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MIST Data Summaries

Overview

The MODIS Interactive Subsetting Tool (MIST) provides subsets of certain Version 5 (V005) MODIS products, over the Greenland Climate Network (GC-Net) and the International Arctic Systems for Observing the Atmosphere (IASOA) stations. Data are provided in a text Comma Separated Value (CSV) file format, courtesy of the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC). Refer to Table 1 for a list of the MODIS products supported by MIST.

Note: To obtain documentation for a particular data set, click on the Long Name in Table 1.

Table 1. MODIS Products Supported by MIST
Short Name
Long Name
Temporal Coverage
MOD09A1 MODIS/Terra Surface Reflectance 8-Day L3 Global 500m SIN Grid 2000-02-24 to present
MOD10A1 MODIS/Terra Snow Cover Daily L3 Global 500m Grid 2000-02-24 to present
MOD11A2 MODIS/Terra Land Surface Temperature/Emissivity 8 Day L3 Global 2000-03-05 to present
MCD43A1 MODIS/Terra+Aqua BRDF/Albedo Model Parameters 16-Day L3 Global 500m SIN Grid 2000-02-24 to present
MCD43A2 MODIS/Terra+Aqua BRDF/Model Quality 16-Day L3 Global 500m SIN Grid 2000-02-24 to present
MCD43A4 MODIS/Terra+Aqua Nadir BRDF-Adjusted Reflectance 16-Day L3 Global 500m SIN Grid 2000-02-24 to present


The Stations

The GC-Net and IASOA station's in-situ data correspond to the MODIS data products listed in Table 1. However, we currently do not supply the in-situ station data. When using the subsetting tool, you need to pick a station or stations for the corresponding MODIS data you want to receive.

GC-Net Stations

GC-Net consists of 20 Automatic Weather Stations (AWS) that collect climate information on Greenland's ice sheet. Each AWS is equipped with a number of instruments to sample the following:

  • air temperature
  • wind speed
  • wind direction
  • humidity
  • pressure
  • accumulation rate at high temporal resolution to identify and resolve individual storms
  • surface radiation balance in visible and infrared wavelengths
  • sensible and latent heat flux fluxes
  • snowpack conductive heat fluxes.

Refer to Table 2 for a listing of the station's Identification (ID) Number, the station names, the station's latitude and longitude coordinates, the date when the station became operational, and the the station's Site ID. The Site ID is used in the output CSV file. To order in situ GC-Net data, visit the Greenland Climate Network Data Request Web site.

Table 2. GC-Net Stations
ID #
Name
Latitude
Longitude
Elev.[m]
Start Date
Site ID
1 Swiss Camp 69.5732 N 49.2952 W 1149 1995.00 fn_dkswcamp
2 CP1 69.8819 N 46.9736 W 2022 1995.39 fn_dkandcp1
3 NASA-U 73.8333 N 49.4953 W 2368 1995.41 fn_dkdnasau
4 GITS 77.1433 N 61.0950 W 1887 1995.43 fn_dkndgits
5 Humboldt Gl. 78.5266 N 56.8305 W 1995 1995.47 fn_dkhumbdt
6 Summit 72.5794 N 38.5042 W 3208 1996.37 fn_dksummit
7 Tunu-N 78.0168 N 33.9939 W 2020 1996.38 fn_dkdtunun
8 DYE-2 66.4810 N 46.2800 W 2165 1996.40 fn_dkdye2
9 JAR1 69.4984 N 49.6816 W 962 1996.47 fn_dkjar1
10 Saddle 66.0006 N 44.5014 W 2559 1997.30 fn_dksaddle
11 South Dome 63.1489 N 44.8167 W 2922 1997.31 fn_dksdome
12 NASA-E 75.0000 N 29.9997 W 2631 1997.34 fn_dkdnasae
13 CP2 69.9133 N 46.8547 W 1990 1997.36 fn_dkandcp2
14 NGRIP 75.0998 N 42.3326 W 2950 1997.52 fn_dkdngrip
15 NASA-SE 66.4797 N 42.5002 W 2579 1998.30 fn_dknasase
16 KAR 69.6995 N 32.9998 W 2400 1999.38 fn_dkandkar
17 JAR2 69.4200 N 50.0575 W 568 1999.41 fn_dkjar2
18 KULU 65.7584 N 39.6018 W 878 1999.46 fn_dkndkulu
19 JAR3 69.3954 N 50.3104 W 323 2000.41 fn_dkndjar3
20 Aurora 67.1352 N 47.2911 W 1798 2000.48 fn_dkaurora


IASOA Stations

IASOA is an organization developed to enhance Arctic atmospheric research by fostering collaborations among researchers during the International Polar Year (IPY) and beyond. The science mission is to collect the information necessary to understand the processes and mechanisms of Arctic climate change. The logistical mission is to coordinate measurement programs on atmospheric properties such as:

  • precipitation
  • atmospheric radiation
  • water vapor
  • ozone
  • aerosols
  • chemistry/radio nuclides
  • cloud properties
  • climate-grade temperature/winds
  • snowfall
  • surface fluxes between observatories.

Refer to Table 3 for a listing of the member stations, the station's Site ID, and the station's latitude and longitude coordinates. The Site ID is used in the output CSV file. To order in situ IASOA station data, you need to go directly to each site for their data. To find the URLs for each site, visit the IASOA Web site and click on the Observatories link in the left-hand navigation. A link to each specific site is listed on that Web page.


Table 3. IASOA Stations
Latitude
Longitude
Location
Site ID
82.5017 N 62.3297 W Alert, Canada fn_caalert2
80.050 N 86.417 W Eureka, Canada fn_caeureka
71.323 N 156.609 W Barrow, USA fn_usbarrow
71.58 N 128.92 E Tiksi, Russia fn_rutiksi1
69 N 161. E Cherskii, Russia fn_ruchskii
78.908 N 11.881 E Ny-Alesund, Norway fn_nyalesun
67.37 N 26.65 E Sodankyla, Finland fn_fisoldpa
67.974 N 24.116 E Pallas, Finland fn_fisoldpa
68.35 N 18.82 E Abisko, Sweden Not Applicable 2
72.5794 N 38.5042 W Summit, Greenland1 fn_dksummit
1NSIDC recommends users use the GC-Net Summit station data acquisitions instead of the IASOA Summit, Greenland data acquisitions since the data are the same.

2The Abisko, Sweden site data has not been delivered so this site is not available on the search yet.


Data Output

CSV Files

The MIST data output are supplied in a text Comma Separated Value (CSV) File format. CSV files are a common interchange format between software packages supporting tabular data, and are also easily manipulated with a text editor such as Note Pad, a spreadsheet application such as Microsoft Excel, or with end-user written scripts or programs. There are two types of CSV files that are generated for each data search: raw and processed.

Note: Each row of data in the CSV file is considered a chip. A chip is equal to a 49 square kilometer area on the Earth. MOD11A2 generates a 7 x 7 size chip at 1 km grid resolution, and MOD09A1, MOD10A1, MCD43A1, MCD43A2, and MCD43A4 generate a 14 x 14 size chip at 500 m grid resolution.

Raw Data CSV File

The raw data CSV file contains the raw chip data with either 49 columns (1 km) or 196 columns (500 m) of data depending on the chip resolution. No processing is done on these data.

Raw Data CSV File Format

The raw data are supplied in either a 7 x 7 (1 km) or a 14 x 14 (500 m) data grid. MOD11A2 generates a 7 x 7 data grid, and MOD09A1, MOD10A1, MCD43A1, MCD43A2, and MCD43A4 generate a 14 x 14 data grid. Tables 4 and 5 show the pixel numbering scheme for each size grid.


Table 4. Pixel Numbering Scheme for MODIS 1km Data Grid
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35
36 37 38 39 40 41 42
43 44 45 46 47 48 49

Note: The red box is the site pixel.



Table 5. Pixel Numbering Scheme for MODIS 500 m Data Grid
1 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16 17 18 19 20 21 22 23 24 25 26 27 28
29 30 31 32 33 34 35 36 37 38 39 40 41 42
43 44 45 46 47 48 49 50 51 52 53 54 55 56
57 58 59 60 61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80 81 82 83 84
85 86 87 88 89 90 91 92 93 94 95 96 97 98
99 100 101 102 103 104 105 106 107 108 109 110 111 112
113 114 115 116 117 118 119 120 121 122 123 124 125 126
127 128 129 130 131 132 133 134 135 136 137 138 139 140
141 142 143 144 145 146 147 148 149 150 151 152 153 154
155 156 157 158 159 160 161 162 163 164 165 166 167 168
169 170 171 172 173 174 175 176 177 178 179 180 181 182
183 184 185 186 187 188 189 190 191 192 193 194 195 196

Note: The site pixel is in one of the four red boxes.


Processed Data CSV File

The processed data CSV file contains aggregated data for each chip. For coded data, the number of valid pixels, value of the center pixel, and the statistical mode of the chip is calculated. For non-coded data, the mean, minimum, maximum, and standard deviation of the valid pixels in the chip are also calculated. The processed CSV file also translates the values for the non-coded rows, converting them from the raw data number to a geophysical parameter, such as albedo, temperature, angle, etc. The processed values are more readily usable, but are aggregated so there are fewer columns available. Thus, the raw file will typically have more columns than the processed file.

The processed coded data CSV file contains the following information:

  • Product Name
  • Site ID
  • Band/Parameter Name
  • Date of Temporal Coverage and/or Intra–annual Range (in day of year format)
  • Num_Valid_Pixels
  • Center_Pixel
  • Mode

The processed non-coded data CSV file contains the following information:

  • Product Name
  • Site ID
  • Band/Parameter Name
  • Date of Temporal Coverage and/or Intra–annual Range (in day of year format)
  • Num_Valid_Pixels
  • Center_Pixel
  • Mode
  • Mean
  • Min
  • Max
  • Standard_Dev

Saving Search Results, Data CSV Files, and Graphs

Cookies are used to retain user options and Session IDs. The search results, data CSV files, and graphs are saved in a Session ID cookie for 72 hours.

Thus, for 72 hours, the search results and the data CSV files can be retrieved in the Results Summary section of the interface, and the graphs can be retrieved in the Graph Results section of the interface. However, the Results Summary information is not the actual data, but displays the following information for each search result:

  • Result ID Number
  • number of rows in the CSV file
  • the product(s)
  • the parameter(s)
  • Site ID Number(s) that were chosen for each search

In order to save the actual data CSV files to a local disk for later use, click on the Save This Search button located in the Subsetter Search section of the interface. And to save a graph, open up the PostScript version of the graph and save it to a local disk.

Types of Graphs

There are three different types of graphs that can be created:

  • Folded - Time Series
  • Normal - Time Series
  • Scatterplot.
Thumbnail image of swiss camp folded graph Click on the thumbnail to view the full resolution image (95 KB jpg).

Figure 1. A Folded - Time Series Graph of MOD09A1 Band 1 Surface Reflectance at Swiss Camp, Greenland for the period 10 May to 15 November, for the years 2000 - 2007. Points are mean with standard deviations for error bars.



Thumbnail image of swiss camp time series graph Click on the thumbnail to view the full resolution image (102 KB jpg).

Figure 2. A Normal - Time Series Graph of MODIS Surface Reflectance from MOD43A4 Band 1, Summit, Greenland and Band 4, Swiss Camp, Greenland; and MOD09A1 Band 4, Swiss Camp.



Thumbnail image of swiss camp time series graph Click on the thumbnail to view the full resolution image (53 KB jpg).

Figure 3. A Scatterplot Diagram of MODIS Band 4 Surface Reflectance at Swiss Camp, Greenland, from MOD09A1 (total) vs. MOD43A4 (nadir).



Share Your Thoughts

In order to aid us in future development of this tool, please share your feedback on the usability of this interface by taking the MIST Usability and Feature Request Survey.