News

Dear Users,

H SAF is pleased to announce that the following Soil Moisture Products Data Records and related extention are currently realeased and available on the H SAF FTP:

• ASCAT SSM CDR v8 12.5 km (H121)
• ASCAT SSM CDR v8 EXT 12.5 km (H139)
• ASCAT SSM CDR v1 6.25 km (H129)
• ASCAT SSM CDR v1 EXT 6.25 km (H130)

All the details regarding these new products can be found in the H SAF website https://hsaf.meteoam.it/Products/ProductsList?type=soil_moisture

Dear Users,

due to an error in the model parameters, the operational H SAF soil-moisture product H28 requires an update (details see below). The update will be implemented starting from the 23rd of September.

Change details: The downscaling (DIREX) parameters for the following Equi7Grid tiles have been re-computed due to a storage issue, where the first layer of the DIREX parameters was mistakenly applied to all layers. As a result, the ASCAT DIS SSM NRT product was limited in that equal weighting was applied to all directional inputs, rather than using the intended directional differentiation. This did not critically impact the overall product performance but may have reduced the spatial representativeness in certain areas.

EU500M_E054N000T6, EU500M_E042N000T6, EU500M_E048N000T6, EU500M_E060N000T6, EU500M_E012N018T6, EU500M_E054N024T6, EU500M_E048N024T6, EU500M_E060N024T6, EU500M_E054N030T6, EU500M_E072N018T6, EU500M_E072N030T6, EU500M_E066N012T6, EU500M_E054N036T6, EU500M_E066N024T6, EU500M_E066N006T6, EU500M_E072N012T6, EU500M_E066N018T6, EU500M_E066N030T6, EU500M_E072N024T6, EU500M_E066N036T6, EU500M_E066N000T6, EU500M_E072N006T6, EU500M_E078N006T6, EU500M_E060N030T6, EU500M_E036N042T6, EU500M_E036N036T6, EU500M_E060N036T6, EU500M_E042N006T6, EU500M_E054N048T6, EU500M_E054N042T6, EU500M_E048N030T6, EU500M_E072N000T6, EU500M_E018N006T6, EU500M_E060N018T6, EU500M_E048N036T6

Additionally, three tiles (EU500M_E054N024T6, EU500M_E048N024T6, EU500M_E060N024T6) were corrected because they were missing DIREX parameters along their southern borders.

Dear User

The H SAF Team is pleased to announce that the h40B, h42B precipitation products and h43 snow product are fully disseminated via Eumetcast. All products are generated for the full Meteosat-12, 0-degree disc and have operational status. .

H40B product, Based on the “Rapid Update” (RU) combined technique, leverages all new capabilities of MTG FCI instrument. Key to the RU blended satellite technique is a real time collection of time and space overlapping pixels from operational geostationary IR imagers and LEO MW sensors that for MTG means generating a full disk precipitation map every 10 minutes with a resolution of 2km (nadir). This increased time and space resolution makes h40 one of the best product for NRT hydrological monitoring, weather situation analysis and emergency management by National meteorological services and operational Agencies.

For further information:

• ATBD
• PUM
• PVR

H42 is a Level 3 precipitation product, providing hourly the 1 hour accumulated precipitation and every six hours (at 00, 06, 12 and 18 UTC) the 24 hours accumulated precipitation. The accumulated precipitation rate is obtained integrating all the available h40B precipitation estimation which means that the products uses all the accessible cross-track and conically scanning passive microwave radiometers (equipped with precipitation sensing channels). For its characteristics, the product can be effectively used for hydrological applications and for data assimilation in hydrological models and can be easily compared with global rainfall gridded datasets.

For further information:

• ATBD
• PUM
• PVR

H43 is a day-1 daily snow extent product covering the full MTG/FCI Disk at 2km resolution at nadir, utilizing the 10 minute temporal resolution of the instrument by combining the observations throughout the day. To provide better accuracy for different landscapes it is produced as two variants, flatland/forested and mountainous regions, that employ specifically tailored algorithms which are then combined and delivered as the final merged product. Final product contains both variants (flatland and mountainous) as well as the merged product to cater to different user needs in hydrological and meteorological applications. H43 product demonstrates strong capability in mapping snow cover across heterogeneous mountain landscapes, including areas with fragmented topography and mixed land cover. It effectively captures the dendritic snow distribution patterns along valley networks and the snow extent gradients on the fringes of slopes, where detection is often complicated by elevation changes, terrain shadowing, and variable vegetation cover.

