Open-File Report 2012-1259 SP_GCM.doc Mars Global Digital Dune Database: MC-30 By R.K. Hayward, L.K. Fenton, T.N. Titus, A. Colaprete, and P.R. Christensen 2012 (http:pubs.usgs.gov/of/2012/1259) Summary See Pamphlet.doc, Mars Global Digital Dune Database Purpose. Description See Pamphlet.doc, Mars Global Digital Dune Database Abstract. Credits There are no credits for this item. Access and use limitations There are no restrictions. ArcGIS Metadata Resource Identification Citation Title: SP_GCM_Geog Alternate Titles: South Pole GCM Presentation Format: digital map Collection Title: Mars Global Digital Dune Database Responsible Party: Individual's Name: Rosalyn K. Hayward Organization's Name: USGS, Astrogeology Contact's Position: Geologist Contact's Role : Originator Contact Information: Phone: Voice: (928) 566-7022 Fax: (928) 566-7014 Address: Delivery Point: 2255 N. Gemini Dr. City: Flagstaff Administrative Area: Az Postal Code: 86001 Country: United States E-Mail Address: rhayward@usgs.gov Publication_Information: Publication_Place: Reston, Virginia Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2012/1259 Themes Or Categories Of The Resource : geoscientificInformation Tags For Searching: Dune, Aeolian, Mars, Database, GCM Discipline Keywords: Planetary Science Place Keywords: Mars Theme Keywords: Dune Theme Keywords: Aeolian Theme Keywords: Database Theme Keywords: GCM Dataset Languages: English (United States) Dataset Character Set Utf8 - 8 Bit Ucs Transfer Format Status: Completed Resource Maintenance: Update Frequency: Not Planned Scope Of The Updates: Dataset Resource Constraints: Constraints: Limitations Of Use: There are no restrictions. Spatial Representation Type: Vector * Processing Environment: Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; Esri Arcgis 10.0.2.3200 Other Extent Information: Geographic Extent: Bounding Rectangle: * Extent Type Extent Used For Searching * West Longitude -174.743410 * East Longitude 180.000000 * North Latitude -58.104367 * South Latitude -85.000000 * Extent Contains The Resource: Yes Point Of Contact: Individual's Name: Rosalyn K. Hayward Organization's Name: USGS, Astrogeology Contact's Position: Geologist Contact's Role: Originator Contact Information: Phone: Voice: (928) 566-7022 Fax: (928) 566-7014 Address: Delivery Point: 2255 N. Gemini Dr. City: Flagstaff Administrative Area: Az Postal Code: 86001 Country: United States E-Mail Address: rhayward@usgs.gov Reference System Reference System Identifier Value 104905 * Codespace Esri * Version 10.0.0 Data Quality Scope Of Quality Information Resource Level: dataset Lineage: Process Step: See Pamphlet.doc, Mars Global Digital Dune Database Process. Data Quality Report - Completeness Omission: See Pamphlet.doc, Mars Global Digital Dune Database ? Completeness of Database. Data Quality Report - Conceptual Consistency Measure Description: All attributes were verified by displaying the lines in both the database and the spatial coverage and they are believed to be logically consistent. Data Quality Report - Topological Consistency Measure Description: These data are believed to be logically consistent. Line geometry is topologically clean. Data Quality Report - Absolute External Positional Accuracy: Measure Description: The horizontal accuracy is derived from the accuracy of the Mars Orbiter Laser Altimeter (MOLA) dataset [Smith and others, 2001]. The globally adjusted MOLA dataset has an absolute horizontal accuracy on the order of 100 m, but individual features in images can probably only be tied to MOLA-derived shaded-relief digital image models with a precision on the order of 200 m. Other bases used included Thermal Emission Imaging System (THEMIS) digital images [Archinal and others, 2003, Christensen and others, 2004]. The digital features were drawn at 20K to 100K scale with a node spacing of approximately 0.3 km to 2 km. ESRI Metadata and Item Properties Metadata Properties: Arcgis: Arcgis1.0 Metadata Style: FGDC CSDGM Metadata Metadata Standard Or Profile: FGDC Created In Arcgis: 2012-05-14t13:03:12 Last Modified In Arcgis: 2012-06-03t15:08:05 Automatic Updates: Last Update: 2012-06-03t15:06:39 Have Been Performed: Yes Item Properties Name: SP_GCM_Geog Content Type: Downloadable Data ESRI Spatial Information Extent In The Item's Coordinate Reference Bounding Rectangle: * West Longitude -174.743410 * East Longitude 180.000000 * North Latitude -58.104367 * South Latitude -85.000000 * Extent Contains The Resource: Yes Coordinate Reference Type: Geographic Geographic Coordinate Reference: GCS_Mars_2000 Coordinate Reference Details Geographic Coordinate System Well-Known Identifier: 104905 X Origin: -399.99999999999989 Y Origin: -399.99999999999989 XY Scale: 1000000000.0000001 Z Origin: -100000 Z Scale: 10000 M Origin: -100000 M Scale: 10000 XY Tolerance: 1.6870604858115214e-008 Z Tolerance: 0.001 M Tolerance: 0.001 High Precision: True Left Longitude: -180 Well-Known Text GEOGCS["GCS_Mars_2000",DATUM["D_Mars_2000",SPHEROID ["Mars_2000_IAU_IAG",3396190.0,169.8944472236118]],PRIMEM ["Reference_Meridian",0.0],UNIT["Degree",0.0174532925199433],AUTHORITY ["ESRI",104905]] ESRI Feature Class Feature Class Name: SP_GCM_Geog * Feature Type: Simple * Geometry Type: Polyline * Has Topology: False * Feature Count: 1998 * Spatial Index: True * Linear Referencing: False ESRI Fields and Subtypes SP_GCM_Geog Feature Class * ROW COUNT 1998 DEFINITION (shape ? polyline) Polylines represent output from the NASA/Ames General Circulation Model (GCM). The model output, created for the database by A. Colaprete, was created with a grid spacing of 6 degrees longitude by 5 degrees latitude for each degree of solar longitude (Ls) in one Martian year. Shear stress, wind velocity and wind azimuth were provided 8 times daily for each Ls, resulting in ~3000 vectors per grid location. Haberle and others (2003) have shown that setting a threshold stress of 0.0225N/m2 with the Ames Mars GCM will lift dust (through bombardment from sand saltation) in spatial patterns that qualitatively agree with observed dust storm occurrences. Thus only output records with a wind stress value >0.0225 N/m2 are included. We also excluded output if modeled surface temperature was <160 K because the surface would likely be covered with CO2, thus sand would not be available for transport. Model output is provided for the area from 60ø N to 90ø N (5 degrees latitude beyond the southern extent of the study area). (1998 records) FIELD OBJECTID_1 * ALIAS OBJECTID_1 * DATA TYPE OID * WIDTH 4 * FIELD DESCRIPTION Internal feature number. * DESCRIPTION SOURCE ESRI * DESCRIPTION OF VALUES Sequential unique whole numbers that are automatically generated. FIELD Shape * ALIAS Shape * DATA TYPE Geometry * FIELD DESCRIPTION Feature geometry. * DESCRIPTION SOURCE ESRI * DESCRIPTION OF VALUES Coordinates defining the features. FIELD OBJECTID * ALIAS OBJECTID * DATA TYPE Integer * WIDTH 4 FIELD DESCRIPTION none DESCRIPTION SOURCE none FIELD LS ALIAS Solar_Longitude * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION This is the position of Mars relative to the Sun measured in degrees from the vernal equinox (start of northern Spring). It is used as a measure of Martian seasons: Northern Spring/Southern Autumn start at 0ø. Northern Summer/Southern Winter start at 90ø. Northern Autumn/Southern Spring start at 180ø. Northern Winter/Southern Summer begin at 270ø. Also known as heliocentric longitude and abbreviated Ls. DESCRIPTION SOURCE none FIELD UDT ALIAS Universal_Daylight_Time * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION Local time at the Mars prime meridian. DESCRIPTION SOURCE none FIELD LMT ALIAS Local_Mean_Time * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION This is the local time on Mars relative to a division of the Martian day into 24 equal parts. A Martian day is slightly longer than 24 hours and 37 minutes long. "DAY" is a local time of 08:00-20:00 (8am-8pm). "NIGHT" is a local time of 00:00-07:59 or 20:01-24:59 (0:00-7:59am or 8:01-11:59pm). DESCRIPTION SOURCE none FIELD LON ALIAS GCM_Longitude_East * DATA TYPE SmallInteger * WIDTH 2 FIELD DESCRIPTION Position of the GCM grid point in decimal degrees east longitude. DESCRIPTION SOURCE none FIELD LAT ALIAS GCM_Latitude_Aerocentric * DATA TYPE SmallInteger * WIDTH 2 FIELD DESCRIPTION Position of the GCM grid point in decimal degrees latitude (aerocentric). DESCRIPTION SOURCE none FIELD STRESS ALIAS Shear_Stress * DATA TYPE Single * WIDTH 4 FIELD DESCRIPTION GCM model output. Wind stress in Newtons/meter2. DESCRIPTION SOURCE none FIELD WINDMAG ALIAS Wind_Velocity * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION GCM model output. Wind azimuth in decimal degrees. Note that because SP_GCM is a polyline shapefile, it will display correctly in ArcMap in any projection. However, if you convert the polylines to points, do not use the Wind_Azimuth (geog_bear) values to display direction, except in Geographic coordinate system or Simple Cylindrical projection. The display would be inaccurate in most other projections, including Polar Stereographic projection. DESCRIPTION SOURCE none FIELD geog_bear ALIAS Wind_Azimuth_Geog * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION GCM model output. Wind azimuth in decimal degrees as calculated in Geographic coordinate system, is included for consistency with Equatorial and North Pole parts of MGD3. We recommend using Wind_Azimuth_Mercator (merc_bear) for numerical comparison to other azimuths. Note that because SP_GCM is a polyline shapefile, it will display correctly in ArcMap in any projection. However, if you convert the polylines to points, do not use the Wind_Azimuth_Geog (geog_bear) values to display direction, except in Geographic coordinate system or Simple Cylindrical projection. The display would be inaccurate in most other projections, including Polar Stereographic projection. DESCRIPTION SOURCE none FIELD PS_bear ALIAS Wind_Azimuth_Ster * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION GCM model output. Wind azimuth in decimal degrees, calculated in the Polar Stereographic projection. If the user converts the polylines to points, and wants to display them as arrows in the Polar Stereographic projection, use this column to rotate the arrows. DESCRIPTION SOURCE none FIELD merc_bear ALIAS Wind_Azimuth_Mercator * DATA TYPE Double * WIDTH 8 FIELD DESCRIPTION GCM model output. Wind azimuth in decimal degrees, calculated in the Mercator projection. We recommend use of this field for numerical comparison to other azimuths. If you convert the polylines to points, do not use the Wind_Azimuth_Mercator (merc_bear) values to display direction, except in Mercator projection. DESCRIPTION SOURCE none FIELD Shape_Length * ALIAS Shape_Length * DATA TYPE Double * WIDTH 8 * FIELD DESCRIPTION Length of feature in internal units. * DESCRIPTION SOURCE ESRI * DESCRIPTION OF VALUES Positive real numbers that are automatically generated. Metadata Details Metadata Language: English Metadata Character Set: Utf8 - 8 Bit Ucs Transfer Format Scope Of The Data Described By The Metadata: Dataset * Scope Name: Dataset Metadata Contact: Individual's Name: Rosalyn K. Hayward Organization's Name: USGS,Astrogeology Contact's Position: Geologist Contact's Role: Originator Contact Information: Phone: Voice: (928) 566-7022 Fax: (928) 566-7014 Address: Delivery Point: 2255 N. Gemini Dr. City: Flagstaff Administrative Area: Az Postal Code: 86001 Country: United States E-Mail Address: rhayward@usgs.gov * Last Update: 2012-06-03 Maintenance: Update Frequency: Not Planned Scope Of The Updates: Dataset