N: 85.044 S: -85.044 E: 180 W: -180
TABLE OF CONTENTS
Description
This Level-2 (L2) soil moisture product provides estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. SMAP L-band brightness temperatures are resampled to an Earth-fixed, global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) [and made available as the SPL1CTB product], and the gridded brightness temperatures are then used to derive gridded soil moisture data.
Version Description
Changes to this version include:
- Improved calibration methodology was applied to the Level-1B radiometer brightness temperatures.
- Improved land surface model outputs from the NASA Global Modeling and Assimilation Office (GMAO) were used to estimate the effective soil temperature used as input to Level-2 soil moisture geophysical inversion. This effective soil temperature is not to be confused with the physical soil temperature at a given depth (Choudhury et al., 1982).
- Improved retrieval performance of DCA (formerly known as MDCA or "the option 3" option algorithm in previous releases). DCA retrieves both soil moisture and vegetation optical depth (VOD or tau).
- Use of a new global 250-meter resolution soils database called SoilGrid250m available at https://openlandmap.org. Work is underway to address limited spatial anomalies of these soil property estimates at high latitudes over areas rich in organic soils.
- Data quality flags were updated and corrected where faulty.
- The baseline algorithm (SCA-V) remains unchanged.
For the full major and minor version history, go to https://nsidc.org/data/smap/version-history
Product Summary
Platforms
Instruments
Spatial Extent
Spatial Resolution
36 Kilometers x 36 Kilometers
Spatial Reference System(s)
WGS 84 / NSIDC EASE-Grid 2.0 Global (EPSG:6933)
Location
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2015-03-31 to 2021-10-28
Temporal Resolution
49 Minute
Concept ID
C2830464714-NSIDC_CPRD
Data State
DEPRECATED
Number of Files/Granules
0
Processing Level
2
Published
Updated
Science Keywords
Surface Soil Moisture
Citation
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.
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ONeill, P., Chan, S., Njoku, E., Jackson, T., Bindlish, R., & Chaubell, J. (2020). SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 7 [Data set]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/F1TZ0CBN1F5N Date Accessed: 2026-06-16
ONeill, Peggy, Steven Chan, Eni Njoku, Thomas Jackson, Rajat Bindlish, and Julian Chaubell. “SMAP L2 Radiometer Half-Orbit 36 Km EASE-Grid Soil Moisture, Version 7.” NASA National Snow and Ice Data Center Distributed Active Archive Center, 2020. doi:10.5067/F1TZ0CBN1F5N. Date Accessed: 2026-06-16
ONeill, Peggy, et al. SMAP L2 Radiometer Half-Orbit 36 Km EASE-Grid Soil Moisture, Version 7. NASA National Snow and Ice Data Center Distributed Active Archive Center, 2020, doi:10.5067/F1TZ0CBN1F5N. Date Accessed: 2026-06-16
TABLE OF CONTENTS
Documents
ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)
DATA PRODUCT SPECIFICATION
PRODUCT QUALITY ASSESSMENT
Publications Citing This Dataset
Filters
| Title | Year Sort ascending | Author | Topic |
|---|---|---|---|
| Use of a new Tibetan Plateau network for permafrost to characterize satellite-based products errors: An application to soil moisture and freeze/thaw | Zheng, Jingyao, Zhao, Tianjie, Lu, Haishen, Zou, Defu, Rodriguez-Fernandez, Nemesio, Mialon, Arnaud, Richaume, Philippe, Xiao, Jianshe, Ma, Jun, Fan, Lei, Song, Peilin, Zhu, Yonghua, Li, Rui, Yao, Panpan, Yang, Qingqing, Du, Shaojie, Wang, Zhen, Peng, Zhiqing, Xiong, Yuyang, Xing, Zanpin, Zhao, Lin, Kerr, Yann, Shi, Jiancheng | Surface Soil Moisture | |
| Assessment of 24 soil moisture datasets using a new in situ network in the Shandian River Basin of China | Zheng, Jingyao, Zhao, Tianjie, Lu, Haishen, Shi, Jiancheng, Cosh, Michael H., Ji, Dabin, Jiang, Lingmei, Cui, Qian, Lu, Hui, Yang, Kun, Wigneron, Jean-Pierre, Li, Xiaojun, Zhu, Yonghua, Hu, Lu, Peng, Zhiqing, Zeng, Yelong, Wang, Xiaoyi, Kang, Chuen Siang | Surface Pressure, Heat Flux, Longwave Radiation, Shortwave Radiation, Surface Temperature, Humidity, Evapotranspiration, Surface Winds, Rain, Precipitation Rate, Snow, Soil Moisture/Water Content, Soil Temperature, Land Surface Temperature, Snow Water Equivalent, Runoff, Soil Heat Budget, Soil Heat Budget, Soil Temperature, Soil Infiltration, Soil Infiltration, Surface Soil Moisture, Root Zone Soil Moisture, Soil Moisture/Water Content, Evaporation, Surface Water, Runoff Rate, Average Flow, Average Flow, Precipitation, Snow/Ice, Snow Depth, Snow Melt, Snow/Ice Temperature, Leaf Area Index (LAI), Leaf Area Index (LAI) | |
| Irrigation characterization improved by the direct use of SMAP soil moisture anomalies within a data assimilation system | Kwon, Yonghwan, Kumar, Sujay V, Navari, Mahdi, Mocko, David M, Kemp, Eric M, Wegiel, Jerry W, Geiger, James V, Bindlish, Rajat | Land Surface Temperature, Emissivity, Surface Soil Moisture | |
| Net irrigation requirement under different climate scenarios using AquaCrop over Europe | Busschaert, Louise, de Roos, Shannon, Thiery, Wim, Raes, Dirk, De Lannoy, Gabrielle J. M. | Surface Soil Moisture | |
| Information-based uncertainty decomposition in dual-channel microwave remote sensing of soil moisture | Li, Bonan, Good, Stephen P. | Leaf Characteristics, Photosynthetically Active Radiation, Leaf Area Index (LAI), Fraction Of Absorbed Photosynthetically Active Radiation (fapar), Surface Soil Moisture |
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