Cooperative Institute for Research in Environmental Sciences

CIRES Researchers Presenting at the 2012 AMS meeting

CIRES Researchers Presenting at the 2012 AMS meeting


Hurricane WRF: Transition of research to operations facilitated by the Developmental Testbed Center

Ligia Bernardet1*%, Shaowu Bao1,%, Vijay Tallapragada2, Samuel Trahan3, Zhan Zhang3, Mrinal Biswas3, Timothy Brown1,%, Donald Stark3, Laurie Carson3

1NOAA Earth System Research Laboratory – Global Systems Division, Boulder, CO
2NOAA National Centers for Environmental Prediction – Environmental Modeling Center, Camp Springs, MD
3National Center for Atmospheric Research, Boulder CO
% Also affiliated with the Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder.

The NCEP/EMC operational HWRF model is an important component of the numerical guidance used at the National Hurricane Center, making it critical that the HWRF model be continuously improved. The Developmental Testbed Center (DTC) has partnered with NOAA NCEP to work with the transfer of new technologies onto HWRF.

The DTC’s approach follows two strategies. First, the DTC recognizes that the use of a single code base between research and operations facilitates seamless exchange between the two groups. Over the last year, the DTC has worked with NCEP to merge the components of the operational HWRF onto Community codes. This work has culminated with the transfer of a community model for operational implementation for the 2011 hurricane season. Since March 2010, the DTC has been providing code management and user support for the community HWRF. Our presentation will describe the process used to transfer the community model onto operations and the support that DTC provides to its users.

The second strategy is to maintain a functionally-similar HWRF testing infrastructure to evaluate new research that has potential for transition to operations. The DTC has access to research computational platforms which make it possible to conduct comprehensive multi-season tests as well as diagnostic case studies. We will present results of the latest tests performed at the DTC and how these activities support operations.

A multi-diagnostic intercomparison of tropical width time series using models, reanalyses, and satellite observations

Sean Davis, Karen Rosenlof, Paul Young

Poleward migration of the latitudinal edge of the tropics of ~0.25 – 3º decade-1 has been reported in several recent studies based on satellite and radiosonde data, and reanalysis output covering the past ~30 years. To date, it has been unclear to what extent this large range of trends can be explained by the use of different data sources, time periods, and edge definitions. In this presentation, we address these issues by applying a suite of tropical edge latitude diagnostics based on tropopause height, winds, precipitation/evaporation, and outgoing longwave radiation (OLR) to six reanalyses and four satellite data sets. These diagnostics include both previously used definitions and new definitions designed for more robust detection. The wide range of widening trends is shown to be primarily due to the use of different data sets and edge definitions, and only secondarily due to varying start/end dates. We also show that the large trends (> ~ 1º decade-1) previously reported in tropopause and OLR diagnostics are partially due to the use of subjective definitions based on absolute thresholds. Statistically significant Hadley cell expansion based on the mean meridional streamfunction of 1.0 – 1.5º decade-1 is present in three of four reanalyses that cover the full time period (1979-present), whereas other diagnostics yield trends of -0.5 – 0.8° decade-1 that are mostly insignificant. These results are compared to model trends calculated over both the 20th and 21st century in the CMIP3 output.

Towards a framework for assessing stakeholder needs in responding to climate change across spatial and temporal scales.

Lisa Dilling, and John Berggren, University of Colorado Boulder, Boulder, CO
Kirstin Dow, Kirsten Lackstrom, and Ben Haywood, University of South Carolina
Maria Carmen Lemos and Scott Kalafatis, University of Michigan

The federal government is seeking to build an ongoing assessment capacity for climate change impacts and supporting decision making across sectors at multiple scales.  The question arises of how such a capacity can be efficiently and effectively constructed so that it can the most helpful within available resource constraints.  Over the past two decades, experience has been building in understanding both how climate science has been applied in decision making, and how communities are responding to climate variability and change.  To harvest this experience, investigators from three RISA programs: the Great Lakes Regional Integrated Scientific Assessment (GLISA); the Western Water Assessment (WWA) and the Carolinas Integrated Sciences and Assessments (CISA) have been looking retrospectively and currently at stakeholder needs and constraints with respect to climate variability and change.  We are seeking to understand the commonalities and differences across regions, and aiming to construct an assessment support framework for future assessments. 

