Geographic Information Network of Alaska

University of Alaska Fairbanks - Geographic Information Network of Alaska

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Today GINA celebrates the 17th Anniversary of satellite data imagery reception by the GINA owned and operated “Big Dog” antenna located on the roof of UAF’s Akasofu building.  The featured image is the first satellite pass down linked on August 23, 2001, at 01:22 GMT.

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In case you are wondering what the scaffolding around our UAF antenna is all about, we are doing regular maintenance on the housing.  It should be completed in 7-10 days.

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Ship Tracks: Contrails of the Sea

Just as aircraft can leave a condensation trail (or “contrail”) as they zip across the sky, some ships can leave a stripe in the clouds revealing their location and course.  

The GOES-16 geostationary satellite cannot see Alaska, but here is a nice movie loop over the north Atlantic showing some ship tracks at night and then during the day after the sun has risen.  Special thanks to the crew at the Cooperative Institute for Research in the Atmosphere (CIRA) for posting this loop!

http://rammb.cira.colostate.edu/ramsdis/online/loop.asp?data_folder=loop_of_the_day/goes-16/20171031000000&number_of_images_to_display=200&loop_speed_ms=100

Just like not every airplane leaves a contrail, not ever ship leaves a ship track.  The determining variables are the ambient atmospheric conditions: what is the temperature, what’s the humidity, what are the winds?  When atmospheric conditions are right, the addition of comparatively small amounts of heat and water vapor from an internal combustion engine can tip the balance and yield a distinct ribbon of cloud.  

Below is a longwave thermal infrared (IR) image over Alaska as taken by the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on the polar-orbiting Suomi National Polar Partnership (SNPP) satellite taken at about 4:30am on November 2nd of this year.   When you look at a thermal IR image like this, you see temperatures, either the temperature of a cloud top or the temperature of the land or sea surface in places that are free of clouds.  Warm temperatures (comparatively warm, that is) appear as dark gray, and the color scheme changes to whiter temperatures as cool, eventually showing as yellow or even red for very cold cloud tops or very cold inland valleys where clear skies allow a temperature inversion to develop.

It’s tough to see here in this IR image, but there is a mix of cloudy and clear areas over the Gulf of Alaska and over the north Pacific south of the Alaska Peninsula and eastern Aleutians.  Look closely, and you can see slightly different shades of gray in this area.  The reason it’s tough to discern which regions are cloudy and which are clear is that the temperature of the clouds and the temperature of the sea surface are almost identical.  Infrared imagery only reveals temperatures.  If two objects have similar temperatures, like the clouds and the open ocean in this case, then those objects will appear very similar in the thermal infrared imagery.  

This problem is easily solved during the daytime by also consulting visible spectrum imagery, the wavelengths that the human eye sees, where cloudy skies and clear skies look very different even if their temperatures are similar.  But at 4:30am in Alaska in November it is quite dark out, so visible spectrum imagery will be of no help.  Or will it?  The amazing Day Night Band (DNB) on the VIIRS instrument senses every last bit of moonlight or starlight to produce visible spectrum imagery even in the middle of the night.  

The above DNB image is from exact time as the longwave thermal IR image at the top of this blog post.  Note how in this DNB picture the distinction between cloudy areas and clear areas is easy to make.  And getting back to the theme, there are some ship tracks in the clouds south of the Alaska Peninsula and eastern Aleutians.  A zoom into this area will highlight the ship tracks more clearly:

To learn more about ship tracks, consult this nifty Wikipedia page:  

 https://en.wikipedia.org/wiki/Ship_tracks  

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GINA is now producing sea surface temperature (sst) products from direct broadcast data for MODIS, AVHRR, and VIIRS.  We are producing these products on a test basis to evaluate their usefulness to our users.

The satellite data is processed using the ACSPO the Community Satellite Processing Package (CSPP) release of the NOAA/STAR Advanced Clear Sky Processor for Oceans (ACSPO) processing package.

Since this product is derived from infrared imager data, areas covered by clouds are masked and assigned “no data” SST values. This is also true for land and other areas determined to have invalid SST values.

The GeoTIFF files are being produced for each pass along with a mosaic and are intended for desktop GIS users (like ArcMap).  The geotiff contain a floating point temperature value in Kelvin and are made at the sensor resolution.   A index of the geotiff data available can be found here.

AWIPS ready data is also being produced for use by the National Weather Service Alaska.

