Staff Notes Daily Calendar Events

Monday, August 20, 2018 - 3:30pm

ACOM SEMINAR

TITLE:  Changes in transport and mixing of polar ozone during sudden stratospheric warmings

PRESENTER:  Álvaro de la Cámara, Universidad Complutense de Madrid

ABSTRACT:  Understanding the impact of dynamical processes such as sudden stratospheric warmings (SSWs)  on Arctic ozone is key to interpreting the observed interannual variability and better quantify polar ozone evolution. In the first part of this seminar, we will focus on quantifying the changes in the stratospheric circulation and the mixing properties of the flow during SSWs. Using 34 years of reanalysis data (ERA-Interim), and 240 years of output from the Whole Atmospheric Community Climate Model version 4 (WACCM4), we find: i) A weakened residual circulation and intensified isentropic mixing after the onset of SSWs that persist for more than two months in the lower stratosphere; ii) sufficiently deep SSWs (i.e. those followed by Polar-night Jet Oscillation events, or PJO) have a stronger and more persistent response in the meridional circulation and isentropic mixing; and iii) long after the strong wave forcing that drives the SSWs has declined, diffusive fluxes of potential vorticity (PV) remain anomalously high in the lower stratosphere delaying the recovery of the vortex.

In the second part of the seminar, we will explore how these alterations in the circulation affect Arctic ozone. The composite evolution of ozone displays positive mixing ratio anomalies up to 0.5 – 0.6 ppmv above 550 K (∼50 hPa) around the central warming date and negative anomalies below (-0.2 to -0.3 ppmv), consistently in observations, reanalysis and model. We will show the fundamental role of irreversible mixing of ozone in delaying the recovery of climatological values, and contributing to maintain the ozone anomalies in the lower stratosphere over 2 to 3 months after the occurrence of SSWs.

Monday, August 20, 2018, 3:30 p.m Refreshments 3:15 p.m FL-1001, Small Auditorium Live webcast: http://ucarconnect.ucar.edu/live

Type of event:
Seminar/Symposium
Building:
FL2
Room:
1001

Posted by Bonnie Slagel (bonnie@ucar.edu) at x8318
Hosting lab/division or program:
ACOM
Will this event be webcast?
Thursday, August 30, 2018 - 12:00pm

A plain-language abstract is an incredibly effective science communication tool because it allows researchers to reach a wider audience by summarizing papers in terms that are accessible to people outside of a specific scientific circle.

In this webinar, learn how to identify your audience, reduce jargon, determine what key points to hit, and more.

American Geophysical Union Webinar

Thu, Aug 30, 2018

12:00 - 1:00 PM MDT (2:00 - 3:00 PM EDT)

Register to attend: https://register.gotowebinar.com/register/2391323833530123266

Type of event:
Tutorial/Training

Posted by Zhenya Gallon (zhenya@ucar.edu) at x8607
Will this event be webcast?
No
Tuesday, September 4, 2018 - 11:00am

Title: The role of the land surface in weather and climate

Speaker: Paul Dirmeyer, George Mason University

Date: Tuesday, 4 September 2018

Time: 11 am - 12 pm

*Refreshments at 10:45 am*

Location: Mesa Lab, Main Seminar Room, ML-132

Abstract: Similar to the ocean, the land surface is a slow manifold relative to the atmosphere that provides predictability and prediction skill across a range of time scales.  Land-atmosphere feedbacks occur when and where three ingredients are in place: sensitivity (a.k.a. coupling), variability and memory (persistence of land anomalies).  Although the peak influence of land surface states like soil moisture is in the “sub-seasonal” time range between 1-3 weeks, significant impact of land and errors in its representation begin the first day of simulation, and manifest at all time scales.  The process chains that link soil moisture, vegetation, snow, and other land states through the energy and water cycles manifest through their effects on the growing daytime boundary layer, cloud formation and convection.  Thus, the diurnal cycle is key to assessing and improving model performance related to land-atmosphere interactions.  We show evidence of land surface impacts from a variety of global weather and climate models and highlight some current shortcomings that may inform model development.

