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Gravity waves in the global 7-km GEOS-5 Nature Run
Dr. Laura Holt
NorthWest Research Associates
Gravity waves are important drivers of atmospheric motion on both local and global-scales, from the upper troposphere to the thermosphere and ionosphere. However, most global climate models are too coarse to resolve the full spectrum of gravity waves and use gravity wave drag parameterizations to approximate the effects of gravity waves on the circulation. These parameterizations are a large source of uncertainty in models, in part because we do not yet have a global understanding of gravity wave properties and their sources from observations to constrain parameterizations. As computational power increases, atmospheric general circulation models are able to resolve smaller and smaller-scale waves, reducing, but not (yet) eliminating, the need for parameterizations. High-resolution models can also provide guidance for gravity wave drag parameterizations where observations are lacking through investigation of the modeled small-scale waves, their sources, and how they interact with the large-scale circulation. This talk will explore some of the aspects of the resolved small-scale waves in the global 7-km horizontal resolution Goddard Earth Observing System model (GEOS-5) Nature Run. In particular, the talk will focus on the wave driving of the quasi-biennial oscillation in the tropics and nonorographic gravity waves and sources related to convection and frontogenesis in the Southern Hemisphere winter.
Monday, May 1, 2017
Refreshments 3:15 p.m.
NCAR Foothills Laboratory, FL2-1022, Large Auditorium
Live webcast: http://ucarconnect.ucar.edu/live
Posted by Caitlyn Quinn at ext. 1308, firstname.lastname@example.org
Register now to join a free National Academies of Sciences, Engineering, and Medicine webinar to explore the themes discussed at the workshop Antarctic Sea Ice Variability in the Southern Ocean-Climate System.
May 4, 2017
2:00 PM EDT - 3:00 PM EDT / noon - 1:00 PM MDT
The workshop focused on the potential mechanisms driving increases in the extent and concentration of the sea ice surrounding Antarctic from the late 1970s until 2015—increases that were not reproduced by climate models, and that came despite the overall warming of the global climate and the region (summarized in the Workshop Proceedings).
The webinar will feature presentations from the chair of the workshop planning committee, Julienne Stroeve of the University of Colorado, Boulder, and from committee members Marika Holland of the National Center for Atmospheric Research, Boulder, and Marilyn Raphael of the University of California, Los Angeles.
Please register to attend: http://dels.nas.edu/Upcoming-Event/Webinar-Antarctic-Variability/AUTO-7-...
Posted by Zhenya Gallon at ext. 8607, email@example.com
April 28th from 8:30am-5:00pm at CG Auditoriums
Please be sure to RSVP for the Lunch - Click Here
UCAR Sponsored Reception begins at 4:00 pm (no need to RSVP)
Posted by Annette Lampert at ext. 8719, firstname.lastname@example.org
Antarctic sea ice should be melting but it's not:
Connections to global temperature trends and
decadal variability in the tropical Pacific
Gerald Meehl, NCAR/CGD
Antarctic sea ice extent has been slowly increasing in the satellite record since it began in 1979. Since the late 1990s, the increase has accelerated, but the average of all climate models shows a retreat of Antarctic sea ice as could intuitively be expected in a warming climate. Meanwhile, the Interdecadal Pacific Oscillation, an internally-generated mode of climate variability, transitioned from positive to negative about the time Antarctic sea ice retreat accelerated, with an average cooling of tropical Pacific sea surface temperatures, a slowdown of the global warming trend, and a deepening of the Amundsen Sea low near Antarctica that has contributed to regional circulation changes in the Ross Sea region and expansion of sea ice. Here we show that the negative phase of the Interdecadal Pacific Oscillation in global coupled climate models is characterized by anomalies similar to the observed sea level pressure and near-surface 850 hPa wind changes near Antarctica since 2000. These are conducive to expanding Antarctic sea ice extent, particularly in the Ross Sea region in all seasons, involving a deepening of the Amundsen Sea Low. These atmospheric circulation changes, and thus the expansion of Antarctic sea ice, are shown mainly to be driven by internally-generated IPO-related precipitation and convective heating anomalies in the equatorial eastern Pacific, with additional contributions from convective heating anomalies in the South Pacific Convergence Zone and tropical Atlantic regions.
Tuesday, 25 April 2017
11:00 AM, refreshments at 10:45
Mesa Lab, Main Seminar Room
Posted by Gaylynn Potemkin at ext. 1618, email@example.com
True or False: The AMS Education Program is located in Boston.
