Yellow Sea
3 Followers
Most cited papers in Yellow Sea
The present study reveals climate features of low-level jets (LLJs) over the Bohai Sea and Yellow Sea (BYS) based on a 35-year (1979 – 2013) high-resolution (7 km) atmospheric hindcast. The regional climate model COSMO-CLM driven by the... more
The present study reveals climate features of low-level jets (LLJs) over the Bohai Sea and Yellow Sea (BYS) based on a 35-year (1979 – 2013) high-resolution (7 km) atmospheric hindcast. The regional climate model COSMO-CLM driven by the ERA-Interim reanalysis dataset was used to obtain the hindcast. Through comparison with observations, the hindcast was proved to robustly reproduce the climatology, the diurnal cycle, the variability of wind profiles and specific LLJ cases. LLJs over the BYS feature a strong diurnal cycle, intra-annual and inter-annual variability but weak decadal variability. LLJs are more frequent in April, May and June (LLJ-season) and less frequent in winter over the Bohai Sea and western coastal areas of the Yellow Sea, which is due to the intra-annual variations of large-scale circulation and local land-sea thermal contrast. In the LLJ-season, the heights of jet cores are generally lower than 500 m above sea level. The maximum wind speed of LLJs is mostly in the range of 10 – 16 m/s, and prevailing wind directions are southerly and southwesterly. The LLJs are of the nocturnal type, with the highest occurrence frequency at approximately 2300 local time. Furthermore, a low-frequency link between anomalies of LLJ occurrence and regional large-scale barotropic circulation was identified using canonical correlation analysis and associated correlation patterns. Pressure systems over the East Asia-Northwest Pacific region are significantly correlated with the variations of LLJ occurrence over the BYS in terms of the intra-annual and inter-annual variability.
- by Delei Li and +1
- •
- Regional Climate Modeling, Yellow Sea, Low-Level Jets, Bo Hai
Reanalysis data sets have been widely used in regional climate dynamical downscaling studies. In this study, we test the use of various reanalysis data sets in constraining dynamical downscaling by assessing the skill of the... more
Reanalysis data sets have been widely used in regional climate dynamical downscaling studies. In this study, we test the use of various reanalysis data sets in constraining dynamical downscaling by assessing the skill of the reconstruction of the coastal winds of the Yellow Sea using the COSMO model in CLimate Mode (CCLM) with 7-km resolution. Four reanalysis forcing data sets are used as lateral boundary conditions and as internal large-scale constraints (spectral nudging): the NCEP/NCAR reanalysis data set (NCEP1) downscaled to an intermediate domain with 55-km resolution (CCLM_55km), the ERA-interim reanalysis data set (ERAint), the NCEP climate forecast system reanalysis data set (CFSR) and the Japanese 55-year reanalysis data set (JRA55).
Several statistical analysis methods are employed to assess the modeled winds through comparison with observed offshore wind data from 2006, and it is found that the downscaled simulations yield good-quality wind speed products. However, they all tend to overestimate observed low wind speeds and to underestimate observed high wind speeds. Furthermore, the quality of the modeled wind direction is strongly associated with the wind speed intensities, exhibiting much better reproduction of wind direction at strong wind speeds than at light wind speeds.
The downscaling simulations driven by ERAint, JRA55 and CFSR are consistent with each other in the reproduction of local wind speed and direction; the simulations driven by ERAint and JRA55 are slightly better for strong winds, and those driven by CFSR are better for light winds. All three simulations generate local wind estimates that are superior to those of the simulation driven by CCLM_55km. This superiority reflects the better quality of the CFSR, ERAint and JRA55 reanalyses with regard to assimilated local observations compared with the CCLM_55km hindcast, which exploits only upper-air large-scale NCEP1 wind fields.
Several statistical analysis methods are employed to assess the modeled winds through comparison with observed offshore wind data from 2006, and it is found that the downscaled simulations yield good-quality wind speed products. However, they all tend to overestimate observed low wind speeds and to underestimate observed high wind speeds. Furthermore, the quality of the modeled wind direction is strongly associated with the wind speed intensities, exhibiting much better reproduction of wind direction at strong wind speeds than at light wind speeds.
The downscaling simulations driven by ERAint, JRA55 and CFSR are consistent with each other in the reproduction of local wind speed and direction; the simulations driven by ERAint and JRA55 are slightly better for strong winds, and those driven by CFSR are better for light winds. All three simulations generate local wind estimates that are superior to those of the simulation driven by CCLM_55km. This superiority reflects the better quality of the CFSR, ERAint and JRA55 reanalyses with regard to assimilated local observations compared with the CCLM_55km hindcast, which exploits only upper-air large-scale NCEP1 wind fields.
- by Delei Li and +1
- •
- Downscaling, Reanalysis, Yellow Sea, Ocean Surface Winds
CHINA’S MARITIME PERIPHERY OR ‘‘NEAR SEAS—the Yellow Sea, the East China Sea, and the South China Sea—are waters through which a great deal of vital commerce flows, as China, Japan, Korea, and numerous Southeast Asian countries are all... more
CHINA’S MARITIME PERIPHERY OR ‘‘NEAR SEAS—the Yellow Sea, the East
China Sea, and the South China Sea—are waters through which a great deal
of vital commerce flows, as China, Japan, Korea, and numerous Southeast
Asian countries are all major trading nations that import the energy and raw
materials that sustain their thriving economies. Since 2009 the East and
South China Seas have become increasingly fraught with tension. This has
generally been attributed to rising Chinese assertiveness, but not because
China has started making a lot of assertions it never made before. As the
authors assembled here point out in replete detail, China’s explicit claims to
the Diaoyu/Senkaku islets in the East China Sea date back at least to 1971,
while it can trace its claim in the South China Sea back to the publication of
the famous ‘‘nine-dashed line’’ map by the Nationalists in 1947 (at the time it
contained eleven segmented lines; the victorious Communists subsequently
dropped two). What has changed since 2009 is China’s more rigorous
enforcement of existing claims. This too is brought out in the articles collected
below: its actors have seized islands well within the exclusive economic
zones (EEZs) of neighboring Southeast Asian nations, detained fishing boats
and confiscated their catch, cut the cables of ships engaged in oil exploration,
harassed American surveillance vessels, and most recently undertaken ‘‘reclamation’’
of subsurface islets in order to construct airstrips and harbors.
What accounts for the sea change (and just how far will it go)?
China Sea, and the South China Sea—are waters through which a great deal
of vital commerce flows, as China, Japan, Korea, and numerous Southeast
Asian countries are all major trading nations that import the energy and raw
materials that sustain their thriving economies. Since 2009 the East and
South China Seas have become increasingly fraught with tension. This has
generally been attributed to rising Chinese assertiveness, but not because
China has started making a lot of assertions it never made before. As the
authors assembled here point out in replete detail, China’s explicit claims to
the Diaoyu/Senkaku islets in the East China Sea date back at least to 1971,
while it can trace its claim in the South China Sea back to the publication of
the famous ‘‘nine-dashed line’’ map by the Nationalists in 1947 (at the time it
contained eleven segmented lines; the victorious Communists subsequently
dropped two). What has changed since 2009 is China’s more rigorous
enforcement of existing claims. This too is brought out in the articles collected
below: its actors have seized islands well within the exclusive economic
zones (EEZs) of neighboring Southeast Asian nations, detained fishing boats
and confiscated their catch, cut the cables of ships engaged in oil exploration,
harassed American surveillance vessels, and most recently undertaken ‘‘reclamation’’
of subsurface islets in order to construct airstrips and harbors.
What accounts for the sea change (and just how far will it go)?