Coupling, Energetics, And Dynamics Of Atmospheric Regions Research Articles

Multi-instrument study of a spread-F event at Arecibo linked to solar wind variations

Using five diverse data sets, we demonstrate that apparently local ionospheric spread-F activity, observed with an HF radar and the Arecibo Observatory (AO) Incoherent Scatter Radars (ISR) under geomagnetically quiet conditions, is likely the local manifestation of a mesoscale or larger ionospheric response to relatively weak solar wind activity. The solar wind activity included a weak pressure pulse and Interplanetary Magnetic Field (IMF) realignment events. The mid-latitude spread-F activity was observed with a 4.42 MHz radar located near AO and the dual-beam 430 MHz AO ISRs. Additionally, the Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) Madrigal Global Navigation Satellite System-Total Electron Content (GNSS-TEC), the NASA OMNI, and the SuperMAG datasets were used to establish the (mesoscale/global) wide-context of the local, deep-context radar results. While the ISR event appears to be “classical” local spread-F, often attributed to Perkins-like plasma instabilities, the HF radar reveals large ionospheric structures coincident with the ISR event. However, that the apparently AO-local event was part of a very dynamic mesoscale event that lasted for over ten hours, is shown via independent AO-sector and AO-conjugate sector keograms constructed using detrended vertical TEC (delta-vTEC) data. The keograms reveal a prominent F-region feature that appears to propagate from west-to-east and then back to the west passing over AO twice. The ISR manifestation of this mesoscale event is indistinguishable from decades of similar ISR results which were assumed to be strictly “local”. The strong non-local (mesoscale) properties revealed by the delta-vTEC keograms suggest a possible space weather influence. Study of the relevant NASA OMNI solar wind and superMAG magnetometer data points to modest solar wind features including IMF realignment that may have electrodynamically launched, with little time delay, the observed mesoscale ionospheric events. Given the apparent rapid ionospheric response to the solar wind features, we suggest that limited latitudinal scale, prompt penetration electric fields (PPEF), associated with highly-localized partial ring current activity, be considered in the system-of-systems context of our observations. In any case, the need to examine magnetospheric/ionospheric electrodynamics across a wide range of instruments and data sets is demonstrated.

Assessing the demographics of the 2021 and 2022 CEDAR workshop

The Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) community is made of engineers, scientists, physicists, and students with a mission to understand the fundamental properties and predictability of the space-atmosphere interaction region, including the mesosphere, thermosphere, ionosphere, and inner magnetosphere. At the 2020 CEDAR annual workshop, community-wide feedback received on diversity, equity, and inclusion (DEI) in CEDAR warranted a grassroots effort focused on addressing the DEI issues raised. This led to the creation of the CEDAR DEI task force, whose goals were to 1) Assess and formalize DEI efforts in CEDAR; 2) Establish and normalize a DEI presence in the CEDAR community; and 3) Foster improvement in CEDAR through implementation of actionable initiatives that promote diversity, equity, and inclusion. Of these actionable items collecting demographic information on those participating in the Annual CEDAR Workshop was identified as the top priority. This paper therefore, reports the demographic information obtained from CEDAR registrants for the virtual workshop in 2021 and in-person workshop in 2022. In general, the demographics of CEDAR are consistent with those in broader science, technology, engineering, and mathematics (STEM) fields, that is, most participants identify as male, White, and or Asian/Middle Eastern. On average, women and historically underrepresented races and ethnicities in STEM fields make up roughly 30% and 10%, respectively, of all 2021 and 2022 CEDAR Workshop registrants over the past 2 years. We further discuss the demographics of CEDAR relative to reports published in recent years by other organizations, where possible.

The Second Annual Space Weather Community Operations Workshop: Advancing Operations Into the Next Decade