 

 

 

Type of event:
Seminar/Symposium
Building:
Mesa Lab
Room:
ML-132 Main Seminar Room

Posted by Teresa Foster (teresaf@ucar.edu) at x1741
Will this event be webcast?
Yes - ML-Main Seminar Room - http://ucarconnect.ucar.edu/live
Wednesday, September 5, 2018 - 12:00pm

"Stability Analysis of Inline ZFP Compression for Floating-Point Data in Iterative Methods"

Alyson Fox Lawrence Livermore National Lab

ZFP, a state-of-the-art lossy compression algorithm, can easily be used inline during numerical simulations due to the inherent locality of the algorithm. ZFP decomposes a solution state into 4d blocks, which are subsequently compressed (decompressed) independently. In a numerical simulation, the solution state already contains traditional errors, e.g., floating-point round-off, truncation error, and discretization error. The information that is lost during ZFP compression may represent the traditional errors, however, any additional error caused by ZFP could contaminate the current iterate. It is important to understand if the error from ZFP compression overwhelms the other sources of error. The goal of this work is to analyze the stability of using ZFP in fixed precision inline in time-evolving iterative methods. We introduce the infinite bit vector space and define corresponding operators for each step of ZFP, to establish an error bound for both a static and iterative implementation of ZFP in fixed precision. To conclude, we present results from several numerical experiments to observe the validity of our established error bounds.

Bring your lunch!

Wednesday, September 5, 2018 12:00pm - 1:00pm ML, Room 680 Tower B (Penthouse)

Type of event:
Seminar/Symposium
Building:
Mesa Lab
Room:
Room 680 Tower B (Penthouse)

Posted by Kathy Peczkowicz (kathyp@ucar.edu) at x2431
Hosting lab/division or program:
TDD
Will this event be webcast?
No
Thursday, August 23, 2018 - 1:00pm

Satellite Wind Data Assimilation in HRRRAK-like Model

Jiang Zhu University of Alaska

High-Resolution Rapid Refresh for Alaska (HRRR-AK) model is one of the NOAA operational convective scale forecast system. Satellite wind data are not assimilated in the HRRR-AK model. Thanks to its high latitude, Alaska benefits from many polar-orbiter passes each day. Wind data derived from satellite observations have a good potential to improve the HRRR-Alaska short-term forecast. The purpose of the research is to investigate if the assimilation of satellite wind data can improve accuracy of the HRRR-AK model forecast. Experimental environment was setup in AWS cloud system, as well as the local machine in University of Alaska. The experimental model is HRRR-like model. It uses similar configuration, parameters, and initial fields as HRRR-AK model. In the experiment, the model run in three modes. Control run does not assimilate any observation data. Two experiment runs, one assimilates wind data only, and one assimilates wind data plus conventional observation, respectively. For simplicity, GSI 3D-Var analysis is used in the data assimilation experiments. The case study shows that valid VIIRS wind data is coarse in the domain; the impact of data assimilation of VIIRS wind data is very limited. The WRF model configured like HRRR-AK (smaller domain size and grid resolution) was used to do 24-hour forecasts 4 times daily. A month of forecasts are analyzed in terms of RMSEs. The preliminary conclusion shows that the VIIRS wind data does not improve the HRRR-AK-like model short-term forecast due to very coarse data distribution in the model domain. Further study includes evaluation of assimilation of all available satellite-derived wind data into the model.

Thursday, August 23, 2018

1:00-2:00pm

FL2–1001

Type of event:
Seminar/Symposium
Building:
FL2
Room:
1001

Posted by Jessa Johnson (jessaj@ucar.edu) at x2751
Hosting lab/division or program:
DTC
Will this event be webcast?
Tuesday, August 21, 2018 - 3:30pm

The Sundowner Winds Experiment (SWEX) First Intensive Campaign: understanding downslope windstorms in the Santa Ynez Mountains, Santa Barbara, CA

