Publications
A space-time multiscale analysis system: a sequential variational analysis approach
April 1, 2011
Journal Article
Published in:
Monthly Weather Rev., Vol. 139, No. 4, April 2011, pp. 1224-1240.
Topic:
R&D area:
R&D group:
Summary
As new observation systems are developed and deployed, new and presumably more precise information is becoming available for weather forecasting and climate monitoring. To take advantage of these new observations, it is desirable to have schemes to accurately retrieve the information before statistical analyses are performed so that statistical computation can be more effectively used where it is needed most. The authors propose a sequential variational approach that possesses advantages of both a standard statistical analysis [such as with a three-dimensional variational data assimilation (3DVAR) or Kalman filter] and a traditional objective analysis (such as the Barnes analysis). The sequential variational analysis is multiscale, inhomogeneous, anisotropic, and temporally consistent, as shown by an idealized test case and observational datasets in this study. The real data cases include applications in two-dimensional and three-dimensional space and time for storm outflow boundary detection (surface application) and hurricane data assimilation (three-dimensional space application). Implemented using a multigrid technique, this sequential variational approach is a very efficient data assimilation method.
Summary
As new observation systems are developed and deployed, new and presumably more precise information is becoming available for weather forecasting and climate monitoring. To take advantage of these new observations, it is desirable to have schemes to accurately retrieve the information before statistical analyses are performed so that statistical computation...
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Route availability planning tool evaluation vizualizations for the New York and Chigaco departure flows
March 29, 2011
Conference Paper
Published in:
AIAA Infotech at Aerospace Conf. and Exhibit, 29-31 March 2011.
Summary
When operationally significant weather affects a region of the National Airspace System (NAS) a Severe Weather Avoidance Program (SWAP) is initiated for that region. Each SWAP event is a unique mix of demand, weather conditions, traffic flow management (TFM) initiatives and traffic movement. On the day following a SWAP, the SWAP events are reviewed by FAA and airline representatives as part of the daily planning teleconference, and the TFM initiatives used are evaluated to understand their impact on the traffic flows, benefits, and disadvantages. Due to the complexity of the situation various exploratory visualizations were designed in order to evaluate aspects of the aviation environment and the responsive actions of the NAS during outbreaks of convective weather as well as to gain insights on the interaction of weather and traffic operations. From these visualizations, analyses and metrics were developed that could be used to objectively evaluate the effectiveness of TMIs. This paper will present three visualizations that have directly resulted in the development of analyses for TMIs or lead to insights into air traffic operations.
Summary
When operationally significant weather affects a region of the National Airspace System (NAS) a Severe Weather Avoidance Program (SWAP) is initiated for that region. Each SWAP event is a unique mix of demand, weather conditions, traffic flow management (TFM) initiatives and traffic movement. On the day following a SWAP, the...
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Collaborative Decision Making (CDM) Weather Evaluation Tool (WET) operational bridging for convective weather: demonstrations and implementation plans
January 25, 2011
Conference Paper
Published in:
2nd Aviation, Range and Aerospace Meteorology Special Symp. on Weather-Air Traffic Management Integration, 22-27 January 2011.
Summary
The purpose of this manuscript is twofold. First, it provides a review of the activities of the Weather Evaluation Team (WET), which is part of a joint Industry and Federal Aviation Administration (FAA) effort called Collaborative Decision Making (CDM). Over ten years ago, the predecessor to the WET, the Weather Action Group (WAG), developed a process that involved industry and government participants in the production of the Collaborative Convective Forecast Product (CCFP). The CCFP was developed in response to the need of industry and government Air Traffic Managers to have a common forecast of convective information used in their decision making processes. In light of the concepts introduced by the Next Generation Air Transportation System (NextGen), the CCFP could be viewed as one predecessor to the Single Authoritative Source. During the period 2008 through 2010, the WET worked on a task to increase the amount of detail as well as extend its forecast time period. At the same time, new automated convective forecasts were developed and introduced to both the WET and Traffic Flow Management (TFM) community. The manuscript includes a description of how the WET has strived to integrate both Human-in-the-Loop (HITL) and fully automated products, including the Localized Aviation Model Output Statistics (MOS) Product (LAMP)/CCFP Hybrid (LCH), the Aviation Impact Guidance for Convective Weather, the Corridor Integrated Weather System (CIWS) and the Consolidated Storm Prediction for Aviation (CoSPA). The second purpose of this manuscript is to introduce the new concept called Operational Bridging. The WET first discussed Operational Bridging at the 2010 Friends and Partners of Aviation Weather (FPAW) Vision Meeting in July, 2010. Foundational materials such as a Concept of Operations (CONOPS) and a demonstration plan are now being developed by the WET. Operational Bridging is first described from within a meteorology-centric view of the CCFP forecast process. Not only does this allow the new concept to be further defined, it also lays out a transition path for the current CCFP. Operational Bridging is next described from the broader conceptual perspective of Air Traffic Management (ATM)/Weather Integration, and two key areas are explored: 1) the role of the CDM weather community in the area of automated probabilistic and deterministic convective weather forecast information and 2) the integration of probabilistic forecast information into both strategic and deterministic (tactical) ATM decision making process.