Data collection was carried out in three phases. First, we identified focus areas and sectors in each region according to expected impact/sensitivity to climate risk and socio-economic importance. Second we identified a large number (over 200 altogether) of reports related to climate issues and a baseline database of stakeholders currently engaged with climate-related decisions for each sector. Third we contacted key informants to expand the scope of the search. Fourth, we identified critical variables of interest, including: the types of adaptation or mitigation activities occurring in each sector, identified needs and barriers that hinder adaptation actions; and recommendations or possible solutions to address adaptation limits and barriers. Then we developed a common coding guiding book focusing on activities being undertaken to address issues associated with climate change mitigation and adaptation, existing needs to address these issues, trusted sources of information, perceived constraints and opportunities, and how the perceptions of these topics have evolved over time. Fifth, we organized the database in N-Vivo for further analysis. Finally we identified stakeholders and their characteristics such as sector, area of focus and affiliation in order to identify and map the social networks that were associated with the creation of documents and participation in key events that have produced and disseminated climate information. 

This presentation reports the data mainly on the document and key informant interview phases of the project.  In the interest of time, we also will present work focused on one particular sector, the water sector, which was well represented in all three regions’ databases.  Stakeholders indicated that they shared some concerns across regions, including concerns over increased variability in precipitation, and uncertainty at the local scale. Naturally there were differences across regions as well.  Stakeholder needs fell into three main categories: data and information, governance and leadership, and collaboration and communication.  While there were some specific items that were found across all three regions, what was of particular interest was how the needs expressed correlated with the governance structure in place for water allocation and permitting.  We suggest there is a complex interplay between perceptions of risk, drought events, public awareness and legal frameworks and they all work to influence needs and constraints.  We also found evidence of an “adaptation deficit,” in which existing data, infrastructure, coordination and relationships between information producers and consumers were inadequate to support the additional activity that might be expected to arise as climate becomes more unpredictable and variable.

Providing Usable Sea Ice Information to Native Coastal Communities in Arctic Alaska

Matthew L. Druckenmiller, PhD
Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder

The climate, sea ice, and coastal regime of Alaska’s North Slope has substantially changed over the last few decades as coastal temperatures have increased and sea ice concentration in the adjacent seas has decreased. Indigenous users of sea ice and local planners increasingly face difficulty in assessing the relevance of regional change to their decision making environment, which includes issues relating to subsistence hunting of marine mammals, sea ice related hazards, coastal erosion, and offshore oil and gas development. Such decisions require science-based datasets that are often not easily accessible, digestible or immediately relevant. Furthermore, information products are needed that can interface with local and traditional knowledge such that local perspectives can contribute to a more comprehensive understanding of important environmental processes.

This presentation will outline a project that is working between the National Snow and Ice Data Center (NSIDC) and Alaska’s North Slope Borough (NSB) to develop sea ice information tailored to local ways of understanding and observing the environment and the unique decisions facing coastal communities in Alaska. The three primary goals of this effort are to: (1) survey local community decision makers and ice-users regarding their broader information needs, preferred types of data products, and the technological, educational, or epistemological challenges they face in using science-based information, (2) identify the NSB’s baseline data needs in order to track how ice conditions are impacting community activities and the marine mammals they depend on, and (3) assist the NSB in communicating environmental change to the local communities in a manner that complements their local and traditional knowledge and strategies for assessing ice conditions and associated hazards.

This work is building off a five-year collaborative project with the indigenous whaling community of Barrow, Alaska to provide sea ice information (maps of the community’s ice trails, ice trail thickness surveys, real-time coastal radar imagery of ice movement, satellite imagery of shorefast ice extent, etc.) to active hunters during the traditional spring whaling season.

Arctic to Archive:  End-to-End Data Support Services for the NSF Arctic Program

Fetterer, F., J. Moore, M. Parsons, M. Serreze, and S. Williams

NSF supported investigators are obligated to contribute their data to a national data center as part of strong new NSF data management procedures.  Whether scientists find this to be simple or tortuous largely depends on the operational process the receiving data center has designed.  The NSIDC, NCAR, and UCAR partners that built the Cooperative Arctic Data and Information System (CADIS) for the NSF/OPP Arctic Observing Network (AON) are now funded to develop data management services for all NSF Arctic research projects.  We aim to ease and clarify the scientist's role in good data stewardship, and will measure success by the assessment of contributing investigators, obtained through user surveys and via direct interaction with the investigators.   Advanced CADIS (ACADIS) will house data from existing projects supported by the NSF/OPP/ Arctic Section (ARC) and build on features of CADIS that investigators and program managers appreciate.  These include the ability to access data files as soon as they are contributed (uploaded), and to author standard metadata using limited controlled vocabularies.