Sundowner winds (Sundowners for short) are the northerly gusty winds frequently observed leeward of the Santa Ynez Mountains (SYM) in coastal Santa Barbara (SB), CA. These winds typically peak from early evening through early morning with gale force gusts exhibiting features of downslope windstorms. The SYM rise abruptly from coastal SB separating the Pacific Ocean on its south face from the Santa Ynez Valley on its north face. Sundowners are considered the most relevant fire weather condition in all seasons and represent a major hazard for aviation, particularly small crafts. All major wildfires affecting the region exhibited significant fire spread rates toward the SB wildland-urban interface during Sundowners. The Sundowner Wind Experiment-first intensive campaign (hereafter, SWEX-I) was the first to evaluate vertical profiles of winds, temperature, humidity and other thermodynamic variables from the boundary layer to mid-high troposphere and leeward of the SYM during episodes of Sundowners (wind gusts exceeding 13 m/s or 30 mph). This was accomplished by launching 3-hourly radiosondes during the Sundowner events on April 28-29, 2018. SWEX-I demonstrated that cross-mountain winds in the lee of the SYM exhibit complex spatial and temporal patterns. Profiles of wind speed and direction, temperature and humidity near ground level showed a transition from humid onshore winds from morning-to-mid afternoon hours to very pronounced offshore winds during the evening. These offshore winds accompanied a northerly nocturnal low-level jet leeward of the SYM with variable behavior. The experiment showed evidence of mountain waves and critical layers associated with the intensification of winds. Around sunset (April 28, 20:00 PDT), the jet was characterized by a layer with strong wind speeds (~17m/s) around 273m asl. Winds weakened considerably at 23:00 PDT (peak ~ 9. 5m/s at 186m asl) but enhanced dramatically at 2:00 PDT on April 29 (peak ~14 m/s) at much lower elevations (150asl), when the jet was confined to a much narrower layer compared to observations at 20:00 PDT. These transitions were accompanied by changes in stability profiles and the Richardson number. Additionally, we examined the skill of the Weather and Forecast Model (WRF) (at 1km grid spacing) in forecasting this event, with focus on profiles of winds and stability. These results advanced our understanding of Sundowners and indicated that a comprehensive field campaign is critical to properly characterize the main mechanisms driving these winds and to advance studies on predictability of these events.

Tuesday, 21 August 2018, 3:30 PM Refreshments 3:15 PM NCAR-Foothills Laboratory • 3450 Mitchell Lane • Bldg 2 Small Seminar (Rm1001) Webcast: https://ucarconnect.ucar.edu/live

Type of event:
Seminar/Symposium
Building:
FL2
Room:
1001

Posted by Erin Fundalinski (erinf@ucar.edu) at x8713
Hosting lab/division or program:
EOL
Will this event be webcast?
Wednesday, September 5, 2018 - 2:00pm

The Nature of Streamer Blowout Coronal Mass Ejections

We investigate a particular class of coronal mass ejections (CMEs), named streamer-blowout CMEs (SBOs). The events are characterized by a gradual swelling of the overlying streamer, lasting hours to days, followed by a slow, wide CME, generally exhibiting a 3-part structure, which leaves the streamer significantly depleted in its wake. SBOs have a long history constituting the earliest detected CME type. however, they have not been studied in much detail as a distinct CME class. Most of our understanding of their properties, origin, and solar cycle dependence were based on individual cases or small sample sizes. We attempted to remedy this situation with a comprehensive study of LASCO observations across two solar cycles (1996-2015). Among the intriguing results of our study are: (1) that some events can take days to evacuate the corona challenging our conventional approach in defining CMEs, (2) that the locations of SBOs follow the tilt of the global dipole (but not from 2014 onwards---why?) and, (3) that they exhibit flux rope morphology at a much higher rate (61%) than regular CMEs (40%).

We propose that these characteristics are consistent with SBOs arising from extended polarity inversion lines outside active regions (e.g. quiet sun and polar crown filaments) through the release, via reconnection, of magnetic energy, likely accumulated via differential rotation.

Type of event:
Seminar/Symposium
Building:
CG1
Room:
2126

Posted by Sheryl Shapiro (sheryls@ucar.edu) at x1567
Hosting lab/division or program:
HAO
Will this event be webcast?
Wednesday, August 22, 2018 - 2:00pm

The Magnetic and Plasma Properties of Coronal Loops

The heating of the solar atmosphere remains to be one of the outstanding questions in Solar Physics. Despite the difficulty in finding a comprehensive and satisfactory explanation (model), significant progress has been made over the years in our understanding of the corona. Our observational constrains to theory and numerics are today far more demanding than simply producing million degree plasma. In this presentation, we discuss the current status of our understanding of the formation and evolution of the building blocks of the atmosphere, coronal loops, looked through the lens of our recent work on the spectroscopic and topological properties of EUV loops, and our efforts to reproduce the data with (Magneto) Hydrodynamic models.

