Hugh Morrison
MMM/NCAR
The representation of cloud and precipitation microphysics is a critical element in atmospheric models of all scales. It affects the thermodynamics and dynamics from latent heating/cooling and condensate drag, strongly influences cloudy radiative transfer, and is a key component of the hydrological cycle through the generation and fallout of precipitation. An overview of the historical development of microphysics schemes in cloud and mesoscale models will be presented first. Advances over the last decade will be covered in more detail, particularly the recent development of a scheme called Predicted Particle Properties (P3) that predicts and smoothly evolves ice particle properties such as density and fall speed. This approach is a significant departure from traditional microphysics schemes that separate ice into categories with fixed properties corresponding to particular ice types (small ice, snow, graupel, hail, etc.). Simulations using P3 implemented in the Weather Research and Forecasting (WRF) model will be presented and contrasted with those using traditional schemes. Additional developments related to P3, including an improved numerical treatment of cloud and precipitation transport, will also be presented. Finally, more “outside of the box” ideas for parameterizing microphysics will be highlighted, including a Bayesian statistical-physical parameterization framework that facilitates observational constraint of process rates and a rigorous characterization of uncertainty. The talk with conclude with a broader outlook and commentary on future microphysics scheme developments over the next 5-10 years and beyond.
Refreshments: 3:15 PM
Shane KeatingUniversity of New South Wales Australia
The era of earth-observing satellites has revolutionised our understanding of our planet and the dynamical processes that shape it. In many real-world geophysical systems, however, estimates of turbulent mixing and transport are limited by the resolution of available observations. In this talk, I will describe a suite of stochastic filtering strategies for estimating mixing in turbulent geophysical flows from “superresolved” satellite imagery obtained by combining coarse observations with an efficient stochastic parameterization for the unresolved scales. The method enhances the effective resolution of satellite observations by exploiting the effect of spatial aliasing and generates an optimal estimate of small scales using standard Bayesian inference. The technique is tested in quasigeostrophic simulations driven by realistic climatological shear and stratification profiles. Two applications are considered: calculating poleward ocean eddy heat flux from satellite altimetry, and estimating the three-dimensional upper ocean velocity field from superresolved sea-surface temperature imagery. In each case, the superresolved satellite observations result in a considerable improvement in estimates of turbulent fluxes compared with the raw observations.
Refreshments: 3:15 PM
Shane Keating
University of New South Wales
Australia
The era of earth-observing satellites has revolutionised our understanding of our planet and the dynamical processes that shape it. In many real-world geophysical systems, however, estimates of turbulent mixing and transport are limited by the resolution of available observations. In this talk, I will describe a suite of stochastic filtering strategies for estimating mixing in turbulent
geophysical flows from “superresolved” satellite imagery obtained by combining coarse observations with an efficient stochastic parameterization for the unresolved scales.
The method enhances the effective resolution of satellite observations by exploiting the effect of spatial aliasing and generates an optimal estimate of small scales using standard Bayesian inference. The technique is tested in quasigeostrophic simulations driven by realistic climatological shear and stratification profiles. Two applications are considered: calculating poleward ocean eddy heat flux from satellite altimetry, and estimating the three-dimensional upper ocean velocity field from superresolved sea-surface temperature imagery. In each case, the superresolved satellite observations result in a considerable improvement in estimates of turbulent fluxes compared with the raw observations.
Refreshments: 3:15 PM
2018 NORTH AMERICAN WORKSHOP ON HAIL & HAILSTORMSAUGUST 14 - 16, 2018, BOULDER, COLORADONCAR CENTER GREEN CAMPUS
Across North America, hailstorms are responsible for over $10 billion dollars in annual property damage. The increase in the impact of hailstorms has outpaced advances in detection, forecasting, and mitigation. The National Science Foundation, the National Center for Atmospheric Research and the Insurance Institute for Business & Home Safety are organizing the first North American Workshop on hail, and hailstorms. The workshop will bring together public and private stakeholders to discuss the current state of the science regarding all facets of this peril and provide a look to the future. The workshop will be held at the NCAR Center Green 1 (CG1) campus, 3080 Center Green Drive, Boulder, Colorado.
Call For Abstracts: The deadline for abstract submissions is May 1, 2018.
For information: https://www.mmm.ucar.edu/north-american-hail-workshop
Buo-Fu ChenNational Taiwan UniversityNCAR/MMM
Although deep-layer (200−850 hPa) vertical wind shear (VWS) is generally an inhibiting factor for tropical cyclone (TC) intensification, there is still a considerable variability of TC intensification and structural evolution under similar VWS magnitudes. A hypothesis to address this variability is that the interaction between a vertically-sheared TC and the shear-relative low-level mean flow (LMF) modifies the convective structure and its azimuthal distribution, resulting in various pathways of TC structure evolution. This hypothesis was explored from three different perspectives: (1) a global, climatological statistical analysis of the correlations between the 24-hour intensity/size changes and the shear-relative LMF orientations, (2) examining the structural evolution of 180 western North Pacific TCs based on satellite composites, (3) a set of idealized numerical simulations produced with Weather Research and Forecasting (WRF) Model. Based on the best track data of 775 TCs from all basins during 2003−2016, statistical results suggest that a TC affected by an LMF orienting toward down-shear-left favors a relatively large intensification rate, while an LMF orienting toward up-shear-right is favorable for TC expansion. Also, in a storm-motion-relative and shear-relative framework, the analyses based on satellite observations and idealized WRF simulations reveal possible mesoscale processes in the boundary layer causing the distinct convective features associated with TCs affected by various shear-relative LMF.
