, and various data analysis techniques |
Post docs |
| Joel Finnis
(joelf@cires.colorado.edu) |
Joel's research focuses on the integrated freshwater budget of the Arctic, a
complex system that links atmosphere, ocean, and land surface processes. Along with researchers at the National Snow and Ice Data Center and the National Center for Atmospheric Research, he uses general circulation models to examine this budget and its interactions with climate change. This work contributes to the CHAMP Freshwater Initiative (http://arcticchamp.sr.unh.edu/), a cooperative effort between multidisciplinary researchers across North America.
The complexity of the freshwater budget of the Arctic makes this system an
ideal
candidate for modeling studies. Models provide self-consistent, complete sets
of data that can be used to track freshwater as it moves from one part of the
Arctic climate system to another, from origins as precipitation to river
runoff, to transport in ocean currents, and through storage as sea ice or
snowpack. By examining the budget in a simplified model environment the mean
state and variability of each budget term can be estimated, providing some
constraints to researchers examining the same system through observations. In
addition GCMs can be used to examine the budget's response to, and effect on,
global climate change.
Recently his work has focused on examining the role that changing cyclone
activity has on high latitude precipitation. From autumn through spring
extratropical cyclones produce a good deal of the precipitation seen in middle
and high latitudes. Several studies have shown that the frequency and
intensity of these systems can be affected by global warming; similarly
precipitation frequency and intensity are expected to change. He is examining
the connection between these changes, and connecting them to other terms in the
freshwater budget. |
| Mark Seefeldt (seefeldm@cires.colorado.edu) |
 Mark's research involves developing a greater understanding of the near-surface wind field across the Ross Ice Shelf, Antarctica. Past research has indicated a dominant northerly transport of mass from the Antarctic continent towards the middle-latitudes through the Ross Ice Shelf corridor. This transport has been termed the Ross Ice Shelf air stream (RAS). The surface wind field across the Ross Ice Shelf is composed of katabatic winds through the glacier valleys in the Transantarctic Mountains and along the Siple Coast, barrier winds along the Transantarctic Mountains, and in relation to the passage of cyclones and mesocylones over or near the Ross Ice Shelf. Through the use of automatic weather station observations a pattern has been realized where the strong northerly surface wind is composed of a series of katabatic an barrier wind events in combination with the passage of a cyclone or mesocylone. This series is referred to as a RAS event. The goal of the research is to gain a more complete understanding of the characteristics and composition of the frequent RAS events. |
Associate Scientists |
| Elizabeth Cassano |
 Liz's main focus of research over the past few years has been studying
cyclones which affect the North Slope of Alaska, if and how they are changing and formation mechanisms of these cyclones. Liz's current work is data analysis in support of the FWI and SNACS projects. Future work
will be to expand to sea ice studies (i.e. what are the mechanisms resonsible for a sea ice parcel melting or surviving the summer
melt season?) and extend the cyclone work to determine a cyclone climatology of formation mechanisms for cyclones in the North Slope
area. |
Graduate Students |
Michael Shaw |
 Michael is an assistant scientist (CIRES title) for the group. As such, he is responsible for writing and adapting computer programs for various tasks (statistics, visualization, simulation, automation, e.g.); learning and implementing "regional" numerical atmospheric models (e.g., WRF, and Polar MM5); and combing through the relevant literature. He is contributing to the GRACE, FWI, ARCMIP, and Greenland mass balance efforts. He has also contributed to Amanda Lynch and John Cassano's text book, Applied Atmospheric Dynamics.
Michael also been pursuing some of his own interests in
finding new approaches to analysis and prediciton of spatio-temporal
systems in general, and Polar Climate and meteorology in particular. In
this vein, he is interested in numerical model physics/numerics interactions, nonequilibrium thermodynamics, statistical mechanics, filtering, and complex systems. |
| Keah Schuenemann |
|
 Keah is working on organizing the large wealth of synoptic scale atmospheric data around the Greenland ice sheet to allow a better understanding of precipitation over Greenland. The self-organizing map (SOM) technique is being used to analyze the synoptic weather patterns for the second half of the twentieth century using climate models and reanalysis. Twenty-first century weather patterns will also be studied using several climate model predictions. This analysis will allow us to understand what is forcing the predicted changes in precipitation over the Greenland ice sheet for the twenty-first century, and thereby, a better understanding of the future of the mass balance of the Greenland ice sheet.
|
| Matt Higgins |
|
 Matt's research interests include understanding how our changing climate is affecting local weather systems in the Alaskan North Slope area. For example, as sea ice
retreats with rising temperatures, this leads to changes in the surface sensible and latent heat fluxes. Will this mean more intense weather
patterns for the area? Mean state variables such as average temperatures do not adequately capture this variability. With that in
mind, what are the best ways to measure these changes?
Matt is working under the SNACS - Study of Northern Alaskan Coastal System Project, and his current focus is producing a high resolution data set for the North Slope of Alaska region using the Polar MM5 model and comparing observed and modeled turbulent surface fluxes in the model domain.
|
| Dave Porter (PorterDF@Colorado.EDU) |
|
 Dave is interested in the energy budget of the Arctic polar cap and
how it is affected by climate indices and changes in storm tracks, sea-
ice extent, and cloud cover. The storage of moist-static energy over
the polar cap, which is defined after Mark Serreze as the region north
of the 70 deg N latitude circle, is the summation of three terms.
These are the radiation budget at the top of the atmosphere, the
surface heat flux, and the convergence of energy through atmospheric
motions.
He is currently comparing the energy budget of the Arctic as
represented in the NCEP/NCAR reanalysis, the ECMWF's ERA-40
reanalysis, and the new Japan Meteorological Agency's JRA-25
reanalysis. These reanalyses are particularly useful tools for
scientists interested in the polar regions. The hindcasting nature of
the reanalysis presents an opportunity for better quality control and
the inclusion of many data assimilation products that are not
available in real-time. One important area of his work is to
determine how well the reanalyses capture the variability of the
surface heat flux over the Arctic cap, a source error in previous
energy budget work.
|
| Melissa Richards (Melissa.Richards@Colorado.EDU) |
|
 Melissa's research project involves analyzing observed changes in the Antarctic atmospheric state including near surface temperature, winds, cloud cover, radiative fluxes and cyclones. The data will be analyzed for seasonal variations, cyclic patterns and overall trends. The project has a specific focus on the Terra Nova Bay region and the effect these changes have on atmosphere-ocean interactions in this region. The hypothesis is that if the atmospheric state has varied over time, then it will impact oceanic processes in Terra Nova Bay and may alter production of Antarctic bottom water, leading to global changes in the climate system.
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Affiliates |
Where are they now? |
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