How can we continue to advance the space weather operational community from lessons already learned when it comes to data reliability, maintainability, accessibility, dependability, safety, and quality? How can we make space weather more easily accessible to each other and outside users? Representatives from operational, commercial, academic, and government organizations weighed in on these important questions at the second annual Space Weather Community Operations Workshop, held 22–23 March 2012 in Park City, Utah, with the unofficial workshop motto being Don’t Reinvent the Wheel. The workshop, hosted by the Space Weather Center (SWC) at Utah State University (USU), had an objective of building on preexisting distributed space weather networks. W. Kent Tobiska, director of USU SWC, introduced this objective by pointing to the operations-level information exchange already occurring between 11 organizations: NOAA Space Weather Prediction Center (SWPC); NASA Community Coordinated Modeling Center; Laboratory for Atmospheric and Space Physics; Atmospheric and Environmental Research; Center for Space Plasma and Aeronomic Research; Exploration Physics International; Rice Space Institute; U.S. Geological Survey (USGS); Space Environment Center; Space Environment Technologies; and the event host, USU SWC. The workshop brought together two dozen core commercial, agency, and university space weather operational personnel to promote a robust data exchange capacity within the space weather enterprise. This data exchange focuses on sharing common operational problems and solutions as well as working toward developing best practices that will eventually become standards for space weather operations. Each participant discussed mission assurance best practices in terms of reliability, maintainability, accessibility, dependability, safety, and quality. For example, recommendations for reliability best practices would be to maintain redundancy by creating several channels for data access making systems more reliable by allowing data customers multiple access points and relieving strain on systems. Unreliable source data are detrimental to space weather products when downstream users are unable to ingest data. Looking at maintainability, simple practices such as consistent, intuitive file-naming conventions; maintainable software; documentation (e.g., user guides and test plans); and attention to other best practices in software development are vital. Structural and descriptive metadata are key players in accessibility. Following the simple outline of Who, What, Where, When, Why, How, and Whose is recommended for creating and developing meaningful metadata that will benefit the end user. Dependability of data and systems becomes a main focus for data producers and maintainers. The direct access servers (non-Web) such as the External Space Weather Data Store used by NOAA SWPC and Earthworm used by USGS are examples of different systems used to bolster dependability of data access for users. Finally, safety and quality of products and data can be tested against several different challenges, including Geospace Environment Modeling (GEM) Metrics, Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) Electrodynamics Thermosphere Ionosphere (ETI), GEMCEDAR (Dst), and Solar Heliosphere and Interplanetary Environment (SHINE) program (see http://ccmc.gsfc.nasa.gov/ support/CETI2010/). Quality products will help improve the safety of the same products, fostering a community perception of trustworthy space weather data providers. Topics of coronal mass ejection forecasts and ensemble modeling, high-latitude energy inputs, and products and services were discussed in breakout sessions. These sessions generated ideas for creating accessible data distribution systems, ensuring reliability in operational data systems, building dependable data networks, establishing and implementing operational space weather best practices, and developing maintainable operational systems. The 2012 workshop concluded with action items for improving common space weather operations. The success of the first Space Weather Community Operations Workshop in 2011 led to sponsorship of the second workshop by the Amer-

CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge for systematic assessment of ionosphere/thermosphere models: NmF2, hmF2, and vertical drift using ground‐based observations

Objective quantification of model performance based on metrics helps us evaluate the current state of space physics modeling capability, address differences among various modeling approaches, and track model improvements over time. The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) Electrodynamics Thermosphere Ionosphere (ETI) Challenge was initiated in 2009 to assess accuracy of various ionosphere/thermosphere models in reproducing ionosphere and thermosphere parameters. A total of nine events and five physical parameters were selected to compare between model outputs and observations. The nine events included two strong and one moderate geomagnetic storm events from GEM Challenge events and three moderate storms and three quiet periods from the first half of the International Polar Year (IPY) campaign, which lasted for 2 years, from March 2007 to March 2009. The five physical parameters selected were NmF2 and hmF2 from ISRs and LEO satellites such as CHAMP and COSMIC, vertical drifts at Jicamarca, and electron and neutral densities along the track of the CHAMP satellite. For this study, four different metrics and up to 10 models were used. In this paper, we focus on preliminary results of the study using ground‐based measurements, which include NmF2 and hmF2 from Incoherent Scatter Radars (ISRs), and vertical drifts at Jicamarca. The results show that the model performance strongly depends on the type of metrics used, and thus no model is ranked top for all used metrics. The analysis further indicates that performance of the model also varies with latitude and geomagnetic activity level.

