1. JRBids

    JRBids Senior Member

    What are these blue splotches? I did do a search, can't find.


    [Mod Edit] It's migrating birds, see discussion below
    Last edited by a moderator: May 12, 2016
  2. Mick West

    Mick West Administrator Staff Member

    Looks like it's an unprocessed dataset showing artifacts near each stations from bugs, birds, and bats.



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  3. deirdre

    deirdre Moderator Staff Member

    image search pulls up alot of similar maps and they all say "birds"
    birds1. birds2.PNG
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  4. Spectrar Ghost

    Spectrar Ghost Senior Member

    Last edited by a moderator: May 12, 2016
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  5. Chew

    Chew Senior Member

    Before radar they used the moon to estimate the populations of birds that migrated at night:

    Last edited by a moderator: May 12, 2016
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  6. Mick West

    Mick West Administrator Staff Member


    Some keywords for searches: Aerofauna, Bioscatter, biological scatterers.
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  7. JRBids

    JRBids Senior Member

    Thanks. Doh! I should have known that. Sorry Mick I saw you'd asked where I got it from, had a bit of food poisoning and haven't been online the last couple of days. ;(
  8. CeruleanBlu

    CeruleanBlu Member

    Another example of this tonight:


    National Weather Service Greenville-Spartanburg, SC reports the following:

    Source: https://twitter.com/NWSGSP/status/851984022972624897
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  9. chemfiend

    chemfiend New Member

    those blooms happen at night, every night,unless it is workin a storm,not birds or bats cause it happens at night in the winter too!
  10. chemfiend

    chemfiend New Member

    only geese and cranes migrate at night and it isnt in a circular blob, the bloom starts at the radome and goes outward in a circle
  11. Spectrar Ghost

    Spectrar Ghost Senior Member

    The lowest elevation on a WSR-88D is 0.5 deg. It starts at the radar and works outward because the beam is lowest to the ground nearest the radar. You're not seeing the returns spread outward, you're seeing them spread upward.
  12. scombrid

    scombrid Senior Member

  13. scombrid

    scombrid Senior Member

    This is a really cool year-long timelapse of radar and infrared satellite imagery. You can see the pattern of nocturnal radar "blooms" in the spring and fall in relation to weather systems. If you skip to the 8 minute mark and watch from 8:00 to 9:00 you can really see the fall migration pouring down to the southeast and gulf coasts. The birds come down behind the cold fronts and then really pool up along the coast then the fronts stall out over Florida. We get to see a lot of cool birds here for a couple of days until the next bigger front clears the state and the birds decide to make the trans-gulf flight to South America.

    Source: https://www.youtube.com/watch?v=D13pthfl0bM&t=15s
    Last edited: Apr 12, 2017
  14. scombrid

    scombrid Senior Member

    Someone asked in the comments about the "stationary blobs" that formed almost every day from April to June. I paste my reply here:

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  15. chemfiend

    chemfiend New Member

    so these radar blooms the blossomed around nine pm like every night , and that are still blooming at 2am, are migrating birds and bats? highly unlikely considering nothing is migrating and there isnt swarms of bats all night long.
  16. Trailblazer

    Trailblazer Moderator Staff Member

    Read the above posts. Yes, millions of birds migrate at night each spring and autumn.

    No, again read the links above. Many, in fact most, species of land birds migrate at night.


    That same article states that as many as 5 billion birds migrate in North America each fall (autumn), so presumably a similar number migrate in the other direction each spring.
    Last edited: Apr 14, 2017
  17. scombrid

    scombrid Senior Member

    I'll reiterate:

    Type bird migration radar into Google Scholar to learn more than you may care to know about tracking bird migration with radar.


    Some of the articles go back quite a few decades. As soon as radars were deployed to detect other stuff in the air there were biologists that had the idea that radars could provide a glimpse into the unseen world of nocturnal bird migrations.
  18. chemfiend

    chemfiend New Member

    ionization of the atmosphere for geoengineering maybe, migrating birds it is not!
  19. Svartbjørn

    Svartbjørn Senior Member

    State your source.

    State your source.

    State your source.
  20. Whitebeard

    Whitebeard Senior Member

    Many small birds migrate at night, fewer predators around to hunt them. OK there are owls, but owls are on the whole hunters of ground prey not aerial targets

    And don't forget nocturnal insectivorous species such as the Nightjars, which prey on night flying insects such as moths
  21. solrey

    solrey Senior Member

  22. Trailblazer

    Trailblazer Moderator Staff Member

    These radars show what is happening at relatively low altitude, where rain is falling (and birds are flying). If the atmosphere was being "ionised" then it would be conductive, and you'd see obviously effects such as overhead power lines arcing to ground. Have you got any evidence for this? And are you suggesting that the numerous scientists who track migrating birds by radar are mistaken?
  23. scombrid

    scombrid Senior Member

    Weather radar just an antenna scanning the sky for reflections of its own broadcast radio waves and then a computer displaying graphical representations of the returned signal.

    If there is "ionization" in the atmosphere you won't see it on a weather surveillance radar. The weather radar is showing you things that are big enough and solid enough to reflect the radio waves back. Doppler shift of the signal tells you the velocity of the target relative to the radar station. Intensity of the signal is used to estimate the number of targets after other mathematical gyrations estimate the average size of the targets.

    But the simple fact is that the weather radar only "sees" objects that are reflective of the wavelength that it broadcasts in the first place.
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  24. Ross Marsden

    Ross Marsden Senior Member

    They could also be insects; moths, for instance.