If this data might be useful, please drop us a line at [email protected]  .

-Jay, Carl, and the rest of the folks at GINA

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Satellites that see through clouds

Typically, weather forecasters use satellites to monitor changing cloud formations, but traditional views of clouds from space are limited to the tops. At times, something much more interesting is going on below.  Wouldn’t it be great if there was a satellite sensor that could see into the cloud, or even all the way through to the earth’s surface?  Well in fact there is. Microwave radiation emitted from the earth and the atmosphere has a much longer wavelength than visible light or infrared radiation, so it is less affected by tiny cloud droplets. 

To take advantage of this characteristic, there are currently a number of polar orbiting satellites with sensors that measure emitted microwave radiation. The information they collect is used to detect atmospheric and surface features regardless of whether they are obscured by clouds or not.  Microwave sensors can detect rainfall, sea ice, soil moisture, snow cover, ocean winds and many other things.

Two microwave products are particularly important for monitoring moisture in the atmosphere. One is “Total Precipitable Water” (or TPW), and the other is “Rain Rate”. TPW is a measure of the depth of water in a column of the atmosphere if all the water in that column were precipitated as rain.  Rain Rate is an estimate of the amount of rain actually falling at that instant. So the units of TPW are millimeters (or inches) and the units of rain rate are millimeters (or inches) per hour.

These two microwave products are especially important for weather forecasting in Alaska because storms that approach from the Pacific Ocean often have very little observed information that can help assess intensity. Even when these storms near the Alaskan coast, there area a limited number of weather radars and their coverage is significantly blocked by high terrain.

The animation above is a sequence of traditional 11um Infrared images from SNPP and MetOp polar satellites between 1118 UTC 17 Aug 2017 and 0447 UTC 18 Aug 2017. The color enhancement highlights colder temperatures where red to fuchsia are the coldest. Typically the coldest clouds are also the highest, and high cloud tops are assumed to have the strongest development with the most rain, but that is not always the case.

The next animation above is the microwave TPW or Total Precipitable Water product for the same time period as shown above. Here we are looking at moisture. The largest moisture values are shown in green to yellow colors.  From this set of images you can see that there is a huge area of very moist air. When compared with the Infrared animation, you’ll notice this falls to the southeast of the highest cloud tops. This may indicate a potential for rain, but we still are not sure what is currently making it to the ground. 

This final animation above is similar to the previous one but with Rain Rate plotted on top of TPW.  In these images, pink shows lighter rain rates with blue to cyan (and a few yellow) pixels showing where the rain rates are the greatest.  Maximum rain rates reach .20-.25 inches per hour in each of the passes. Although there are some areas where the cold (and thus, higher) cloud tops match the heaviest rain rates, significant rain rates extend over a much larger area than the cloud tops alone would suggest. 

Also, traditional IR animation shows the clouds becoming less organized by the last frame, while significant rain rates are still indicated along the coast over central and southern southeast Alaska. Although difficult to see in this animation, one other thing to note is that the high rain rates did not extend to the northern portion of southeast Alaska.

So, what actually happened on the day of this event?  Below are 24 hour rain amounts on 17 Aug 2017 for a few southeast Alaska cities. The heavier amounts were indeed significant and primarily located in the central and southern portions of the panhandle: Southeast Alaska Rainfall August 17, 2017 Skagway      0.18 in  (northern SE Alaska) Haines         0.20 in  (northern SE Alaska) Juneau        1.20 in  (central SE Alaska) Annex Cr.    1.61 in  (central SE Alaska) Sitka            1.65 in  (central SE Alaska) Point Baker  1.11 in  (central SE Alaska) Annette        1.01 in  (southern SE Alaska) Hyder           1.48 in  (southern SE Alaska)

In the previous event, the areas of high rain rates were not far from the coldest (highest) cloud tops, but as mentioned earlier this is not always the case. 

In the image sequence above, the microwave rain rate is toggled on/off as an overlay on an 11um infrared image with the same color enhancement used previously.  In this example the coldest cloud tops are well to the east of the main rain area, more than 250 miles in some locations. 

As these examples illustrate, microwave TPW and Rate Rates can be important tools for monitoring what is occurring in the whole atmosphere and not just at the top of clouds. They are especially critical for ocean storm systems where radar and other in situ observations are few and far between.

