2016 CIRA Seminars
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.
GSD's Forecast Impact and Quality Assessment Section provides quality assessment services to the FAA and NWS to support the evaluation of their aviation weather products. For the FAA’s Aviation Weather Research Program (AWRP), they serve as the Quality Assessment Product Development Team (QA PDT) to perform in-depth evaluations of AWRP-sponsored products as part of the formal process for transition into operations. For the NWS they perform assessments as well as develop automated verification tools to track NWS product performance according to operational performance requirements. Produc
Max Marchand is a candidate for a Postdoctoral Position open at CIRA related to initializing forecast models with high-resolution information from next-generation geostationary environmental satellites.
The launch of the proof-of-concept mission GPS/MET (Global Positioning System/Meteorology) in 1995 began a revolution in profiling Earth’s atmosphere through radio occultation (RO). The six-satellite constellation, FORMOSAT-3/COSMIC (Formosa Satellite mission #3)/Constellation Observing System for Meteorology, Ionosphere, and Climate), launched in 2006, has proven the theoretical capabilities of RO to provide accurate and precise profiles of electron density in the ionosphere and refractivity, containing information on temperature and water vapor, in the stratosphere and troposphere.
From operational NWP model output, global turbulence forecasts are used to compute a set of diagnostics that identify regions of strong spatial gradients, and using an empirical mapping technique, convert these indicators into an equivalent energy dissipation rate to the 1/3 power. This atmospheric turbulence metric is the ICAO standard for aircraft reporting and thus provides a convenient basis for verification.
Ju Hye Kim is a candidate for a Postdoctoral Position open at CIRA related to initializing forecast models with high-resolution information from next-generation geostationary environmental satellites.
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 ago, the dynamics of its origin have long remained unclear and climate models continue to struggle with simulating realistic MJO events.
The Super-Parameterized Community Atmospheric Model (SPCAM) is a shining light among contemporary models in the dark abyss of simulated tropical variability, particularly for the Madden-Julian oscillation (MJO). In atmosphere-only mode, SPCAM simulates a robust MJO, which grows stronger when SPCAM is coupled to a dynamical ocean (SPCCSM). However, SPCCSM shows similar cold tropical SST errors to those that degrade the representation of the MJO in other models, such as the Hadley Centre model. The representation of air-sea interactions in SPCCSM is rather poor -- the diurnal cycle is abse
Abstract to be posted soon
In this paper, we provide an overview of the progress on the evaluations of the Visible Infrared Imaging Radiometer Suite (VIIRS) ocean color products with long-term time series and more in situ data for matchup analysis.
It is well known that the inviscid, adiabatic equations of atmospheric motion constitute a non-canonical Hamiltonian system, and therefore posses many important conserved quantities such as as mass, potential vorticity and total energy. However, until recently, few numerical models possessed similar conserved quantities. Over the past decade, there has been a great deal of work on the development of mimetic and conservative numerical schemes for atmospheric dynamical cores using Hamiltonian methods.
From the first instrumental climate observations in 1697 up to the global temperature record set last year, professional climate scientists owe a debt of gratitude to the millions of observations taken by volunteers around the world. In addition to describing how average global temperatures are determined and their implications, this talk will highlight the results of the latest science on global climate data as well as the latest political developments on sharing climate data across the world.
Born in polar regions, a tropopause polar vortex (TPV) is an often sub-synoptic cyclone embedded within the larger-scale tropospheric polar vortex. TPVs can be long-lived phenomena with monthly time scales, and have complex interactions with features such as sea ice, moisture, and surface cyclones. Unfortunately little is known regarding how polar processes interact with lower latitude weather and climate.
Biomass burning (BB) is the second largest global emissions source of non-methane organic compounds (NMOCs). Chemical transformations of emitted NMOCs lead to the production of ozone (O3) and secondary particulate matter (PM), thereby affecting air quality and climate. Until recently, a significant mass fraction of NMOCs in BB emissions (up to 80%) has remained uncharacterized or unidentified. Models used to simulate the air quality impacts of BB thus have relied on very limited chemical characterization of the emitted compounds.