Summary
The purpose of this manuscript is twofold. First, it provides a review of the activities of the Weather Evaluation Team (WET), which is part of a joint Industry and Federal Aviation Administration (FAA) effort called Collaborative Decision Making (CDM). Over ten years ago, the predecessor to the WET, the Weather...
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Modeling convective weather avoidance of arrivals in the terminal airspace
January 25, 2011
Conference Paper
Published in:
2nd Aviation, Range, and Aerospace Meteorology Special Symp. on Weather-Air Traffic Management Integration, 22-27 January 2011.
Summary
For several years the NASA sponsored Convective Weather Avoidance Model (CWAM) has been under development at Lincoln Lab to correlate pilot behavior with observable weather parameters available from convective weather systems. To date, the current CWAM has focused primarily on the enroute airspace used by aircraft at cruise altitude. At these altitudes there is a strong correlation between the observable echo tops from the Corridor Integrated Weather System (CIWS) and the probability that a pilot will deviate around weather. The CWAM has lead to the development of a Weather Avoidance Field (WAF) that combines the echo tops and vertically integrated liquid (VIL) into a probabilistic forecast of the likelihood of pilot deviation. In recent years the WAF has become widely acceptance as a reliable indicator of the impact of convective weather on air traffic operations. This paper will explore the adaptation of the CWAM into the terminal airspace with a focus on the weather impact on arrival decision making. A database of convective weather impacts on several major terminals from 2009 has been collected and identification of the impact on arriving aircraft has begun. Past studies of terminal weather impact have identified aircraft that penetrated severe weather or made clear deviations around convective cells within the terminal. This study will expand the definition of an impact to identify pilot decision making occurring outside of the terminal with regard to the expected weather impact upon arrival in the terminal. Examples include rerouting to an alternate corner post, holding in enroute airspace, or diverting to an alternate airport when weather is expected along the planned terminal trajectory. These types of terminal weather avoidance decisions can often be made many miles outside of the terminal. The enroute CWAM uses spatial filters applied to the echo tops and VIL to obtain the best correlation between the weather and pilot behavior. This paper will evaluate the current CWAM filters and identify alternate spatial filters or additional weather products that may best correlate pilot decision making in the terminal. Ultimately the goal of this work is provide ATC managers and automated decision supports tools with a weather avoidance field for effective management of convective weather in terminal airspace.
Summary
For several years the NASA sponsored Convective Weather Avoidance Model (CWAM) has been under development at Lincoln Lab to correlate pilot behavior with observable weather parameters available from convective weather systems. To date, the current CWAM has focused primarily on the enroute airspace used by aircraft at cruise altitude. At...
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Observations of a 25 January 2010 gravity wave in the New York City metropolitan area and its impact on air traffic
January 24, 2011
Conference Paper
Published in:
2nd Aviation, Range and Aerospace Meteorology Special Symp. on Weather-Air Traffic Management Integration, 22-27 January 2011.