Type of event:
Seminar/Symposium
Building:
CG1
Room:
2126

Posted by Sheryl Shapiro (sheryls@ucar.edu) at x1567
Hosting lab/division or program:
HAO
Will this event be webcast?
Wednesday, August 29, 2018 - 3:00pm

Jim Moore, Project Manager with EOL, will be retiring after a successful and rewarding career with NCAR. Since 1983, Jim has guided generations of observational scientists in the planning and conduct of over 80 field campaigns, sharing his in-depth knowledge and expertise. Throughout his 35 year career with NCAR, Jim has held various positions including Deputy Manager for ATD's Field Observing Facility, Project Manager for RAP's Terminal Doppler Weather Radar, Liaison to the STORM and TOGA COARE Project Offices, Project Manager for EOL's Airborne Phased Array Radar, and Operations Director for the MAP and DYNAMO campaigns. Jim's foresight, attention to detail, and people, negotiation and management skills has made him an invaluable asset to UCAR/NCAR throughout his tenure and he will be greatly missed. His well-deserved retirement will officially commence on September 1, 2018.

Please join us for a gathering on Wednesday, August 29th from 3:00 to 5:00 PM in the FL1 Courtyard to celebrate and honor Jim's accomplishments and outstanding service to the organization. RSVP to Erin Fundalinski (erinf@ucar.edu) by August 24th.

Type of event:
Celebration
Building:
Foothills Labs
Room:
Courtyard

Posted by Erin Fundalinski (erinf@ucar.edu) at x8713
Hosting lab/division or program:
EOL
Will this event be webcast?
No
Thursday, August 23, 2018 - 3:30pm

Speaker: Sean Healy

Affiliation: ECMWF

*Please note Special Location- FL2-1001 Small Seminar Room

ECMWF has assimilated GPS radio occultation (GPS-RO) measurements operationally since December 2006, and they are now considered to be a key component of the global observing system. Importantly, these measurements complement the information provided by satellite radiances, because they have good vertical resolution and they can be assimilated without bias correction to the background model. This talk will review how the assimilation of the GPS-RO data at ECMWF has evolved since 2006, and summarise the current impact of this data in the numerical weather prediction system. Current efforts to improve the forward modelling of the GPS-RO data will be described, and areas which require further improvement, such as improved observation error statistics, will be highlighted. Recent wave optics simulation results estimating the size of both the instrument errors and forward model/retrieval errors in the troposphere will be presented.

The importance of GPS-RO measurements for climate reanalyses will be demonstrated. It will be shown that the consistency of ERA5, JRA55 and MERRA-2 temperature estimates in the lower/middle stratosphere has improved since the active assimilation of COSMIC data in 2006.

 

Refreshments: 3:15pm

Type of event:
Seminar/Symposium
Building:
FL2
Room:
FL2-1001 Small-Seminar Room

Posted by Nancy Kerner (nskerner@ucar.edu) at x8946
Hosting lab/division or program:
MMM
Will this event be webcast?
Friday, October 26, 2018 - 8:00pm

Training Workshop: The Community WRF-Hydro Modeling SystemOctober 23-26, 2018 || Boulder, CO

NCAR is pleased to partner with CUAHSI to offer the Training Workshop: The Community WRF-Hydro Modeling System, a 3.5-day hands-on training workshop on the use and applications of the Community WRF-Hydro Modeling System.

Course DescriptionThis training workshop will provide graduate students and early career scientists with formal instruction on the structure and application of the WRF-Hydro system and will offer hands-on experience in setting up and running the system for several different research and prediction applications.

Specific topics to be covered during the workshop include:

  • Conceptualization and structure of the WRF-Hydro system
  • Description of physics components and options within WRF-Hydro
  • Model porting and compilation, and an overview of parallel computing with WRF-Hydro
  • Hands-on model input data preparation and creation of an example test case
  • Hands-on model configuration and execution
  • Hands-on experimental model simulations and comparisons with a prepared example test case
  • Overview of the open source Rwrfhydro hydrologic model evaluation package  with example vignettes
  • Overview of model calibration
  • Overview of data assimilation
  • Open discussion on class participant interests and applications

Class participants will receive in-depth training via lectures and hands-on activities on the implementation and use of the WRF-Hydro system where all hands-on tutorial activities will be conducted in a formal computer laboratory located at NCAR in Boulder, CO.

