> **[Report of Steering Committee for the TR&T Program of
> LWS]{.underline}**
>
> Spiro Antiochos (Chair), Janet Barth, Sunanda Basu, Geoff Crowley,
> John Eddy, Lennard Fisk, Joe Giacalone, Mary Hudson, Neal Hulburt,
> Charles Jackman, Boon-Chye Low, Jimmy Raeder, Pete Riley
>
> April 16, 2004
>
> The TR&T Steering Committee (TSC) held its first meeting on March 30 -
> 31, 2004. All members were in attendance, as well as representatives
> from NASA HQ including the LWS Program Officer, Lika Guhathakurta, and
> the TR&T Project Scientist, David Sibeck. As a result of its
> deliberations the TSC reached the following conclusions:
>
> **Overall Program Structure**:

-   The TSC reviewed the needs of the TR&T program and endorsed the
    three program element strategy defined by the SDT, *targeted
    investigations, strategic capabilities,* and *cross-discipline
    infrastructure building programs*.

-   The TSC devoted the bulk of the meeting to developing an innovative
    implementation plan for the *targeted investigations* element and to
    determining possible strategies for the *cross-discipline programs*.
    Given the time constraint on preparing the amendment to this year's
    NRA, and given the uncertainty in the funding, the TSC concluded
    that it would be prudent to postpone implementation of the
    *strategic capabilities* element until next year's NRA. The TSC will
    develop a concrete implementation plan for this element during the
    coming year.

> **Targeted Investigations:**

-   The TSC recommends restructuring the *targeted investigations*
    program element into three components that are described below:
    *focused science targets*, *tools and methods*, and *independent
    investigations*. Approximately 75% of the resources within the
    *targeted* program element would be allocated to the *focused
    science targets*, 10% for *tools and methods* and 15% for
    *independent investigations*.

-   The *tools and methods* component would support studies which, by
    themselves, may not deliver significant new science understanding,
    but deliver instead tools/methods that enable critically needed
    science advances. Examples include the development of new empirical
    methods or analysis techniques, such as local helioseismology, that
    can be used to predict the occurrence of solar, interplanetary, and
    geospace activity, and the development of software tools that
    identify, retrieve, assimilate, or portray data and model results
    from different sources for LWS forecasting and research objectives.

-   The *independent investigations* component would support
    exceptionally high-priority studies that are not appropriate for
    either the *focused science targets* or *tools and methods*
    components. Simply failing to fit into the other two components does
    **not** make a project suitable for the *independent investigations*
    component. Among the criteria that will be used to determine whether
    a proposed study should be supported by this component are
    **urgency** and **impact**. Examples include studies that are
    urgently needed in preparation for the imminent launch of a new
    mission that supports LWS science and goals, or investigations that
    would have high impact on operational capabilities or government
    policy decisions.

-   The TSC defined a new implementation strategy for the *focused
    science targets* component; therefore, we describe this
    implementation and its motivation in some detail in the section
    below.

> **Implementation Plan for *Focused Science Targets* Component**:
>
> The stated goal of LWS, achieving Sun-Earth system understanding that
> has direct impact on life and society, poses two great challenges for
> the TR&T program. First, the TR&T must tackle large-scale problems
> that cross discipline and technique (data analysis, theory, modeling,
> etc) boundaries. Second, the TR&T must identify how the new
> understanding will have a direct impact on life and society.
>
> To address these requirements, the TR&T SDT recommended that the TR&T
> program be focused on major science targets at each proposal cycle.
> The TSC not only reaffirms this recommendation, but also emphasizes
> that the program must be structured so that the proposed TR&T
> investigations can be coordinated into a coherent attack on the
> large-scale science targets. Furthermore, maximizing the impact of the
> TR&T science advances on life and society will invariably require
> integration of the results of all the investigations aimed at a
> particular target. Therefore the TSC recommends the following
> implementation plan for the TR&T targeted investigations.

-   At the start of each funding cycle a set of *focused science
    targets* will be recommended to NASA by the TSC. For this first year
    of the implementation plan, the targets will be defined by the TSC,
    but for subsequent years, target recommendations will be solicited
    from the community and a set of these will be selected by the TSC
    for forwarding to NASA. The *focused science targets* recommended by
    the TSC for this year are attached below.