Summary
A strong low pressure system moved through the Northeast United States on 25 January 2010. As the day progressed, a north-south line of convection formed ahead of an approaching cold front and intensified very rapidly as it passed over the four major New York City airports. Exceptionally strong winds and low-level shears occurred throughout the terminal areas and forced arriving aircraft to divert to alternate airports, hold in the air and on the ground, or abort the landing approach. Analysis shows that a narrow but intense squall line developed as a result of a gravity wave or buoyancy wave and caused vertical shear of the horizontal winds from the surface up through cruise flight levels throughout all of the Terminal Radar Approach Control airspace. Air traffic control planning procedures are examined because the extent and severity of the weather was underestimated; consequently, air traffic managers over-delivered aircraft which lead to excessive airborne holding in regions of known turbulence. Although not available to the operational aviation community at the time, evidence is also shown that the NOAA Earth System Research Laboratory experimental High-Resolution Rapid Refresh (HRRR) model forecasted the event. HRRR supplemental output fields could have provided the spatial and temporal resolution necessary for Managers to plan and execute an orderly reduction in air traffic demand, which, in-turn, would have improved safety and significantly reduced passenger delays. A framework for incorporating HRRR data into Air Traffic Management (ATM) Decision Support Tools and specific ATM Collaborative Decision Making guidance is offered.
Summary
A strong low pressure system moved through the Northeast United States on 25 January 2010. As the day progressed, a north-south line of convection formed ahead of an approaching cold front and intensified very rapidly as it passed over the four major New York City airports. Exceptionally strong winds and...
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Use of a high-resolution deterministic weather forecast for strategic air traffic management decision support
January 14, 2011
Conference Paper
Published in:
91st American Meteorological Society Annual Meeting, 22-27 January 2011.
Topic:
R&D area:
Summary
One of the most significant air traffic challenges is managing the National Airspace System (NAS) in a manner that optimizes efficiency and mitigates avoidable delay, while maintaining safety, when convective weather is present. To do this, aviation planners seek to develop strategic air traffic management (ATM) plans and initiatives that anticipate weather constraints 2-8 hours in the future and identify options and alternatives for efficient operations during the off-nominal NAS conditions. In support of strategic planning, traffic managers currently conduct bi-hourly Strategic Planning Telcons (SPTs) and devise weather impact mitigations plans using the human-generated Collaborative Convective Forecast Product (CCFP). However, most operational decision-makers agree that the quasi-deterministic CCFP "polygons" (accompanied by a "low/high" forecast confidence rating) lack the granularity and temporal resolution to adequately support efficient strategic ATM plans and decisions. Moreover, traffic managers also assert that probabilistic forecasts of convective weather likelihood, while helpful in highlighting regions of possible airspace disruptions, generally lack the ability to resolve specific weather characteristics pertinent to strategic planning. MIT Lincoln Laboratory, NCAR Research Applications Laboratory, and NOAA Earth Systems Research Laboratory (ESRL) have collaborated to develop a high-resolution, rapidly updating 0-8 hour deterministic precipitation and echo tops forecast, known as CoSPA, to aid operational decision-makers in developing strategic plans for weather impact mitigation. In the summer of 2010, a comprehensive field study was conducted to assess potential benefits and the operational performance of CoSPA in the context of strategic ATM planning. The data were gathered by simultaneous real-time observations of I5 FAA and airline operations facilities during 15 convective weather impact days affecting the Northern Plains, Great Lakes, and East Coast regions of the NAS. CoSPA field evaluation results will be presented to demonstrate the various ways aviation planners have utilized the increased spatial and temporal resolution of CoSPA - the ability of CoSPA to resolve storm structure and refine forecasts with high update rates - to make more detailed assessments of potential weather impacts and to determine the subsequent need for airspace management initiatives. Results will also be presented that highlight CoSPA enhancement needs, primarily related to forecast uncertainty, that would improve the operational effectiveness of CoSPA-derived weather impact mitigation plans. Finally, opportunities to translate CoSPA deterministic forecasts into integrated weather-ATM decision support for specific strategic planning tasks will be discussed
Summary
One of the most significant air traffic challenges is managing the National Airspace System (NAS) in a manner that optimizes efficiency and mitigates avoidable delay, while maintaining safety, when convective weather is present. To do this, aviation planners seek to develop strategic air traffic management (ATM) plans and initiatives that...
