Staff Notes Daily Calendar Events

Title: Discrepancy in radiative feedbacks between models and observations tied to models' inability to reproduce tropical Pacific temperature changes

Speaker: Cristian Proistosescu, University of Illinois at Urbana - Champaign

Date: Tuesday 31, March 2020

Time: 11 am - 12 pm

*Refreshments at 10:45*

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

Abstract:  Earth's climate sensitivity to CO2 forcing is determined by its net radiative feedback, which quantifies how much more energy is radiated to space for a given increase in surface temperature.  Estimates from present day observations of temperature and earth's energetic imbalance yield a strongly negative radiative feedback, or, equivalently, a very low climate sensitivity. This value lies outside the range of net radiative feedbacks in coupled climate models. This discrepancy in radiative feedbacks can be linked to discrepancies between models and observations in the pattern of historical sea-surface temperature (SST) anomalies that drive tropical atmospheric circulation and radiative damping.  Indeed, we find that an atmospheric model forced with observed SSTs (CAM5 AMIP) yields a net feedback that is consistent with observational estimates, but up to three times more negative than that from the same period (2000-2017) in historical simulations where the same atmospheric model is coupled to a dynamical ocean model (CESM1 Large Ensemble).

To understand the role natural variability plays in this discrepancy, we compare the radiative feedbacks generated by the observed pattern of SSTs to those within the CESM1 large ensemble over the same period. The large ensemble produces a wide range of feedbacks due to internal variability alone. Yet, global radiative feedbacks (cloud feedbacks in particular) generated by observed warming patterns are far outside the range of natural variability in the ensemble. Using both a Green's function approach, as well as a simple metric based on the East-West tropical pacific gradient, we show that none of the control simulations of CMIP5 climate models can generate sufficiently large natural variability to explain the discrepancy between models and observations. We conclude that the discrepancy in SST patterns, and the resulting discrepancy in radiative feedbacks, is caused by the inability of models to  simulate either natural variability or the forced response over the recent historical period.

For more information contact Tracy Baker, tbaker@ucar.edu, 303-497-1366

Title: The Atmospheric Signature of Southern Ocean Carbon Fluxes

Speaker: Matt Long, NCAR

Date: Tuesday, 28 January 2020

Time: 11AM - 12PM

*Refreshments at 10:45*

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

Abstract:

The Southern Ocean is a critical component of the global carbon cycle, but air-sea carbon dioxide fluxes in the region are poorly constrained by observations and models.

In this talk, I present a comprehensive analysis of regional atmospheric carbon dioxide observations from aircraft and surface monitoring stations; these data show a spatially coherent depletion of carbon dioxide in the lower atmosphere over the Southern Ocean during austral summer and a more homogeneous distribution in winter. I demonstrate that summertime carbon dioxide depletion in the lower atmosphere is directly attributable to Southern Ocean air-sea exchange. The observations suggest that the Southern Ocean is a strong carbon dioxide sink during summer and the magnitude of this sink has likely strengthened over the past 15 years. This analysis has important implications for quantifying and detecting changes in the Southern Ocean carbon sink.

The next NCAR Python tutorial is being planned for the spring of 2020.  Currently, we are planning 3 separate events:

• Beginner Track:  March 26-27, 2020
• Intermediate Track:  April 6-7, 2020
• Hackathon:  April 8-10, 2020

The Beginner and Intermediate/Hackathon events are separated by a week to give beginners time to digest new information before (if they wish) attending the Intermediate tutorial and the Hackathon.

The Beginner Track tutorial is intended to introduce participants to the basics, such as Git, GitHub, Jupyter Notebooks & Lab, the Python Language, itself, as well as common Python packages such as Numpy, Pandas, Matplotlib, and Cartopy.

The Intermediate Track tutorial is designed to build upon the basic information, covering such things as Xarray, Dask, Holoviews, Intake and Intake-ESM, as well as covering how to solve common real-world problems with these tools, such as computing climatologies, dealing with unstructured grids, etc.

