Figure 1
Example of satellite data coverage inside the MetCoOp NWP system domain. Dots indicate locations of the Advanced Microwave Sounding Unit -A (AMSU-A) observations from Metop-C satellite in three-hour time windows centred at synoptic times (a) 06, (b) 09, (c) 12, (d) 15, (e) 18, and (f) 21 UTC on 1 February 2023. Arrows indicate the approximate ground tracks of the satellite.
Figure 2
Cycling of VarBC coefficients in the Single Stream Continuous Update variant.
Figure 3
Cycling of VarBC coefficients in the Multiple Stream Daily Update variant.
Figure 4
Cycling of VarBC coefficients in the Single Stream Daily Update variant.
Figure 5
Frequency distributions of data count collected at different scan positions in August 2021. Panels (a)–(c) are for NOAA-20 ATMS and panels (d)–(f) for Metop-C AMSU-A. Thick solid, thick dashed, thin solid, and thin dashed lines indicate the data at different analysis hours in members run at S0, S1, and S2 hours, as shown in the legends.
Table 1
The proposed daily update hours at MetCoOp NWP suites.
| SATELLITE | S0 | S1 | S2 |
|---|---|---|---|
| NOAA-18 | 12 UTC | 19 UTC | 20 UTC |
| NOAA-19 | 06 UTC | 07 UTC | 17 UTC |
| S-NPP | 12 UTC | 01 UTC | 02 UTC |
| NOAA-20 | 12 UTC | 01 UTC | 02 UTC |
| FengYun-3D | 12 UTC | 01 UTC | 02 UTC |
| Metop-B | 09 UTC | 19 UTC | 20 UTC |
| Metop-C | 09 UTC | 19 UTC | 20 UTC |
Figure 6
Time series of mean observation minus background (O-B) departure in representative sounder channels. (a) Channel 7 of Metop-B AMSU-A, (b) channel 9 of NOAA-20 ATMS, (c) channel 5 of Metop-B MHS, and (d) channel 236 of Metop-B IASI. In each panel, the data at S0, S1, and S2 hours are shown at the top, middle, and bottom, respectively. Data of the control runs are shown by triangles, circles and squares; that of the test runs by dots, diamonds and asterisks. The thick dashed line indicates the start of the 36-day evaluation period.
Figure 7
Observation minus background (O-B) departure statistics in the actively-assimilated channels of NOAA-20 ATMS. Control and test runs are shown by thick and thin lines, respectively. Dashed and solid lines represent mean and standard deviation. Bars indicate the 95% confidence intervals. The different panels indicate data at different analysis hours as shown in the headings.
Figure 8
Observation minus background (O-B) departure statistics in the actively-assimilated microwave sounder channels of Metop-C. Channel indices go from 3 to 5 in MHS and from 6 to 9 in AMSU-A. Lines are as in Figure 7.
Figure 9
Short-range forecast impact of switching from MSDU to SSDU. The O-B data fit is shown in independent conventional measurements based on radiosondes and aircraft reports. The score is the control-normalized standard deviation of the O-B departure such that x-axis values less than one indicate a positive impact. The bars show the confidence intervals at 95% statistical significance level. (a)–(c) vector wind, (d)–(f) temperature, and (g)–(i) specific humidity. Panels (a), (d), and (g) are from the experiment run at S0 hours, panels (b), (e), and (h) at S1 hours, and panels (c), (f), and (i) at S2 hours.
Figure 10
Forecast verification of switching from MSDU to SSDU. The scores are computed against verifying observations taken at synoptic ground stations. The score is the control-normalized root-mean-square of forecast error and positive impact manifests itself by negative values on the y-axis. The bars indicate the confidence intervals at 95% statistical significance level. (a)–(c) mean sea level pressure, (d)–(f) temperature, and (g)–(i) specific humidity. Panels (a), (d), and (g) are from the experiment run at S0 hours, panels (b), (e), and (h) at S1 hours, and panels (c), (f), and (i) at S2 hours.