Staff Notes Daily Calendar Events

Thursday, November 6, 2014 - 10:30am

Stratospheric Water Vapor Processes and Trends from In Situ Observations

In-situ observations of water vapor in the stratosphere and in the tropopause region are an important tool to study trends and processes of stratospheric water vapor.

Balloon-borne in-situ observations of stratospheric and tropospheric water vapor, ozone, and temperature are currently launched at a number of operational and campaign-based sites. At Lindenberg, Germany, these soundings are launched twice per month, with one sounding during daytime and one during nighttime. The nighttime soundings carry an additional backscatter instrument to provide cloud and aerosol information at two wavelengths. These observations allow studies of cloud microphysics and provide an in-situ consistency check of the water vapor observations.

At Boulder, CO (which has by far the longest record of stratospheric water vapor), at Hilo, HI, and at Costa Rica, water vapor soundings are launched at a roughly monthly schedule. The data set at Costa Rica is currently the most extensive data set of in-situ water vapor in the tropical upper troposphere and lower stratosphere. These soundings provide relative humidity over ice at the cold point tropopause and constitute the only long term data set for water vapor entering the stratosphere. Costa Rica has a pronounced rainy season with widespread deep convection, as well as a distinct dry season with nearly complete absence of deep convection. On average, high relative-humidity values, which are observed at the tropopause, are a strong indication that dehydration may occur throughout the year.

Studying data from different sites provides indications about the consistency of the observations and emphasizes that routine in-situ observations are needed at multiple locations to understand the details of water vapor processes and trends in the stratosphere.


Thursday, 6 November 2014, 10:30AM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg. 2 Large Auditorium (Rm 1022)

Presenter(s):
Holger Vömel
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022 (Large Auditorium)

Posted by Whitney Robinson (wrobs@ucar.edu) at x8713
Lab/division hosting the event:
NCAR, EOL
Affiliation or organization:
Tuesday, November 11, 2014 - 11:00am

Problems concerning the evolution planetary atmospheres on geologic timescales were once reserved for conceptual models.  However, three-dimensional climate models are now commonly used to simulate extremes of planetary climate for Earth, other solar system objects, and most recently extrasolar planets.  In this study, I use a modified version of the Community Earth System Model to examine two fundamental problems concerning the evolution of Earth’s atmosphere: the faint young Sun paradox and the runaway greenhouse.  Both problems are motivated by the long-term evolution of the solar constant.  All stars gradually brighten over their main sequence lifetimes.  Thus, if we wind the clock backwards, the early Earth was irradiated by up to ~25% less solar energy than the present day, yet geologic evidence indisputably points toward a warm planet that teemed with life.  Conversely, as time marches into the future the Sun will continue to brighten, inevitably pushing the Earth into a thermal runaway and thus permanently ceasing habitability.  While this study remains geocentric in nature, results are considered within the broader context of planetary atmospheres.

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

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x3034
Lab/division hosting the event:
NCAR, NESL, CGD
Affiliation or organization:
Thursday, November 20, 2014 - 1:30pm

Date: Thursday, November 20, 2014
Time: 1:30-2:30
Location: 
FL2-1022 (also webcast at http://ucarconnect.ucar.edu/live?room=fl21022)

Collisional Thermalization of Hydrogen and Helium in Solar Wind Plasma

In situ observations of solar wind plasma frequently show the temperature of alpha-particles (fully ionized helium) to significantly differ from that of protons (ionized hydrogen). Many heating processes in the solar wind act preferentially on alpha-particles, even as collisions among the plasma's ions act to gradually establish thermal equilibrium. Measurements from the Wind spacecraft's Faraday cups reveal that, at 1.0 AU from the Sun, the values of the alpha-proton temperature ratio has a complex, bimodal distribution. For this study, a simple, analytic model was developed for the evolution of this ratio with solar distance and then applied to each observation from the Wind Faraday cups to infer the value that the alpha-proton temperature ratio had been at 0.1 AU from the Sun. The distribution of these inferred values shows no trace of the bimodality observed at 1.0 AU but is instead consistent with known mechanisms for alpha-particle preferential heating. This result underscores the importance of collisional processes in the dynamics of the solar wind and suggests that similar mechanisms may lead to preferential alpha-particle heating in both slow and fast wind.