While CADIS emphasized serving AON field project investigators, ACADIS will embrace long-term data stewardship for the wider research community as well.   Challenges are both technological and human in nature.  For example, technology can address data visualization needs well, but only after data are in a standard format and described with standard vocabularies. We must work with communities of scientists to develop these standards and allow the investigators to meet their obligations promptly and efficiently.    Even so, rising to a gold standard of stewardship for all data contributions will not be possible.    An advisory board will help us prioritize data collections.   Growing use of ACADIS data by the broad science community to address the changes underway in the Arctic will be a key measure of success.

Monitoring Arctic Sea Ice: Product Development Considerations

F. Fetterer, A. Windnagel, K. Gergely, W. Meier, D. Scott

As one of NASA's Distributed Active Archive Centers, the National Snow and Ice Data Center (NSIDC) has extraordinary access to satellite data that make monitoring sea ice over time and space possible, and to the scientific research and algorithm development NASA has supported as well.  At the same time, NSIDC works with agencies, primarily NOAA and the Navy, to assist in projects that in some way transition sea ice research to operations, or enable scientists to more easily benefit from the ice monitoring carried out operationally.    Our user community includes researchers, the scientifically literate public, and news organizations.

Six products illustrate considerations that come into play when designing for these users.   Three are data products:  the sea ice Climate Data Record (CDR), now in final stages of development at NSIDC; the weekly or biweekly ice chart record produced by analysts at the National Ice Center (NIC); and the daily IMS snow and ice product also produced by analysts at the National Ice Center and archived and distributed by NSIDC as well as by NIC.   While the CDR emphasizes consistency, stability, and reproducibility, the products from NIC are made to meet the day's operational needs as well as possible, without the same emphasis on consistency.

Three other sea ice products are distinguished as data dissemination products.  These are based on data products, but through processing or presentation, the information these data hold is made more readily usable by a wider audience.  These are the Sea Ice Index, soon to be based on the new sea ice Climate Data Record; Multisensor Analyzed Sea Ice Extent (MASIE), based on the NIC IMS product, and National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format, based on the NIC chart series.   Some of the difficult issues faced in developing these products were what base period to use for showing averages and anomalies, whether archives should be rolling or not, and how far to go in making products available in multiple formats.

These products are among the most broadly used ice monitoring data sets, but NSIDC distributes many other sea ice remote sensing, in situ, derived, and historical sea ice data collections as well.

Tim Fuller-Rowell, CIRES/Univ. of Colorado, Boulder, CO; and R. A. Akmaev, F. Wu, H. Wang, T. W. Fang, M. Fedrizzi, R. Viereck, and M. Iredell

The plasma density and electrodynamic response to the January 2009 sudden stratospheric warming (SSW) has been well documented and extensively modeled. The changes in the local time variation of plasma density and total electron content has be attributed to changes in electrodynamics, which in turn can be associated with changes in the tidal wind fields propagation from the lower atmosphere into the lower thermosphere dynamo region. Much of the change in electrodynamics during the SSW has been attributed to an increase in the terdiurnal migrating tide at the expense of the semidiurnal. The migrating tide should not introduce longitude dependence in the electrodynamic response. However, by modeling the system, the interaction of the winds with the global wave number one number associated with the offset of the geomagnetic pole, does change the phase of the electrodynamic response, and is consistent with observations in the American and Asian sectors.

The CHAMP accelerometer satellite observations during the 2009 SSW appeared to show a neutral density decrease, indicating an upper thermospheric cooling. Modeling the period indicated that the main cooling signature could be attributed to changes in geomagnetic activity, rather than as a result of the SSW itself. On the contrary, whole atmosphere modeling indicated a slight warming in response to the SSW. However, this warming was relatively small and would have been difficult to discern in the local-time sampling of the satellite, and due to a much larger contribution to the variability from geomagnetic sources. At this stage, therefore, it is not possible to ascertain if a cooling or warming occurred in the upper thermosphere in response to the stratospheric warming.

In January 2010, a weaker warming occurred, which enables the physical interpretation of the whole atmosphere, electrodynamic, plasma density, and neutral density response to be tested. The 2010 event was quite different from the 2009 warming. In 2009, the stratosphere polar vortex split, with a large increase in zonal wave number two. In 2010, however, the conditions were more indicative of a displaced vortex, with predominantly an increase in zonal wave number one. In spite of these differences, modeling of the event in 2010 still showed a significant change in the amplitude of the migrating tidal modes in the lower thermosphere. Comparing the two events provides an ideal opportunity to test and validate whole atmosphere models, and enable the physical processes involved in the dynamic, electrodynamics, and plasma and neutral density response to be unraveled.

