Abstract
Intensive atmospheric observations were carried out with five research vessels in total across the sea surface temperature (SST) front along the Kuroshio Extension in the early summer of 2012, to identify the effects of the front on the thermal structure and cloud formation in the marine atmospheric boundary layer (MABL). Three of the vessels were aligned together along the 143°E meridian with latitudinal separation of as small as 30′ or 45′, going back and forth across the SST front for in situ observations during 2–6 July. The SST front was quite sharp and moved northward by about 50 km in 3 days, which was not well represented in objectively analyzed SST data sets. The observations captured rapid changes of the mesoscale MABL structure across the SST front, which were particularly evident in cloud base height and downward longwave radiation (DLR) at the surface. The higher base of low-level clouds observed over the warmer water resulted from stronger turbulent mixing in the MABL, which became prominent under the northerlies. The most frequently measured DLR value was greater by 20 W m−2 to the south of the SST front than to the north. High-resolution atmospheric model experiments conducted with and without the frontal SST gradient have confirmed its critical importance for the MABL structure and low-level clouds. These imprints of the SST front simulated in the models are sensitive to SST data assigned at the lower boundary of the model.
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Notes
The Japanese standard time (JST) is 9 h ahead of UTC.
References
Bony S, Dufresne J-L, Le Treut H, Morcrette J-J, Senior C (2004) On dynamic and thermodynamic components of cloud changes. Climate Dyn 22:71–86
Boucher O et al (2013) Clouds and aerosols. In: Stocker TF et al (eds) Climate change 2013: the physical science basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, pp 571–657
Dee DP et al (2011) The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Quart J R Meteorol Soc 137:553–597
Hotta D, Nakamura H (2011) On the significance of sensible heat supply from the ocean in the maintenance of mean baroclinicity along storm tracks. J Clim 24:3377–3401. doi:10.1175/2010JCLI3910.1
Katsaros KB, Soloviev AV (2004) Vanishing horizontal sea surface temperature gradients at low wind speeds. Bound Layer Meteor 112:381–396
Kawai Y, Tomita H, Cronin MF, Bond NA (2014) Atmospheric pressure response to mesoscale sea surface temperature variations in the Kuroshio Extension: in situ evidence. J Geophys Res Atmos 119:8015–8031. doi:10.1002/2013JD021126
Kelly KA, Small RJ, Samelson RM, Qiu B, Joyce TM, Kwon Y-O, Cronin M (2010) Western boundary currents and frontal air–sea interaction: Gulf Stream and Kuroshio Extension. J Clim 23:5644–5667. doi:10.1175/2010JCLI3346.1
Kwon Y-O, Alexander MA, Bond NA, Frankignoul C, Nakamura H, Qiu B, Thompson L (2010) Role of the Gulf Stream and Kuroshio-Oyashio system in large-scale atmosphere-ocean interaction: a review. J Clim 23:3249–3281. doi:10.1175/2010JCLI3343.1
Liu J-W, Xie S-P, Norris JR, Zhang S-P (2014) Low-level cloud response to the Gulf Stream front in winter using CALIPSO. J Clim 27:4421–4432. doi:10.1175/JCLI-D-13-00469.1
Masunaga R, Nakamura H, Miyasaka T, Nishii K, Tanimoto Y (2015) Separation of climatological imprints of the Kuroshio Extension and Oyashio fronts on the wintertime atmospheric boundary layer: Their sensitivity to SST resolution prescribed for atmospheric reanalysis. J Clim (in press)
Miyazawa Y, Zhang R, Guo X, Tamura H, Ambe D, Lee J-S, Okuno A, Yoshinari H, Setou T, Komatsu K (2009) Water mass variability in the western North Pacific detected in a 15-year eddy resolving ocean reanalysis. J Oceanogr 65:737–756
Nakamura H, Sampe T, Tanimoto Y, Shimpo A (2004) Observed associations among storm tracks, jet streams and midlatitude oceanic fronts. In: Wang C, Xie SP, Carton JA (eds) Earth’s climate: the ocean-atmosphere Interaction. Geophys Monogr Ser, vol 147. AGU, Washington, DC, pp 329–345. doi:10.1029/147GM18
National Centers for Environmental Prediction/National Weather Service/NOAA/US Department of Commerce (2000) NCEP FNL operational model global tropospheric analyses, continuing from July 1999. Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory, Boulder. http://rda.ucar.edu/datasets/ds083.2. Accessed 24 Jul 2012
