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Archive for the 'global warming' Category

Google Earth Gets Live Weather, Sort Of

Figures that the week after I posted about US National Weather Service live network KMZ links, Google added live weather data to Google Earth. Look in the Layers pane for the Weather folder, where you’ll find layers for Clouds, Conditions And Forecasts, and Radar. The Clouds layer is worldwide and appears to be fairly up-to-date, though there’s no time stamp to confirm this. Clicking on a “Conditions” icon brings up “current” conditions and the forecast” for the entire world (even including locations in Antarctica).


But the time stamps shows the current conditions are about 3-4 hours behind the actual time.

Last week, I compared the National Weather Service radar conditions using their KMZ overlay:


With Google’s radar data for the same area and time:


Fairly close, but it looked to me as though Google’s data was about 30-60 minutes behind. And the NWS data not only showed a better-defined range of precipitation intensity, but was available in animated format, so you could see where the rain was heading. Google Earth only has radar data for North American and Western Europe. So, it’s a decent start for weather in GE, but it needs some work; for the US, the National Weather Service KMZ overlays are a much better choice.

Current National Weather Service Radar Data In Google Earth And GIS Formats

I’ve been using the website of my local National Doppler Radar Station for years now to monitor the animated radar precipitation loop, but I just noticed that there are a pair of links labeled KML and GIS Users. The KML link takes you to a page where you can select and generate a KML/KMZ link to live radar data from any single radar station, or from custom combinations of multiple radar stations. You can select from the data type you want:

  • Short-Range Reflectivity
  • Long-Range Reflectivity
  • Composite Reflectivity
  • Velocity
  • Storm Relative Motion
  • 1 Hour Precipitation
  • Storm Total Precipitation

and choose either animated loops or static images to display in Google Earth:


For animated loops, I’d recommend setting the animation speed slider in the middle of the range or higher, and checking the Loop Animation box:


And it usually takes several loops before all the image overlays fully load in for display.

The generated KMZ files are network links, updated every two minutes so that they’re always current. So if you download a KMZ link from this site, open it in Google Earth, then save it in My Places, you’ll always have it available for up-to-date radar views.

The GIS Users link takes you to a general info page, and then to a directory page where you can download static GIF images with current radar data. You’ll need to know the three-letter code designation for your desired radar station, but there doesn’t seem to be an easy way to look that up; go to the main page, click on the desired radar station, then hunt around on the page to find the 3-letter code. The GIF images have corresponding .gfw worldfiles for georeferencing (latitude/longitude, NAD83), so you can load them into your GIS viewer. The GIF background color is transparent, so if your GIS viewer supports it, you can display the data as an overlay on top of another map, like this one of one-hour-total precipitation on top of a topo map:


Mapping Anthropogenic Biomes

Yesterday’s post was about a site that categorized biomes with very fine divisions based on vegetation, soil moisture, surface lithology, etc., all with the underlying concept that for most areas this was a representation of an actual natural biome. The creators of the concept of anthropogenic biomes go in a different direction; they believe that the impact of man upon the natural landscape has been so profound, with only about 11% of the earth’s surface still truly6 wild,  that most of the biomes of the world must be described by at least partially including the effects of mankind. They’ve broken down biomes into just 21 categories:


And created a world map using these categories:


You can download a PDF of the above image, an ArcGrid file for use in ArcGIS, or a KML file for viewing in Google Earth on this page. Viewed in Google Earth:


Also available are map viewers for this data in Google Maps and Virtual Earth (latter didn’t work on Firefox for me).

You can watch a Discovery Channel video on the concept of anthropogenic biomes here.

Via Highly Allochthonous.

High-Resolution Terrestrial Biome Data

The USGS Global Ecosystems Viewer (background info here) lets you view terrestrial biome data in very fine detail, with extensive categorization levels. Coverage is currently limited to the US, but the background page indicates that the rest of North America, South America and Africa are currently being worked on. Click on the map, and get a popup detailing vegetation classification, lithology, moisture, terrain, and other data:


For this example, the Ecosystems data is:

Southern Rocky Mountain Ponderosa Pine Savanna (580)

Topo Moisture Potential:
Dry Uplands (3)

Land Surface Form:
Hills (6)

Surficial Lithology:
Non-Carbonate Residual Material (3)

Upper Supramediterranean Dry (51)

and the Topographic data:

2248 meters

7375 feet


102° (E)

You can also do a colored plot of any of the ecosystems parameters by themselves, like this one of the Surficial Lithology:


With a button to bring up the legend in a pop-up window:


Background imagery can be satellite photos (as in the example above) with and without borders and placenames, topographic maps (USGS 100K), or no background at all. Finally, you can order data for your current view for download in georeferenced format (UTM, Albers or geographic projection) in ArcGrid, GeoTiff or ERDAS IMAGINE formats. Data will be prepared and available for download via FTP; you get email notice of this, but there’s also a status update page you can use. When I tried it, the data was ready for download in less than five minutes.

