Research papers

WMO Air Quality and Climate Bulletin - No. 2

Ongoing climate change, caused by the accumulation of greenhouse gases in the atmosphere, is happening on a timescale of decades to centuries and is driving environmental changes worldwide.

Weathering the Storm: Unmanned Aircraft Systems in the Maritime, Atmospheric and Polar Environments

Unmanned systems have the potential to efficiently, effectively, economically, and safely bridge critical observation requirements in an environmentally friendly manner.

Weather Research and Forecasting Model Sensitivity Comparisons for Warm Season Convective Initiation

Mesoscale weather conditions can significantly affect the space launch and landing operations at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS).

Weighting Statistical Inputs for Data Used to Support Effective Decision Making During Severe Emergency Weather and Environmental Events

National Aeronautical and Space Administration (NASA) weather and atmospheric environmental organizations are insatiable consumers of geophysical, hydrometeorological and solar weather statistics.

Analysis of Rapidly Developing Low Cloud Ceilings in a Stable Environment

Forecasters at the Space Meteorology Group (SMG) issue 30 to 90 minute forecasts for low cloud ceilings at the Space Shuttle Landing Facility (TTS) to support Space Shuttle landings.

Aircraft performance in a JAWS microburst

Attention is given to the detailed features of a servere microburst event, the flight behavior of a 727 airliner in such an event as predicted by a numerical simulation, and several low level wind shear detection and war…

Assessment of microburst models for downdraft estimation

The effectiveness of three microburst models in estimating the downdraft from horizontal velocity measurements is assessed. The development of the models and their characteristics are discussed.

Windshear avoidance - Requirements and proposed system for airborne lidar detection

A generalized windshear hazard index is derived from considerations of wind conditions and an aircraft's present and potential altitude.

Windshear detection and avoidance - Airborne systems perspective

The generalized windshear hazard index presently defined is derived from aircraft-position wind data and remotely sensed data obtained along the extended flight path by such candidate sensor technologies as microwave Dop…

Time Relevance of Convective Weather Forecast for Air Traffic Automation

The Federal Aviation Administration (FAA) is handling nearly 120,000 flights a day through its Air Traffic Management (ATM) system and air traffic congestion is expected to increse substantially over the next 20 years.

Some Measured Characteristics of Severe Storm Turbulence

Measurements of atmospheric turbulence obtained from airplane flights through severe storms in connection with the National Severe Storms Project will be discussed.

Low-visibility visual simulation with real fog

An environmental fog simulation (EFS) attachment was developed to aid in the study of natural low-visibility visual cues and subsequently used to examine the realism effect upon the aircraft simulator visual scene.

Low-Visibility Visual Simulation with Real Fog

An environmental fog simulation (EFS) attachment was developed to aid in the study of natural low-visibility visual cues and subsequently used to examine the realism effect upon the aircraft simulator visual scene.

Convectively Induced Turbulence Encountered During NASA's Fall-2000 Flight Experiments

Aircraft encounters with atmospheric turbulence are a leading cause of in-flight injuries aboard commercial airliners and cost the airlines millions of dollars each year.

Fog dispersion

A study of economically viable techniques for dispersing warm fog at commercial airports is presented. Five fog dispersion techniques are examined: evaporation suppression, downwash, mixing, seeding with hygroscopic mate…

Downdrafts within High Plains cumulonimbi. I - General kinematic structure

Results from a comprehensive investigation in which observations from several case studies are integrated with three-dimensional cloud model results to examine the general kinematic structure of downdrafts associated wit…

Nowcasting Thunderstorm Anvil Clouds Over KSC/CCAFS

Electrified thunderstorm anvil clouds extend the threat of natural and triggered lightning to space launch and landing operations far beyond the immediate vicinity of thunderstorm cells.

Weather Research and Forecasting Model Sensitivity Comparisons for Warm Season Convective Initiation

Mesoscale weather conditions can significantly affect the space launch and landing operations at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS).

Observations of severe turbulence near thunderstorm tops

Data derived from the flight tapes of two airliners that experienced severe turbulence near thunderstorm tops are used to produce quantitative descriptions of the turbulence and its environment.

