OMI Ozone Time Series

OMI/OMPS Ozone Time Series Data

Satellite:

Latitude: +90 to -90 (+)North, (-)South

Longitude: -180 to +180, (-)West, (+)East ***NOTE SIGN CHANGE***

Start Date: Starting Date for query (yyyy-MM-dd)

End Date: Ending Date for query (yyyy-MM-dd)

Date Format: Format for Date encoding in output (text mode only)

Include Missing Data: YES=All dates included with missing values set to zero

Inperpolation Info: Output Metadata used in Interpolation Calculations (text mode only)

View: Output data format CSV-Text or XY-Plot Image

Image Width: Image Width in Pixels

Image Height: Image Height in Pixels

Image BG Color: XY-Plot Image Background Color

Show Data Points: Show Data Point Shapes on XY-Plot

(Long time scale datasets will take longer to generate, be patient.)

This tool allows OMI or OPMS daily ozone values to be retrieved as a time series for a specific latitude and longitude coordinate and date range. The resulting dataset can be generated in either CSV-text or an XY-Plot in PNG format. For text-based datasets, missing data values can be filtered from the text dataset by setting Include Missing Data to NO. The ozone values returned include the value from the nearest satellite lat/lon data point, and an interpolated value. OMI data are gridded at 0.25 degrees, OMPS data are gridded at 1.0 degrees. Data are rendered in a new browser window or tab (browser setting specific).

OMI Satellite Level 3e daily averaged ozone data gridded at 0.25 x 0.25 degrees are being obtained from the EarthDATA GES DISC website. Availability of the OMI data cover October of 2004 to present, and have about two days latency. NetCDF files containing Total Column Ozone are an alternate source for OMI O3 data.

OMPS Satellite daily averaged ozone data gridded at 1.0 x 1.0 degrees have been obtained from the EarthDATA GES DISC OPMS website. Availability of the OMPS data cover Jan 26, 2012 to present, and have about two days latency.

Example Text Format Output

#          Satellite: OMI
#           Latitude: 40.125
#          Longitude: -105.238
#            Sat Lat: 40.125
#            Sat Lon: 105.125
#           Lat Diff: 0.000
#           Lon Diff: 0.113
# Interp X1,X2,Y1,Y2: 105.125, 105.375, 39.875, 40.125
#          StartDate: 2014-12-20
#            EndDate: 2015-01-10
#           All Data: False
#          Entry Cnt: 14
#

yyyy, MM, dd, DDD, O3_Nearest, O3_Interpolated, InterpolPos
2014, 12, 21, 355,    313.000,         313.000,           Y
2014, 12, 22, 356,    337.000,         338.808,           Y
2014, 12, 23, 357,    315.000,         315.000,           Y
2014, 12, 24, 358,    282.000,         282.000,           Y
2014, 12, 26, 360,    344.000,         344.904,           Y
2014, 12, 28, 362,    345.000,         345.452,           Y
2014, 12, 30, 364,    336.000,         336.904,           Y
2014, 12, 31, 365,    291.000,         291.904,           Y
2015, 01, 02, 002,    269.000,         269.452,           Y
2015, 01, 04, 004,    310.000,         310.000,           Y
2015, 01, 06, 006,    271.000,         271.000,           Y
2015, 01, 07, 007,    256.000,         253.740,           Y
2015, 01, 08, 008,    265.000,         265.000,           Y
2015, 01, 09, 009,    271.000,         271.000,           Y

Description:

Header Information summerizes the user's supplied parameters, and the total count of data points in the returned dataset.

Date Column Fields:

yy[yy] - two or Four Digit Year
MM - Two Digit Month Number
MMM - Three Letter Month Name {Jan,Feb,...}
dd - Two Digit Day of Month
DDD - Three Digit Day Of Year

Total Column Ozone:

Daily Average Total Column Ozone values in Dobson Units

Lat/Lon Diff:

The difference between the requested Lat/Lon and the closest OMI data point Lat/Lon in degrees

Example showing values used in Ozone Interpolation

#          Satellite: OMI
#           Latitude: 40.125
#          Longitude: 105.238
#            Sat Lat: 40.125
#            Sat Lon: 105.125
#           Lat Diff: 0.000
#           Lon Diff: 0.113
# Interp X1,X2,Y1,Y2: 105.125, 105.375, 39.875, 40.125
#          StartDate: 2014-12-20
#            EndDate: 2015-01-10
#           All Data: False
#          Entry Cnt: 14
#

yyyy, MM, dd, DDD, O3_Nearest, O3_Interpolated, InterpolPos,   Q11,   Q21,   Q12,   Q22, Quad
2014, 12, 21, 355,    313.000,         313.000,           Y, 312.0, 312.0, 313.0, 313.0,   4
2014, 12, 22, 356,    337.000,         338.808,           Y, 349.0, 357.0, 337.0, 341.0,   4
2014, 12, 23, 357,    315.000,         315.000,           Y, 315.0, 315.0, 315.0, 315.0,   4
2014, 12, 24, 358,    282.000,         282.000,           Y, 283.0, 280.0, 282.0, 282.0,   4
2014, 12, 26, 360,    344.000,         344.904,           Y, 346.0, 346.0, 344.0, 346.0,   4
2014, 12, 28, 362,    345.000,         345.452,           Y, 345.0, 345.0, 345.0, 346.0,   4
2014, 12, 30, 364,    336.000,         336.904,           Y, 335.0, 339.0, 336.0, 338.0,   4
2014, 12, 31, 365,    291.000,         291.904,           Y, 290.0, 289.0, 291.0, 293.0,   4
2015, 01, 02, 002,    269.000,         269.452,           Y, 271.0, 262.0, 269.0, 270.0,   4
2015, 01, 04, 004,    310.000,         310.000,           Y, 312.0, 312.0, 310.0, 310.0,   4
2015, 01, 06, 006,    271.000,         271.000,           Y, 270.0, 270.0, 271.0, 271.0,   4
2015, 01, 07, 007,    256.000,         253.740,           Y, 253.0, 253.0, 256.0, 251.0,   4
2015, 01, 08, 008,    265.000,         265.000,           Y, 266.0, 266.0, 265.0, 265.0,   4
2015, 01, 09, 009,    271.000,         271.000,           Y, 272.0, 271.0, 271.0, 271.0,   4

Shows the values used in the interpolation process. See below for more info about how the ozone interpolated values are calculated.

Q11=Lower Left
Q21=Lower Right
Q12=Upper Left
Q22=Upper Right
Quad = Quadrant Location Number

Example Graphical Format Output

Description:

User definable parameters include:

Image Size: Height and Width in Pixels.
Plot Background Color: Black, White, Gray
Data Points: Enable/Disable Datapoint Visibility

Nearest Point Calculation

Satellite data are read from files into indexed Vectors for latitude, longitude, and O3 values. The index of the closest lat/lon is determined by comparing the sum of the difference of absolute values of tagetLat-SatLat and targetLon-SatLon. Once the index is known then the values are extracted from the Vectors. The Figure below illustrates the closest point algorithm.

Bi-linear Interpolation Algorithm

Interpolated values of ozone at the target lat/lon are calculated with a Bi-linear Interpolation algorithm that first determines what quadrant the target lat/lon fall with reference to the closest point, then applies the interpolation to the four ozone values of the quadrant (q11, q21, q12, q22) as shown in the Figure below.