• ES Picture of the Day 23 2021

    From Dan Richter@1:317/3 to All on Fri Jul 23 11:00:34 2021
    EPOD - a service of USRA

    The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
    captions and links exemplifying features within the Earth system. The
    community is invited to contribute digital imagery, short captions and
    relevant links.


    Arcus Cloud over the Villa Gesell Province of Buenos Aires

    July 23, 2021

    _D2_4106 Panorama

    Photographer: Christian Grosso

    Summary Authors: Christian Grosso; Jim Foster

    Featured above is a panoramic view of a severe storm that slammed
    into the Villa Gesell Province of Buenos Aires, Argentina, on February
    14, 2021. The rounded cloud formation is known as an arcus cloud.
    In this case, since it appears to be affixed to the base of the parent
    thunderstorm, it’s called a shelf cloud. A roll cloud is
    detached from its parent storm. These clouds take shape along the
    leading edge of approaching thunderstorm cells as cool air from strong
    downdrafts is pushed into the warmer and moister air that’s feeding
    the storm.

    Photos details: panorama of 9 photos; Canon EOS 7D Mark II camera; 1/40
    sec. exposure; f / 4; ISO 160; 17 mm focal length; Canon EF17-40mm f /
    4L USM lens; 19:30 local time.
    * Villa Gesell, Buenos Aires, Argentina Coordinates: -37.29969,
    -57.00049

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    Severe Weather Links

    * World Severe Weather Information Center
    * Enhanced Fujita Scale
    * A Lightning Primer
    * More About Thunderstorms
    * Staying Safe Outdoors in Severe Weather
    * NOAA Storm Prediction Center
    * Patterns of Lightning Activity
    * US National Weather Service

    -
    Earth Science Picture of the Day is a service of the Universities
    Space Research Association.

    https://epod.usra.edu

    --- up 11 weeks, 12 hours, 15 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)
  • From Dan Richter@1:317/3 to All on Mon Aug 23 11:00:28 2021
    EPOD - a service of USRA

    The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
    captions and links exemplifying features within the Earth system. The
    community is invited to contribute digital imagery, short captions and
    relevant links.


    Midnight Drama

    August 23, 2021


    PSX_20210610_091127 (1)

    Photographer: Soumyadeep Mukherjee

    Summary Authors: Soumyadeep Mukherjee

    The state of West Bengal, along with other parts of India, has seen
    a surge in the number of lightning strikes in 2021. Actually, the
    number of strikes has been increasing over the past several years.
    Meteorologists aren’t sure of the cause, however, one theory points to
    increased air pollution, at least in areas where wildfires are
    prevalent.

    On June 8 of this year, the state of West Bengal alone recorded the
    death of 26 people due to cloud-to-ground lightning strikes. Photo
    taken on June 9, 2021, in Kolkata, India.
    Photo details: This image is a stack of 13 separate images; Nikon D5600
    camera; 18-55 mm lens; f/6.3; 30 seconds exposure; ISO 100; 20 mm.
    Adobe Camera Raw, Photoshop.
    * Kolkata, India Coordinates: 22.5726, 88.3639

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    Cloud Links

    * Atmospheric Optics
    * The Cloud Appreciation Society
    * Cloud Atlas
    * Color and Light in Nature

    -
    Earth Science Picture of the Day is a service of the Universities
    Space Research Association.

    https://epod.usra.edu

    --- up 15 weeks, 3 days, 12 hours, 15 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)
  • From Dan Richter@1:317/3 to All on Thu Sep 23 11:00:30 2021
    EPOD - a service of USRA

    The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
    captions and links exemplifying features within the Earth system. The
    community is invited to contribute digital imagery, short captions and
    relevant links.


    Dazzling Atmospheric Phenomena on Painted Pavement

    September 23, 2021

    IMG_4525-upr-ww(1)

    Photographer: Miroslav Grnja

    Summary Author: Miroslav Grnja; Cadan Cummings

    The picture above is an example of an optical phenomena called the
    opposition effect. The opposition effect occurs when a rough
    surface is illuminated from directly behind and causes an area of
    apparent brightness around the object’s shadow. Specifically, the area
    of brightness is centered around the anti-solar point, which is the
    point directly opposite of the Sun. Similar to the opposition effect,
    glory is another form of optical phenomenon that appears at an
    object’s anti-solar point. Instead of depending on light scattering
    from a surface, a glory happens due to moisture or water droplets in
    the air that reflect and refract sunlight to create a circular
    shaped rainbow.

