Demonstrational H-SAF Full Disk Precipitation Products

 

Some full-disk precipitation products are briefly described below. These demonstrational products are evaluated useful to be disseminated (even if not operative yet - without any commitment on their quality or availability) in order to enabling users to test the products and to provide relevant feedbacks for the product's evolution. The products are available for download at hsaf.meteoam.it/user_support.php, registration is required (free of charge). For any questions please contact our help desk at us_hsaf@meteoam.it.

We thank in advance for any suggestions or comments regarding the products, they will help us to improve their quality.

 

P-IN-ONN-AMSU (H02B)

Precipitation rate at ground by MW cross-track scanners AMSU/MHS

 

The rainfall rate estimated by the H02B product on 14th Feb 2017 2355 UTC. Note the tropical cyclone Dineo active over the Mozambique channel.

 

The PR-OBS-2B (ver. 1.0) product is based on the instruments AMSU-A and MHS aboard the NOAA and MetOp satellites.

The main operational features are:

 

·         The horizontal resolution (Dx). Lower resolution AMSU-A data is resampled over the MHS/MHS grid by means of bilinear interpolation.  The product resolution corresponds to the nominal resolution of MHS, varying with the viewing scan angle from 16 x 16 km2 / circular at nadir to 26 x 52 km2 / ovate at scan edge.  The sampling distance also varies with viewing scan angle and corresponds to the sampling geometry of MHS (1.1 degrees), which corresponds to 16 km at nadir.

·         The observing cycle (Dt).  NOAA-18 and NOAA-19 follow approximately the same orbit, close to 14:00 LST.  MetOp has LST around 9:30.  On average the observing cycle over Europe is Dt ~ 6 h, with actual interval ranging from 4.5 to 7.5 hours.  The gaps are filled by the product PR-OBS-1, that also has observing cycle Dt ~ 5 h, but LST around 7:00 and 18:00, with actual intervals ranging from 2 to 7 hours.  So:

o    for PR-OBS-2B as stand alone (from NOAA and MetOp satellites): cycle Dt = 5 h, but it changes with latitude and then the sampling spans from 4.5 to 7.5 h.

·         The timeliness (d).  Direct-read-out is provided by all NOAA satellites and, after partial recovery from the AHRPT transmitter failure, also by MetOp-A.  By adding the processing time, the timeliness d is about 0.5 h.

·         The accuracy is evaluated a-posteriori by means of the validation activity.

·         Spatial coverage. The H-SAF area has been extended to Africa and southern Atlantic: LAT 60°S - 75°N, LON 60°W - 60°E


 

P-IN-GRU-SEVIRI (H03B)

Precipitation rate at ground by blended MW and IR

 

 The rainfall rate estimated by the H03B product on 14th Feb 2017 2345 UTC. Note the tropical cyclone Dineo active at the Mozambique channel.

 

The PR-OBS-3B (Precipitation rate at ground by GEO/IR supported by LEO/MW) product is based on the IR images from the SEVIRI instrument on-board the Meteosat Second Generation (MSG) satellites. The spatial coverage of the product is the whole MSG area and corresponds to 60°S – 67.5°N, 60°W – 60°E. The product is generated at the 15-min imaging rate of SEVIRI and the spatial resolution is comparable with the SEVIRI pixel.

The PR-OBS-3B precipitation estimates are obtained by combining IR GEO equivalent blackbody temperatures (TBB) at 10.8 μm with rain rates from Passive Microwave (PMW) measurements (PR-OBS-1 and PR-OBS-2B). The main operational features are:

 

·         The horizontal resolution (Dx)The Integrated Field of View (IFOV) of the SEVIRI images is 4.8 km at nadir, and degrades moving away from nadir, becoming about 8 km over Europe. Sampling distance at the sub-satellite point is about 3 km. So the resolution spans from 4.8 to 8 km and the sampling distance is about 3 km at the sub-satellite point.

·         The observing cycle (Dt)is defined as the average time interval between two measurements over the same area. In the case of PR-OBS-3B the product is generated soon after each new SEVIRI acquisition. The observing cycle Δt is 15 min and the sampling time is 15 min.

·         The timeliness (d): about 15 min.

·         The accuracy is evaluated a-posteriori by means of the validation activity.

 

 

P-AC-G-SEVIRI (H05B)

Accumulated precipitation at ground by blended MW and IR

 

 The H05B cumulative rainfall referring to the previous 3 hours with reference date 15th Feb 2017. Note the estimated cumulative rainfall over the Mozambique channel.

 

 

The PR-OBS-5B product is based on the frequent precipitation measurements as retrieved by blending LEO MW-derived precipitation rate measurements and GEO IR imagery.  The input data are therefore PR-OBS-3B.

The main operational features are:

·         The horizontal resolution (Dx). The resolution is about 30 km and the sampling distance is about 5 km.

·         The observing cycle (Dt).  The product is generated every 3 h by integrating over the previous 3, 6, 12 and 24 h. The observing cycle is 3 h and the sampling time is 3 h.