Physics and chemistry of the mesopause region

This paper is based on a tutorial presentation given at the 2001 CEDAR (Coupling Energetics and Dynamics of Atmospheric Regions) workshop. It gives an overview of chemical and physical processes important in the mesopause region. Topics covered include composition, photochemistry, dynamics and transport, and energy budget. Special emphasis is placed on the role of variations in composition in linking the physical and chemical processes. Examples from numerical models and observations are given to illustrate the points. Two specific cases where composition plays a role are described. The first illustrates that hemispheric differences in CO 2 due to transport by the mean circulation enhance the mesopause temperature extremes near solstices. The second shows how transport of chemical species by gravity waves can alter the heating structure in such a way as to destabilize the gravity wave.

Candidates for office 2004–2006

Timothy L. Killeen. AGU member since 1981. Director of the National Center for Atmospheric Research (NCAR); Senior Scientist, High Altitude Observatory; Adjunct Professor, University of Michigan. Major areas of interest include space physics and aeronomy remote sensing, and interdisciplinary science education. B.S., Physics and Astronomy (first class honors), 1972, University College London; Ph.D., Atomic and Molecular Physics, 1975, University College London. University of Michigan: Researcher and Professor of Atmospheric, Oceanic, and Space Sciences, 1978–2000; Director of the Space Physics Research Laboratory 1993–1998; Associate Vice‐President for Research, 1997–2000. Visiting senior scientist at NASA Goddard Space Flight Center, 1992. Program Committee, American Association for the Advancement of Science; Council Member, American Meteorological Society; Editor‐in‐Chief, Journal of Atmospheric and Solar‐Terrestrial Physics; Chair, Jerome K.Weisner National Policy Symposium on the Integration of Research and Education, 1999. Authored over 140 publications, 57 in AGU journals. Significant publications include: Interaction of low energy positrons with gaseous atoms and molecules, Atomic Physics, 4, 1975; Energetics and dynamics of the thermosphere, Reviews of Geophysics, 1987; The upper mesosphere and lower thermosphere, AGU Geophysical Monograph, 1995, Excellence in Teaching and Research awards, College of Engineering, University of Michigan; recipient of two NASA Achievement Awards; former chair, NASA Space Physics Subcommittee; former chair, National Science Foundation (NSF) Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) program; former member, NSF Advisory Committee for Geosciences, and chair of NSF's Atmospheric Sciences Subcommittee, 1999–2002; member, NASA Earth Science Enterprise Advisory Committee; member of various National Academy of Science/National Research Council Committees; cochair, American Association for the Advancement of Science National Meeting, 2003. AGU service includes: term as associate editor of Journal of Geophysical Research‐Space Physics; chair, Panel on International Space Station; Global Climate Change Panel; Federal Budget Review Committee; member of AGU Program, Public Information, Awards, and Public Affairs committees; Chapman Conference Convener and Monograph editor; Section Secretary and Program Chair, Space and Planetary Relations Section; President of Space Physics and Aeronomy Section; AGU Council Member.

Solar‐Heliospheric Group “SHINE” Sheds light on murky problems

Like a flashlight beam in muddy water, attention focused on murky science issues scatters a great deal, but reveals broad features of fundamental importance for future progress. The value of this approach was apparent at a recent meeting of the Solar Heliospheric Interplanetary Environment (SHINE) community. SHINE held its third annual workshop this summer simultaneously with those of its sister organizations, Geospace Environment Modeling (GEM) and Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR). All three meetings were held in close proximity and were sponsored by the National Science Foundation.

Effects of a large mesospheric temperature enhancement on the hydroxyl rotational temperature as observed from the ground

The rotational temperature obtained from the rotational population distribution in the bands of the hydroxyl airglow has been shown to be a suitable proxy for the temperature at a height of 87 km [She and Lowe, 1998]. In this paper we examine in detail simultaneous observations on November 2–3, 1997, at Fort Collins, Colorado (41°N, 105°W), with both a sodium temperature lidar and the Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) OH mesospheric temperature mapper during which significant differences between the hydroxyl and lidar temperatures occur. The large differences are associated with a major temperature enhancement in the region of the peak of the hydroxyl emission. We model the effect on the shape of the emission rate profile of the hydroxyl airglow caused by the large temperature enhancement observed on this night by the lidar. As a result of the temperature sensitivity of the processes that give rise to the airglow, the profile shows major distortions from its normal shape. These distortions in turn lead to hydroxyl rotational temperatures that differ significantly from the 87‐km lidar observations. The mean rotational temperature deduced in this way agrees well with the observed values. Such deviations in the temperature are expected to be rare, occurring only when a large temperature enhancement occurs near the peak of the airglow emission profile.

