{ "count": 8, "next": null, "previous": null, "results": [ { "id": 12908, "url": "https://svs.gsfc.nasa.gov/12908/", "result_type": "Produced Video", "release_date": "2018-03-29T11:00:00-04:00", "title": "Scientists Create First-Ever 3D Model of a Melting Snowflake", "description": "This visualization is based on the first three-dimensional numerical model of melting snowflakes in the atmosphere, developed by scientist Jussi Leinonen of NASA's Jet Propulsion Laboratory in Pasadena, California. A better understanding of how snow melts can help scientists recognize the signature in radar signals of heavier, wetter snow -- the kind that breaks power lines and tree limbs -- and could be a step toward improving predictions of this hazard.The model reproduces key features of melting snowflakes that have been observed in nature: first, meltwater gathers in any concave regions of the snowflake's surface. These liquid-water regions merge as they grow and eventually form a shell of liquid around an ice core, finally developing into a water drop. The visualization shows a typical snowflake less than half an inch (one centimeter) long. The snowflake is composed of individual ice crystals whose arms became entangled when they collided in the air. The extremities of the arms melt first because they are more exposed to heat from the surrounding air. Water first fills small cavities within the ice crystals, and then these overflow, allowing water to pool into droplets.\"I got interested in modeling melting snow because of the way it affects our observations with remote sensing instruments,\" Leinonen said. A radar \"profile\" of the atmosphere from top to bottom shows a very bright, prominent layer at the altitude where falling snow and hail melt, much brighter than the layers above and below. \"The reasons for this layer are still not particularly clear, and there has been a bit of debate in the community,\" Leinonen explained. Simpler models can reproduce the bright melt layer, but a more detailed model like this one can help scientists to understand it better, particularly how the type of melting snow and the radar wavelengths used to observe it relate to the brightness of the layer.A paper on the numerical model, titled \"Snowflake melting simulation using smoothed particle hydrodynamics,\" recently appeared in the Journal of Geophysical Research - Atmospheres. || ", "hits": 20 }, { "id": 4629, "url": "https://svs.gsfc.nasa.gov/4629/", "result_type": "Visualization", "release_date": "2018-03-29T00:00:00-04:00", "title": "Snowflakes Melting Simulation Over Turntable", "description": "Clockwise rotating turntable of a cluster of melting snowflakes. || turntable_v39.0000_print.jpg (1024x576) [69.2 KB] || turntable_v39.0000_searchweb.png (320x180) [34.1 KB] || turntable_v39.0000_thm.png (80x40) [3.4 KB] || turntable_v39_1080p30.mp4 (1920x1080) [13.2 MB] || 1920x1080_16x9_30p (1920x1080) [0 Item(s)] || turntable_v39_1080p30.webm (1920x1080) [2.7 MB] || turntable_v39_1080p30.mp4.hwshow [187 bytes] || ", "hits": 26 }, { "id": 4630, "url": "https://svs.gsfc.nasa.gov/4630/", "result_type": "Visualization", "release_date": "2018-03-29T00:00:00-04:00", "title": "Falling Snowflakes Melting Simulation", "description": "Simulation of a melting snowflakes tumbling. || falling_flake.0000_print.jpg (1024x576) [54.2 KB] || falling_flake.0000_searchweb.png (320x180) [25.3 KB] || falling_flake.0000_thm.png (80x40) [2.6 KB] || falling_flake.0.mp4 (1920x1080) [12.3 MB] || 1920x1080_16x9_60p (1920x1080) [0 Item(s)] || falling_flake.0.webm (1920x1080) [2.7 MB] || falling_flake.0.mp4.hwshow [202 bytes] || ", "hits": 50 }, { "id": 12507, "url": "https://svs.gsfc.nasa.gov/12507/", "result_type": "Produced Video", "release_date": "2017-02-17T05:00:00-05:00", "title": "GPM Gets Flake-y", "description": "The Global Precipitation Measurement can help improve numerical weather predictions of snowfall by measuring the size and shape distribution of snow particles, layer by layer, in a storm. || ", "hits": 31 }, { "id": 40317, "url": "https://svs.gsfc.nasa.gov/gallery/vcearth-video-wall/", "result_type": "Gallery", "release_date": "2017-02-02T00:00:00-05:00", "title": "VC Earth Video Wall", "description": "list of videos to display on video wall in Earth science exhibit at Goddard Visitor Center", "hits": 6 }, { "id": 12185, "url": "https://svs.gsfc.nasa.gov/12185/", "result_type": "Produced Video", "release_date": "2016-03-31T14:00:00-04:00", "title": "Instagram: Why Do Raindrop Sizes Matter In Storms?", "description": "Not all raindrops are created equal. The size of falling raindrops depends on several factors, including where the cloud producing the drops is located on the globe and where the drops originate in the cloud. For the first time, scientists have three-dimensional snapshots of raindrops and snowflakes around the world from space, thanks to the joint NASA and Japan Aerospace Exploration Agency Global Precipitation Measurement (GPM) mission. With the new global data on raindrop and snowflake sizes this mission provides, scientists can improve rainfall estimates from satellite data and in numerical weather forecast models, helping us better understand and prepare for extreme weather events. || ", "hits": 27 }, { "id": 12182, "url": "https://svs.gsfc.nasa.gov/12182/", "result_type": "Produced Video", "release_date": "2016-03-31T13:00:00-04:00", "title": "Why Do Raindrop Sizes Matter In Storms?", "description": "Not all raindrops are created equal. The size of falling raindrops depends on several factors, including where the cloud producing the drops is located on the globe and where the drops originate in the cloud. For the first time, scientists have three-dimensional snapshots of raindrops and snowflakes around the world from space, thanks to the joint NASA and Japan Aerospace Exploration Agency Global Precipitation Measurement (GPM) mission. With the new global data on raindrop and snowflake sizes this mission provides, scientists can improve rainfall estimates from satellite data and in numerical weather forecast models, helping us better understand and prepare for extreme weather events.Watch this video on the NASA Goddard YouTube Channel. || ", "hits": 128 }, { "id": 40118, "url": "https://svs.gsfc.nasa.gov/gallery/gpm/", "result_type": "Gallery", "release_date": "2000-01-01T00:00:00-05:00", "title": "Global Precipitation Measurement", "description": "The Global Precipitation Measurement (GPM) mission is an international network of satellites that provide the next-generation global observations of rain and snow. Building upon the success of the Tropical Rainfall Measuring Mission (TRMM), the GPM concept centers on the deployment of a \"Core\" satellite carrying an advanced radar / radiometer system to measure precipitation from space and serve as a reference standard to unify precipitation measurements from a constellation of research and operational satellites. Through improved measurements of precipitation globally, the GPM mission helps to advance our understanding of Earth's water and energy cycle, improve forecasting of extreme events that cause natural hazards and disasters, and extend current capabilities in using accurate and timely information of precipitation to directly benefit society. GPM, initiated by NASA and the Japan Aerospace Exploration Agency (JAXA) as a global successor to TRMM, comprises a consortium of international space agencies, including the Centre National d'Études Spatiales (CNES), the Indian Space Research Organization (ISRO), the National Oceanic and Atmospheric Administration (NOAA), the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), and others. The GPM Core Observatory launched from Tanegashima Space Center, Japan, at 1:37 PM EST on February 27, 2014.For more information and resources please visit the Precipitation Measurement Missions web site.", "hits": 437 } ] }