Additional file 1 of Multi-year assessment of the impact of ship-borne radiosonde observations on polar WRF forecasts in the Arctic
Creators: name: Choi, Yonghan
name: Kim, Joo-Hong
name: Jun, Sang-Yoon
name: Choi, Taejin
name: Zhang, Xiangdong
Publisher: name: figshare
Year: 2024
Subjects: subject: Neuroscience
subject: Biotechnology
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Mathematical Sciences not elsewhere classified
subject: Science Policy

description: Additional file 1: Figure S1. Geographical area and topography height (m) of computational domain. Names of selected seas are indicated. Figure S2. Root mean square (RMS) of O-B (observation minus background, blue) and O-A (observation minus analysis, red) for a zonal wind (m s-1), b meridional wind (m s-1), c temperature (K), and d water vapor mixing ratio (g kg-1) variables of radiosonde observations. O-B, O-A statistics from all DA cycles of the CTL experiment for the year of 2018 are shown. The number of assimilated observations (black) are also shown. Figure S3. Differences in RMSE (K) between the CTL and NoAraon experiments (CTL minus NoAraon) for the cycling period of a 2017, b 2018, c 2019, and d 2021. RMSEs of 900-hPa temperature analyses are calculated over areas north of 70°N and ERA5 reanalysis is used as a reference. Blue (red) bar denotes the cycle at which the RMSE of the NoAraon experiment is greater (less) than that of the CTL experiment. The black line denotes the average difference over all cycles, and the statistical significance at the 90% confidence level for the difference is indicated by a yellow star. Figure S4. Horizontal distributions of cyclone tracks (open black circles) and storm activities (shading) for a 2017, b 2018, c 2019, and d 2021. Cyclones that passed areas north of 70°N at least once during the cycling period of each year were considered. The cyclone tracking algorithm in Zhang et al. (2023) was used. Synoptic eddies are defined as deviations from a 2-week mean. Eddy kinetic energy is calculated using 850-hPa zonal and meridional winds for each cycle and eddy kinetic energy from all cycles is averaged. Locations of additional radiosonde observations (red filled circles) are also shown. Figure S5. Percentage differences in RMSE (%) between the CTL_12h and NoAraon experiments (CTL_12h minus NoAraon) for the year a 2018 and b 2019. RMSEs of geopotential height are calculated over areas north of 70°N using ERA5 reanalysis as a reference, and RMSEs from all cycles of the corresponding year are averaged. Statistical significance (denoted by yellow dots) for the difference is computed using a bootstrap resampling method and its confidence level is 90%. Figure S6. Error of 500-hPa geopotential height in the NoAraon experiment (shading; gpm) and 500-hPa geopotential height from ERA5 reanalysis (contour; contours from 5280 to 5940 by 60 gpm) at forecast length of a 120 h, b 144 h, c 168 h, and d 192 h. Difference between the CTL and NoAraon experiments (CTL minus NoAraon) for 500-hPa geopotential height (gpm) at forecast length of e 120 h, f 144 h, g 168 h, and h 192 h. Error of 300-hPa potential vorticity in the NoAraon experiment (shading; PVU) and 300-hPa potential vorticity from ERA5 reanalysis (contour; contours from 0 to 15 by 5 PVU) at forecast length of i 120 h, j 144 h, k 168 h, and l 192 h. Difference between the CTL and NoAraon experiments (CTL minus NoAraon) for 300-hPa potential vorticity (PVU) at forecast length of m 120 h, n 144 h, o 168 h, and p 192 h. Forecasts of the CTL and NoAraon experiments from the cycle at 00 UTC 10 September 2018 and the corresponding ERA5 reanalysis data are used.