Solar‐heliospheric community supports grass roots organization

A long‐standing gap in grass roots organization activity in the solar‐terrestrial physics field has been filled by SHINE, an acronym for Solar Heliospheric INterplanetary Environment. SHINE complements its well‐established sister organizations, GEM (Geospace Environment Modeling) and CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions).Together these groups reflect the interests of the three subsections of AGU s Space Physics and Aeronomy Section: Solar and Heliospheric Physics, Magnetospheric Physics, and Aeronomy, respectively. SHINE held its first stand‐alone workshop, SHINE 99, in Boulder,Colorado, on June 14–17, simultaneously with the CEDAR workshop in Boulder and one week before the GEM workshop in Snowmass, Colorado. Joint sessions between the three groups were held on June 18 and June 19 in Boulder. Like the GEM and CEDAR workshops, SHINE 99 was sponsored by the National Science Foundation. Support for SHINEs members, however, is broadbased, reflecting the fact that it is a community‐wide organization.

Electrodynamics of midlatitude spread F: 1. Observations of unstable, gravity wave‐induced ionospheric electric fields at tropical latitudes

In part 1 of our series exploring the role of electrical forces in midlatitude spread F, we present observations of an electrodynamically driven traveling ionospheric disturbance which passed over Arecibo Observatory between 22 and 24 AST on January 26, 1993. The total electric potential differences driving the wave were of the order of 1 kV. Our analysis indicates that this disturbance is the result of a midlatitude F region plasma instability seeded by a thermospheric gravity wave. Two novel measurements, in addition to typical incoherent scatter observations, were crucial to this determination: the use of 6300 Å airglow images from the coupling, energetics, and dynamics of atmospheric regions (CEDAR) allsky imager to track the two‐dimensional, mesoseale dynamics of the disturbance and the use of a portable ionosonde to simultaneously measure the fieldline integrated ionospheric conductivity in the conjugate hemisphere. We have also determined that this disturbance, like several previously observed midlatitude disturbances, is consistent with our theoretical knowledge of the basic instability of the midlatitude ionosphere described originally by Perkins [1973].

Upper thermospheric variability over Millstone Hill during the LTCS‐2 and LTCS‐6 Campaigns

We report on winds and temperatures observed in the upper thermosphere over Millstone Hill during the coupling energetics and dynamics of atmospheric regions (CEDAR) Lower Thermosphere Coupling Study 2 (LTCS‐2) and LTCS‐6 campaigns conducted during December 6–11, 1988, and December 4–11, 1991, respectively. Comparable geophysical conditions which prevailed during these periods facilitate their intercomparison and our investigation of interannual and day‐to‐day variability. Our analyses suggest that variability in exospheric temperature is largely characterized by variations in both the diurnal mean and tidal harmonics. While there may be unresolved signatures of geomagnetic effects in these data, the observed variability appears to be correlated with changes in the EUV forcing as represented by the 10.7‐cm solar radio flux. Conversely, variations on shorter (< 6 hours) timescales characterize the day‐to‐day variability observed in the thermospheric winds for the periods. These signatures may be partially attributable to changes in aurorally driven circulation, but our results are not conclusive. Finally, the wind and temperature signatures that we observe confirm that upward propagating semidiurnal tides do not play a preeminent role in the energy and momentum budgets of the middle latitude upper thermosphere during solar maximum winter conditions.

Millstone Hill incoherent scatter F region observations during the disturbances of June 1991

The extreme geomagnetic disturbances of early June 1991 were accompanied by dramatic effects in the Earth's thermosphere and ionosphere which are the subject of coordinated analysis by the Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) Storm Study project. F region observations taken at Millstone Hill over the interval June 5‐11 using a nine‐position experiment allow estimation of spatial gradients in ionospheric parameters above the station. From these gradients the motion term in the F region continuity equation is obtained and combined with calculations of rates of production and loss of the major ions in a semiempirical model of the F region ionosphere above Millstone Hill. Electron densities calculated from this semiempirical model using MSIS‐86 are generally much smaller than the measurements. This discrepancy could be explained by the presence of vibrationally excited N2 combined with a decrease in the atomic oxygen to molecular composition ratio of ≈2 or more on the most disturbed days. Neutral winds calculated by using the incoherent scatter line‐of‐sight ion drifts show a strong equatorward surge during the day on June 5 and strong equatorward surges during all the disturbed nights. Synoptic observations taken from Millstone Hill by using elevation and azimuth scans during the nights of June 12, 13, and 14 illustrate the large‐scale structure of electron density and its relation to neutral winds and electric fields observed over much of eastern North America.

