The poster session offers an opportunity to share your work with the other participants, in an informal setting, while networking and meeting new people. It will be held on Monday, June 8th starting at 4:30 in the Center Green auditorium and atrium. Electronic posters are welcome, as we will assist you with any electronic or set-up needs. All posters may remain up through the duration of the workshop.
Title and Author:
A Numerical Study of the Evolving Convective Boundary Layer and Orographic Circulation around the Santa Catalina Mountains in Arizona. Part I: Circulation without Deep Convection.
J. Cory Demko, Bart Geerts, and Qun Miao
Poster Abstract:
Observational data collected during the 2006 Southwest Monsoon around the Santa Catalina Mountains approximately 30 km in diameter near Tucson, AZ using radiosonde data, UW King Air data, and surface station data shows the development of anabatic surface flow and Boundary Layer (BL) circulation around and on the mountain. Observations show the development of mountain-scale surface convergence (MSC) a few hours after sunrise, peaking near local solar noon, and decaying through the afternoon and evening. An orographic toroidal circulation with a low-level anabatic component and divergence near the BL top is sometimes but not always present. The data also confirm that the anabatic flow is driven by surface heating over the mountain, resulting in solenoidal forcing and a hydrostatic horizontal pressure gradient force towards the mountain. The present paper summarizes the results from detailed numerical simulations for several cases using the Weather, Research, and Forecasting (WRF) modeling system. The observational data make it possible, for the first time, to validate simulations of flow and convective development over a real mountain by means of measured MSC and cloud top chronology. Initial findings show WRF accurately captures the diurnal variation of MSC at the surface, which is driven by a perturbation pressure gradient forced directed towards the mountain. This daytime pressure deficit is attributed to a warm anomaly over the mountain; therefore, solenoidally driven. The level of non-divergence within the BL generally rises in conjunction with deepening BL. Even benign orographic cumulus congestus can produce localized cool anomalies indicative of dry, weak microburst which temporarily disrupts the MSC.
Title and Author:
Retrieval of boundary layer structures and particulate matter concentrations with Vaisala's CL31 ceilometer
Jackie Miller, Vaisala Reijo Roininen Christoph Muenkel
Poster Abstract:
Vaisala’s CL31 ceilometer is an eye-safe single lens lidar system, capable of operating continuously in an automated, hands-off mode. The CL31 measures attenuated backscatter profiles that are traditionally used for cloud-base height determination. However, research has been completed to evaluate the instrument’s ability to identify boundary layer structures and estimate particulate matter concentrations. Comparison of boundary layer structures measured by the ceilometer versus those from atmospheric soundings indicates that the CL31 is capable of detecting boundary layer structures, including convective mixing height.
Title and Author:
A Web 2.0 "Clicker" System for the Geosciences
Professor Perry Samson, Associate Chair and Professor Institution/Company: University of Michigan
Poster Abstract:
LectureTools (http://www.lecturetools.org) is a free web application that allows students to 1) type notes synchronized with the lecture slides; 2) self-assess their confidence in understanding the material being discussed; 3) pose questions for the instructor and/or teaching assistant; 4) view answers to questions (with questioners names removed) as posed by teaching assistant during or after class; 5) pop up the slide, draw on it (cross-platform on Mac or Windows) and save the drawing; 6) respond to instructor questions, including image-based questions; 7) view podcasts, if any, that are uploaded by the instructor after class; and 8) print the lecture slides and notes for off-line review. Results suggest that a) students are more likely to be do tasks unrelated to lecture with their laptop available, but b) despite that, most students actually feel they are more attentive, significantly more engaged and learn more using this system.
Title and Author:
Connecting climate variability to the water levels of Lakes Michigan and Huro
Janel L. Hanrahan, Sergey V. Kravtsov and Paul J. Roebber of the University of Wisconsin – Milwaukee.
Poster Abstract:
The Great Lakes provide transportation for shipping, hydroelectric power, sustenance and recreation for the more than 30 million people living in its basin. Understanding and predicting lake-level variations is therefore a problem of great societal importance due to their immediate and profound impact upon the economy and environment. While the Great Lakes’ seasonal water-level variations have been previously researched and well documented, few studies thus far addressed longer-term, decadal cycles contained in the 144-yr lake-level instrumental record. In our recent research, analysis of the 1865–2008 Lake Michigan/Huron outflow-removed levels revealed a large scale variation likely associated with the AMO, and spectral analysis identified 6, 8, 12, and 27-yr period oscillations. The 8 and 12-yr time scales match those of large-scale climatic signals previously found in the North Atlantic, and it is suggested that the 27-yr cycle is resulting from the intermodulation of these two near-decadal signals, while the 6-yr cycle is possibly a statistical artifact of the 12-yr cycle. Furthermore, a previous water budget analysis has argued that the North Atlantic decadal climate modes translate to the lake levels primarily through precipitation and its associated runoff, but more current data suggest that evaporation may have recently become a major contributor to a new lake-level trend.