The Hackathon is designed to give participants a chance to use their new knowledge in the development of a tangible project that can be shared and used for real science, or just to provide participants with the opportunity to try out their new skills!

If you are interested in attending any, or all, of these events, we ask that you register here.  Please note that you may change your registration at a later date, so if you are interested but can't be certain you can or will attend, we ask you to indicate as much in the registration form (e.g., by indicating "Maybe" when aswering questions about whether you will attend).  For more information, email Kevin Paul.

SPEAKER:       Professor GyuWon Lee, Kyungpook National University, Republic of Korea

DATE:               January 28, 2020

TIME:                3:30 - 4:30 pm

LOCATION:    FL2-1001 Small Seminar Room

ABSTRACT

The understanding and predicting of winter precipitation over complex terrain is challenging due to the highly variable nature of snowfall. As a World Meteorological Organization (WMO)’s World Weather Research Program (WWRP), ICE-POP 2018 (International Collaborative Experiments for Pyeongchang 2018 Olympic and Paralympic winter games) was held in the PyeongChang region during November 2018 to April 2019 with contribution from 29 agencies from 12 countries. The scientific goal was to understand the precipitation processes over complex terrain during the cold season and to improve the numerical model based on understanding derived from the intensive observation as well as direct utilization of these observational data.

During the field campaign, dense observational networks of upper air (two wind profilers, eight soundings, ship, and aircraft), surface stations (64 stations), remote sensing (three S-Pol, one S-band, two C-band, three X-Pol, one Ku/Ka-Pol radars, and three Doppler lidars), microphysics (2DVD, PIP, Parsivel, MRR, POSS, MASC, Pluvio, and so on) were implemented. The network of the supersite was designed to explore the evolution of precipitation along and across atmospheric flows.

The field experiment with intensive observation has ended and the data analysis and the quality control of data has started. I will show all different types of microphysical products including precipitation types and maps, microphysical information, the three dimensional structure of precipitation and winds, and model re-analysis. I will further provide an overview of phenomena, some statistical results, and preliminary results.

Solar Irradiance Effects on the Upper Atmosphere on Time Scales from Minutes to Multi-Decadal

The upper atmosphere (thermosphere and ionosphere) is a coupled system that is predominantly driven by external forcing. The external forcing consists of solar irradiance, the coupling between the magnetosphere and the upper atmosphere, and the coupling between the mesosphere and the upper atmosphere. The external forcing from solar irradiance, the magnetosphere, and the lower atmopshere, together with internal processes within the system, drive complex temporal and spatial variabilities. In this presentation, I will address upper atmosphere variability driven by solar irradiance, on time scales from minutes to multi-decadal, using model simulations and datasets. Solar irradiance is the primary energy input to the upper atmosphere. The thermosphere absorbs solar irradiance in the soft X-ray Ultra-Violet (XUV, 1–30 nm), Extreme Ultra-Violet (EUV, 30–120 nm), and Far Ultra-Violet (FUV, 120–200 nm). Solar irradiance ionizes, dissociates, and excites thermospheric constituents, creates the ionosphere, and heats the thermosphere. The time scales that will be addressed include minutes to hours due to solar flares, diurnal, solar-rotational, annual/semiannual, solar-cycle, and multi-decadal. The models used are the NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) and Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (WACCM-X). Solar irradiance is provided by the Flare Irradiance Spectral Model (FISM) and data observed by the NASA Thermosphere Ionosphere Mesosphere Energetics Dynamics Solar EUV Experiment (TIMED/SEE). The datasets include thermosphere mass density measured by the Challenging Minisatellite Payload (CHAMP) satellite and derived from satellite drag data, thermosphere composition data measured by the NASA Thermosphere Ionosphere Mesosphere Energetics Dynamics Global UltraViolet Imager (TIMED/GUVI) and the NASA Global-scale Observations of the Limb and Disk (GOLD), and total electron content data from the Global Positioning System (GPS) network.