Lead Instructor: Dave Gochis, NCAR

Presenters: Dave Gochis, NCARAubrey Dugger, NCARKevin Sampson, NCARLaura Read, NCARMichael Barlage, NCARArezoo RafieeiNassab, NCARLogan Karsten, NCARJames McCreight, NCARJoe Mills, NCARKatelyn FitzGerald, NCAR

Workshop Eligibility

Applicants must apply to attend the workshop. Applications will be accepted from current and incoming graduate students, post-docs, academics, and professionals working in hydrology and/or the atmospheric sciences. Instructors will review applications to verify in advance that the applicant has the necessary skills and experience to successfully participate in the workshop and get the most out of the course topics. See the event website to apply.

Requirements

  • Prior hydrologic and/or atmospheric modeling experience is advised.
  • Must be comfortable working in a UNIX environment, running UNIX command line operations and text editors.
  • Familiarity with the R and/or Python programming language is recommended.

How to ApplySee the event website to apply. Applications will be accepted beginning June 25, 2018. Complete applications will be accepted on a rolling basis until 5:00 p.m. ET on July 31, 2018. However, we recommend that you submit your application as soon as possible, as applications will be reviewed on a rolling basis on first-come, first-served. We reserve the right to review only the first 50 applications. Past offerings of this course have filled up very quickly.

Visit the event website for additional information on applying to the workshop.

 

Type of event:
Tutorial/Training
Building:
FL2
Room:
1024

Posted by Molly McAllister (mollymca@ucar.edu) at x8253
Hosting lab/division or program:
HAP
Will this event be webcast?
No
Friday, October 26, 2018 - 8:00pm

Training Workshop: The Community WRF-Hydro Modeling SystemOctober 23-26, 2018 || Boulder, CO

NCAR is pleased to partner with CUAHSI to offer the Training Workshop: The Community WRF-Hydro Modeling System, a 3.5-day hands-on training workshop on the use and applications of the Community WRF-Hydro Modeling System.

Course DescriptionThis training workshop will provide graduate students and early career scientists with formal instruction on the structure and application of the WRF-Hydro system and will offer hands-on experience in setting up and running the system for several different research and prediction applications.

Specific topics to be covered during the workshop include:

  • Conceptualization and structure of the WRF-Hydro system
  • Description of physics components and options within WRF-Hydro
  • Model porting and compilation, and an overview of parallel computing with WRF-Hydro
  • Hands-on model input data preparation and creation of an example test case
  • Hands-on model configuration and execution
  • Hands-on experimental model simulations and comparisons with a prepared example test case
  • Overview of the open source Rwrfhydro hydrologic model evaluation package  with example vignettes
  • Overview of model calibration
  • Overview of data assimilation
  • Open discussion on class participant interests and applications

Class participants will receive in-depth training via lectures and hands-on activities on the implementation and use of the WRF-Hydro system where all hands-on tutorial activities will be conducted in a formal computer laboratory located at NCAR in Boulder, CO.

Lead Instructor: Dave Gochis, NCAR

Presenters: Dave Gochis, NCARAubrey Dugger, NCARKevin Sampson, NCARLaura Read, NCARMichael Barlage, NCARArezoo RafieeiNassab, NCARLogan Karsten, NCARJames McCreight, NCARJoe Mills, NCARKatelyn FitzGerald, NCAR

Workshop Eligibility

Applicants must apply to attend the workshop. Applications will be accepted from current and incoming graduate students, post-docs, academics, and professionals working in hydrology and/or the atmospheric sciences. Instructors will review applications to verify in advance that the applicant has the necessary skills and experience to successfully participate in the workshop and get the most out of the course topics. See the event website to apply.

Requirements

  • Prior hydrologic and/or atmospheric modeling experience is advised.
  • Must be comfortable working in a UNIX environment, running UNIX command line operations and text editors.
  • Familiarity with the R and/or Python programming language is recommended.

