Staff Notes Daily Calendar Events

Thursday, March 26, 2015 - 3:30pm

Tom Auligné
NCAR, Boulder

Hybrid variational/ensemble data assimilation (aka hybrid DA) is widely used in research and operational systems, and it is considered as the current state-of-the-art for the initialization of numerical weather prediction models. However hybrid DA requires a separate ensemble DA to estimate the uncertainty in the deterministic variational DA, which can be suboptimal both technically and scientifically. A new NCAR-developed algorithm called the Ensemble-Variational Integrated Localized (EVIL) data assimilation addresses this deficiency by updating both the deterministic and ensemble analyses within a single variational system. Idealized cases with a simplified model have shown the potential of EVIL to outperform existing DA systems. Recently, the algorithm has been implemented within the GSI framework for regional and global models. Particular attention was devoted to the affordability of the algorithm in preparation for operational applications. In this seminar, we will explain the theory of EVIL, describe various implementation strategies and show early results with the WRF model.

This seminar will be webcast live at: http://www.fin.ucar.edu/it/mms/fl-live.htm

Recorded seminar link can be viewed here: https://www.mmm.ucar.edu/events/seminars

Thursday, 26 March 2015, 3:30 PM
Refreshments 3:15 PM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg 2 Main Auditorium, Room 1022

Presenter(s):
Tom Auligné
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Michelle Menard (menard@ucar.edu) at x8189
Lab/division hosting the event:
NCAR, MMM
Affiliation or organization:
Wednesday, April 8, 2015 - 11:30am

The ocean has intrinsic variability arising from hydrodynamic instabilities of the time mean circulation, analogous to weather systems in the atmosphere. However, the ocean models typically used in climate assessments are too coarse and viscous to resolve these instability mechanisms, and this variability is strongly suppressed or entirely absent. Over the last two decades there has been tremendous progress in parameterizing the integrated effects of ocean eddies on the mean circulation, but the contributions to climate variability remain unrepresented. Recent pioneering integrations with high-resolution coupled climate models and the emergence of high-resolution global remote sensing observations allow us to begin to identify the geographical regions, space scales, and time scales at which the ocean may contribute to climate variability.

Presenter(s):
Frank Bryan
Type of event:
Seminar/Symposium
Building:
Mesa Lab
Room:
Main Seminar Room

Posted by Scott Briggs (sbriggs@ucar.edu) at x1607
Lab/division hosting the event:
NCAR, ASP
Affiliation or organization:
Friday, May 1, 2015 - 11:00am

Local non-profits will visit to promote opportunities for employees and their families to volunteer in our community.

Presenter(s):
EAC
Type of event:
Public Outreach
Building:
FL2
Room:
1001, 1002, 1022, cafeteria atrium

Posted by Jo Zoetewey (zoetewey@ucar.edu) at x2709
Lab/division hosting the event:
UCAR
Affiliation or organization:
Thursday, April 9, 2015 - 3:30pm

Chris Davis
The National Center for Atmospheric Research
Boulder, Colorado

The upscale aggregation of convection is used to understand the emergence of rotating, coherent mid-tropospheric structures and the subsequent process of tropical cyclone formation. The CM1 model is integrated on an f-plane with uniform SST and prescribed uniform background flow. Moist cyclonic vortices form, merge, and eventually result in a single dominant vortex that subsequently forms a tropical cyclone. Consistent with previous studies, the approach to saturation within the mid-tropospheric vortex accelerates the genesis process. A novel result is that, while updrafts do not intensify prior to genesis, downdrafts do. Stronger downdrafts produce cold pools that maximize their negative buoyancy about one day prior to genesis. Shear-cold-pool dynamics promote organization of lower-tropospheric updrafts that spin up the surface vortex. It is inferred that the observed inconsistency between convective intensity and thermodynamic stabilization prior to genesis results from sampling limitations of the observations wherein the important cold pool gradients are unresolved.


This seminar will be webcast live at:
http://www.fin.ucar.edu/it/mms/fl-live.htm

Recorded seminar link can be viewed here:
https://www.mmm.ucar.edu/events/seminars


Thursday, 9 April 2015, 3:30 PM
Refreshments 3:15 PM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg 2 Main Auditorium, Room 1022

Presenter(s):
Chris Davis
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Michelle Menard (menard@ucar.edu) at x8189
Lab/division hosting the event:
NCAR, MMM
Affiliation or organization:
Tuesday, March 31, 2015 - 11:00am

A cumulus parameterization proposed by Chikira and Sugiyama (2010) is an offshoot of the prognostic Arakawa-Schubert scheme. But it is characterized by state-dependent entrainment rates based on Gregory (2001) and spectral representation of cloud types according to cloud base updraft velocity. The scheme naturally represents the effect of free-tropospheric humidity on deep convection through the vertical variation of the entrainment rates without any empirical triggering schemes. A series of papers have been published on the impact of this scheme in one of Japanese GCMs (MIROC5). They showed significant improvements in both climatology and variability, including the double ITCZ, equatorial waves, monsoon and ENSO. In this talk, I will pick up highlights from these papers. This scheme is already implemented in NCAR CAM5 and its preliminary result appears to be promising. Finally, my ongoing research at CSU on the implementation of the unified parameterization proposed by Arakawa and Wu (2013) which makes it possible to apply conventional cumulus parameterizations to models with horizontal resolution of several tens of kilometers will be briefly introduced.