    In the case of the picture above, the crosswalk was repainted several
    days prior. This newly painted surface with high reflecting and
    scattering properties presumably accentuated the rough texture of the
    pavement and combined with moisture in the air led to these optical
    phenomena being visible around the shadow.
    * Bratislava, Slovakia Coordinates: 48.1486, 17.1077

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    Atmospheric Effects Links

    * Atmospheric Optics
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    * The Colors of Twillight and Sunset
    * Refraction Index
    * Image Gallery: Atmospheric Effects
    * What is a Rainbow?

    -
    Earth Science Picture of the Day is a service of the Universities
    Space Research Association.

    https://epod.usra.edu

    --- up 2 weeks, 6 days, 21 hours, 55 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)
  • From Dan Richter@1:317/3 to All on Sat Oct 23 11:00:24 2021
    EPOD - a service of USRA

    The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
    captions and links exemplifying features within the Earth system. The
    community is invited to contribute digital imagery, short captions and
    relevant links.


    Archive - Flosagjá Canyon, Thingvellir National Park, Iceland

    October 23, 2021

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    August 2015 Viewer's Choice Every weekend we present a notable item
    from our archives.

    This EPOD was originally published August 27, 2015.

    Photographer: Tero Marin
    Summary Author: Tero Marin; Jim Foster
    The photo above shows Flosagjá Canyon in Thingvellir National
    Park, Iceland, It's in this rift valley, on the Mid-Atlantic
    Ridge, where the European tectonic plate and the North American
    tectonic plate meet. Both plates are drifting away from each other --
    spreading apart about 1 in (2.5 cm) per year. Thingvellir was chosen in
    the tenth century as a centrally located meeting place for a general
    assembly of the people of Iceland. Photo taken on May 26, 2015.
    Photo Details: Nikon D7100 camera; AF-S Nikkor 12-24 mm, f/4G; 12 mm;
    ISO 400; f/9; 1/320 sec. exposure.
    * Thingvellir National Park, Iceland Coordinates: 64.258056, -21.125

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    Geology Links

    * Earthquakes
    * Geologic Time
    * Geomagnetism
    * General Dictionary of Geology
    * Mineral and Locality Database
    * Mohs Scale of Mineral Hardness
    * This Dynamic Earth
    * USGS
    * USGS Ask a Geologist
    * USGS/NPS Geologic Glossary
    * USGS Volcano Hazards Program

    -
    Earth Science Picture of the Day is a service of the Universities
    Space Research Association.

    https://epod.usra.edu

    --- up 7 weeks, 1 day, 21 hours, 55 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)
  • From Dan Richter@1:317/3 to All on Thu Dec 23 11:00:30 2021
    EPOD - a service of USRA

    The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
    captions and links exemplifying features within the Earth system. The
    community is invited to contribute digital imagery, short captions and
    relevant links.


    Multiple Lunar Halos and Stary Night Sky

    December 23, 2021

    PSX_20210928_192205(2)

    Photographer: Soumyadeep Mukherjee

    Summary Authors: Soumyadeep Mukherjee; Cadan Cummings

    This feature photo captures several atmospheric optical phenomena
    and night sky objects in the sky over Kolkata, India. Most
    prominently, two types of lunar halos are visible, a 9 degree
    odd-radius and 22-degree halo. Both lunar halos are a product of
    light refraction and reflection from ice crystals in the
    atmosphere. As their names imply, lunar halos are described by their
    apparent radii around the Moon. In addition to the lunar halos,
    several additional objects seen in the night sky included the
    Pleiades approaching a near-conjunction with Moon, rise of the
    "hunter" Orion constellation, and an airplane contrail that
    appears to cross the lunar halos. Overall, this photo shows a busy
    night sky with a lot going on all at once!

    Photo details: Nikon D5600, Tokina 11-16mm atx-i, Digitek DTR 520BH
    Tripod; Exif: 30 × 13 seconds, f/3.2, ISO 160, 11mm (Sky), 6 × 6
    seconds, f/4, ISO 800, 11mm (Foreground)
    * Kolkata, India Coordinates: 22.5726, 88.3639

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    Atmospheric Effects Links

    * Atmospheric Optics
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    * The Colors of Twillight and Sunset
    * Refraction Index
    * Image Gallery: Atmospheric Effects
    * What is a Rainbow?

    -
    Earth Science Picture of the Day is a service of the Universities
    Space Research Association.

    https://epod.usra.edu

    --- up 2 weeks, 4 days, 20 hours, 43 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)