*MMM Seminar - Thursday, January 30, 2020 - 3:30pm

*Please note special location - FL2-1001/Small Auditorium

Speaker: Xiaoxu Tian

Affiliation: University of Maryland

A four-dimensional variational (4D-Var) vortex initialization (VI) system is developed for a nonhydrostatic axisymmetric numerical model with convection accounted for (the RE87 model). Derivations of the tangent linear and adjoint models of the RE87 model and the correctness checks are presented. As an initial evaluation of the 4D-Var VI system, a cost function that measures the model fit to satellite microwave retrievals of tropical cyclone (TC) warm-core temperatures and total precipitable water (TPW) from the following four polar-orbiting satellites within a slightly longer than 1-h assimilation window is minimized using the limited-memory quasi-Newton minimization algorithm: the Suomi National Polar-orbiting Partnership, NOAA-20, Fengyun-3D, and Global Change Observation Mission  – Water Satellite 1. An azimuthal spectral analysis in cylindrical coordinates centered on the TC centers shows that the warm core and TPW fields within TCs are dominated by the axisymmetric component. The 4D-Var VI results assimilating the axisymmetric component of the above satellite retrievals produced a significant reduction in the cost function and the norm of the gradient as the minimization process is completed. The gradient of the cost function is accurately computed by a single integration of the RE87 adjoint model. In the cases of Hurricane Florence and Typhoon Mangkhut, improved forecast of intensifications and more realistic vertical structures of all model state variables (e.g., temperature, water vapor mixing ratio, liquid water content mixing ratio, tangential and radial wind components, and vertical velocity) are obtained when compared with a parallel run initialized simply by the European Centre for Medium-Range Weather Forecasts ERA5 reanalysis.

Refreshments: 3:15 PM

We will have a table set up near the cafeteria at the Mesa Lab TODAY, where you will be able to purchase a selection of drinkware with the NCAR pastel print (check, cash, or discretionary account key only).

• Friday, January 24, 11:30-1:30 Mesa Lab Cafeteria

If you are at a campus without a cafeteria, please email or call Peggy Stevens (x8601) in UCAR Communications to discuss how best to serve your campus. We are also offering staff the opportunity to order:

• LL Bean vests branded with the NCAR|UCAR seal

The vests will be available to order twice per year. All items sold will be offered at cost and will not financially benefit NCAR or UCAR. We will not facilitate the return of any items. If you have questions, comments, or suggestions, please let Peggy Stevens or Tracy Baker know.

Mark your calendars for UCAR’s 2020 Pre-Health Fair Bloodwork sessions and the Health & Benefits Fair.  These valuable wellness events are open to all UCAR employees, retirees, their spouses/partners and dependent adult children 18-26 years of age. For more information, visit the UCAR Health & Benefits Fair website.

Pre-Health Fair Bloodwork Registration Site Now Available

To participate in the pre-health fair bloodwork screenings, register to attend one of the following onsite sessions.  The standard full-blood chemistry screenings and PSA blood screening for men 50+ are FREE; optional, additional bloodwork screenings are also available upon request at participant cost. Each participant must register individually.

Pre-Health Fair Bloodwork Session Dates/Locations (Registration and 12-hour fast required; Light refreshments provided at each location)

• FL:          January 24, 2020, 7:30-11:30 am, FL2-1003
• ML:         January 30, 2020, 7:30-11:30 am, ML-Damon Room
• CG:         February 7, 2020, 7:30-11:30 am, CG1- room 2503
• NWSC:   February 13, 2020, 8:00-noon, NWSC Janice Conference Room
• RAF:       February 13, 2020, 8:00-10:30 am, RAF Conference Room

Schedule a blood draw appointment through Health Promotion Management's external, secure registration site: https://pickatime.com/UCAR. The registration site requires account setup for each participant.