1993 CEDAR Meeting planned

The 1993 Annual Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) meeting will be held from June 21 to June 26, in Boulder, Colo. Both workshops and tutorials will be featured.A Data Analysis School at the National Institute of Standards and Technology (NIST) is being organized by Jeffrey Forbes for June 26. It will emphasize the analysis of time series data with gaps and will give each speaker the same data set to look at the different analysis techniques. Several topics to be discussed are digital signal processing, spectral methods, Fourier techniques, fast Fourier transforms, periodograms, nonstationary time series (such as 2‐day waves), wavelets, and curve fitting.

Semidiurnal tidal climatology of the E region

Theoretical predictions of global monthly and seasonally averaged semidiurnal temperatures and winds between 80 and 150 km are presented and compared with seasonal means from measurements at the Arecibo, Chatanika, Millstone Hill, and Sondrestrom incoherent scatter radars. The model values above 100 km are obtained by utilizing a set of tabulated ‘Hough mode extension’ functions to extrapolate the (2,2), (2,3), (2,4), and (2,5) propagating tidal modes at 100 km from a spectral model (not valid in the E region due to the way molecular dissipation is parameterized) to higher altitudes and by superimposing a component driven by in‐situ excitation (important mainly above 140 km). The monthly simulations demonstrate the close coupling that exists between seasonal and latitudinal structures and argue for an observational program emphasizing adequate seasonal and latitudinal coverage. Despite constraints imposed by the distributions of existing data with respect to month and year, comparisons with the model reveal several trends that appear to be real: (1) the model amplitudes are usually 20–50% smaller than those observed; (2) vertical wavelengths are well‐predicted by the model, but model phases generally lead the observations at middle and low latitudes by approximately 2–3 hours at all heights for both winds and temperatures; (3) semidiurnal temperatures at middle and low latitudes, in both the observations and model, indicate significant seasonal changes in the phase of the temperature oscillation, but not in the winds; and (4) the seasonal trends in the model and observations are consistent, with “summer leading winter” at Millstone Hill, while the reverse is true at Arecibo. The sources of the absolute amplitude and phase discrepancies in the model, which are probably connected with the adopted mean wind and thermal excitation specifications, need to be investigated. In addition, a concerted effort must be made within the Coupling Energetics and Dynamics of Atmospheric Regions (CEDAR) program to better delineate the seasonal‐latitudinal thermal structure and dynamics of the E region, following the example of the extensive F region observational data base which has been accumulated over the last decade.

Foreword and Dedication [to Special Section on Lower Thermosphere Coupling Study (LTCS)

The Lower Thermosphere Coupling Study (LTCS) is a coordinated investigation of the lower thermosphere (90–150 km) combining observational (optical and radar) and numerical modeling efforts with the ultimate goal of better understanding the dynamic and electrodynamic processes coupling the mesosphere, lower thermosphere, and upper thermosphere regions. The study, which is being conducted under the auspices of the National Science Foundation CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions) Program, is intended to address such questions as, What is the relative importance of upward propagating tides, planetary waves, and gravity waves, related accelerations of the mean flow, and heating and momentum sources of magnetospheric origin, in determining neutral dynamical fields and ionospheric structures as a function of height between 90 and 150 km? How do these different spatial and temporal scales of motion interact with each other, and how do they influence the vertical, seasonal‐latitudinal, and diurnal variations in turbulent diffusivity and transport of minor chemical constituents? What are the relative roles of magnetospheric currents and the ionospheric wind dynamo in determining ionospheric electric fields?

CEDAR proposal deadline

The deadline for submitting a proposal for the National Science Foundation's Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) initiative is November 1, 1990. This year, according to the CEDAR steering committee, the deadline is firm!The CEDAR program is a broad‐based community‐initiated program to link the various regions of the upper atmosphere (above about 70 km) in terms of coupling, energetics, and dynamics on regional and global scales.