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No Northern Lights, but Plenty of Southern Shadows

Today’s total eclipse may have missed Alaska, but weather satellites had a great view.  Here is a loop from the new GOES-16 satellite showing the moon’s shadow zipping across the Lower 48.  

This imagery is a combination of three channels ranging from visible light into the near infrared spectrum, and these wavelengths all have one thing in common: they respond to sunlight bouncing off of the clouds, land, and ocean.  When the moon briefly blocks out the sun, such as during today’s eclipse, these is no sunlight to bounce of the targets below, and thus briefly darkness becomes visible.

http://col.st/DGcte

GINA works with the satellite proving ground community to bring the newest tools and techniques in satellite meteorology to forecasters working with the National Weather Service and others.  You may note that Alaska is not covered in this imagery, as the longitude at which GOES-16 hovers is simply too far east to allow a good look at Alaska.  But worry not: GOES-17 will be in orbit within another year or two, and at a longitude far enough west to provide a great view of Alaska (and Hawaii, for that matter).  Today’s imagery from GOES-16 offers Alaskans a preview of the improvements yet to come.

This loop, and the website hosting this very nice interface for interrogating all kinds of imagery from the GOES-16 satellite, is maintained by the professionals at the Cooperative Institute for Research in the Atmosphere (CIRA) in Colorado. 

 http://rammb-slider.cira.colostate.edu

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As They Say to the Kid in Right Field, “The Ball Will Find You”

While the 2017 wildfire season has been comparatively quiet to date, there are indeed some fires chewing up the landscape over Alaska’s northeastern Interior, and now much of the state is beginning to notice.

This image below was taken by the Suomi National Polar Partnership (S-NPP) satellite as it glided over Alaska this afternoon.  The wavelengths shown here are exactly what the human eye would see if we could hitch a ride on the S-NPP satellite.  While weather satellites can detect signals across a variety of wavelengths including infrared and microwave, it turns out that the visible spectrum with which we humans are quite familiar is one of the best ways to highlight the smoke plumes from wildfires.  With high pressure draped along the Brooks Range, a northeasterly flow is blowing the smoke from its point of origin in the northeastern Interior toward the southwest and across much of the state.

Here in the Fairbanks area the smoke has thus far mainly remained aloft, with the results being an orange color to the sun and a tinge of smoky smell in the air. The National Weather Service forecasts a change in wind direction after a few more days which will push the smoke eastward into Canada.

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Hello! My name is Roberta Glenn, and I recently graduated from the University of Alaska Fairbanks (UAF) with a B.S. in Geography, focusing on landscape analysis and climate change studies. I’m an intern this summer with ASRC Federal and the UAF Geographic Information Network of Alaska (GINA). 

This summer I’m working on identifying satellite products that may be useful for subsistence hunters on the North Slope. Previously, hunters and whalers were only able to get their hands on good and useful satellite data when scientists were in town doing research. In 2013 I interned with the North Slope Borough Wildlife Management Department in early spring when whaling was just getting started, and the sea ice was taking longer than usual to open up a lead. One of my daily tasks was to pull data directly from the National Snow and Ice Data Center and examine the ice conditions to look out for any open leads around Utqiagvik. 

This summer I hope to put together a collection of useful mapping resources, as well as make these resources easily available to those who may benefit from them. I’m looking forward to speaking with my fellow Utqiagvigmiuts about what kinds of products may be useful and how these products should be made available (webpage, PDF, GIS package, etc.). Quyanaq!

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Thank You

Hello again everyone!

This is my final tumblr post on my final day of work here at GINA!  I graduated this past spring semester so unfortunately will not be able to continue here, but instead will be pursuing graduate school this fall and am currently conducting archaeological field work and research.  

I have been working at GINA as a student employee and intern through EPSCOR since May 2015, and have loved every minute of it! Everyone that I have had the chance to work with over the past few years have been some of the best and supportive people I have had the chance to work with during my undergraduate career.  I have learned invaluable skills since I have been here, and have had the opportunity to create my own projects, be apart of public outreach scenarios, and present projects at conferences at UAF (to name just a few of the many things I have had the chance to do).  

Before working with GINA I was unclear of what GIS (Geographic Information Systems) was about, but now two years later I know not only what it is but have changed my minor to GIS and will be focusing on it and its application in archaeology with future research and graduate school work.  Without a doubt, if it not for my work here at GINA I would not be as ahead as I am in my own personal career, and I deeply appreciate the opportunity I was given here.  