Analysis of Rapidly Developing Low Cloud Ceilings in a Stable Environment

This report describes the work done by the Applied Meteorology Unit (AMU) in developing a database of days that experienced rapid (< 90 minutes) low cloud formation in a stable atmosphere, resulting in ceilings at the Sh…

Stable Low Cloud Phase II: Nocturnal Event Study

This report describes the work done by the Applied Meteorology Unit (AMU) in developing a database of nights that experienced rapid (< 90 minutes) low cloud formation in a stable atmosphere, resulting in ceilings at the …

Analysis of rapidly developing fog at the Kennedy Space Center

Space Shuttle landings at Kennedy Space Center (KSC) are of special concern to NASA's landing community because of Florida's rapidly changing weather conditions.

Analysis of extreme wind shear

New methods utilizing extreme value statistical theory are applied in the analysis of the largest wind component shear in a wind profile as a function of shear layer thickness and season.

A simplified model of the turbulent microburst

A simple model was developed to describe the low altitude shear associated with a microburst (or small downburst) in the atmosphere. Such microbursts are thought to be the cause of convective radial flows near the ground…

Evolution of downdrafts and rotation in an Illinois thunderstorm

Multiple-Doppler radar observations of a non-severe Illinois thunderstorm with nearly rectilinear vertical wind shear and storm motion related to the wind at a height of 2.5 km are discussed.

Fog dispersion

The concept of using the charged particle technique to disperse warm fog at airports is investigated and compared with other techniques.

A simple model of evaporatively driven downdraft - Application to microburst downdraft

It is pointed out that the physics of a downdraft are very different from that of an updraft. An updraft is virtually saturated, while the downdraft can be unsaturated.

Battlespace Forecasting of Aviation Icing Hazards

Aircraft icing endangers aviators, restricts surveillance opportunities, and reduces combat effectiveness.

Accident investigation

Aircraft accident investigations are discussed with emphasis on those accidents that involved weather as a contributing factor. The organization of the accident investigation board for air carrier accidents is described …

Meteorological Input to General Aviation Pilot Training

The meteorological education of general aviation pilots is discussed in terms of the definitions and concepts of learning and good educational procedures.

Overview of FAA's aircraft icing program

An overview of the FAA's icing program is presented. The program involves certification of various types of aircraft for flight in known icing conditions, the study of icing conditions, and the preparation of certificati…

Corporate/commuter airlines meteorological requirements

The meteorological information requirements of corporate and commuter airlines are reviewed. The skill level and needs of this class of aviator were assessed.

Case history of FAA/SRI wind shear models

In order to understand the development of the FAA/SRI wind fields, it is important to understand the operating philosophy of the FAA's Wind Shear Program Office.

Model comparison of July 7, 1990 microburst

Model comparison of July 7, 1990 microburst is presented in the form of view-graphs. The following topics are covered: 7 July 1990 Orlando, FL simulations; model input sounding for 7 July 1990 Orlando case; 7 July 1990 O…

The Canadian Ozone Watch and UV-B advisory programs

The Ozone Watch, initiated in March, 1992, is a weekly bulletin describing the state of the ozone layer over Canada. The UV-B advisory program, which started in May, 1992, produces daily forecasts of clear-sky UV-B radia…

Dense fog on the highway: Visual range monitoring in cars?

This paper reports on the development of a new sensor. Laser range-finders are currently installed in cars and trucks to measure the distance to a proceeding car (LEICA).

Assessment of microburst models for downdraft estimation

Precipitation and kinematic structure of microburst producing storms

Single Doppler radar techniques are used to study the precipitation and kinematic structure of microburst-producing storms. Radar data collected by NCAR radars during the Joint Airport Weather Studies (JAWS) experiment a…

AVE/VAS experiment: Ground truth network

The visible/infrared spin scan radiometer (VISSR) atmospheric sounder (VAS) rawinsonde field program is discussed. Specific items covered include: planning, personnel requirements and training, operational requirement an…

Oceanic Weather Information: Oceanic Convective Nowcasting Demonstration (OCND)

This viewgraph presentation provides information on the Oceanic Convective Nowcasting Demonstration (OCND). The presentation covers oceanic/remote area aviation weather requirements, ongoing research to address the requi…