Title and Author:
Innovative Laboratory for Research
and Education in Urban Meteorology
Jose Galvez, Petra Klein, and Sean Arms of University of Oklahoma
Poster Abstract:
The Innovative Laboratory for Research and Education in Urban
Meteorology (ILREUM) is an NSF funded project that focuses on the
development of a laboratory for research and education in urban
meteorology. It is lead by Petra Klein from the School of Meteorology
(SOM) - University of Oklahoma. The project has two highly interactive components. The educational component seeks to improve
education on urban-, micro- and boundary-layer meteorology at SoM via
hands-on activities. These involve the study, development, and use of
instrumentation platforms to collect different types of meteorological
data. Field campaigns results are later analyzed and presented in
class. The research component focuses on studying turbulence
properties at different sites with the general purpose of improving
the understanding of the effect of obstacles (buildings and
vegetation) on the turbulent exchange of heat and momentum with the
overlying atmosphere. Measurement sites include several urban, suburban and rural locations near Norman Oklahoma. This poster serves
as an introduction to ILREUM, as well as provides some examples of the
educational and research components of the project.
Title and Author:
Recent developments in the netCDF C/FORTRAN libraries
Ed Hartnett of Unidata
Poster Abstract:
Recent developments in the netCDF C/FORTRAN libraries include the
introduction of an enhanced data model, limited interoperability with
HDF5, parallel I/O, built-in data compression, and remote access to
netCDF data from within a C or Fortran program.
Title and Author:
A Discussion of the Pre-storm Environment of
Intense West African Convection
Stephen Nicholls of Rutgers University
Poster Abstract:
Our study used European Centre for Medium-Range Weather Forecasts (ECMWF) 1.125º operational analysis, in-situ soundings, Moderate-Resolution Imaging Spectroradiometer (MODIS) Aqua aerosol optical depth data, and the Tropical Rainfall Measuring Mission (TRMM) satellite microwave imager (TMI) data to diagnose the prestorm environment of intense convection in West Africa. Using a TMI algorithm from Mohr (2004), over 23,000 separate convective systems were identified. These convective systems were classified first by their minimum polarization-corrected temperature (PCT) (intense ≤ 135K; non-intense > 135K). The intense cases were further divided into those near high terrain (near-terrain intense and terrain-intense) and those that were not (farintense). From in-situ sounding data, the average equivalent potential temperature (theta-e) values within the lower troposphere varied no more than 7K among the case types. Fewer than 1% of our cases had surface theta-e values less than 340K. Low-layer shear was twice as large in intense cases then in non-intense cases with the far-intense cases having the largest low-layer shear overall. The boundary layer was noticeably warmer and deeper in cases away from high terrain than near it. We examined synoptic-scale influences on the local environment. From U- and V-wind Hovmöller plots, southerly 925-hPa V-winds were well correlated to the development of intense convection in areas westward of 10ºE due to advection to high theta-e air northward behind the West African Monsoon trough. Cases eastward of 10ºE were found to have low-layer trajectories from the Central African rainforests that underwent orographic lifting and also had significant local evapotranspiration. The African easterly jet (AEJ) was often aligned near the intense cases, accounting for the increased low-layer shear. The intense case axis was orthogonal to the 925-hPa thermal gradient and wind direction. The theta-e gradient was an effective tool for determining regions favorable to convective development. We found that all but a small fraction (<<1%) of cases developed with a theta-e at 925 hPa of 334K and greater. The African easterly wave (AEW) influence upon convective development (½- AEW length criteria) was three times as likely in the west forest, east forest, and west savanna regions than in the east savanna and the Sahel. Under this same criterion, only 8% of non-intense cases and 5% of far-intense cases are influenced by AEWs. Thus, the development of intense convection is better explained by other factors such a theta-e, low-layer shear, and the AEJ than AEWs. The number of cases, regardless of case type, decreased with increasing aerosol optical depth. The cumulative distribution function (CDF) curves revealed that 85% of cases occurred in little or no dust. Given enough low-layer shear and a sufficiently moist BL, intense convection could occur in moderately dusty environments. Only in the presence of both a dusty and dry environment may the development of intense convection be inhibited.
Title and Author:
Using Unidata Products and Tools in Meteorological Education: A Perspective From OU
Kevin H. Goebbert and Mark J. Laufersweiler
Poster Abstract:
With meteorology being a highly visual science it is increasingly important that students are introduced to different tools and methods for plotting and analyzing meteorological data. Throughout the courses offered at the University of Oklahoma (OU) Unidata products and tools are introduced to the students through the completion of homework and lab assignments. This initial introduction leads students to use the data and tools to gain a further understanding of a given meteorological situation. The initial inquiry through the class assignments often leads to independent inquiry and internships. The Oklahoma Weather Lab (OWL) is a prime example of how an introduction meteorological computing can lead to an independent project creating weather graphics for a larger community. The development team members for OWL were initially motivated to create weather graphics after learning the basics of the GEneral Meteorological PAcKage (GEMPAK) during their sophomore year. The group continues today as more students become interested through their coursework and informal sessions with development team members. These interactions create positive feedbacks into the education process, which result in students who are equipped with the essentials to obtain jobs in meteorology.
Workshop Contact
Workshop Coordinator
UCAR Office of Programs, Unidata
P.O. Box 3000
Boulder, CO 80307-3000
phone: 303.497.8643
fax: 303.497.8690