How to ApplySee the event website to apply. Applications will be accepted beginning June 25, 2018. Complete applications will be accepted on a rolling basis until 5:00 p.m. ET on July 31, 2018. However, we recommend that you submit your application as soon as possible, as applications will be reviewed on a rolling basis on first-come, first-served. We reserve the right to review only the first 50 applications. Past offerings of this course have filled up very quickly.

Visit the event website for additional information on applying to the workshop.

 

Type of event:
Tutorial/Training
Building:
FL2
Room:
1024

Posted by Molly McAllister (mollymca@ucar.edu) at x8253
Hosting lab/division or program:
HAP
Will this event be webcast?
No
Saturday, October 27, 2018 - 6:00am

Parents’ Night Out is a great opportunity for you and your significant other to go out to dinner and a movie!Contact Stephanie Ivancic, Director of UCAR’s Child Care Center, to sign your child up from 6 pm - 8 pm ($30 for one child or $40 for two children) or 6 pm - 10 pm ($50 for one child and $60 for two children).Children are welcome to wear their pajamas for a fun evening of movies and pizza! If your child has a video that he or she would like to share, bring it along! Please make sure it is labeled and let the fun begin! Siblings under the age of 7 are welcome, too.We invite all UCAR employees to take advantage of this fun evening as your child does not need to be enrolled at the UCAR Child Care Center to partake! Mark your calendars for future dates:   July 6 & 20, August 3, 17 & 31, September 14 & 28, October 12 & 26, November 2, 16 & 30, December 14.Please contact Stephanie Ivancic for enrollment as well as drop-in care rates.  Stephanie’s email address is sivancic@cclc.comand her phone number is 303-443-5595.


Posted by Laurie Carr (lcarr@ucar.edu) at x8702
Will this event be webcast?
No
Tuesday, August 21, 2018 - 1:30pm

RAL Seminar

Catalyzing Decision Services with Probability Forecasts on Demand

John K. Williams The Weather Company, An IBM Business

An “operations to decisions” divide is preventing much of the available societal value of the weather enterprise’s increasingly accurate forecasts from being fully realized. Existing weather decision support services often target high-impact events, government agencies and large businesses with tailored weather information, but there is also significant potential value in improving the ability of society at large to use weather information to make a broad spectrum of day-to-day decisions. Bridging the “O2D” divide requires an accessible framework that includes the requisite weather forecasts, methods for inferring impacts, techniques for determining optimal actions, compelling ways to communicate supporting evidence and effective means to execute decisions. An optimal decision is one that limits the risk of an unacceptable outcome, provides the greatest expected net benefit, is timely, and can be cogently described and explained.

While some domains may have more limited requirements, weather-based decision services generally require (1) forecasts of all possible future weather scenarios and their likelihoods; (2) a way to determine costs and benefits associated with prospective actions under each scenario; (3) predictions of the benefit versus opportunity cost of waiting for a more certain forecast before making a decision; and (4) tools and strategies for communicating and executing decisions.  Towards this end, The Weather Company has launched a new probability forecasting capability called Probability Forecasts on Demand (PFoD). PFoD builds on our 18-year evolution of the DICast-based automated multi-model consensus forecasting technology, which drives a broad array of business and consumer weather products including the Weather Channel website and mobile applications. PFoD provides probability distribution function (PDF) and related descriptions of forecast uncertainty for several weather variables at any global location.  In addition, it provides a user-specified number of calibrated ensemble “prototype” forecasts that provide the multivariate weather trajectories required to evaluate nonlinear weather impacts and spatiotemporal dependencies. The prototypes are calibrated and constructed to be “equally likely,” giving them an advantage over raw NWP ensembles that may exhibit biases, under- or over-dispersion and unequal skill among members. Coupled with machine-learned, heuristic or physically-based impact models, PFoD provides a basis for quantifying risks and estimating expected values for prospective actions or policies. The availability of PFoD via an API offers easy access to the weather information required to develop a broad array of decision services.  This talk will describe and illustrate PFoD’s capabilities, provide sample decision use cases, and highlight some of the many forecasting and decision service design challenges that remain to be addressed.

Tuesday, August 21, 2018 1:30-2:30 FL2 - 1001

Type of event:
Seminar/Symposium
Building:
FL2
Room:
1001

Posted by Jessa Johnson (jessaj@ucar.edu) at x2751
Hosting lab/division or program:
WSAP
Will this event be webcast?
No

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