Colloquia Fall 2016Spring 2016 | Spring 2017
Colloquia are held in ATS room 101; Discussion will begin at 3:30pm. Refreshments will be served at 3:00pm in the coffee lounge. Please contact Thomas Birner [thomas at atmos.colostate.edu] for more information.
The impact of mesoscale convective systems on global precipitation: A modeling study
December 2, 2016
The importance of precipitating mesoscale convective systems (MCSs) has been quantified from TRMM precipitation radar and microwave imager retrievals. MCSs generate more than 50% of the rainfall in most tropical regions. Typical MCSs hav...
Downward influence from the Stratosphere in the extratropics
November 18, 2016
Evidence from models and observations that the stratosphere imparts a significant downward influence on near-surface weather and climate has grown steadily since landmark papers in the early 2000s. It is now clear that the large-scale ci...
Observational Constraints on Global Aerosol-Cloud Interactions
October 28, 2016
Aerosols arguably remain the single greatest uncertainty among anthropogenic perturbations of the climate system. In particular the effects of aerosol-cloud interactions on global and regional radiation budgets and the hydrological cycle...
The role of shallow cumulus in the climate system, and asking how bad is "good enough" for climate models
October 21, 2016
Shallow cumulus clouds predominate in the trade-wind regions, and the response of this widespread regime has been directly linked to the spread in climate model estimates of cloud feedback and climate sensitivity. These findings will be ...
Homogeneous Ice Formation in Supercooled Water Clouds
October 14, 2016
It is important to know the phase and physical properties of aerosol and cloud particles at the top of mid-level and high tropospheric clouds – anvils and the stratiform cirrus that originate from them – in order to better estimate t...
Quantifying carbon cycle feedbacks through the lens of atmospheric CO2 variations
October 7, 2016
Carbon-cycle feedbacks are one of the most uncertain components of global climate predictions. Over the coming century, atmospheric CO2 will continue to accumulate in the atmosphere at a rate controlled by anthropogenic drivers, natural...
Assessing the impact of the Anthropocene on atmospheric composition using remote sensing from aircraft and space based instrumentation: the SCIAMACHY Project and its legacy
John P. Burrows
October 3, 2016
Between the dawn of the Neolithic revolution and the start industrial revolution the population rose from ~ 4 million to 1 billion using power provided predominantly from natural sources and biomass burning. Since the industrial revolut...
Can the U.S. Become the World Leader in Numerical Weather Prediction?
September 30, 2016
It is well-known that the U.S. skill in numerical weather prediction (NWP), as measured by NCEP's Global Forecast System (GFS), lags behind other centers, most notably the ECMWF. In this talk, we will discuss some of the reasons for thi...
Do mid-latitude jet shifts cause cloud feedbacks?
September 23, 2016
In response to increasing atmospheric greenhouse gas concentrations, most global climate models project that the mid-latitude jet streams will shift poleward over the 21st century. Consequently, the tracks of mid-latitude low-pressure sy...
The Air You Breathe: An Overview and Early Results from the Front Range Air Pollution and Photochemistry Experiment (FRAPPE)
Gabriele Pfister and Frank Flocke (Visiting ATS from NCAR)
September 19, 2016
The Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) was carried out in conjunction with the fourth deployment of the Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant ...
Molecular corridors and global maps of phase state in atmospheric secondary organic aerosols
September 19, 2016
Secondary organic aerosols (SOA) account for a large fraction of submicron particles in the atmosphere and play a key role in aerosol effects on climate, air quality and public health. The formation and aging of SOA proceed through multi...
Sources of methane emissions in North America
September 12, 2016
Methane is the second-most important greenhouse gas after carbon dioxide. The role of methane emissions in climate change is well-known, but the distribution of these emissions from different sources across the globe and the underlying e...
Some problems at the foundation of aerosol-cloud interaction in climate models or Why the IPCC may have got it wrong because of what we do to data, physics and numerics in bin-microphysics LES models
Jorgen B. Jensen
September 9, 2016
Autoconversion, that is the initial formation of drizzle drops from smaller cloud droplets through coalescence, is a critically important process to get right in climate models.
Usually autoconversion is calculated through dependence...
Contributions of Radio Occultation to Weather and Climate Using the world’s most accurate and precise thermometer from space
Richard A. Anthes, Therese Rieckh, Shay Gilpin
September 2, 2016
Richard A. Anthes
President Emeritus, UCAR and UCAR COSMIC program
Ph.D. Student, University of Graz, Austria, and UCAR COSMIC program
UC Santa Cruz , current UCAR SOARS student, COSMIC program
Clouds, Kelvin Waves, and Convective Onset in the Madden-Julian Oscillation
August 26, 2016
The Madden-Julian Oscillation (MJO) is a major component of sub-seasonal variability in tropical precipitation, and it also impacts extreme precipitation events in the subtropics and the mid-latitudes. Although it was discovered 45 years...