Status of the GOES-R EXIS Instrument

I will describe the ongoing activities at LASP in developing the Extreme Ultraviolet and X-ray Irradiance Suite (EXIS)for the GOES-R series of satellites. With the recent award of the development contract for EXIS to LASP we have made significants progress in the instrument definition, and are presently prototyping various detector and data acquisition/processing systems.

Professor, University of Colorado, Aerospace Engineering Sciences. Director, BioServe Space Technologies

Maintaining Muscle Fitness during Long Duration Space Flight: The Challenge of “Use It or Lose It”

When it comes to our muscles, most people understand the use-it-or-lose-it principle. But what happens when “using” muscle through normal daily activity is difficult or even impossible. Disuse muscle atrophy is a serious problem for many people, including those with nerve or spinal injury, those recovering from surgery or a broken bone and those bedridden due to illness. Muscle wasting from loss of loading is no more evident anywhere than for individuals who journey into space. Without on-orbit exercise, astronauts or cosmonauts would lose up to 30% of their leg muscle volume and 50% of their strength in only 2-3 months. Left unmitigated, such muscular deterioration could become a serious risk to an astronaut’s health and even to the mission being undertaken. On the International Space Station (ISS), loading muscle and bone at a level needed to maintain fitness is difficult to achieve. Thus, astronauts still “lose it” even while working hard with daily exercises designed to “use it”. If humans are to safely go beyond low-Earth orbit, musculoskeletal countermeasures that complement exercise must be developed that would enable a crew to be sufficiently fit to carry out whatever demanding mission tasks might be required. This talk will highlight research involving pharmacological countermeasures that could safely, conveniently and effectively maintain muscle fitness in astronauts living on ISS or journeying into deep space. Clearly such therapeutics would also benefit many people right here on Earth, potentially including those with muscular dystrophy, cancer cachexia, and various disuse conditions.

The MASS/ECOMA rocket campaign into the polar summer mesosphere

The MASS (Mesospheric Aerosol Sampling Spectrometer) rocket campaign was conducted from the Andoya Rocket Range, Norway, the first week of August 2007 coincident with the German-Norwegian ECOMA rocket campaign. The first of two rockets was launched into NLC on 3 August approximately 26 minutes after an AIM overpass. The rockets carried electrostatic mass analyzers for the charged fraction of the aerosol particles in noctilucent clouds (NLC). The mass analyzer was mounted on the tip of the payload and pointed in the ram direction. Air enters the instrument through a forward slit and exits through side windows. Aerosol particles with different ranges of charge-to-mass ratio are collected within the instrument housing on two sets of four biased collector plates, with one set for positive particles and one set for negative particles. Extensive numerical modeling was done to optimize the design. NLC were observed through scattered low clouds at 83 km by the ALOMAR RMR lidar pointed along the rocket trajectory. The data show the density of negatively charged particles with radius greater than 3 nm rising sharply at 83 km and continuing to 89 km, collocated with PMSE (Polar Mesosphere Summer Echo) detected by the ALWIN radar. Particles with 1-2 nm radii with both signs of charge and positive particles with less than 1 nm radius were detected at 86-88 km. The relative number of positive particles is much larger than can be explained by standard charging models. The second rocket was launched into PMSE without NLC on 6 August and fewer particles with radius > 3 nm were observed.

Incoming Solar Radiation at Top of the Atmosphere - Measurements and Modelin

Abstract:While assessing various radiation data sets and also the model results for the IPCC-4AR, we found discrepancies in results describing the total amount and its distribution over the entire Earth of the incoming solar radiation at the Top of the Atmosphere (TOA). Some sensitivity studies with climate models have shown that such inconsistencies may affect the computed fields of the atmospheric circulation.

In this seminar several examples will be discussed. We recommend that models and climate data sets on the radiation budget should use the same procedure (and required input on the Earth's orbital parameters) to compute the incoming solar radiation at TOA.

Observing, interpreting, and Using the H-Alpha Chromosphere

Abstract:
Observation: I will summarize the two solar telescopes on La Palma in the Canary Islands, the Dutch Open Telescope and the Swedish 1-m Solar Telescope. They both target the solar chromosphere but differ intrinsically in all other aspects. Movies taken in Halpha with these telescopes illustrate the chromospheric scene and issues.

Interpretation: I will compare Halpha formation between standard solar-atmosphere modeling and a recent numerical MHD simulation.

Usage: I will review recent efforts to determine coronal field topology from photospheric magnetograms including Halpha as chromospheric constraint. This is likely the way to go in solar outburst forecasting.

‘Solar Spectral Variability as measured by the SORCE SIM Instrument’

Abstract:The SORCE mission was launch in January of 2003 during the descending phase of Solar Cycle 23 that includes the current solar minimum. The accumulated data from the SIM instrument represents the first time series that has sufficient precision and stability to discern solar cycle length trends in spectral variability in the visible and infrared portions of the spectrum. The detection of these trends relies on very sensitive degradation correction methods that were incorporated in the instrument design. The presence and evolution of active regions on the solar surface impart spectral signatures that are consistent with observations of total solar irradiance (TSI) and with SRPM modeling of these solar features. However, the long-term trends in solar network features present a difficult challenge for image analysis and consequently for the modeling as well. Because of this, the SIM spectral observations provide a valuable set of constraints for improving the models. On longer time scales, the SIM data shows that at some visible and IR wavelengths the trends are out of phase with those observed in TSI. These trends depend on which depth in the solar atmosphere the radiation is emitted from; the out of phase trends predominantly originate from deep photospheric contributions, whereas the wavelengths that are in phase with TSI originate from the top of the photosphere and the chromosphere. Thus the TSI represents a very delicate balance of offsetting spectral trends. Efforts are now underway to show how these differential trends in solar spectral variability might affect heating rates in the Earth’s atmosphere and some simple modeling examples on this topic will be presented.

Selected topics in cosmic dust research

ABSTRACT: he talk will be an overview of the interdisciplinary field of dust research starting with fundamentals of dusty plasmas through the interaction of cosmic dust with the upper atmosphere, the dusty surface of the Moon and ending with the recent discovery of interstellar dust within the solar system. Dust particles immersed in plasmas will acquire charge and introduce a variety of new phenomena, including dust acoustic waves and the formation of crystal-like structures. The upper atmosphere is the place where incoming meteoritic dust particle ablate and re-condense back to nanometer size smoke particles. These particles provide the seed for the nucleation of water ice in the summertime polar mesosphere that is exhibited as visible noctilucent clouds or as a layer with strong radar backscatter. On the Moon, there are several in-situ and remote sensing observations that indicate that dusty plasma processes are likely to be responsible for the mobilization and transport of lunar soil. These observations remain largely unresolved up today. In 1992 the dust detector on the Ulysses spacecraft identified interstellar dust passing through the solar system. A new and exciting opportunity is now open to directly sample these fundamental building blocks of the Universe.

ABSTRACT : Scientific progress begins often when a researcher finds a small piece of evidence which does not fit in an established view. Several examples are given on the basis of my own experiences from my graduate student days. In this spirit, I examine several established views on auroral phenomena, sunspots, solar flares, the reversal of the earth's magnetic field, the magnetic field of pulsars, etc.

Geology of Martian Sedimentary Deposits and Paleolakes: A Tool to Study the History of Water on the Red Planet

Abstract: Martian climatic history could have been more complex, locally variable and episodic than expected. Simplistic extrapolations from climatic models and scattered mineralogical observations are likely not adequate to reconstruct the overall hydrological evolution of Mars. Therefore, only detailed geological works and correlations across diverse areas can help to constrain the relationships between the coupled climatic and morphological evolutions of the planet. For instance, delta-like deposits, wave-cut terraces, and shorelines are fundamental features to support the hypothesis of standing and long-lived water bodies on Mars. Lakes, due to their relatively limited size and strong climatic coupling, might allow reconstruction of local hydrological cycles and help to better understand the Martian climatic evolution. Our recent works show that current data availability enable detailed analysis of complex lacustrine systems. I will present examples of such investigations and discuss their paleohydrological implications.

LASP Conference Room D-142
Duane Physics Building

1:00 PM

Refreshments Served at 12:45 PM

The SOLSTICE Science Sampler

Abstract:
The SOLar-STellar Irradiance Comparision experiment (SOLSTICE) on the SOlar Radiation and Climate Experiment (SORCE) is an extremely versatile instrument. The primary mission of SOLSTICE is to observe the solar spectral irradiance. With its unique ability to also observe faint targets, we can measure the irradiance from bright stars, comets, and the Moon. We can also observe the Earth's atmosphere through airglow and stellar occultations. This talk will highlight the lunar irradiance measurements. SOLSTICE has the unique ability to measure the ratio of solar to lunar irradiance with the same instrument, thus removing calibration uncertainties from the determination of the lunar ultraviolet albedo. SOLSTICE is continuing to make repeat observations of the Moon at all phase angles and wavelengths in its spectral band, yielding a dataset of very good signal-to-noise that can be used by other missions for calibration as well as providing basic information about the lunar surface properties.

LSTB

299

Time: 4:00

(refreshments  @ 3:45)

The Solar Corona: New insights from spectroscopic observations

ABSTRACT: The solar corona is best observed in the spectral range from soft X-rays to vacuum-UV, where the emission of highly ionized species can be used to probe the million degree plasma. The SUMER instrument on SoHO is a high-resolution spectrometer which can observe the solar corona off-limb out to 1.5 solar radii. The wavelength range from 500 to 1600 A is ideal for unocculted observations of the lower corona, since it covers a huge temperature range from 3.500 K to 20 MK.

New observational results obtained from off-disk studies will be presented, focussing on polar plumes, where new insights on the physical properties has been found. The other focus will be the energy release during the impulsive phase of nano-flares, where observational details seem to be in conflict with standard models.