-   Individuals or small groups will propose to work on some aspect of
    the science targets. The scope of the investigations is expected to
    be similar to that of previous funding cycles. A key difference from
    the previous cycles, however, is that the peer review panels will be
    organized according to the *focused science targets*. The selection
    criteria will be scientific and technical merit, as before, but
    relevance to the *target* will be essential for selection.

-   It is expected that of order 5 -10 selections will be made for each
    *focused science target*. Once selected, these investigators will
    form a team and coordinate their research programs, much like the
    winning PIs and instruments of a NASA hardware mission form a
    coordinated science team and program. The team will define a plan
    for structuring their work into an integrated research program that
    will address the complete *focused science target*. The team will
    also define success measures and deliverables for their integrated
    program, develop strategies for disseminating their results to the
    science community and NASA, and prepare a final report at the end of
    the three-year duration of the selected investigations.

-   As part of the peer-review process, one of the winning PIs will be
    selected to be team coordinator for that *focused science targets*.
    The team coordinator will take the lead role in organizing the team,
    setting up the necessary team meetings and interactions, and
    delivering the success of the project as a whole. The coordinator
    will also act as the lead liaison with the TR&T project office,
    which will monitor and assist the progress of each team. The team
    coordinator will receive supplemental funding to support costs
    associated with these duties, of order \$30K. Proposers are
    encouraged to volunteer to act as team coordinator and to include a
    brief section in their proposal describing how they would lead the
    team effort.

> The advantages of this implementation plan are clear. Substantial
> teams can be formed to attack the large-scale, cross-discipline
> problems that are vital to LWS. These teams will have a broad range of
> expertise and will naturally be cross-disciplinary. Formation of the
> science team **after** the peer-review process ensures that the best
> investigations from throughout the community are selected to
> constitute the team. The TSC strongly believes that implementation of
> this plan will lead not only to major science advances, but to the
> development of a truly Sun-Earth-system science community.
>
> **Cross-Discipline Infrastructure Building Programs:**

-   The TSC recommends that approximately 15% of the annual TR&T funding
    be allocated to the *cross-discipline programs* element. Requests
    for funding from this element should be openly competed through
    peer-reviewed proposals as much as possible. The TSC recommends,
    however, that some funds be held for supporting, at NASA HQ's
    discretion, small requests that may arise occasionally for
    cross-discipline workshops/campaigns.

-   The TSC recommends that the community be encouraged to propose
    summer schools that would be funded, in part, by the TR&T. LWS needs
    researchers who can perform Sun-Earth system science, but few
    universities have depth across all the disciplines of SEC. Summer
    schools with lecturers from various institutions (including
    non-university organizations) would be an effective mechanism for
    training graduate students in Sun-Earth system science. The
    particulars of the summer school: format, location, duration, etc.,
    would be up to the community to define in the proposal to the TR&T.

-   The TSC also recommends the creation of an LWS Post-Doctoral
    program. The program would support a new Post-Doc, within three
    years of PhD, for up to two years. This program would be run much
    like the NRC post-doctoral programs, with the student and
    prospective advisor submitting a brief (no more than five page)
    proposal that describes in three clearly identified sections: **(1)
    the proposed research, (2) the cross-discipline aspects of the
    project, and (3) the relevance to LWS**. The requested funding would
    be only for support of the Post-Doc. The TR&T expects to award
    approximately two LWS Post-Docs per year.

-   The issue of an LWS community science center(s) was discussed, but
    lacking a concrete description of the role and cost of such a
    center, no decision was reached. The TSC will take up this issue
    again at the next meeting, and will invite presentations from
    interested institutions.

**[FOCUSED SCIENCE TARGETS FOR FY05]{.underline}**

TR&T Steering Committee, April 16, 2004

**Quantify the sensitivity of regional and global climate to solar
forcing in the full context of the interactive climate system.**

**Target description**: A critical parameter in climate attribution is
the inherent sensitivity of climate to any change in the receipt of
solar energy at the top of the Earth\'s atmosphere (customarily
expressed as the response in mean surface temperature to given change in
forcing, S= δT/δF). First order approximations of S for the case of
simple solar radiative forcing, acting alone, are unable to explain the
apparent observed responses in in the temperature of surface ocean and
lower atmosphere. What is clearly needed to resolve the apparent
discrepancies and to answer the more fundamental question of the
relative role of the Sun in past or present climate change are intensive
investigations of the likely-nonlinear interactions in the climate
system that couple solar forcing with other internal and external
climate drivers, including atmosphere-ocean oscillations such as ENSO
and NAO, and changes in greenhouse gases, aerosols, and volcanism.

