All of the questions below are linked to descriptive answers in this chapter of the Giovanni-3 Online Users Manual regarding the Giovanni-3 MLS instance. Click the question of interest.
What does MLS stand for? What satellite is the MLS on?
MLS stands for "Microwave Limb Sounder".
The MLS data in this Giovanni-3 instance is from the EOS Aura satellite. An earlier MLS instrument was flown on the Upper Atmosphere Research Satellite (UARS).
For what time period is MLS data available in Giovanni?
MLS data are available from August 8, 2004 to present. The current version 2.2 data are not continuous, due to gaps in the way the data are being reprocessed, as well as interuptions when the instrument is off-line.
What version of MLS data is currently provided in Giovanni-3 MLS?
Giovanni-3 provides the current version 2.2 of MLS data. The data are filtered according to the recommendations from the MLS science team. Please see table 1-1 of the Version 2.2 Level 2 Data Quality and Description Document.
What MLS data types are available?
MLS data are available as atmospheric profiles (Level 2 data). This means that the data is displayed for a single point on the Earth from the Earth's surface to an altitude above that point in the atmosphere.
What data parameters are currently available in the Giovanni-3 MLS instance?
The currently available data parameters are:
How are the data organized? What is the spatial resolution of the data?
The data are organized with all the orbit tracks (usually 15) for a given day. Spatial resolution is 1.5 deg (about 165 km) along the orbit track between profiles.
What are the current data analysis and visualization (output) options in Giovanni-3 MLS?
All MLS data are visualized as atmospheric profiles. The atmospheric concentration of the data parameter is the X-axis of the data plot, and the atmospheric pressure is the Y-axis. Note that the Y-axis is a logarithmic scale.
When an area and time period of interest are selected (see the next two questions), the Giovanni system will choose the profiles which were nearest to the selected point. The plot legend will show the times that the profiles were acquired, and the actual latitude and longitude coordinates of the profiles. The default is three (3) profiles. See the question regarding plotting preferences below for more information.
How is the area of interest selected in Giovanni-3 MLS?
The area of interest is selected by clicking on a point on the Java map, or providing latitude and longitude coordinates. Only a single point on the globe can be selected; an area cannot be selected. The orbit tracks are for reference. If you wish to see where the orbits are on a given day before selecting an area, choose the time period first (see the next question) and click "Update Map", then choose a point for the profiles. Note that it is not necessary to use the orbit map for the day of interest to get the profiles for the selected day. The point can be chosen and then the day of interest can be chosen, and the system will retrieve profiles nearest to that point.
How is the time period of interest selected in Giovanni-3 MLS?
The time period of interest is a single day. A range of dates cannot be chosen, i.e. for averaging atmospheric profiles. To choose a day, select the year, month, and day date using the drop-down calendrical menus. If you wish to see where the Aura orbit swaths were on that, click "Update Map" after providing the date criteria.
Are there any limits on the area or time-period of interest that can be selected?
There are no limits on the area that can be selected, but the data will only be for the point on the orbit nearest to the selected point. The point selected does not have to be directly on an orbit swath for the selected date. The time-period must be a single day and must be for date during the MLS mission (the date range is provided next to the calendrical menus).
If there are no data for that day a message will indicate no data.
Are there limits on the number of parameters that can be plotted?
There are no limits on the number of parameter profiles that can be plotted. However, not all of the parameters will have data at a given point. This is a result of data filtering criteria. If no data is available, the plot will display the message "No valid data for display". To select all the parameters, click the box labeled "Version 2.2" above the parameter list.
How many profiles can I plot in a single visualization?
Up to six (6) profiles can be displayed in a parameter profile plot. It is also possible to choose zero (0) profiles; this option will result in no data being displayed.
What do the plotting preference options do in the Giovanni-3 MLS?
There are four plot preference options in the Giovanni-3 MLS instance. They are:
- Number of profiles - This option allows the selection of the number of profiles displayed in the plot. The default option is 3, the maximum is 6, and the minimum is zero.
- Show Error Bars - This option designates if error bars should be shown or not shown on the plot. The default option, "Yes", displays the error bars. Select "No" to remove the error bars from the plot.
- Image X Size - This option adjusts the horizontal dimension of the plot. The data values and the axis labels are not changed.
- Image Y Size - This option adjusts the vertical dimension of the plot. The data values and the axis labels are not changed.
Why do I always get a plot of the CO parameter when I create a data visualization? I'm not interested in carbon monoxide.
CO is the default parameter option (the first listed in alphabetical order). Selecting a different parameter does not remove the default selection. To remove CO from the parameter selections, click on the box to the left of the CO symbol.