Improved understanding of methane emissions and their trends is critical for climate policy. Satellite observations provide an emerging resource for continuous global mapping of atmospheric methane. I will talk about ongoing work in my group to use satellite observations for quantifying methane emissions in North America, including integration with new information from aircraft campaigns and from bottom-up emission inventories.
Some of the most fundamental and complex problems in climate and weather research today are our poor understanding of the basic properties of clouds and our inability to determine quantitatively the many effects that clouds have on weather and climate.
We developed radar instrumentation operating over a frequency range extending from approximately 14 MHz to 36 GHz for operation on long- and short-range aircraft and Uninhabited Aircraft Systems (UASs). We developed our existing radar instrumentation primarily to sound ice and image the ice-bed interface, map near-surface internal layers in polar firn and ice, measure the thickness of snow cover over sea ice, map near-surface internal layers in polar firn with fine resolution of about 3 cm), and measure surface elevation with high precision.
The ongoing climate emergency of 2016 emphasizes ever more strongly the central role of humans in the climate system. Many of the climate changes that we are making involve the exchange of trace gases, water, and energy between the land surface and the atmosphere. It is our responsibility to understand these processes. Here, I address the ability of surface-atmosphere exchange measurements to help reduce major uncertainties in our understanding of anthropogenic radiative forcing, namely the role of trace gases and aerosol/cloud interactions.
Tropical clouds and relative humidity play a key role in both the planetary energy balance and the sensitivity of global climate to radiative forcing. Both clouds and relative humidity are also strongly modulated by the organization of tropical convection, which results in a large fraction of tropical cloudiness and rainfall. Here, we investigate the organization of tropical convection in the context of self-aggregation, a spontaneous transition in idealized numerical simulations from randomly distributed to organized convection despite homogeneous boundary conditions.
Recent upgrades to the U.S. operational radar network now allow for polarimetric measurements of tropical convection and cyclones near Hawaii and the U.S. coast, providing new opportunities for studying these weather phenomena. In addition to the operational radar observations, a Doppler on Wheels mobile polarimetric radar was deployed to Oahu from 22 October to 13 November 2013 as part of the Hawaiian Educational Radar Opportunity (HERO). The project was the first dual-polarization field experiment performed on the island of Oahu, and one of the few research radar deployments in Hawaii.
Cities account for less than 5% of total land surface, yet are home to over half the world’s population and the majority of anthropogenic greenhouse gas emissions. Relative to more natural environments, urban areas are characterized by extremely heterogeneous landscapes and the presence of intense anthropogenic activity. This results in drastically altered surface-atmosphere exchanges of energy, water, trace gases, and momentum across a range of scales.
The seasonal cycle in the continental Tropics remains poorly understood. Climate models for instance do not reproduce the main features of tropical climates and exhibit major deficiencies in the Amazon with incorrect phase of photosynthesis and evapotranspiration.
In this presentation I will present how the diurnal and seasonal cycles of the hydrologic cycles are intertwined, using the weak temperature gradient approximation and in situ observations. These results will emphasize the role of early morning fog as a key switch and regulator of rainforest seasonality.
For over 16 years, the Precipitation Radar of the Tropical Rainfall Measuring Mission (TRMM) satellite detected the three-dimensional structure of significantly precipitating clouds in the tropics and subtropics. The multi-year dataset shows convection varying not only in amount but also in its very nature across the oceans, continents, islands, and mountain ranges of the tropics and subtropics. Extreme convection tends to form in the vicinity of mountain ranges, and the Andes in subtropical South America help spawn some of the most intense deep convection in the world.
Advancements in computing power have created new opportunities for the use of numerical models in wildfire research. Models like the Wildland Fire Dynamics Simulator (WFDS) and FIRETEC attempt to represent interactions between the dominant processes that determine wildfire behavior such as convective and radiative heat transfer, aerodynamic drag and buoyant response of the atmosphere to heat released by the fire.
The Just In Time Training (JITT) plugin for Advanced Weather Information Processing System (AWIPS) II will allow training to be integrated directly into the decision support system of the National Weather Service. By integrating training into the decision support system the barrier for operational forecasters to access training while interrogating meteorological data will be lowered therefore enhancing the training process.