Refreshments: 3:15 PM
Note Special Location
Buo-Fu Chen
National Taiwan University
NCAR/MMM
Although deep-layer (200−850 hPa) vertical wind shear (VWS) is generally an inhibiting factor for tropical cyclone (TC) intensification, there is still a considerable variability of TC intensification and structural evolution under similar VWS magnitudes. A hypothesis to address this variability is that the interaction between a vertically-sheared TC and the shear-relative low-level mean flow (LMF) modifies the convective structure and its azimuthal distribution, resulting in various pathways of TC structure evolution. This hypothesis was explored from three different perspectives: (1) a global, climatological statistical analysis of the correlations between the 24-hour intensity/size changes and the shear-relative LMF orientations, (2) examining the structural evolution of 180 western North Pacific TCs based on satellite composites, (3) a set of idealized numerical simulations produced with Weather Research and Forecasting (WRF) Model. Based on the best track data of 775 TCs from all basins during 2003−2016, statistical results suggest that a TC affected by an LMF orienting toward down-shear-left favors a relatively large intensification rate, while an LMF orienting toward up-shear-right is favorable for TC expansion. Also, in a storm-motion-relative and shear-relative framework, the analyses based on satellite observations and idealized WRF simulations reveal possible mesoscale processes in the boundary layer causing the distinct convective features associated with TCs affected by various shear-relative LMF.
Refreshments: 3:15 PM
Note Special Location
Julia SlingoChief Scientist, UK Met Office, EmeritusUnited Kingdom
Today, we live in a global economy, relying on global trade, efficient transport systems and resilient and reliable provision. As we see time and time again, all these systems are vulnerable to adverse weather and climate conditions. The additional pressure of climate change creates a new set of circumstances and poses new challenges about how secure we will be in the future. More than ever, the weather and climate of food, energy and water have considerable direct and indirect impacts on us – our livelihoods, property, health, well-being and prosperity. In this talk I will describe recent advances in understanding, simulating and predicting our weather and climate and how these developments can be deployed to help us manage our risks, now and in the future.
Refreshments: 3:15 PM
Julia Slingo
Chief Scientist, UK Met Office, Emeritus
United Kingdom
Today, we live in a global economy, relying on global trade, efficient transport systems and resilient and reliable provision. As we see time and time again, all these systems are vulnerable to adverse weather and climate conditions. The additional pressure of climate change creates a new set of circumstances and poses new challenges about how secure we will be in the future. More than ever, the weather and climate of food, energy and water have considerable direct and indirect impacts on us – our livelihoods, property, health, well-being and prosperity. In this talk I will describe recent advances in understanding, simulating and predicting our weather and climate and how these developments can be deployed to help us manage our risks, now and in the future.
Refreshments: 3:15 PM
The Weather Research and Forecasting (WRF) model Tutorial will be held at the NCAR Foothills Laboratory (FL2) located at 3450 Mitchell Lane, Boulder, Colorado from 22 January - 2 February 2018.
The Basic tutorial will consist of lectures on various components of the WRF modeling system along with hands-on practice sessions. (22 - 26 January 2018)
The WRF-Chem tutorial will provide lectures on main components of the model and associated tools along with hands-on practice sessions. (29 - 30 January 2018)
The MET tutorial and the associated database and display system (METViewer) is a suite of state-of-the-art verification tools that can be used to read post-processed WRF output and match it to observed data to compute both traditional and non-traditional statistics. MET and METViewer are being wrapped with python to extend the MET capability and make it easier to set-up a verification system. This tutorial will provide lectures on main tools along with hands-on practice sessions.
The Weather Research and Forecasting (WRF) model Tutorial will be held at the NCAR Foothills Laboratory (FL2) located at 3450 Mitchell Lane, Boulder, Colorado from 22 January - 2 February 2018.
The Basic tutorial will consist of lectures on various components of the WRF modeling system along with hands-on practice sessions. (22 - 26 January 2018)
The WRF-Chem tutorial will provide lectures on main components of the model and associated tools along with hands-on practice sessions. (29 - 30 January 2018)
The MET tutorial and the associated database and display system (METViewer) is a suite of state-of-the-art verification tools that can be used to read post-processed WRF output and match it to observed data to compute both traditional and non-traditional statistics. MET and METViewer are being wrapped with python to extend the MET capability and make it easier to set-up a verification system. This tutorial will provide lectures on main tools along with hands-on practice sessions.
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