**Goals and measures of success**: Success in this endeavor will be
measured by the ability of climate models to specify global and
regionally-specific impacts of interactive solar and other external and
internal forcing of the coupled climate system, and the abililty of
solar-coupled-climate models to replicate global and regional climatic
records.

**Types of investigations**: A focused, coordinated study to addresses
this science high visibility target will require collaboration between
solar and climatological data and modeling communities, and
contributions from all of the following elements: (1) Specification and
recovery of established changes in total and spectral irradiance and
other energetically-significant inputs from the Sun; (2) Multivariate
analyses of empirical climatic data, as a function of geographic region,
height in the atmosphere, and the phase and amplitudes and combined
impacts of other climate drivers; and (3) Theoretical modeling of
responses of the coupled climate system for comparison and validation.

**Quantify the influence of the upper atmosphere on the lower atmosphere
over a solar cycle.**

**Target description**: The impact of the upper atmosphere
(thermosphere, ionosphere, mesosphere) on the lower atmosphere
(stratosphere, troposphere) is very difficult to quantify over an
11-year solar cycle. The upper atmosphere is continuously being
perturbed by solar output including X-rays, extreme ultraviolet light,
and charged particles, which cause changes over several different
timescales from minutes (solar and geomagnetic storm periods) up to
seasonal and longer variations. The upper atmosphere is also impacted in
several ways by the lower atmosphere (e.g., the upward propagation of
atmospheric waves redistributing energy and momentum from below and the
upward transport of certain minor constituents like H2O, CO2, CH4, etc.
from below). Conversely, the more dense lower atmosphere may also be
influenced by the tenuous upper atmosphere. Although there may be other
ways, the most plausible upper atmospheric influence on the lower
atmospheric levels occurs during polar night, when very significant
downward transport of upper atmospheric constituents is likely. Several
past data analysis and modeling studies suggest that the upper
atmosphere does impact the lower atmosphere in this way. The magnitude
of this effect is somewhat controversial with certain studies indicating
a significant impact on the lower atmosphere (primarily, the
stratosphere) from upper atmospheric variations and others indicating a
much smaller impact.

**Goals and measures of success**: This focus area has as its goal the
development of usable models that determine quantitatively the impact of
the upper atmosphere on the lower atmosphere over a solar cycle. These
models need to be validated quantitatively using observations from
satellite instruments observing the atmosphere, especially the
mesosphere and stratosphere where the coupling is thought to be the
largest. The new models are to provide the understanding that is
necessary for the development of a predictive capability for the dynamic
Sun-Earth system. This should allow further clarification of the effects
of solar variability on the atmosphere and climate.

**Types of investigations**: It is expected that the focus group will
include, but certainly not be limited to, the following types of
investigations: the analysis and interpretation of upper and lower
atmospheric observations particularly related to their coupling; the
development of theories for the fundamental processes that control the
source of upper atmospheric constituents that may impact the lower
atmosphere and the transport these constituents to the lower atmosphere;
the study of other processes that show upper atmospheric impacts on the
lower atmosphere; and the development of numerical models that
incorporate the relevant physical processes and that can be tested with
the observations.

**Quantify the response of thermospheric density and composition**

**to solar and high latitude forcing.**

# Target description: Thermospheric density variations exist on the global and local scale. These fluctuations create variable satellite drag, adversely affecting our ability to identify and track objects in space, and to predict or control their re-entry into the atmosphere. Underlying the neutral density variations are global and local composition changes that produce dramatic effects on ionospheric electron densities. Both the composition and density changes are produced by wind systems driven from high latitude heat and momentum sources. We are currently unable to simulate accurately the behavior of thermospheric density and composition, and the dynamics driving them. Much of the uncertainty in existing global first-principles thermosphere models is due to uncertainty in specifying high-latitude particle precipitation and electric fields, and the inputs of solar fluxes at a range of wavelengths. There is an urgent need to improve thermosphere-ionosphere models, including improved specification of solar and high latitude forcings, in order to understand and quantify the thermospheric density and composition responses.

**Goals and**

# measures of success: The research will produce improved first principles thermosphere-ionosphere models, and their input specifications, that will specify thermospheric density and composition, and their variability with latitude, longitude, local time, solar flux, season, magnetic activity level, and changes in the IMF. The predictions will be validated against both empirical models and data. The research will also produce improved ability to specify solar radiative and high latitude inputs for first principles models. Progress will result in an ability to quantify thermospheric density and composition variations, and to accurately simulate observed responses to high latitude and solar variability.

# Types of investigations: It is expected that the focus group will include investigations that deal with: techniques to improve specification of solar radiative inputs to the T-I system; techniques to improve the specification of high latitude inputs for global first principles thermosphere-ionosphere models; energy transfer from the magnetosphere to the T-I system; thermosphere-ionosphere coupling; neutral wind responses; fundamental understanding of processes driving thermospheric density and composition; improved numerical models of these thermospheric fields; validation of the resulting thermospheric simulations by comparison with related data sets.

## 

## 

## 

## 

## 

## 

## 

## Quantify the effects of ionospheric electrodynamics on plasma structuring at middle and low latitudes. 

# Target description: The middle and low latitude ionosphere are constantly changing, controlled both by processes that are driven internally within the ionosphere-thermosphere system and others that are imposed externally by the solar wind-magnetosphere interaction. One of the main drivers is the electric field, which strongly controls the magnitude and altitude distribution of electron density. The day-to-day variability of the internally driven dynamo electric field is most pronounced in the equatorial region resulting in extreme variations of the F-region density distribution. At night such variability is associated with presence or absence of ionospheric irregularities of electron density and scintillation of satellite signals that greatly impact space weather and space climate. During magnetic storms, the penetration of high latitude electric fields, and coupling with the equatorial region cause plumes of enhanced ionization density to form at mid-latitudes that convect very rapidly towards high latitudes. The convecting plumes, associated with plasma density irregularities, severely impact communication and navigation systems within the continental United States. The changed neutral wind patterns resulting from energy deposition at high latitudes during magnetic storms also affect the ionization distribution, neutral composition and dynamics. Current models are unable to reproduce the observed large and small scale ionospheric variability during magnetically quiet and active periods. 

**Goals and measures of success:** This focus area has as its goal the
development of coupled models that determine quantitatively the impact
of electric fields and neutral winds on the ionospheric plasma density,
composition and dynamics during magnetically quiet and active periods.
The models should include the self-consistent coupling of
magnetospherically driven penetration electric fields into low
latitudes. The models should specify and predict the effects of the
internal and external forces and their variability with solar flux;
changes in the solar wind density, velocity and IMF; magnetic activity
level; latitude, longitude, local time, and season. In addition, such
models should have the capability to specify conditions conducive to the
generation of sub-km plasma density structures at middle and low
latitudes.

**Types of investigations:** It is expected that the focus group will
include, but not be limited to, the following types of investigations:
the analysis and interpretation of solar wind-magnetosphere coupling;
energy transfer from magnetosphere to ionosphere-thermosphere system;
electric field penetration and disturbance dynamo processes;
measurements of spatial and temporal variations of neutral and plasma
parameters and their dynamics including small scale irregularity
generation and scintillation effects of satellite signals; the
development of coupled models that incorporate the relevant physical
processes and that can be validated against related datasets.

**Develop solar cycle dependent specification models of the energetic
particle distribution\[s\] in the Earth\'s radiation belts in the tens
of eV to GeV energy range. The models can be used as empirical tools for
mission planning, spacecraft design, and validation of physics-based
models of the radiation belts.**

**Target description**: Current specification models of the Earth\'s
radiation belts (AE-8 and AP-8) predict the trapped radiation
environment over long-term averages (6-years for solar maximum and 5
years for solar minimum), and they are based on instrument data that
were collected in the 1970s and 1980s. The poor representation of solar
cycle variations and the inaccuracies in the AE-8 and AP-8 models impose
large margins on system designs and mission planning in order to reduce
risks. The current models hamper efforts to reduce health risks to
astronaut during extra-vehicular activities (EVAs) and transits through
the radiation belts, limit the use of radiation-sensitive breakthrough
technologies, and prevent the deployment of missions into regions of the
radiation belts not previously exploited. New data from more recent
science and operational missions can be incorporated into improved
specification models for the radiation belts that also take advantage of
recent progress in understanding particle loss and acceleration
processes and the effects of solar storms.

**Goals and measures of success**: This focus area has as its goal
time-dependent specification models of the Earth\'s trapped particles in
the 10s of eV to GeV energy range. The models will be candidates for
standardization for use in NASA, DoD, and industry programs.

**Types of investigations**: In the past five years, NASA and the DoD
have funded several small projects to acquire, calibrate, and analyze
trapped particle measurements from science and operational missions and
to develop prototype models of various regions of the radiation belts.
In addition, recent successes in understanding particle loss and
acceleration and the effects of solar storms on the radiation belts will
be essential to explain measurements and infuse physics-based knowledge
into the models.

It is expected that the focus group will include but not be limited to
these efforts.

**Determine the mechanisms responsible for the formation and loss of new
radiation belts in the slot region in response to geo-effective solar
wind structures.**

**Target description**: The prompt trapping of Solar Energetic Particles
(SEPs) in the inner magnetosphere slot region around L=2-3, including
protons and heavier ions, is observed upon arrival of fast ICMEs.
Detrapping is also observed in this region in conjunction with ring
current buildup during major geomagnetic storms (Dst \< -300 nT),
typically driven by the same type of geoeffective solar wind structures.
Relativistic electrons fill the slot region during such events with a
typical delay of a day or two following shock arrival for storms driven
by ICMEs. While SEP events and their geoeffective trapping and loss
occur with greater frequency around solar maximum, relativistic electron
fluxes on average are greater during the declining phase of the solar
cycle, when geomagnetic storms are driven primarily by high speed solar
wind stream interaction with the magnetosphere.

**Goals and measures of success**: This focus area has as its goal the
development of usable models that determines quantitatively, and can be
validated quantitatively, the dynamic evolution of the radiation belt
slot region and adjacent outer zone flux peak around L=4.

Such models must include losses as well as injection rates, and use
particle flux measurements at geosynchronous and other orbits (HEO and
LEO loss-cone measurements) which provide input on radial distribution
of fluxes. Measurements of input solar wind conditions are essential
both for MHD and empirical models of the magnetospheric response to
solar wind driving conditions. Input solar wind and plasma sheet
particle measurements further constrain model calculations of evolving
particle phase space density.

**Types of investigations**: It is expected that the focus group will
include, but not be limited to, the following types of investigations:
the analysis and interpretation of measured solar wind parameters,
including the variables needed as specification to MHD simulations
(solar wind density, velocity, IMF) and magnetospheric observations,
both in the ULF and VLF frequency ranges; particle measurements both in
the solar wind for ions, the inner plasma sheet for electrons and at
geosynchronous for both, as well as in the L=2-3 slot region and the
region around the plasmapause (L \~ 4), for validation of modeling both
ICME injection and diffusive processes; the development of numerical
models that incorporate the relevant physical processes and that can be
tested with the observations.

**Relate solar-energetic particles to their origin at the sun and inner
heliosphere.**

**Target description:** Understanding high-energy radiation in the form
of cosmic rays is central to space weather and space climate.
Solar-energetic particles observed at Earth are accelerated near the Sun
and in the inner heliosphere. However, direct comparisons between
observations, models, and theories have been unimpressive. It is now
clear that in order to make progress in understanding the solar
radiation environment near Earth, a cross-disciplinary approach is
needed. It is necessary to combine studies of energetic-particle
acceleration and propagation, CME eruption and evolution in the
heliosphere, and coronal and heliospheric magnetic fields.

**Goals and measures of success:** The goal of this focus group is to
have usable, quantitative, models of solar-energetic particles
accelerated near the Sun by realistic CMEs, and which propagate in
realistic coronal and heliospheric magnetic fields, in the heliosphere.
Another goal of this focus group is to identify the particle sources and
to assess their relative contributions to intensities observed at 1 AU.

**Types of investigations:** We encourage proposals that relate
solar-energetic particles to their origin at the Sun and inner
heliosphere, and to characterize their variability at L1. Proposals
involving numerical models should emphasize combining particle
acceleration and transport with realistic, three-dimensional CME
structure, and coronal and heliospheric magnetic fields. They should
also emphasize comparisons with observations, including various particle
species, including ultra-heavy ions (trans Ni) which cause system
damage. Theoretically based proposals should target aspects of this
problem which lead to basic scientific understanding of the necessary
coupling described above. They are also important for providing feedback
to modelers regarding the importance of necessary assumptions. Proposals
involving spacecraft observations should make specific constraints for
numerical and analytic models. These include: (a) what is the time scale
for accelerating particles? (b) where does the acceleration take place?
(c) what are the observed particle distributions? (d) what is the
variability at L1?

Determine the topology and evolution of the open magnetic field of the
Sun connecting the photosphere through the corona to the heliosphere.

**Target description**: The open magnetic flux of the Sun, which creates
the heliospheric magnetic field, is in dynamic evolution, driven by
processes occurring in the photosphere and corona. The resulting
distribution of magnetic flux and its evolution are a fundamental
property of the Sun, essential for understanding the coupling of the Sun
and the heliosphere, the propagation of Coronal Mass Ejections,
acceleration of energetic particles, etc. Current models for the
distribution and evolution of open flux have not captured the dynamic
evolution or the complexity of the open flux.

**Goals and measures of success:** This focus area has as its goal the
development of useable models that determine quantitatively, and can be
validated quantitatively, the dynamic evolution and complexity of the
open magnetic flux of the Sun from input of the type of observations
expected from LWS missions. The new models are to provide the
understanding that is necessary for the development of a predictive
capability for the dynamic Sun-heliosphere system.

**Types of investigations:** It is expected that the focus group will
include, but certainly not limited to, the following types of
investigations: the analysis and interpretation of solar and/or
heliospheric observations, the development of theories for the
fundamental processes that control the evolution of open and
heliospheric flux, the development of numerical models that incorporate
the relevant physical processes and that can be tested with the
observations.

**Determine the solar origins of the plasma and magnetic flux observed
in an Interplanetary Coronal Mass Ejection.**

**Target description**: Interplanetary Coronal Mass Ejections (ICME) are
the primary drivers of the most destructive forms of space weather, such
as energetic particle events and major geomagnetic storms and,
therefore, are of great interest to NASA's human exploration and LWS
programs. In order to develop the capability of nowcasting and
forecasting ICMEs at 1 AU, it is essential that we develop an
understanding of how their measured physical properties, such as speed,
magnetic field strength and direction, are related to the observed
properties of their onset at the Sun. Extensive observations of solar
CMEs are presently available from a variety of instruments, such as
magnetographs, white light and XUV imaging telescopes, and coronagraphs.
Detailed in situ measurements of ICME particles and fields at L1 and
other locations in the heliosphere are also available. Furthermore,
large-scale numerical models for CME development and propagation are now
in use. Consequently, it is timely to mount a focused attack on this
problem of determining ICME properties from CME observations.

**Goals and measures of success:** The goal of this focused science
target is to advance our understanding of the relation between the
physical properties of ICMEs and CMEs. The prime measure of success for
this work would be a quantitative improvement in our ability to predict
the geo-effective properties of ICMEs at Earth from solar/heliospheric
observations. However, the development of models/understanding that
directly enable such an improvement in capability would also constitute
a measure of success for this target.

**Types of investigations:** It is expected that the focus group will
include, but certainly not be limited to, the following types of
investigations: the analysis and interpretation of solar and/or
heliospheric observations, the development of theoretical, empirical and
numerical models for the initiation and evolution of a CME as it
propagates through the corona and heliosphere.

**Develop and validate local helioseismology techniques for forecasting
solar activity.**

Target description: Long-duration missions to the moon and beyond will
be highly dependent on our ability to make predictions of solar activity
on timescales of weeks to months. The only means available for such
forecasting relies on helioseismic techniques.

Goals and measures of success: We seek projects that can bring these
techniques to the point where they could be delivered to the CCMC for
transition to operations.

Types of investigations: We anticipate that this will entail
investigations into local helioseismology techniques and their
optimization; artificial datasets based on models; and cross-comparisons
with other observables and alternative inversion techniques.