Dorman, C.E., R.C. Beardsley, R. Limeburner, S.M. Varlamov, M. Caruso, and N.A. Dashko, Summer atmospheric conditions over the Japan/East Sea , Deep Sea Research II, 52, 1393-1420, 2005. [ Abstract ]
Dorman, C.E., R.C. Beardsley, N.A. Dashko, C.A. Friehe, D. Khelif, K. Cho, R. Limeburner, and S. Varlamov, Winter atmospheric conditions over the Japan Sea , Journal of Geophysical Research, 109, C12011, 10.1029/2001JC001197, 2004. [ Abstract ]
Dorman, C.E., C.A. Friehe, D. Khelif, A. Scotti, J. Edson, R.C. Beardsley, R. Limeburner, and S.S. Chen, Winter atmospheric conditions over the Japan/East Sea: The structure and impact of severe cold-air outbreaks, Oceanography, 19, 68-81, 2006.
Scotti, A.D., Orographic effects during winter cold-air outbreaks over the sea of Japan (East Sea): Results from a shallow-layer model , Deep-Sea Research II, 52, 1705-1725, 2005. [ Abstract ]
Cruise Report: Hydrographic survey on R/V Revelle HNR07, 24 June 199917 July 1999 (November 1999; CTD updated April 2006).
Cruise Report: Hydrographic survey on R/V Professor Khromov KH36, 22 July 199913 August 1999 (September 1999; updated April 2006).
Cruise Report: Hydrographic survey on R/V Professor Khromov KH38, 28 February 200017 March 2000
Processing of surface meteorological data collected on the R/V Revelle winter SeaSoar cruise (Revelle3) (MS Word document draft, 12/30/00)
Dorman et al., 2005.
Atmospheric conditions over the Japan/East Sea (JES) during the 1999 warm season (May-August) were investigated using research vessel surface and sounding observations in conjunction with coastal station and moored buoy meteorological data. In the broad center of the sea, surface winds were weak and variable with a tendency to be northward in direction. Air temperatures were close to the sea-surface temperature but warmer on average. The lower atmospheric profiles were weakly unstable or stable with shallow inversions. The summer surface heat flux was dominated by radiation components. The large solar short-wave flux caused a large net gain of heat by the sea that was unchecked by the weaker, long-wave flux. Sensible and latent heat fluxes were both small due to modest air-sea temperature differences and weak winds. The surface wind stress was also weak.
European Center for Medium-range Weather Forecasting (ECMWF) model surface fields compare favorably with our ship measurements in both summer of 1999 and the winter of 2000. The ECMWF model analysis followed the observed synoptic scale variations well but missed smaller scale variations. The ECMWF air temperature, dew point, pressure, wind speed, and wind direction were correlated with ship values at 0.8 or better. ECMWF forecasts and ship measurements of surface heat fluxes were well related. In the center of the JES, net fluxes in the winter and summer were correlated to 0.7-0.9, with winter the greater. ECMWF short-wave heat flux tended to exceed the ship-based values by 25-55 W/m2. ECMWF wind stress magnitude was best correlated with winter ship measurements, with correlations that reached 0.76-0.89, while wind stress components were more poorly correlated. In both seasons, ECMWF underestimated the wind stress by 15-25%.
Monthly mean climatologies of the JES surface heat flux and wind stress were computed using the 1991-2001 ECMWF surface flux time series. The annual heat flux cycle varies from a maximum heating of +182 W/m2 in June to a maximum cooling of -322 W/m2 in December with the greatest loss at the SW edge of the sea. The annual-mean flux is -48 W/m2. The monthly mean wind stress in winter is nearly four times the mean summer value of 0.057 N/m2, with the winter stress towards the S-SE replaced by stress towards the N-NE in summer. The strongest stresses are over the North-central portion of the sea. Our ship/model comparisons suggest that the ECMWF heat flux is biased roughly 25-55 W/m2 high due to systematic model short-wave flux overestimation and that the ECMWF wind stress is biased roughly 15-25% low due to model under-estimation of wind stress.
Dorman et al., 2004
Four basic types of synoptic-scale conditions describe the atmospheric structure and variability observed over the Japan Sea during the 1999/2000 winter season: (1) flow of cold Asian air from the northwest, (2) an outbreak of very cold Siberian air from the north and northeast, (3) passage of a weak cyclone over the southern Japan Sea with a cold air outbreak on the backside of the low, and (4) passage of a moderate cyclone along the northwestern side of the Japan Sea. In winter, the Russian coastal mountains and a surface-air temperature inversion typically block cold surface continental air from the Japan Sea. Instead, the adiabatic warming of coastal mountain lee-side air results in small air-sea temperature differences. Occasional outbreaks of very cold Siberian air eliminate the continental surface-based inversion and stability, allowing very cold air to push out over the Japan Sea for 1-3 days. During these outbreaks, the 0°C surface air isotherm extends well southward of 40°N, the surface heat losses in the center of the Japan Sea can exceed 600 W m-2, and sheet clouds cover most of the Japan Sea, with individual roll clouds extending from near the Russian coast to Honshu. During December through February, 1991-2002, these strong cold-air outbreak conditions occur 39% of the time and contribute 43% of the net heat loss from the Japan Sea. The average number of strong cold-air events per winter (November-March) season is 13 (ranging from 5 to 19); the 1999/2000 winter season covered in our measurements was normal.
We study the effects of the coastal topography on the western shore of the Sea of Japan (East Sea) on the flow of cold-air coming from the interior during winter cold-air outbreaks. The flow was modeled using a rotating 11/2 shallow-layer model. We consider two cases in detail: a layer constrained to follow the valley north of Vladivostok, the only direct access to the ocean, and a thicker layer able to flow over the coastal range as well. Several interesting phenomena emerge, related to the transition to supercritical flow near topographic features. It is shown that the flow along the Vladivostok valley will detach from the eastern side of the channel to form a jet aligned with the coast southwest of the opening. For the flow over the range, we were able to reproduce some of the features observed from satellite scatterometer wind measurements, such as the wakes (vortex street) in the lee of peaks along the range. Our model supports the existence of a heat-flux center for the formation of deep water southeast of Vladivostok during outbreaks only when the layer is thicker than the coastal range.