Via Spatial Sustain.

Snow Cover Maps

So, the week of December 15-19, when I was supposed to be out doing field surveys in northern Arizona, we got snow. A lot of snow. And it kept going until about December 26th. It’s kind of hard to do a field survey when the ground is covered with snow, but I’ve been hoping the recent bout of warm weather would melt that snow quickly, and let me get back out in the field.

To monitor that situation, I’ve been consulting the US National Weather Service’s National Operational Hydrological Remote Sensing Center (with the snappy acronym NOHRSC). At this time of year, they supply a large number of snow-related data products, including:

Continue reading ‘Snow Cover Maps’

Clickable World Climate Map

The World Weather Map lets you click on a location, and get a plot by month of temperature (max/average/min), rainfall, and average number of hours of sunshine. A fourth tab supposedly gives you “Experiences”, a link list of things to do at that location, but the list sometimes includes activities a long distance (> 100 miles) from that location. You can also add an overlay showing what areas are “Hot”, “Warm” or “Wet” for a particular month.

The main website’s map is also flawed in that there’s no zoom feature, so for areas where the climate can change dramatically over a short distance (like the American Southwest), getting the climate for the exact location you want can be difficult to impossible. (1/24/2008: Fixed by the good folks at WorldReviewer; see the comment below) Oddly enough, there’s a widget version of this map that does include a zoom feature, and which can be embedded in any website, as below. Click and drag to move the map; click on +/- to zoom in and out; click on any point to get the climate data for that location:

For more specific climate data, downloadable for any location on the Earth, try some of the applications described in this post. Via GoogleMapsMania.

Glaciers Of The American West

Portland State University’s Glaciers Online site has maps, photos and data for glaciers of the American West. Contents include:

  • Shapefiles of glaciers and glaciated regions
  • PDF maps from the 1975 government report “Mountain Glaciers Of The Northern Hemisphere”
  • Glacier photos by location and time, highlighting the gradual retreat of glaciers with global warming
  • A queryable online map
  • Bibliography and links to more general info about glaciers (did you know there’s a glacier in Nevada?!)

Sea Level Rise Google Mapplet

From the people who brought you Hey, What’s That? and two Google Mapplets for adding contour lines and terrain profiling to Google Maps comes the Sea Level Rise Visualization mapplet, more advanced than the Flood Maps website mentioned in a previous post. You can set three different flooding levels, and assign different colors to them (red, orange, and yellow):

sea level rise in south Florida

For those diehards out there, you can choose English units (feet) instead of meters, and modify the flooding level numbers and update the map quickly by clicking on the “Go” button. Leaving a level blank omits that color from the map. Here’s an image from south Florida that uses the numbers above:


As the mapplet and my earlier post on Flood Maps point out, there are limitations to this approach deriving from the data. The SRTM data used for this has a spatial resolution of 90 meters, so the results will have a comparable spatial resolution. And SRTM data includes the heights of building and vegetation in the terrain, so urban areas like Miami will have SRTM terrain heights that are higher than the true terrain level, and the flooding level there will be undermapped by this mapplet. You’ll need to use higher resolution data with building/vegetation effects for more accurate results, as is done in this post. But for a quick estimate, this Mapplet does a nice job.Two additional tips on Google Mapplets:

– Google Mapplets aren’t currently accessible from the main Google Maps page; use this Preview link to reach a Google Maps page with an Mapplets tab

– You can reach any Mapplet by creating a single link like this one:; to test it out, just click on the link, and you’ll be given the option of adding this mapplet to Google Maps MyMaps. To create a direct link to any other Mapplet, just replace the text “” with the address of the Mapplet you want to reach. Thanks to Mike Kosowsky of for this tip.