The NASA Soil Moisture Active Passive Mission (SMAP) Status and Early Results

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1 20154 California Institute of Technology. Government sponsorship acknowledged. National Aeronautics and Space Administration The NASA Soil Moisture Active Passive Mission (SMAP) Status and Early Results ESA and GEWEX Earth Observation for Water Cycle Science 2015 October 2015 ESA-ESRIN, Italy Dara Entekhabi, Simon Yueh*, Peggy E. O Neill**, Eni Njoku*, Kent Kellogg*, Jared Entin*** Massachusetts Institute of Technology Jet Propulsion Laboratory, California Institute of Technology* Goddard Space Flight Center** NASA Headquarters***

2 SMAP Data So Far Exceptional quality global L-band radiometry science acquisition continuing Limited-duration (April 14-July 7) but valuable L-band active-passive global field campaign (radar failure on `July 7, 2015) Available beta-data L1 products at NSIDC and ASF public-access (since August) Available beta-data L2 passive soil moisture products at NSIDC public-access (since September) Soon-available (November) beta-version of remainder L2-L4 products Data assessment reports posted with each product (includes validation statistics) Intense Cal/Val Period on-going 2015 field campaigns completed (August for SMAPVEX15 and September for SMAPEx-5)

3 SMAP Observations of Land and Ocean Surface Water Cycles 11/17/2015 2

4 Radiometer Products: Reduced RFI Data Loss and High Performance Example of radiometerbased soil moisture cal/val Texas Soil Observation Network (TxSON): Pick example of a good comparison. Shows height/upper-limit of what comparisons can be if algorithm and in situ representativeness errors can be minimized.

5 Details and heterogeneity captured by L2_SM_AP at 9 km L2_SM_P L2_SM_AP (36(9 km) km)

6 Value of Limited-Duration But High-Quality Data Active-Passive Data April 14 to July 7 (2.5+ months = 84 days) of high-quality 3km and 9km Global surface soil moisture data NH Spring/Summer science analyses Test-bed for resolution-enhancement and disaggregation approaches

7 SMAP Science and Application Returns Impact of Lower Resolution Data Science Returns Applications Returns Soil Moisture Links the Global Land Water, Energy, and Carbon Cycles Floods Soil Moisture Radiation Droughts Freeze/ Thaw 1 ~ 80% of pixels with less than 5% inland water body at 3 km ~70% of pixels with less than 5% inland water body at 18 km 1. Estimating global surface water and energy fluxes 2. Quantifying net carbon flux in boreal landscapes 3. Reduce uncertainty of climate model projections 4. Enhancing weather forecasts Current NWS Operational Flash Flood Guidance (FFG) 5. } 5. Improving flood prediction and drought monitoring No major impact Increase data-loss due } to in-land water bodies 1 } No major impact } Current Operational Drought Indices by NOAA and National Drought global Mitigation NWP. Center (NDMC) } No impact on Reduced capability for regional NWP. 2 No impact on drought monitoring. Much reduced capability for flood monitoring 2 NWS Global NWP at km. NWS North America NWP at 12 km.

8 Precipitation and SMAP Soil Moisture Increments Randy Koster (GSFC) Temporal correlations between rain-gauge precipitation observations and positive timeincrements of SMAP soil moisture Higher at where the rain gauge density is higher Density of rain gauges underlying the precipitation observations

9 Optical Depth Retrieval for Global Ecology and Improved Soil Moisture Retrievals Vegetation Optical Depth (VOD) retrieval using SMAP multi-temporal observations

10 Example over Punjab Valley and North India Intensive Agriculture

11 Additional Radiometer-Based Products that Increase Science Returns SMAP TB-Only Salinity [psu] May 2015 Wind direction from NCEP SMAP Radiometer Wind Speed for Super Typhoon Maysak on Mar 31, 2015 reached 120 knots SMAP TB-Only Vegetation Microwave Optical Depth

12 SMAP Wind Speed for Hurricanes/Typhoons SMAP Captured three Category 4 hurricanes in late August-early September The maximum SMAP wind for Jimena agrees well with the Tropical Prediction Center s best track analysis The maximum NECP wind speed is too low.

13 Path Forward: SMAP Resolution Enhancement Process Over-Sampled SMAP Radiometer Data Take advantage of SMAP radiometer over-sampling to produce 20 km 1 (TBC) resolution brightness temperature product Global coverage every 2 3 days Compares to global 10 km activepassive SMAP baseline Use Multi-Platform Data Use other radar data in SMAP s active-passive algorithm Better-than 10 km resolution but 12-day revisit with Sentinel-1A Regional coverage (60% of land) C- versus L-band will affect performance over moderate to dense vegetation Active data assisted by passive L-band Sentinel-1 IW Scan-Mode (Green) 1 Adequate resolution of an object can only be achieved if at least two samples are made for each resolvable unit

14 Preliminary Radiometer Resolution Enhancement Results Using the Backus-Gilbert (BG) Algorithm Use high-fidelity and resolution SMAP radiometer instrument simulator as test- and evaluationdata Apply the BG algorithm to optimally interpolate the data 3 km gridded resolution Take advantage of overlapping IFOV (every 4 km) and antenna pattern to deconvolve brightness temperature contribution at fine scales Differences Mean = -2.5e-4 [K] Std = 0.95 [K]

15 Summary SMAP data provides overlapping global L-band radiometry together with SMOS Potential for long-term and high-revisit water cycle observations (land and ocean) SMAP radar loss on July 7 is set-back for community Science recovery efforts now underway taking advantage of substantial SMAP radiometer oversampling and Sentinel-1A (and - 1B) joint observations Science uses of SMAP in characterizing both land and ocean branches of the water cycle underway at the same time