Thank you again to my coworkers at GINA and EPSCOR for the past two years, and I wish you all the best!

-Nicolette Edwards

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Hello everyone! 

My name is Nicolette Edwards, and I have been working at GINA as a student employee through EPSCOR since May 2015, and this summer will mark my third one here.  My degree is a BA of Anthropology with a focus on archaeology and a Geographic Information Systems (GIS) minor, and I am especially interested in how humans impact their surrounding environment in the past and present.  Since I graduated in May, I will only be here until the end of June, but I am excited about the projects I will be working on and finishing up until then! 

The main project I have been working on over the past couple of months is EPSCOR’s Salmon 2050 Project which is a “A Participatory Scenario Planning Project for the Kenai River Watershed” that created a total of five different scenarios based on the possible different environmental conditions that may occur in 2050.  Each of these scenarios has their own specific guidelines and stipulations.  My focus is on the urban development side of this project, where I utilize ArcGIS to create a visual for each scenario and provide realistic expectations of both domestic housing and commercial businesses based on the potential environmental conditions.  An example of this is provided in the picture above! It is only one scenario (out of five) but it provides a good example of how much the environment could be effected based upon human’s expansion and growth. For more information of the project as a whole, here is a link to EPSCOR’s page: 

http://southcentral.epscor.alaska.edu/salmon-2050

Also, on June 10th I will be showcasing our Augmented Reality Sandbox at Denali’s Summerfest.  If you are not familiar with it, it is a sandbox with a projection simulating landscapes (specifically with distinct elevations) that changes based on on how the sand is formed.  It also has the ability to imitate water in both flow and accumulation and how it would move about the formed landscape! Here is a YouTube link for those interested: 

https://www.youtube.com/watch?v=lqj4gxCE128

Thank you for reading and have a great summer!

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Hi! My name is Ianjon Brower and I'm working for ASRC-Federal and GINA this summer. My project for this summer is going to be prototyping a Raspberry Pi with specific sensors that monitor the temperature (and other things) of ice cellars that is easy for anyone to use! These ice cellars are in native villages such as Utqiagvik, Nuiqsut, and many more.  The reason we need to do this work is that some of the ice cellars have been filling up with water by melting and this is ruining their storage for all year around. 

What's in an ice cellar you ask? It's use to store all the hunted game that's found locally to preserve. It's a natural big freezer that’s supposed to stay ice cold all year around. We are going to get some data to figure out why this is happening! I have a lot of learning to do for this project and the people here are a great help.

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UAF GINA recently orthorectified historical aerial photography from 1950 and 1984 covering Anchorage for the Alaska EPSCoR program.  These images are useful for conducting a variety of change detection analyses on the landscape.  The image data is freely available by contacting UAF GINA at: [email protected].

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An Eruption of Bogoslof Seen Through Multispectral Imagery

On the morning of 03/08/17, Eric Stevens and I had the opportunity to visit the Anchorage NWS Weather Forecast Office as part of a coordinated trip to discuss a collaboration between the Satellite …

Volcanic eruption monitoring using both geostationary (Himawari) and polar orbiting (SNPP) satellite imagery, RGBs, and derived volcanic ash products. 

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Spring is in the Air

With days getting longer and daily high temperatures tending to occur in the afternoons as opposed to at random hours day or night, spring breakup in Alaska cannot be far away.   GINA receives satellite data from the Visible Infrared Imaging Radiometer Suite (VIIRS), and this data is then turned into several kinds of satellite imagery useful for the National Weather Service (NWS). 

One such product, shown below, is designed to highlight floods associated with spring breakup.  This is a screen capture from the NWS’ operational workstation at the River Forecast Center in Anchorage.  The big image is derived from GINA’s VIIRS data.  Since Alaska is still mostly covered with snow, this product is still mostly white.  But as the snow melts, the white will recede, and any overland flooding will be shown in hot colors ranging from yellow to fire-engine red.  

Get your breakup boots out of the closet and stand by for further updates as Spring Breakup 2017 gets underway.

--Eric

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Holy Mackerel, Look at Those Clouds

The Suomi National Partnership Program (S-NPP) weather satellite flies over Alaska several times a day, and shortly before noon on Saturday, February 25 caught the above image highlighting the classic “mackerel sky” over Alaska’s Interior composed of parallel rows of altocumulus clouds.  