Your appointment confirmation email will include additional information plus a link to the Blood Test Descriptions, a listing all of the tests offered at the bloodwork sessions. The Blood Test Descriptions document is provided for reference only to determine optional tests that you might want to have performed.  Please bring a credit card, check or cash to the screening for any optional test fees. 

Requisition forms will be available at the screening. You do not need to complete any paperwork in advance of your appointment.

You'll also receive appointment email reminders closer to your appointment date.  Please note, bloodwork screening results can be claimed at the Health Fair. To have a proxy claim your results, they must bring your signed Proxy Release Form to the Health & Benefits Fair.  All unclaimed results will be mailed to participants.

For those who can't make any of the onsite sessions, click here for information, forms and instructions to have bloodwork done at a local Quest Lab location.  All Quest Lab appointments must be completed by February 13, 2020.  Results will be mailed to participants. 

UCAR 2020 Health & Benefits Fair

Thursday, March 19, 2020

9:00 am - noon

CG1-Auditorium

No registration required to attend the Health & Benefits Fair

Health Fair events include:  Blood Screening Results and Private Consultations; Blood Pressure Screening, Full Blood Chemistry, PSA Prostate Cancer Screening; Optional Blood Screening Screenings; Pulmonary Screening; Bone Density Screening; Body Mass Analysis; Skin Cancer Screening; Vision/Hearing Screening; Ergonomics; Child and Elder Care Resources; Benefits Information; Chair Massage; Health Information Booths, Refreshments, Giveaways; Prizes; and much, much more!

UCAR offers these events as a service and participation is voluntary.  UCAR does not recommend or endorse any products, services or resources associated with these events. For more information, visit UCAR's Health & Benefits Fair website.

This is a UCAR-sponsored event.

UCAR Game Night is a recurring event for UCAR/NCAR staff and their family members.  It is currently running every other Tuesday night.  It is a time to come together, have fun, chat and play games.

Game nights will be scheduled using Google Calendar and this group will comprise the invite list as well as be the conduit for various information. The location of Game Nights will rotate between FL2, CG1, and ML cafeterias. Join the Google Group.

UCAR Game Night Policy Information: 

• UCAR Staff and their family members and friends are welcome at UCAR Game Night. Friends and Family are escorted by a member of UCAR staff at all times.
• No Alcohol at UCAR Game Nights.
• No Gambling for real money or other tangible assets. (Some board games include gambling as part of their mechanics and is for “in-game” assets. This is allowed.)
• You may bring your own food.  It is your responsibility to clean up after yourself.  Please also be respectful of the games and aware of food residue that may be on your hands.
• Please no open top beverage containers on game tables.
• You are allowed and encouraged to bring games of your own.
• UCAR is not responsible for loss or damage of your personal game.
• Please be aware of the appropriateness of a game you may bring for a workplace event.  (As an example, we would not consider Cards Against Humanity appropriate for the workplace)
• Have fun!

UCAR Game Night is a recurring event for UCAR/NCAR staff and their family members.  It is currently running every other Tuesday night.  It is a time to come together, have fun, chat and play games.

Game nights will be scheduled using Google Calendar and this group will comprise the invite list as well as be the conduit for various information. The location of Game Nights will rotate between FL2, CG1, and ML cafeterias. Join the Google Group.

UCAR Game Night Policy Information: 

• UCAR Staff and their family members and friends are welcome at UCAR Game Night. Friends and Family are escorted by a member of UCAR staff at all times.
• No Alcohol at UCAR Game Nights.
• No Gambling for real money or other tangible assets. (Some board games include gambling as part of their mechanics and is for “in-game” assets. This is allowed.)
• You may bring your own food.  It is your responsibility to clean up after yourself.  Please also be respectful of the games and aware of food residue that may be on your hands.
• Please no open top beverage containers on game tables.
• You are allowed and encouraged to bring games of your own.
• UCAR is not responsible for loss or damage of your personal game.
• Please be aware of the appropriateness of a game you may bring for a workplace event.  (As an example, we would not consider Cards Against Humanity appropriate for the workplace)
• Have fun!