Presenter(s):
Ben Maruca
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Sheryl Shapiro (sheryls@ucar.edu) at x1567
Lab/division hosting the event:
NCAR, HAO
Affiliation or organization:
Tuesday, November 18, 2014 - 11:00am

The transition to a summer ice-free Arctic Ocean has attracted much attention, but climate model simulations in CMIP5 vary widely in their prediction of when we will reach a summer ice-free state. To quantify the contribution of internal variability to the spread of projections and to assess the limit of predictability of the year we will reach a summer ice-free Arctic, I will present new results from the new Large Ensemble (LE) with the Community Earth System Model (CESM). Specifically, I will show that in the CESM LE the individual ensemble members first reach an ice-free Arctic in September over a period of 21 years (2032-2053), with the majority of the ensemble members first reaching September ice-free conditions in the 5-year period from 2040-2044. This spread of over 20 years shows the large impact of internal variability on the timing of reaching an ice-free Arctic, which severely limits the predictability of a summer ice-free Arctic we can expect even from perfect CMIP-type climate models.

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

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x3034
Lab/division hosting the event:
NCAR, NESL, CGD
Affiliation or organization:
Tuesday, November 4, 2014 - 9:30am

Two meetings are scheduled on November 4 to give all staff the chance to discuss the results of the IT Assessment with Deloitte and members of the President's Council.  Everyone is welcome to attend. 

9:30 a.m. to 11:00 a.m. - Mesa Lab Main Seminar Room

1:00 p.m. to 2:30 p.m. - FL2 Room 1022

Presenter(s):
Julia Richman
Type of event:
Workshop
Building:
Mesa Lab
Room:
Main Seminar Room

Posted by Rebecca Swisher (rebeccas@ucar.edu) at x8609
Lab/division hosting the event:
UCAR, UCAR President's Office, Comms
Affiliation or organization:
Thursday, November 13, 2014 - 9:00am

November 13, 2014
9:00-11:30 am
ML-Damon 
Administered by Passport Health
Walk-In Clinic - No registration required

FREE seasonal flu vaccination shots to eligible participants.  Nasal FluMist available upon request and co-payment of $19/pp.  Open to UCAR staff/visitors/retirees, their spouses/partners and dependent children 18-26 years of age.  More information @ UCAR Flu Vaccination Program website

UCAR Onsite Vaccination Clinic Schedule
FL - October 14, 2014, 9:00-11:30 am, FL2-1003
NWSC - October 21, 2014, 10:00-11:30, NWSC Conf Room
CG - October 28, 2014, 9:00-11:30 am, CG1-2126
RAF/Jeffco - November 4, 2014, 10:00-11:30 am, RAF/Jeff Conf Room
ML - November 13, 2014, 9:00-11:30, ML-Damon

Here's to your good health.  Sponsored by your friends on the Wellness Advisory Committee (WAC).

Presenter(s):
Passport Health
Type of event:
Wellness/Benefits
Building:
Mesa Lab
Room:
Damon

Posted by Cheryl Cristanelli (cherylc@ucar.edu) at x3034
Lab/division hosting the event:
UCAR, F&A
Affiliation or organization:
Tuesday, November 4, 2014 - 10:00am

November 4, 2014
10:00-11:30 am
RAF/Jeffco Conf Room 
Administered by Passport Health
Walk-In Clinic - No registration required

FREE seasonal flu vaccination shots to eligible participants.  Nasal FluMist available upon request and co-payment of $19/pp.  Open to UCAR staff/visitors/retirees, their spouses/partners and dependent children 18-26 years of age.  More information @ UCAR Flu Vaccination Program website

UCAR Onsite Vaccination Clinic Schedule
FL - October 14, 2014, 9:00-11:30 am, FL2-1003
NWSC - October 21, 2014, 10:00-11:30, NWSC Conf Room
CG - October 28, 2014, 9:00-11:30 am, CG1-2126
RAF/Jeffco - November 4, 2014, 10:00-11:30 am, RAF/Jeff Conf Room
ML - November 13, 2014, 9:00-11:30, ML-Damon

Here's to your good health.  Sponsored by your friends on the Wellness Advisory Committee (WAC).

Presenter(s):
Passport Health
Type of event:
Wellness/Benefits
Building:
RAF/Jeffco
Room:
Conf Room

Posted by Cheryl Cristanelli (cherylc@ucar.edu) at x3034
Lab/division hosting the event:
UCAR, F&A
Affiliation or organization:
Tuesday, November 11, 2014 - 10:30am

RAL SEMINAR SERIES

Speaker:  David Gochis  
Date:       November 11, 2014
Time:      10:30am
Place:      FL 2 – Room 1022
Title:       Recent developments and applications of the WRF-Hydro modeling system for continental scale water cycle predictions

Abstract:

The translation of weather and climate forcing through complex landscapes to drive terrestrial hydrologic processes is a true multi-scale problem.  Model architectures that attempt to capture these processes and feedbacks in a physically realistic way must be able to bridge spatial scales from meters to kilometers.  To represent these processes across continental domains modeling systems must fully embrace high performance computing.  Also, because there are both scientific and computational trade-offs in modeling many terrestrial hydrologic and land-atmosphere exchange processes, it is often highly advantageous to support multiple physics options in order to test competing hypotheses and apply scale-appropriate parameterizations for different prediction problems.  In this talk we provide an update of new developments to the WRF-Hydro system in meeting these needs from both a process representation and high performance computing perspective.  A key feature of these developments centers on new multi-scale modeling capabilities recently added to WRF-Hydro.  We will discuss prediction and computational performance metrics for several recent large river basin and continental scale applications of the WRF-Hydro system over the coterminous U.S. and over Mexico in modes both coupled and uncoupled to the Weather Research and Forecasting (WRF) model.  We will also provide updates on new developments to the WRF-Hydro system in the areas of water management applications and hydrologic data assimilation.

This seminar will be webcast
FL2_1022 (Large Auditorium) Webcast link
http://www.fin.ucar.edu/it/mms/fl-live.htm or http://ucarconnect.ucar.edu/live?room=fl21022

Presenter(s):
David Gochis
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Marybeth Zarlingo (zarlingo@ucar.edu) at x2751
Lab/division hosting the event:
NCAR, RAL, HAP
Affiliation or organization:
Tuesday, November 4, 2014 - 2:00pm

IPCC Chapter 10: Detection and Attribution of Climate Change: From Global to Regional

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says?  Learn more Tuesday and Thursday afternoons this fall during a seminar series by IPCC authors and contributors. This fall’s focus is on Climate Change 2013: The Physical Science Basis (Working Group I’s contribution to the IPCC 5th Assessment Report).

Presenter(s):
Judith Pearlwitz
Type of event:
Seminar/Symposium
Building:
CIRES Auditorium at CU-Boulder

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
External:, CIRES-ATOC
Tuesday, November 11, 2014 - 2:00pm

IPCC Chapter 4: Observations: Cryosphere

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says?  Learn more Tuesday and Thursday afternoons this fall during a seminar series by IPCC authors and contributors. This fall’s focus is on Climate Change 2013: The Physical Science Basis (Working Group I’s contribution to the IPCC 5th Assessment Report).

Presenter(s):
Tad Pfeffer
Type of event:
Seminar/Symposium
Building:
CIRES Auditorium at CU-Boulder

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
External:, CIRES-ATOC
Tuesday, November 18, 2014 - 2:00pm

IPCC Chapter 9:  Evaluation of Climate Models

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says?  Learn more Tuesday and Thursday afternoons this fall during a seminar series by IPCC authors and contributors. This fall’s focus is on Climate Change 2013: The Physical Science Basis (Working Group I’s contribution to the IPCC 5th Assessment Report).

Presenter(s):
Clara Deser
Type of event:
Seminar/Symposium
Building:
CIRES Auditorium at CU-Boulder

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
External:, CIRES-ATOC
Affiliation or organization:
Tuesday, December 2, 2014 - 2:00pm

IPCC Chapter 13: Sea Level Change

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says?  Learn more Tuesday and Thursday afternoons this fall during a seminar series by IPCC authors and contributors. This fall’s focus is on Climate Change 2013: The Physical Science Basis (Working Group I’s contribution to the IPCC 5th Assessment Report).

Presenter(s):
Steve Nerem
Type of event:
Seminar/Symposium
Building:
CIRES Auditorium at CU-Boulder

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
External:, CIRES-ATOC
Tuesday, December 9, 2014 - 2:00pm

IPCC Chapter 14: Climate Phenomena and their Relevance for Future Regional Climate Change

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says?  Learn more Tuesday and Thursday afternoons this fall during a seminar series by IPCC authors and contributors. This fall’s focus is on Climate Change 2013: The Physical Science Basis (Working Group I’s contribution to the IPCC 5th Assessment Report).

Presenter(s):
Kevin Trenberth
Type of event:
Seminar/Symposium
Building:
CIRES Auditorium at CU-Boulder

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x1618
Lab/division hosting the event:
External:, CIRES-ATOC
Affiliation or organization:
Saturday, November 8, 2014 - 10:00am

2014 Super Science Saturday brings together science and learning in one fun-filled day! Please join us for our "SUPER" annual event where both kids and adults explore hands-on activities, think about new ideas and learn how we study the weather.

Super Science Saturday, is a free day of science, learning, and fun at the NCAR Mesa Lab on November 8, 2014 from 10:00 am - 4:00 pm!