While snow, clouds, and ice all appear white to the human eye, the wavelengths of light and energy detected by the S-NPP weather satellite can be combined to depict clouds as pink, and snow and ice on the ground appear as cyan. In scenarios like this, the lower the clouds are, the more pink they look.  Clouds at higher elevations appear wispier and include overtones of white or even blue tints. A zoomed version of the image is included below and better shows these amazing clouds.

This type of satellite imagery requires that sunshine bounce off the clouds and the landscape, so as the sun returns to Alaska with the transition from winter to spring, this kind of satellite imagery will be available more and more often.  

For additional examples of this imagery, and other kinds of imagery as well, check out GINA’s “Puffin Feeder” website at http://feeder.gina.alaska.edu/  More information about the S-NPP satellite and the new series of Joint Polar Satellite System (JPSS) satellites to be launched in the future can be found at the website http://www.jpss.noaa.gov/ 

--Eric Stevens

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“Too Many Lights, Too Many Sources”  ...or...  “Who Put the Bogus in Bogoslof?”

As described in this blog post, https://uafgina.tumblr.com/post/155398902124/volcanoes-aurora-and-clouds-oh-my, during hours of darkness, the Day Night Band detects visible light from a number of sources including reflected moonlight, the northern lights, city lights, ships, and even volcanoes.  

Satellite imagery, and not just the Day Night Band, has been used before to identify volcanoes.  For example, here’s a blog post from the University of Wisconsin showing imagery capturing the eruption of Pavlof Volcano in 2014. http://cimss.ssec.wisc.edu/goes/blog/archives/17179

So one might ask, is it possible to see a bright spot from Bogoslof Volcano in Day Night Band imagery?  It turns out this is unlikely.  Dave Schneider of the USGS’ Alaska Volcano Observatory mentions that the business end of Bogoslof Volcano, its “vent,” is under water and is thus not able to shine particularly brightly from the point of view of a weather satellite.  But wait, then what’s that bright spot in the Day Night Band imagery if it is not a volcano?  It turns out this is actually the town of Unalaska.  As shown in the map below, Bogoslof is about 35 miles northwest of Unalaska Island, and if you’re not careful, the lights of the small town of Unalaska could be mistaken for the lights of a volcano’s vent…and that is exactly the error in the previous blog post.  

Just this very morning Bogoslof got out of bed in a bad mood, perhaps upset about recent inaccuracies in this blog, and unleashed an explosive eruption sending a volcanic cloud up to 30,000 ft.  For the latest information on developments at Bogoslof, please consult the Alaska Volcano Observatory’s web site https://www.avo.alaska.edu/activity/Bogoslof.php

Also, a general description of Bogoslof is available at this link http://www.avo.alaska.edu/volcanoes/volcinfo.php?volcname=Bogoslof

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Volcanoes, Aurora, and Clouds, Oh My!

The Day Night Band is a special channel on the Suomi National Polar Partnership (SNPP) weather satellite that can detect very faint sources of light even over Alaska during the darkest time of the year.  This image was taken at 3:21 am Alaska Standard Time on Friday, December 23.  

Note the prominent waves of aurora streaking across the state.  Sometimes the aurora can move faster than the Day Night Band can really keep up with, and in those situations the aurora can have a slightly smeared or striped appearance.  Zoom into the aurora shown in this image, and you can see the aurora’s jagged edge.  This phenomenon has been observed before and is described nicely in this blog post http://rammb.cira.colostate.edu/projects/npp/blog/index.php/uncategorized/aurora-australis-from-the-day-night-band/ 

Also note in the lower left corner of this image a faint smudge of light shining through a deck of clouds down at the end of the Alaska Peninsula (area highlighted in the yellow circle).   This is Bogoslof Volcano erupting, and is right next door to Palvolf Volcano whose previous eruptions have also been observed in the Day Night Band.   Similar activity at Bogoslof continued through the holidays and into this first week of January.  The latest information concerning Bogoslof is available at the Alaska Volcano Observatory’s website https://www.avo.alaska.edu/  

And lastly, even in the middle of an Alaskan night just a couple of days after the winter solstice, the Day Night Band detects clouds and their associated weather systems.  Note the clear skies over Kodiak Island and the western Gulf of Alaska, while much of the Bering Sea and Southeast Alaska have patchy cloud cover.  Day Night Band imagery, as well as other kinds of imagery from weather satellites, are available at GINA’s website http://feeder.gina.alaska.edu/