True or False: The AMS Education Program is more than a quarter century old.
True or False: AMS Education Programs have directly taught weather, water, ocean, and climate science to >20,000 K-12 teachers.
True or False: The AMS Education Program publishes textbooks.
If you are unsure of the answers to any of these questions, join us to learn the answers and much more as Wendy Abshire, DBAMS member and AMS Education Program Director, discusses the many activities and impacts of the AMS Education Program as well as programmatic goals for the future.
When: Wednesday, April 26th, 2017
6:00 PM – Arrive, socialize, light refreshments served
6:30 PM – Presentation and discussion
7:30 PM – Meeting adjourns
Where: National Center for Atmospheric Research,
Mesa Laboratory (large auditorium)
1850 Table Mesa Drive, Boulder, CO
Posted by Matthew Paulus at ext. 2025, firstname.lastname@example.org
News clips at a glance: April 15 – 21
Total: ~ 60
Summary: A potpourri of topics attracted the media's attention, including atmospheric wave patterns, snowpack, weather models, and geoengineering. President Donald Trump signed bipartisan legislation to improve weather forecasting and research, a bill UCAR provided extensive information about to Congress.
Legislation to Improve Weather Forecasting (UCAR):
Trump Signs Monumental Weather Bill Into Law to Help Forecasting, Researching Capabilities Across Weather Enterprise
Atmospheric Waves and Weather (Haiyan Teng, Grant Branstator, CGD):
California's Recent Weather Extremes: A Planetary-Scale Pattern of Atmospheric Waves May be Responsible for the State's Droughts and Floods
Climate Change and Snowmelt (Keith Musselman, RAL):
Scientists Look to Colorado to Improve Snowpack Science in a Warming Climate
(KMGH-TV, Channel 7 Denver, ABC affiliate)
Unifying Weather Forecasts and Climate Models (NCAR):
Take that Europe: Computer Modeler Aims to Give U.S. Lead in Weather Predictions
(Science Magazine, mentions NCAR's MPAS model)
Geoengineering (Kevin Trenberth, CGD):
Everything You Need to Know About Geoengineering
Heat's Impact Amid Changing Climate (Caspar Ammann, RAL):
Hundreds of Millions of Poor Menaced by 'Silent Killer': Heat
(Times of Oman/Thomson Reuters Foundation Ammann quoted, story also cites NCAR heat-impact estimates)
Climate and Rising Sea Levels (Claudia Tebaldi, CGD):
Climate Experts Release Latest Science on Sea Level Rise Projections
Design of Mesa Lab (NCAR):
A Portrait of I.M. Pei at (Nearly) 100
(New York magazine)
Social media highlights:
NCAR scientist Kevin Trenberth talked climate change on Facebook Live with Mike Nelson of KMGH-TV, Channel 7, Denver. The 20-minute interview has attracted nearly 14,000 views so far. Paul Douglas featured the Facebook Live interview in his weather blog in the Minneapolis Star-Tribune newspaper.
Posted by Jeff Smith at ext. 2679, email@example.com
WHO: All staff who travel internationally
WHAT: Don’t travel with data that is not needed for your trip. Don’t take export controlled or other sensitive or controlled data on international travel if it is not required and authorized.
WHY: U.S. customs officials are authorized to search or retain electronic devices, including digital cameras, cell phones, media players, disk drives, flash drives, tablet devices, and laptops, even without probable cause, to look for violation of export control regulations as well as other laws and regulations. To prepare for this possibility:
Posted by Rebecca Swisher at ext. 8609, firstname.lastname@example.org
Wednesday, April 26, 2017 1-2pm
Statistical Data Integration Methods for Environmental Exposures
Dr. Howard Chang
Accurate and reliable exposure estimates are crucial to the success of any environmental health study. However, monitoring measurements are often available sparsely in space and time. One approach to improve exposure assessment is by supplementing measurements with additional data sources, such as computer model simulations and satellite imagery. I will discuss methods development for three statistical approaches to perform data integration: statistical downscaling, ensemble averaging, and quantile mapping. One important advantage of statistical methods for data integration is the ability to incorporate and quantify various sources of uncertainty. These methods are applied to (1) estimate daily fine particulate matter concentration at fine spatial resolution, (2) bias-correct climate model projections, and (3) estimate source-contributions to air pollution. Results from population-based health studies utilizing these data fusion products will also be presented.
Posted by cassie Olenick at ext. 2821, email@example.com