Presenter(s):
Minoru Chikira
Type of event:
Seminar/Symposium
Building:
Mesa Lab
Room:
Main seminar room

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
NCAR, CGD
Affiliation or organization:
Tuesday, April 7, 2015 - 11:00am

The Dominica Experiment (DOMEX) took place in the eastern Caribbean in the spring of 2011 with 21 research flights of the University of Wyoming King Air (UWKA) aircraft. The goal was an improved understanding of the physics of convective orographic precipitation in the tropics. The UWKA measured upstream and downstream airflow properties as well as the convective clouds and precipitation over the island of Dominica. This flight data along with an idealized numerical model have been used to understand the role of the ambient upstream wind speed in controlling the transition from thermally to mechanically forced moist orographic convection. Additionally, a modified version of Woodcock's 1960 moist convective initiation theory will be evaluated using a unique set of upstream sub-cloud measurements from DOMEX.

Presenter(s):
Alison Nugent - NSF Postdoc
Type of event:
Seminar/Symposium
Building:
Mesa Lab
Room:
Main Seminar Room

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
NCAR, CGD
Affiliation or organization:
Monday, April 6, 2015 - 2:00pm

Speaker: Ligia Bernardet
             NOAA Earth Systems Research Laboratory, Boulder, CO
             CU Cooperative Institute for Research in the Environmental Sciences, Boulder, CO     
Date:      April 6, 2015
Time:     2:00pm
Place:     FL 2 – Rm 1001

In order to support its forecast needs, the US National Oceanic and Atmospheric Administration (NOAA) has several operational Numerical Weather Prediction (NWP) systems, each requiring ongoing development to improve forecast skill. While the NOAA National Weather Service (NWS) centralizes the development and determines which updates are implemented in operations, research and development (R&D) are also conducted by the research branch of NOAA and by the academic community in general.  This distributed model of development creates a potential for NOAA to benefit from a large body of scientific work, but also poses some challenges.

In order for scientists to contribute relevant R&D, it is important that they work with the current operational codes, suites, and relevant input datasets. However, obtaining such codes and inputs, and configuring the system to run with data assimilation and cycling workflows identical to the ones used in operations, can be a daunting task for those within and ouside of the NOAA Environmental Modeling Center (EMC).

To facilitate the use of operational NWP systems by the R&D community, NOAA has partnered with the Developmental Testbed Center (DTC) to create the design of the NWP Information Technology Environment (NITE).  In this presentation we will review the various elements of the NITE infrastructure, which include data management, source code management and build systems, suite definition and configuration tools, scripts, workflow management system, experiment database, and documentation and training.

UCAR Connect Link
http://ucarconnect.ucar.edu/live

Presenter(s):
Ligia Bernardet
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1001

Posted by Marybeth Zarlingo (zarlingo@ucar.edu) at x2751
Lab/division hosting the event:
NCAR, RAL - JNT/DTC
Affiliation or organization:
Wednesday, April 8, 2015 - 1:00pm

Date:       April 8, 2015    
Time:      1:00pm
Place:      FL 2 – Rm 1022

Advancing A Clean Energy Agenda in America: What Researchers Need to Know about Current and Future Renewable Energy Policy  

Abstract:

Governor Bill Ritter led the successful effort to increase the State of Colorado’s renewable energy standard to 30% by 2020 in 2010. Establishing the most aggressive standard in the Rocky Mountain West, Colorado became both the first state to adopt a Renewable Energy Standard by a vote of the people and a national and international leader in developing a clean energy economy. Upon leaving office as Colorado Governor in 2011, Bill founded and took on the role as director of Colorado State University’s Center for the New Energy Economy. The Center works directly with policy makers, governors, planners, and other decision makers to create a road map that will accelerate the development of a new energy economy nationwide. It provides technical assistance to help officials create the policies and practices that will facilitate America’s transition to a clean-energy economy. In his talk, Bill will discuss the future of renewable energy, providing an overview on state, national and international policy trends and how these may affect renewable energy research and implementation.

Presenter(s):
Governor Bill Ritter
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Marybeth Zarlingo (zarlingo@ucar.edu) at x2751
Lab/division hosting the event:
NCAR
Affiliation or organization:
Thursday, April 2, 2015 - 3:30pm

James Done
The National Center for Atmospheric Research
Boulder, Colorado

An approach to assessing the damage potential of tropical cyclones is developed using a combination of physical reasoning and empirical assessment. Using readily available and key damaging cyclone parameters of intensity, size, and translational speed a Cyclone Damage Potential index is developed that represents offshore damage and onshore wind and coastal surge damage. The index is applicable to individual tropical cyclones, and to seasonal and global summaries. Actual damage assessment or prediction requires the additional step of incorporating historical damage data and regional peculiarities.

The index is then modified to use large-scale climate data available from global climate models, thereby sidestepping the need for information on individual cyclones. Relative sea surface temperature and steering flow are used as proxies for cyclone intensity, size, and translational speed. Application to climate model simulations under representative concentration pathways (RCPs) 4.5, 6.0, and 8.5 shows a future reduction in damage potential, driven by a cooling relative SST. However, the spread in damage potential reduction among the RCPs is less than the spread due to internal variability over the 21st century, as assessed using a climate model initial condition large ensemble. Improving understanding of spatial SST change may therefore be key to understanding future change in TC damage potential.

This seminar will be webcast live at:
http://www.fin.ucar.edu/it/mms/fl-live.htm

Recorded seminar link can be viewed here:
https://www.mmm.ucar.edu/events/seminars

Thursday, 2 April 2015, 3:30 PM
Refreshments 3:15 PM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg 2 Main Auditorium, Room 1022

Presenter(s):
James Done
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Michelle Menard (menard@ucar.edu) at x8189
Lab/division hosting the event:
NCAR, MMM
Affiliation or organization: