An Ocean of Temperature Data

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08-24-2018 11:09 AM
TamaraGrant1
Occasional Contributor III
0 7 1,416

by Dan Pisut and Keith VanGraafeiland

Ever dip your foot into the ocean and think, “This water is perfect…I bet it’s about 82 degrees.” Well, there’s one way to be sure for any place around the world: satellite sea surface temperature data.  

Besides hunting for prime beach spots, SST is a key climate and weather measurement used for weather prediction, ocean forecasts, tropical cyclone forecasts, and in coastal applications such as fisheries, pollution monitoring and tourism. El Niño and La Niña are two examples of climate events, which are forecasted and monitored using sea surface temperature maps.   

A daily updated SST analysis is available in the Living Atlas (with an archive going back to 2008). By default, time animation is enabled. But if you disable time in the Properties, you can take advantage of the layer’s multidimensional settings using definition queries on the time to return just that particular layer. This selection works in ArcGIS Desktop or .

properties option

In addition to time analysis, this layer can be used for visualization  in web maps and in ArcGIS Desktop.  Two server-side processing template options can be used to help in these visualizations: cartographic vs analytic renderer, and convert Celsius to Fahrenheit. Convert C to F is pretty self-explanatory. The cartographic render presents the map as RGB values stretched from 0-255, which displays efficiently for fast visualization. The analytic renderer provides the map as its range of temperature values (-2 to 34.5). Using the analytic renderer means you can change the display of the data (e.g., range, color, etc).

In ArcGIS Pro, access these options from the Processing Templates in the layer Properties.

processing templates in ArcGIS Pro

Or in ArcGIS , you’ll click on Image Display to access the processing templates.

processing templates in ArcGIS

Since I’m iridisophobic, I use this render option to quickly change the color palette…maybe to something like my favorite “hurricane formation zone” color palette with a break at 26oC, or a luminance-controlled palette from dark purple to bright yellow.

GIF of two SST color palettes

Additionally, many other analyses can be performed using this layer, including:

  • Apply contours using Raster Functions
  • Chain together several operations using the Raster Function Editor and Model Builder.
  • Generate summary statistics
  • Plot a graph of temperatures

SST histogram graph

In other words, use the archive of SST as if it were local on your desktop. Combine it with other layers from the Living Atlas or your local data to explore the Earth-system or author beautiful maps. You can also quickly browse SST data in the Daily Sea Surface Temperaturetime aware application. 

Have questions or comments about this blog? Post them in our GeoNet.

7 Comments
kmsmikrud
Occasional Contributor III

Hi,

This is really a great resource being able to view by day. In viewing the data in Pro how would a person show the values displayed in the map? For instance I have a specific day shown how do I show the range of values represented on the map?

Thanks,

Kathy

DanPisut
New Contributor III

Hi Kathy, 

You can use either the time slider or a definition query on the date field to define a specific date. 

Cheers,

Dan

kmsmikrud
Occasional Contributor III

Hi Dan,

Thanks for the info but I am able to display the dataset by a specific day but what I'm wondering is how to show the actual sea surface temperature range of values displayed on the map? For example the values could be shown in the map legend?

Thanks!,
Kathy

DanPisut
New Contributor III

When you choose one of the analytic processing templates (see above), the legend will change to the range. You can also get the values in the pop-ups. "None" is Degrees C and the other option is Degrees F. 

Does that help? 

kmsmikrud
Occasional Contributor III

Yes that definitely helps! I did have the processing template changed to cartographic renderer and can see the temperature values in Celcius in the pop-up but the legend just displays Red: Band_1, Green: Band_1, Blue Band_1. I should mention I did have the time set to "Each feature has a single time field" so I could have it select a certain day so maybe that is messing it up?

I feel like I'm missing something simple on getting that changed? Is it also possible to have it render with a custom range so it could have the same legend for multiple maps with different days?

Thank-you!

AprilRebert
New Contributor

Hi! Same issue here! I want to the legend to show the range in the display. More on this particular issue here: https://community.esri.com/thread/244240-raster-legend-to-show-only-displayed-ranges 

Thanks for any help!

DanPisut
New Contributor III

Don't modify the time settings on the service, those are fine. Just add a definition query on the time attributes. I also responded to April's question below on that thread for defining a custom data/color range. 

About the Author
I promote the ArcGIS Living Atlas of the World through blog posts, webinars, and social media.
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