Find out how "measuring weather happens!" by:

  • Exploring activity tables
  • Performing experiments with CSU's Little Shop of Physics
  • See the Doppler on Wheels (DOW) in action
  • Learning about science with the NCAR Wizards
  • And more!

Super Science Saturday is open to the public and welcomes science explorers of all ages!

Events included:
  • Science Shows
  • Weather Balloon Launches
  • NCAR 3D Visualization Lab Demos
  • NCAR Wizards' Showcase
Activity tables:
  • UCAR Center for Science Education Wind Tunnel
  • The GLOBE Program
  • NCAR Computational and Information Systems Lab (CISL)
  • CSU Little Shop of Physics
  • Center for Severe Weather Research (CSWR)
  • UNAVCO
  • Front Range Community College
  • CU Atmosphere and Ocean Science Club
  • Face Fiesta - weather face painting
Date of the event:  November 8, 2014 - 10:00am to 4:00pm
Presenter(s):
UCAR Center for Science Education
Type of event:
Public Outreach
Building:
Mesa Lab

Posted by Natalie Ponsford (nataliep@ucar.edu) at x3034
Lab/division hosting the event:
UCAR Community Programs, UCAR Center for Science Education
Thursday, October 30, 2014 - 3:30pm

Jacob Berg
DTU Wind Energy
Roskilde, Denmark

In wind energy applications the turbulent velocity field of the Atmospheric Boundary Layer (ABL) is often characterised by Gaussian probability density functions. When estimating the dynamical loads on wind turbines this has been the rule more than anything else. From numerous studies in the laboratory, in Direct Numerical Simulations, and from in-situ measurements of the ABL we know, however, that turbulence is not purely Gaussian: the smallest and fastest scales often exhibit extreme behaviour characterised by strong non-Gaussian statistics. In this contribution we want to investigate whether these non-Gaussian effects are important when determining wind turbine loads, and hence of utmost importance to the design criteria and lifetime of a wind turbine.

We devise a method based on Principal Orthogonal Decomposition where non-Gaussian velocity fields generated by high-resolution pseudo-spectral Large-Eddy Simulation (LES) of the ABL are transformed so that they maintain the exact same second-order statistics including variations of the statistics with height, but are otherwise Gaussian. In that way we can investigate in isolation the question whether it is important for wind turbine loads to include non-Gaussian properties of atmospheric turbulence.

Using the load simulation software HAWC2 with both the non-Gaussian and newly constructed Gaussian fields, respectively, we show that the Fatigue loads and most of the Extreme loads are unaltered when using non-Gaussian velocity fields. The turbine thus acts like a low-pass filter which average out the non-Gaussian behaviour on time scales close to and faster than the revolution time of the turbine. For a few of the Extreme load estimations there is, on the other hand, a tendency that non-Gaussian effects increase the overall dynamical load, and hence can be of importance in wind energy load estimations.

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, 30 October 2014, 3:30 PM
Refreshments 3:15 PM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg 2 Main Auditorium, Room 1022

Presenter(s):
Jacob Berg
Type of event:
Seminar/Symposium
Building:
FL2
Room:
1022

Posted by Michelle Menard (menard@ucar.edu) at x8189
Lab/division hosting the event:
NCAR, NESL, MMM
Affiliation or organization:
Tuesday, November 4, 2014 - 11:00am

Observations indicate that cloud feedbacks over the southern hemisphere stratocumulus regions (i.e., Peruvian and Namibian) co-vary with the respective equatorial modes of variability: El Niño Southern Oscillation (ENSO) and Atlantic Niño. However, from observations alone it is not possible to quantify the influence of regional cloud feedbacks on large-scale climate variability. To address this question, a set of sensitivity experiments are conducted using an atmospheric general circulation model (ECHAM6) coupled to a slab-ocean in which the strength of positive cloud feedback is enhanced over the Peruvian and Namibian regions. Enhanced positive cloud feedback increases the variance and the persistence of local as well as equatorial SST anomalies, enhancing ENSO and Atlantic Niño variability. We explore the role of cloud feedbacks over other regions in the tropical Atlantic and Pacific Oceans, and find that they increase local SST variability but exhibit negligible responses at the equator. Our results indicate that the subtropical stratocumulus regions play a central role in enhancing equatorial SST variability because they are located where the SST anomalies have the largest growth rates, that is, where the variance of SST is largest and the damping rate of SST is weakest.

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

Posted by Gaylynn Potemkin (potemkin@ucar.edu) at x3034
Lab/division hosting the event:
NCAR, NESL, CGD
Affiliation or organization: