NASA Scientific and Technical Aerospace Reports

46
GEOPHYSICS
Includes Earth structure and dynamics, aeronomy; upper and lower atmosphere studies; ionospheric and magnetospheric physics; and
geomagnetism. For related information see 47 Meteorology and Climatology; and 93 Space Radiation.
20040111131 California Univ., Lawrence Berkeley National Lab., Berkeley, CA, USA
Estimating Large-Scale Fractured Rock Properties from Radon Data Collected in a Ventilated Tunnel
Unger, A.; Finsterle, S.; Bodvarsson, G. S.; 2003; In English
Report No.(s): DE2004-822801; No Copyright; Avail: National Technical Information Service (NTIS)
To address regulatory issues regarding worker safety, radon gas concentrations have been monitored as part of the
operation of a deep tunnel excavated from a highly fractured tuff formation. The objective of this study was to examine the
potential use of the radon data to estimate large-scale formation properties of fractured rock. An ITOUGH2 model was
developed to predict radon concentrations for prescribed ventilation rates. The numerical model was used (1) to estimate the
permeability and porosity of the fractured formation at the length scale of the tunnel and extending tens of meters into the
surrounding rock, and (2) to understand the mechanism leading to radon concentrations that potentially exceed the regulatory
limit.
NTIS
Rocks; Petrology; Igneous Rocks
20040111393 Harvard Univ., MA, USA
Global 3-D Modeling Studies Of Tropospheric Ozone And Related Gases
Jacob, Daniel J.; Logan, Jennifer A.; [2003]; 10 pp.; In English
Contract(s)/Grant(s): NAG1-2307; No Copyright; Avail: CASI; A02, Hardcopy
Our research was targeted at three issues: (1) the factors controlling ozone in the tropical troposphere, (2) the Asian
outflow of ozone and its precursors, and (3) the causes of decadal trends observed in ozone and CO. We have also used support
from this ACMAP grant to (1) work with Kelly Chance on the retrieval and interpretation of HCHO and NO2 observations
from GOME, and (2) develop GEOS-CHEM into a versatile model supporting the work of a large number of users including
outside Harvard. ACMAP has provided the core support for GEOS-CHEM development. Applications of the GEOS-CHEM
model with primary support from ACMAP are discussed below. A list of publications resulting from this grant is given at the
end of the report.
Derived from text
Ozone; Three Dimensional Models; Troposphere; Atmospheric Chemistry; Gases
20040111397 NASA Glenn Research Center, Cleveland, OH, USA
Paschen Considerations for High Altitude Airships
Ferguson, D. C.; Hillard, G. B.; [2004]; 4 pp.; In English; 42nd AIAAAerospace Sciences Meeting and Exhibit, 5-8 Jan. 2004,
Reno, NV, USA; No Copyright; Avail: CASI; A01, Hardcopy
Recently, there have been several proposals submitted to funding agencies for long-lived high altitude (about 70,000 feet)
airships for communications, surveillance, etc. In order for these airships to remain at altitude, high power, high efficiency,
lightweight solar arrays must be used, and high efficiency power management and distribution systems must be employed. The
needs for high power and high efficiency imply high voltage systems. However, the air pressure at these extreme altitudes is
such that electrical power systems will be near the Paschen discharge minimum over a wide range of electrode separations.
In this paper, preliminary calculations are made for acceptable high voltage design practices under ambient, hydrogen and
helium gas atmospheres.
Derived from text
Electromagnetic Spectra; Paschen Series; High Voltages; Solar Arrays; Atmospheric Pressure; Gas Pressure
20040111410
Correction to ‘Asian chemical Outflow to the Pacific in Spring: Origins, Pathways, and Budgets’ by Isabelle Bey et al.
Bey, Isabelle; Jacob, Daniel J.; Logan, Jennifer A.; Yantosca, Robert M.; Journal of Geophysical Research; March 11, 2003;
ISSN 0148-0227; Volume 108, No. D5, pp. 2-1 - 2-27; In English; Original contains color illustrations
Contract(s)/Grant(s): NAG1-2307; Copyright; Avail: Other Sources
We analyze the Asian outflow of CO, ozone, and nitrogen oxides (NOx) to the Pacific in spring by using the
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