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Analysis of ground-based radar low-altitude wind-shear detection in OEP terminal airspace for NextGen
December 2, 2010
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-375
Summary
To support the Next Generation Air Transportation System (NextGen), the Reduce Weather Impact Sensor RightSizing program is identifying and analyzing gaps in the current sensor network coverage relative to the Four-Dimensional Weather Data Cube Single Authoritative Source performance requirements. In this study, we look for shortfalls in low-altitude wind-shear sensing by ground-based radars and lidar in the NextGen super-density operations (SDO) terminal airspace. Specifically, 2D gridded wind-shear visibility (an upper bound to detection probability) data are generated for microbursts and gust fronts separately for different sensors, namely the Terminal Doppler Weather Radar, Next Generation Weather Radar, Airport Surveillance Radar-9 with Weather Systems Processor, and Doppler lidar.
Summary
To support the Next Generation Air Transportation System (NextGen), the Reduce Weather Impact Sensor RightSizing program is identifying and analyzing gaps in the current sensor network coverage relative to the Four-Dimensional Weather Data Cube Single Authoritative Source performance requirements. In this study, we look for shortfalls in low-altitude wind-shear sensing...
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A statistical learning approach to the modeling of aircraft taxi time
October 3, 2010
Conference Paper
Published in:
29th Digital Avionics Systems Conf., 3 October 2010.
Summary
Modeling aircraft taxi operations is an important element in understanding current airport performance and where opportunities may lie for improvements. A statistical learning approach to modeling aircraft taxi time is presented in this paper. This approach allows efficient identification of relatively simple and easily interpretable models of aircraft taxi time, which are shown to yield remarkably accurate predictions when tested on actual data.
Summary
Modeling aircraft taxi operations is an important element in understanding current airport performance and where opportunities may lie for improvements. A statistical learning approach to modeling aircraft taxi time is presented in this paper. This approach allows efficient identification of relatively simple and easily interpretable models of aircraft taxi time...
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Field & (data) stream: a method for functional evolution of the Air Traffic Management Route Availability Planning Tool (RAPT)
September 27, 2010
Conference Paper
Published in:
HFES 2010, Proc. of the 54th Human Factors and Ergonomics Society Annual Mtg., 27 September 2010, pp. 104-108.
Summary
A method coupling field evaluation with operations data analysis is presented as an effective means to functionally evolve a decision support system. The case study used to illustrate this method is the evaluation of the Route Availability Planning Tool (RAPT), a decision support tool to improve departure efficiency in convective weather in New York air traffic facilities. It was only through a combination of quantitative performance data analysis and field observations to identify key elements of the decision making process that the designers were able to determine the most critical departure management decision requiring support, leading to significant improvements in departure efficiency.
Summary
A method coupling field evaluation with operations data analysis is presented as an effective means to functionally evolve a decision support system. The case study used to illustrate this method is the evaluation of the Route Availability Planning Tool (RAPT), a decision support tool to improve departure efficiency in convective...
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Assessment and interpretation of en route Weather Avoidance Fields from the Convective Weather Avoidance Model
September 13, 2010
Conference Paper
Published in:
ATIO 2010: 10th AIAA Aviation Technology Integration and Operations Conf., 13-15 September 2010.
Summary
This paper presents the results of a study to quantify the performance of Weather Avoidance Fields in predicting the operational impact of convective weather on en route airspace. The Convective Weather Avoidance Model identifies regions of convective weather that pilots are likely to avoid based upon an examination of the planned and actual flight trajectories in regions of weather impact. From this model and a forecast of convective weather from the Corridor Integrated Weather System a probabilistic Weather Avoidance Field can be provided to automated decision support systems of the future impact of weather on the air traffic control system. This paper will present three alternative spatial filters for the Convective Weather Avoidance Model, quantify their performance, address deficiencies in performance, and suggest potential improvements by looking at the ATC environment and common situational awareness between the cockpit and air traffic control.
Summary
This paper presents the results of a study to quantify the performance of Weather Avoidance Fields in predicting the operational impact of convective weather on en route airspace. The Convective Weather Avoidance Model identifies regions of convective weather that pilots are likely to avoid based upon an examination of the...
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