not applicable

Mariner 10 Plasma Experiment (PLS) derived ELECTRON MOMENTS data at Mercury.

Abstract ======== This data set consists of the MESSENGER MAG calibrated observations, also known as CDRs. The MAG experiment is a miniature three-axis ring-core fluxgate magnetometer with low- noise electronics. There are five MAG CDR data products, which mainly differ in the coordinate system.

Abstract ======== This data set consists of the MESSENGER MAG reduced observations, also known as RDRs. The MAG experiment is a miniature three-axis ring-core fluxgate magnetometer with low- noise electronics. There are five types of MAG RDR data products, which differ in the coordinate system. For each type, one or more averaging intervals are available.

This MESSENGER Magnetic field data set contains cruise-phase magnetic field vectors in RTN coordinates at time resolutions typically of 0.5 s or 1.0 s and sometimes as fine as 0.05 s. The Mercury Surface, Space Environment, Geochemistry, and Ranging, MESSENGER, mission is designed to study the characteristics and environment of Mercury from orbit. The nominal orbit is planned to have a periapsis of 200 km at 60° N latitude, an apoapsis of 15,193 km, a period of 12 hours, and an inclination of 80°. The periapsis will slowly rise due to solar perturbations to over 400 km at the end of 88 days, one Mercury year, at which point it will be readjusted to a 200 km, 12 hour orbit via a two burn sequence. Data will be collected from orbit for one Earth year, the nominal primary mission was planned to end in March 2012. Specifically, the scientific objectives of the mission are to characterize: * the chemical composition of the surface of Mercury * the geologic history * the nature of the magnetic field * the size and state of the core * the volatile inventory at the poles * the nature of the Hermean exosphere and magnetosphere The MESSENGER mission should also yield: * global composition maps * a 3-D model of the magnetosphere of Mercury * topographic profiles of the northern hemisphere * gravity field to degree and order sixteen * altitude profiles of elemental species * a characterization of the volatiles in permanently shadowed craters at the poles The MESSENGER spacecraft is a squat box (1.27 m ⨯ 1.42 m ⨯ 1.85 m) with a semi-cylindrical thermal shade, roughly 2.5 m tall and 2 m wide, for protection from the Sun and two solar panel wings extending radially about 6 m from tip to tip. Five science instruments are mounted externally on the bottom deck of the main body: the Mercury Dual Imaging System, MDIS, Gamma-Ray and Neutron Spectrometer, GRNS, X-ray Spectrometer, XRS, Mercury Laser Altimeter, MLA, and Atmospheric and Surface Composition Spectrometer, MASCS. Radio Science, RS, experiments will use the existing communications system. The Energetic Particle and Plasma Spectrometer, EPPS, is mounted on the side and top deck, and the magnetometer, MAG, is at the end of the 3.6 m boom. The Messenger MAG instrument is a miniature three-axis ring-core fluxgate magnetometer with low-noise electronics. It is mounted on a 3.6 m boom in the anti-sunward direction. The MAG has ±1530 and ±51300 nT ranges with 20-bit internal resolution and 17-bit output resolution. The MAG probe samples magnetic field values along the X, Y, and Z axes at a rate of up to 20 samples/s. The rate is commandable and can vary. This data set has 3-axis calibrated samples of the magnetic field in heliospheric RTN coordinates, Br, Bt, Bn, in units of nT. The spacecraft position data in these files are identified by radial distance from the Sun, latitude above the ecliptic plane, and azimuth with respect to the Earth-Sun line in the ecliptic plane. The MESSENGER Magnetometer data are also available from the Planetary Data System, Planetary Plasma Interactions, PDS/PPI, node via the URL; https://pds-ppi.igpp.ucla.edu/search/view/?f=yes&id=pds://PPI/MESS-E_V_H_SW-MAG-3-CDR-CALIBRATED-V1.0/DATA/RTN/. Hovever, the data are listed in plain text, space delimeted ASCII tables. Note that this SPASE Numerical Description only describes the MESSENGER Magnetometer data stored in Common Data Files.

USGS conducted preliminary assays on aged (3 mo.) surface sediment (0-4 cm) collected from 13 sites during October 1998 in order to decipher general spatial trends in Hg-speciation, microbiology and relevant biogeochemistry. During the second field campaign sample processing and incubations were conducted at ambient temperature within hours of sediment collection to provide a more accurate measure of in-situ process rates and analyte concentrations. The third field sampling (October 1999), involving 14 sampling and was conducted with a similar approach as in June 1999. The latter two data sets provide a direct seasonal comparison (summer/fall, high/lo flow conditions) of Hg transformation dynamics in the CRS. Sediment depth profiles (0-16 cm) were investigated at four sites during June 1999 and at two of these four during October 1999. Eroding vertical bank material was sampled in the Hg-contaminated Fort Churchill region during both 1999 dates. Laboratory experiments were conducted using sediment collected during the latter two sampling dates. The study purpose sought to: a) identify important zones of net methylmercury (MeHg) production and consumption within the CRS, b) determine which environmental factors most strongly influence these processes and c) provide estimates of seasonal variability. Measurements were made of microbial Hg-transformations (via radiotracer) and in-situ Hg speciation (total mercury (Hgt), MeHg, and particle-associated acid-extractable Hg(II)). Acid extractable Hg(II) was used as a surrogate measure for the Hg(II) most readily available to bacteria for methylation. A novel Hg-biosensor technique was also used to assess bioavailable Hg(II) in pore-water. A suite of ancillary microbial processes and sediment geochemical parameters were also measured to more fully characterize each site, and to relate these measurements to observed Hg-transformation rates and Hg-speciation. The EPA is publishing this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU2 Remedial Investigation Report (EPA, 2017), which describes the nature and extent of contamination from the Site. The report contains the Human Health Risk Assessment and Ecological Risk Assessment. Literature and other source Hg data are summarized in the RI for surface waters, sediments, and biological tissues.

GMOS global surface elemental mercury (Hg0) observations from 2013 & 2014. This dataset is associated with the following publication: Sprovieri, F., N. Pirrone, M. Bencardino, F. D'Amore, F. Carbone, S. Cinnirella, V. Mannarino, M. Landis, R. Ebinghus, A. Weigelt, E. Brunke, C. Labuschagne, L. Martin, J. Munthe, I. Wangberg, P. Artaxo, F. Morais, W. Cairns, C. Barbante, M.d.C. Dieguez, P.E. Garcia, A. Dommergue, H. Angot, O. Magand, H. Skov, M. Horvat, J. Kotnik, K.A. Read, L. Mendes Neves, B. Manfred Gawlik, F. Sena, V. Arckadievich Obolkin, D. Wip, X.B. Feng, H. Zhang, X. Fu, N. Mashyanov, R. Ramachandran, D. Cossa, J. Knoery, N. Marusczak, M. Nerentrorp, and C. Norstrom. Atmospheric Mercury Concentrations Observed at Ground-Based Monitoring Sites Globally Distributed in the Framework of the GMOS Network. Atmospheric Chemistry and Physics. Copernicus Publications, Katlenburg-Lindau, GERMANY, 16(0): 11915-11935, (2017).