For further information:

• ATBD
• PUM
• PVR

Dear User

The H SAF Team is pleased to announce that the new H SAF Metop ASCAT Surface Soil Moisture Near Real-Time 12.5km sampling product (ID: H29) is now available on EUMETCast .

This product is based on ASCAT data from the Metop satellites and provides soil moisture content in the surface layer (less then 5cm).

It is the successor of the H16 (Metop-B ASCAT NRT SSM 12.5km sampling) and H104 (Metop-C ASCAT NRT SSM 12.5km sampling) products

Main characteristics of ASCAT SSM 12.5km (H29):

• Variable: Soil moisture content in the surface layer (less then 5cm)
• Unit: Degree of saturation (0–100%)
• Spatial sampling/resolution: 6.25km/15x15km2 or 12.5km/25x25km2
• Spatial coverage: Global (65°S, 180°W, 80°N, 180°E)
• Timeliness: 115 min (for the NRT product)
• Format: netCDF4 and BUFR

For more information: https://hsaf.meteoam.it/Products/Detail?prod=H29

Dear users,

The Metop ASCAT Soil Moisture products currently generated at the EUMETSAT Central Facility, and distributed on EUMETCast, will be replaced by new, upgraded soil moisture products generated by the H SAF, as follows:

• H16 (Large-scale surface soil moisture by radar scatterometer) and H104 (Metop-C ASCAT NRT SSM orbit geometry 12.5km sampling) will be replaced by H29 (Metop ASCAT Surface Soil Moisture Near Real-Time 12.5km sampling V2).
• H103 (Metop-B ASCAT NRT soil moisture 25km sampling) and H105 (Metop-C ASCAT NRT SSM orbit geometry 25km sampling) will be replaced by H122 (Metop ASCAT Surface Soil Moisture Near Real Time 6.25km sampling).

Main changes introduced with the new products include:

• Projection on to a fixed Earth grid (6.25km for H122, 12.5km for H29) using the ASCAT Level 1b full resolution backscatter product as input. As well as dropping the coarse resolution ASCAT SSM product (25km sampling) and introducing a better spatial resolution (6.25km sampling), one of the key differences is that there is no sampling of data using swath orbit nodes. The new fixed Earth grid makes it easy to build time series without applying any resampling procedure beforehand. In addition, individual backscatter echoes provided in the ASCAT Level 1b full resolution backscatter product allow for more accurate filtering of signals coming from areas not sensitive to soil moisture changes (eg, open water, cities).
• The underlying core soil moisture retrieval algorithm — a semi-empirical change detection method — will not change. However, the estimation of the model parameters (slope/curvature, dry/wet backscatter reference) has evolved (Hahn et al., 2017, Hahn et al. 2020), and is based on a much longer backscatter time series (2007–2023) than before. The retrieval method itself is not changing, but the updated model parameters have a significant impact on the dynamics of soil moisture and its extremes, rendering the old ASCAT SSM NRT product inconsistent with the upcoming SSM NRT product.
• A more adaptive vegetation correction has been introduced by using spatially varying cross-over angles instead of static angles. In addition, the computation of the slope and curvature climatology is now based on a kernel smoother function. Moreover, long-term land cover changes are introducing trends in backscatter, eg, in areas affected by urban growth. In order to mitigate those effects, the dry/wet backscatter reference is now estimated on a yearly basis, taking data from neighbouring years into account.

Main characteristics of ASCAT SSM 6.25km (H122) and ASCAT SSM 12.5km (H29):

• Variable: Soil moisture content in the surface layer (< 5cm)
• Unit: Degree of saturation (0–100%)
• Spatial sampling/resolution: 6.25km/15x15km2 or 12.5km/25x25km2
• Spatial coverage: Global (65°S, 180°W, 80°N, 180°E)
• Timeliness: 115 min (for the NRT product) Format: netCDF4 and BUFR

It is planned that the old products will be discontinued in Q2 2025. To ensure a smooth transition for users, the new products, H29 and H122, will be distributed on EUMETCast, in parallel to the old products for a few months. More information will be provided in due course. In the meantime, sample files of the new products are available on the H SAF FTP server: ftphsaf.meteoam.it (registration on the H SAF website is required).