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<div style='text-align:Left;'><p><span style='font-weight:bold;'>Background</span><span>:</span></p><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><span style='font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>Land Information System (LIS) Snow Depth from NASA’s SPoRT Center.</span></p><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><span style='font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>The NASA Short-term Prediction Research and Transition (SPoRT) Center runs the Alaska LIS (LIS-AK), a near-real-time version of the Noah land surface model at 0.03 degree resolution utilizing the NASA Land Information System (LIS) software. The model input is the Global Data Assimilation (GDAS) forcing dataset, which is a near-real-time analysis of various observational data (ground, radar, satellite) consisting of surface meteorology (temperature, humidity, pressure, winds, precipitation) and downwelling long- and short-wave radiation. </span></p><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><span style='font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>Within LIS, the Noah Land Surface Model (LSM) is forced by this input data and produces analyses of soil temperature and moisture in 4 layers plus the snow state and fluxes of energy and water at the surface. The Noah LSM accounts for snow accumulation based on the current LIS snow values in the continuous run and the forcing data from the atmospheric model. Forcing variables influencing the snow depth in LIS include precipitation, air temperature, solar radiation. Relevant modeled processes include compaction of snow, sublimation, and melting.</span></p><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><span style='font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'><br /></span></p><p style='margin: 0in; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><font face='Avenir Next, sans-serif'><span style='font-size: 12pt;'>The Image Service is published using a Raster </span><span style='font-size: 16px;'>Mosaic</span><span style='font-size: 12pt;'> populated with GeoTiffs collected from the Short-term Prediction and Research Transition (SPoRT) FTP sire daily</span></font></p><p><span style='font-weight:bold;'>Data Visualization:</span></p><p style='margin: 0in; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><font size='3'><span style='font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>Snow Depth is shown using a <a style=''>Classified Color Ramp</a></span><span style=''><span style='font-family: "Avenir Next", sans-serif;'> </span></span></font><span style='font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'><font size='3'>(Multi-Color, 16 classes). Snow depth units are inches.</font><span style='font-size: 12pt;'></span></span></p><div style='color: rgb(0, 0, 0);'><div style='font-size: medium;'><div><br /></div></div><div style=''><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><a><b><span style='font-size: 11.5pt; font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>Limitations:</span></b></a></p><div style='font-size: medium;'><div><div><br /></div></div></div></div></div><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><span style='font-size: 11.5pt; font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>Inaccuracies in the forcing data will result in inaccuracies in model data. Large portions of the state are data-sparse so the GDAS forcing data, and hence the LIS output, may be subject to larger errors than usual. Snow depth in coastal areas is subject to higher error and is often underestimated. In some high-altitude, permanently glaciated areas, the model may accumulate too much snow. The Noah (LSM) used within LIS does not represent snow removal or transport from wind scouring. </span></p><p><span style='font-weight:bold;'>Update Frequency:</span></p><p><span>Daily</span></p><p><span style='font-weight:bold;'>Suggested Usage:</span></p><p style='margin: 0in; font-size: 12pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;'><span style='font-size: 11.5pt; font-family: "Avenir Next", sans-serif; color: rgb(76, 76, 76);'>Estimating snow depth. Determining snow-free regions. Informing forecasts of future soil moisture, ground water, and streamflow.</span></p><p><span style='font-weight:bold;'>Further Reference:</span></p><p><a href='https://weather.msfc.nasa.gov/sport/training/articles/202105140234_Nasa-Land_Info_Sys_for_Alaska_starter_guide/media/LISAKstarter/content/#/' target='_blank'>NASA SPoRT Land Information System for Alaska - Starter Guide</a><br /></p><p><a href='https://weather.msfc.nasa.gov/sport/' target='_blank'>Learn more about NASA SPoRT program</a><br /></p></div> |