Content: Volumetric Soil Moisture

datasets/sport-lis.data.mdx

@@ -0,0 +1,101 @@
+---
+featuredOn: []
+id: soil-moisture
+name: SPoRT Land Information System
+description: SPoRT’s real-time instance of the Land Information System provides low-latency soil moisture analyses that help diagnose rapid drought onset and elevated wildfire threat.
+media:
+ src: ::file ./soil-moisture-main.jpg
+ alt: Dry Clay Wall with Cracks
+ author:
+ name: Clay Banks
+ url: https://unsplash.com/photos/EdscD_R28bM
+thematics:
+ - eis
+layers:
+ - sourceParams:
+ resampling: bilinear
+ bidx: 1
+ colormap_name: rdylbu
+ rescale:
+ - 0
+ - 100
+ nodata: 9999.0
+ name: 0-100 cm Soil Moisture Percentile of normal
+ legend:
+ type: gradient
+ min: "0"
+ max: "100"
+ stops:
+ - "#a50026"
+ - "#f46d43"
+ - "#fee090"
+ - "#e0f3f8"
+ - "#74add1"
+ - "#313695"
+ type: raster
+ id: sport-lis-vsm0_100cm-percentile
+ description: "The NASA Short-term Prediction Research and Transition (SPoRT) Center has developed a Real-Time Land Information System (LIS). The Volumetric Soil Moisture product represents the actual moisture in a soil column from 0-100cm in depth."
+ stacCol: sport-lis-vsm0_100cm-percentile
+ zoomExtent:
+ - 2
+ - 16
+ compare:
+ datasetId: soil-moisture
+ layerId: sport-lis-vsm0_100cm-percentile
+ mapLabel: |
+ ::js ({ dateFns, datetime, compareDatetime }) => {
+ return `${dateFns.format(datetime, 'MMM yyyy')} VS ${dateFns.format(compareDatetime, 'MMM yyyy')}`;
+ }
+---
+
+<Block>
+ <Prose>
+ The NASA Land Information System (LIS) is a high-performance land surface modeling and data assimilation system used to characterize land surface states and fluxes by integrating satellite-derived datasets, ground-based observations, and model re-analyses. The NASA SPoRT Center at MSFC developed a real-time configuration of the LIS (“SPoRT-LIS”), which is designed for use in experimental operations by domestic and international users. SPoRT-LIS is an observations-driven, historical and real-time modeling setup that runs the Noah land surface model over a full CONUS domain. It provides soil moisture estimates at approximately 3-km horizontal grid spacing over a 2-meter-deep soil column and has been validated for regional applications.
+
+ SPoRT-LIS consists of a 33-year soil moisture climatology spanning from 1981 to 2013, which is extended to the present time and forced by atmospheric analyses from the operational North American Land Data Assimilation System-Phase 2. The 33-year soil moisture climatology also provides the database for real-time soil moisture percentiles evaluated for all U.S. counties and at each modeled grid point. The present-day soil moisture analyses are compared to daily historical distributions to determine the soil wet/dry anomalies for the specific time of year. Soil moisture percentile maps are constructed for the model integrated layers, and these data are frequently referenced by scientists and operational agencies contributing to the weekly U.S. Drought Monitor product. 
+
+ The SPoRT-LIS bridges the 4-day latency gap in NLDAS-2 atmospheric forcing input by incorporating forcing from the National Centers for Environmental Prediction Global Data Assimilation System in combination with hourly Multi-Radar Multi-Sensor precipitation estimates. The real-time component of the SPoRT-LIS updates every 6 hours, and also includes a forecast component that produces soil moisture percentiles out to 2 weeks. Another unique feature of SPoRT-LIS is the incorporation of daily, real-time satellite retrievals of Green Vegetation Fraction since 2012, which results in more representative evapotranspiration and ultimately soil moisture estimates than using a fixed seasonal depiction of vegetation in the model. 
+
+ </Prose>
+</Block>
+
+<Block>
+ <Prose>
+ ## Interpreting the Data
+
+ A variety of output variables are used to depict soil moisture in the SPoRT-LIS analyses. Volumetric soil moisture shows the fraction of volume of water occupying the total soil volume and typically ranges from ~0.03 to 0.45, depending on the defined sand-silt-clay soil classification defined at a given grid point. The volumetric soil moisture is often spatially correlated to the pattern of soil classification; therefore, the relative soil moisture (or percent saturation) can be a preferred method to analyze the soil moisture based on the water-holding capacity of the soils. The relative soil moisture (RSM) is defined as the ratio of the modeled volumetric soil moisture (θ) between the wilting and saturation reference values for a given soil classification:
+
+ *RSM=((θ - θ<sub>wilt</sub>)/(θ<sub>sat</sub> - θ<sub>wilt</sub> )) x 100%. ... (1)*
+
+ The RSM essentially normalizes the volumetric soil moisture based on the specified characteristics of each unique soil texture classification (sand-silt-clay composition).
+
+Meanwhile, the soil moisture percentiles depict where the current analysis value lies within the histogram distribution of historical soil moisture values. An example of the 0-2 meter soil moisture percentile over Napa County, California shows how the wet 2022-23 winter over central California has contributed to historically high soil moisture values, averaged over all SPoRT-LIS points lying within Napa County, yielding a soil moisture percentile value of 92.9 for 23 March 2023:
+
+ <Image
+ src={new URL('./soil-moisture-histogram.png', import.meta.url).href}
+ alt='SPoRT LIS Soil Moisture Histogram for 23rd march 2023'
+ />
+
+ The national soil moisture percentile map on 23 March 2023 is shown below:
+
+ <Image
+ src={new URL('./soil-moisture-percentile.png', import.meta.url).href}
+ alt='SPoRT-LIS 0-200 cm Soil Moisture percentile valid 24 March 2023'
+ />
+
+ </Prose>
+</Block>
+
+<Block>
+ <Prose>
+ ## Additional Resources
+
+ - [Real-time SPoRT-LIS viewer](https://weather.ndc.nasa.gov/sport/viewer/?dataset=lis_conus&amp;product=rsoim0-100)
+ - [Access to real-time rolling archive of digital data and in various
+ formats](https://geo.nsstc.nasa.gov/SPoRT/modeling/lis/conus3km/)
+ - [Daily animations of experimental 2-week forecasts of SPoRT-LIS soil moisture
+ percentiles](https://geo.nsstc.nasa.gov/SPoRT/modeling/lis/conus3km/forecasts/)
+ - [NASA Land Information System project page](https://lis.gsfc.nasa.gov/)
+
+ </Prose>
+</Block>