Relating a Convective Translation Metric to Convective Impact

Steven A. Lack, CIRES/Univ. of Colorado, Boulder, CO; and G. J. Layne, M. P. Kay, M. A. Petty, and J. L. Mahoney

The Flow Constraint Index (FCI), based on the Mincut-Bottleneck technique, has been used in the evaluation of convective forecast products by translating both forecasts and observations into a common convective impact field. Convective forecasts can be translated using this methodology whether it is deterministic, probabilistic or categorical. The resultant translated field estimates the flow constraint (i.e. permeability) due to the presence of hazardous convection over a defined geometric grid given flow corridors of interest.

This grid is often represented by hexagons over the CONUS at sizes that approximate high-altitude sectors or Air Route Traffic Control Centers (ARTCCs) in order to perform meteorological evaluations on scales of interest for the strategic decision process. The FCI also can be evaluated on a non-regular grid defined by actual high-altitude sector geometry, or ARTCC boundaries, and uses traffic density-weighted jetways to define the corridors of interest. The research herein will explore the FCI translation as it relates to the issuance of Traffic Management Initiatives (TMIs). In particular, correlations of measured enroute FCI values to Airspace Flow Programs (AFPs) across common Flow Constrained Areas (FCAs) will be shown. Additionally, terminal convective impact will be examined as it pertains to Ground Stops (GS) and Ground Delay Program (GDP) issuances.

This research is in response to requirements and funding provided by the Federal Aviation Administration. The views expressed are those of the authors and do not necessarily represent the official policy and position of the U.S. Government.

Houjun Wang, NOAA SWPC and CIRES Univ. of Colorado, Boulder, CO; and T. J. Fuller-Rowell, R. A. Akmaev, M. Hu, D. T. Kleist, and M. Iredell

The Gridpoint Statistical Interpolation (GSI) analysis system is used at NCEP for both regional and global operational data assimilations. It uses the 3-dimensional variational (3DVAR) analysis technique. The Developmental Testbed Center (DTC) support of the community GSI has expanded its community users, such as users of the Weather Research and Forecasting (WRF) model for regional numerical weather prediction applications. The community GSI has added features that make it flexible in adding state and control variables. GSI has also been used for chemical/aerosol and cloud data assimilation.

WAM is an extension of NCEP's Global Forecast System (GFS) model from 64 model levels (with the model top at about 60 km) to 150 model levels (with the model top at about 600 km). It covers the regions of important ionospheric processes and their variability. WAM includes basic ionospheric effects on neutral atmosphere, i.e., ion drag and Joule heating. Free annual run with WAM produced comparable climatology of tidal wave variability in the mesosphere and low thermosphere (MLT) region.

GSI was extended for data assimilation for WAM. The first simulations with the data assimilation (DA) system have produced realistic dynamic and electrodynamic responses to real large-scale sudden stratospheric warming (SSW) events. In this talk, some on-going works with the DA system will be presented. First, update of the background error statistics derived from yearlong short-term forecasts from the current DA system will be described. Then, the effects of assimilating observations in the MLT regions, such as SABER temperature and TIDI wind data from the TIMED satellite will be assessed. Assimilation of other observational data, such as CHAMP temperature/density data, SSM/IS upper air channel radiance, will also be discussed. Assimilation and error/bias quantification of these new data sources provides new opportunities to validate WAM simulations and forecasts.

Up-Scaling Disdrometer, Profiler, and Scanning Radar Observations to Satellite Footprints

Christopher R. Williams, CIRES/Univ. of Colorado, Boulder, CO; and A. Tokay and D. B. Wolff

In order to link surface hydrologic applications and satellite observations, we need to understand how the spatial distribution of precipitation at sub-satellite footprint scales impacts satellite retrieved precipitation products. In most ground-based precipitation radar estimates, it is assumed that the rain is uniformly distributed throughout the sample volume. If this assumption was true, then the reflectivity probability distribution function (PDF) from disdrometers and scanning radars would have similar shapes. But in many NASA Global Precipitation Mission (GPM) Ground Validation(GV) program field campaigns, the reflectivity PDF from disdrometers is wider than the reflectivity PDF from scanning radars. This difference is consistent with scanning radars averaging the reflectivity over a larger spatial domain reducing the range of observed reflectivity values whereas the disdrometers sample the higher range of reflectivities in their smaller sample volume. This study investigates the temporal correlations in disdrometer and vertically pointing profiler observations to up-scale consistent precipitation features to spatial scales larger than the original point and columnar observations. This temporalto-spatial transformation assumes the precipitation structure does not vary as the precipitation system passes over the disdrometer and profiler sites. Simultaneous scanning radar observations are used to scale the precipitation features to the 5 by 5 km footprint of the GPM Dual-frequency Precipitation Radar (DPR).


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