The lower thermosphere coupling study of the cedar and wits programs

The Lower Thermosphere Coupling Study (LTCS) is a coordinated investigation of the lower thermosphere (80 – 150 km) combining observational (optical and radar) and numerical modelling efforts with the ultimate goal of better understanding the dynamic and electrodynamic processes coupling the mesosphere, lower thermosphere, and upper thermosphere regions. The study, which is being conducted under the auspices of the CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions) and WITS (World Ionosphere and Thermosphere Study) Programs, is intended to address such questions as: What is the relative importance of upward propagating tides, planetary waves, and gravity waves, related accelerations of the mean flow, and heating and momentum sources of magnetospheric origin, in determining neutral dynamical fields and ionospheric structures as a function of height between 90 and 150 km? What are the seasonal-latitudinal and diurnal variations in turbulent diffusivities due to gravity wave saturation, and related implications on the vertical transport of O and NO? What are the relative roles of magnetospheric currents, the E-region wind dynamo, and nighttime conductivities in determining ionospheric electric fields? Emphasis of the study will be placed on neutral winds, temperatures, electric fields, and currents during a series of coordinated measurements campaigns each consisting of a 30-day ‘background’ period and a 4–6 day ‘core period’. The first campaign was conducted during 15 September 1987 – 15 October 1987 with a core period during 21 – 25 September 1987. The scientific basis for the LTCS, its organization, and preliminary results from the 1987 campaign are reviewed in this paper.

CEDAR 88

The third workshop session of the National Science Foundation's Coupling Energetics, and Dynamics of Atmospheric Regions (CEDAR) initiative took place at the National Bureau of Standards and National Center for Atmospheric Research institutions in Boulder, Colo., June 6–10, and was attended by 155 participants, including about 40 graduate students.The CEDAR initiative represents the fruit of many years of efforts by the aeronomy community and NSF to modernize the techniques used to understand the many processes of the upper atmosphere both theoretically and experimentally. Since the beginning of this initiative (under the old name of Ground‐Based Optical Aeronomy) with a summer meeting in Logan, Utah, in 1983, there has been a workshop meeting every summer. The 1988 CEDAR meeting, in particular, reflected the growing maturity of the CEDAR initiative. The meeting was well attended, and, in general, we found fewer participants drawn to the meeting just by curiosity and more who came because they expected the workshop activities would be time well spent.

The CEDAR data base

The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) program is an international cooperative effort within the aeronomy community to further our understanding of Earth's upper atmosphere [Romick et al., 1987]. This program will be high‐lighted by numerous multi‐instrument measurement campaigns, and global simulations of the magnetosphere‐ionosphere‐atmosphere system. The results obtained from these studies promise a great leap forward in our understanding of the physics and chemistry of the atmosphere. To achieve these results, however, will require the ability to access large amounts of data from many different instruments and models.

CEDAR: A us program initiated for scientific achievement in aeronomy emphasizing the role, need and development of modern optical facilities

In early 1983 a campaign was initiated in the U.S.A. to acquire modern optical facilities focusing on the use of imaging detector technology to strengthen our spectroscopic interferometric, imaging and lidar capabilities to solve some of the major aeronomic scientific problems. These scientific problems were addressed by sub-committees for spectroscopic, interferometric, imaging and lidar facilities as well as by the aeronomy modeling and theoretical community. The sub-committees further defined the science and answered the question of how each facility could help solve the posed scientific problems using current capabilities, upgraded systems and new Class I facilities. The individual sub-committee reports are assembled in Volume II of the Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) report. Volume I, synthesized by the Steering Committee, presents a three phase program over the next seven years aimed at the solution of the various CEDAR Science issues as the new facilities are developed. Recently, the CEDAR program expanded to include two additional sub-committee contributions from the radar community (both incoherent scatter, IS, and coherent) covering their roles in addressing the CEDAR Science issues. The solution of major aeronomic scientific problems through the cooperation and coordination of observations using all types of instruments, not exclusively optical, is now the main theme of the CEDAR program. In addition, it is clearly recognized that the global nature of many of the CEDAR Science issues requires the active support and involvement of the worldwide aeronomy scientific community. The scientific challenges are many, and the tasks of coordination and cooperation will be trying. However, the world aeronomy community will be justly rewarded by the resultant strides in understanding of the Coupling, Energetics and Dynamics of the Atmospheric Regions around the globe. This report will provide an overview of the CEDAR program, the types of optical facilities of interest and some of the scientific issues and proposed campaigns resulting from the 28–31 July 1986 CEDAR workshop.