·         The timeliness (d). The timeliness is about 0.5 h.

·         The accuracy is evaluated a-posteriori by means of the validation activity.

 


 

P-IN-GCO-SEVIRI (H15B)

Blended SEVIRI Convection area / LEO MW Convective Precipitation

 The rainfall rate estimated by the H15B product on 14th Feb 2017 2330 UTC. Note the tropical cyclone Dineo active at the Mozambique channel.

 

 

The PR-OBS-6B (Blended SEVIRI Convection area/ LEO MW Convective Precipitation) product is based on the SEVIRI instrument on-board of the Meteosat Second Generation satellites. The product exploits the full disk of MSG-SEVIRI to cover the box defined by the coordinated LAT 60S - 75N, LON 60W - 60E. An objective analysis of the equivalent blackbody temperatures (TBB) is implemented to detect the convective structures of cloudy areas, by means of NEFODINA, an automatic tool running at CNMCA dedicated to now-casting applications. A map of convective clouds is performed to combine precipitation fields from Microwave (MW) channels. The product is generated according to SEVIRI acquisition time. The delay spans within the range of 3 to 5 minutes with a potential maximum of 10 minutes, after end of reception of whole disk SEVIRI data.

The main operational characteristics are:

 

·         identification of convective areas

·         association of MW retrieved rain rate present in the same area

 

This processing is performed by recomposing rain intensity given by PR-OBS-1 and PR-OBS-2B with respect to the convective objects detected by NEFODINA in the growing, mature or dissipating phase.

PR-OBS-1 ver.2 (H17)

Auxiliary Product

The rainfall rate estimated by the H17 product on 14th Feb 2017 2253 UTC. Note the tropical cyclone Dineo active at the Mozambique channel.

The H17 product is the newborn of the new release of PMW based products within the H-SAF project. The main improvement from the previous versions consists into the exploiting of the extensive dataset of coincident passive and active observations of the Global Precipitation Measurement (GPM) mission. H17 (also called Cloud Dynamics and Radiation Database Bayesian Algorithm for Precipitation Retrieval algorithm – CDRD v2) is based on the Bayesian approach and it represents an evolution of the previous (CDRD) algorithm (Sanò et al., 2013, Casella et al. 2013, Smith et al. 2013) that has been applied to the TMI radiometer (Casella et al. 2012) and to the SSMIS radiometer (Mugnai at al. 2013).

 


 

P-IN-ONN-ATM S (H18)

Precipitation rate at ground by MW cross-track scanners ATMS

 

 The rainfall rate estimated by the H18 product on 24th Jan 2017 0230 UTC.

 

The H18 (also called Passive Microwave Neural-network Precipitation Retrieval algorithm – PNPR v2) algorithm, which applies a neural network (NN) approach, represents an evolution of the H02A/B (PNPR) algorithm (Sanò et al., 2015) and contains some improvements to take advantage of the increased performance of ATMS with respect to AMSU/MHS.

The availability of data from the Advanced Technology Microwave Sounder (ATMS), a cross-track scanner radiometer on-board the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, represents an important step in short and long-term weather forecasting and environmental monitoring.  Combining the capabilities of its predecessor sounders such as the Advanced Microwave Sounding Unit-A (AMSU-A) and the Microwave Humidity Sounder (MHS) aboard the NOAA-18 and NOAA-19 and the ESA MetOp-A and MetOp-B satellites, ATMS provides sounding observations with improved resolution, sampling and coverage for retrieving atmospheric vertical temperature and humidity profiles. Moreover, this new-generation instrument provides more information about surface, vertical distribution of hydrometeors, precipitation, and other key environmental variables.

 


 

P-DM-RME-PMW (H23)

Gridded daily mean precipitation based on PMW instantaneous precipitation rate estimates

 

 


The mean rainfall rate estimated by the H23 product on 16th Feb 2017. Note the tropical cyclone Dineo active at the Mozambique channel.

 

The H23 product has been proposed as a Level 3 (gridded) PMW precipitation product, i.e. as a gridded daily mean precipitation based on PMW instantaneous precipitation rate estimates, with the aim of expanding the precipitation product portfolio available among the SAFs.

The gridded PMW mean precipitation is obtained from H01 (CDRD algorithm for conical scanning radiometers) and H02B (PNPR algorithm for AMSU/MHS) instantaneous precipitation rate estimates using all the available DMSP SSMIS and MetOp/NOAA AMSU/MHS overpasses. The product is provided on a regular grid with a resolution of 0.25° x 0.25° on a daily basis over the whole MSG disk (LAT 60°S - 75°N, LON 60°W – 60°E). It is not intended as a near real time product, but it is processed off-line. It is delivered once a day to provide the mean precipitation estimated over the previous day (from 00 UTC to 24 UTC).

For each box with a resolution of 0.25° x0.25°, the output is:

 

1.    Daily mean precipitation (mm/h),

2.    Total number of PMW overpasses within the last 24 hours used for the estimate.