Onogi K et al (2007) The JRA-25 reanalysis. J Meteorol Soc Jpn 85:369–432
Randall DA et al (2007) Climate models and their evaluation. In: Solomon S et al (eds) Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, pp 589–662
Reynolds RW, Smith TM, Liu C, Chelton DB, Casey KS, Schlax MG (2007) Daily high-resolution-blended analyses for sea surface temperature. J Clim 20:5473–5496
Sakurai T, Kurihara Y, Kuragano T (2005) Merged satellite and in situ data global daily SST, in Geoscience and Remote Sensing Symposium, 2005. IGARSS ‘05. Proceedings. 2005 IEEE International, vol 4. Inst Electr Electron Eng, New York, pp 2606–2608. doi:10.1109/IGARSS.2005.1525519
Shimada T, Minobe S (2011) Global analysis of the pressure adjustment mechanism over sea surface temperature fronts using AIRS/Aqua data. Geophys Res Lett 38:L06704. doi:10.1029/2010GL046625
Skamarock WC, Klemp JB, Dudhia J, Gill DO, Barker DM, Duda MG, Wang W, Powers JG (2008) A description of the advanced research WRF version 3, pp 113, NCAR technical note, NCAR/TN-475 + STR, National Center for Atmospheric Research. http://www.mmm.ucar.edu/wrf/users/docs/arw_v3.pdf. Accessed 20 Apr 2011
Small RJ, deSzoeke SP, Xie SP, O’Neill L, Seo H, Song Q, Cornillon P, Spall M, Minobe S (2008) Air-sea interaction over ocean fronts and eddies. Dyn Atmos Oceans 45:274–319. doi:10.1016/j.dynatmoce.2008.01.001
Stevens DE, Ackerman AS, Bretherton CS (2002) Effects of domain size and numerical resolution on the simulation of shallow cumulus convection. J Atmos Sci 59:3285–3301
Taguchi B, Nakamura H, Nonaka M, Xie S-P (2009) Influences of the Kuroshio/Oyashio Extensions on air-sea heat exchanges and storm track activity as revealed in regional atmospheric model simulations for the 2003/4 cold season. J Clim 22:6536–6560. doi:10.1175/2009JCLI2910.1
Tanimoto Y, Xie S-P, Kai K, Okajima H, Tokinaga H, Murayama T, Nonaka M, Nakamura H (2009) Observations of marine atmospheric boundary layer transitions across the summer Kuroshio Extension. J Clim 22:1360–1374. doi:10.1175/JCLI2420.1
Tanimoto Y, Kanenari T, Tokinaga H, Xie S-P (2011) Sea level pressure minimum along the Kuroshio and its extension. J Clim 24:4419–4434. doi:10.1175/2011JCLI4062.1
Tochimoto E, Kawano T (2012) Development processes of Baiu frontal depressions. SOLA 8:9–12. doi:10.2151/sola.2012-003
Tokinaga H, Tanimoto Y, Xie SP, Sampe T, Tomita H, Ichikawa H (2009) Ocean frontal effects on the vertical development of clouds over the western north Pacific: in situ and satellite observations. J Clim 22:4241–4260. doi:10.1175/2009JCLI2763.1
Vellore R, Koračin D, Wetzel M, Chai S, Wang Q (2007) Challenges in mesoscale prediction of a nocturnal stratocumulus-topped marine boundary layer and implications for operational forecasting. Weather Forecasting 22:1101–1122
Wang Y, Xie S-P, Wang B, Xu H (2005) Large-scale atmospheric forcing by Southeast Pacific boundary layer clouds: a regional model study. J Clim 18:934–951
Yasuda I (2003) Hydrographic structure and variability in the Kuroshio-Oyashio transition area. J Oceanogr 59:389–402
Acknowledgments
This work was supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, Grants-in-Aid for Scientific Research on Innovative Areas (22106007, 22106003, 22106004, 22106005, 22106006 and 22106009). The authors would like to sincerely thank the captains, crews, and cruise leaders of R/V Seisui-maru, R/V Wakataka-maru, and R/V Tansei-maru. Weather charts, MGDSST and MSM data were provided by the Japan Meteorological Agency. Dr. Miyazawa of JAMSTEC and his colleagues kindly provided their JCOPE2 product. The authors thank Dr. Y. Wang of IPRC, University of Hawaii, for providing the IPRC-RAM. The authors are also extremely grateful to Prof. T. Murayama of Tokyo University of Marine Science and Technology, Dr. H. Tomita of Nagoya University, and all the colleagues who got involved in the intensive observation campaign. The editor and anonymous reviewers provided us with valuable comments and helped us to improve the paper.
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Appendix: Simulations by the AR-WRF
Appendix: Simulations by the AR-WRF
The simulation results of the AR-WRF are qualitatively similar to those of the IPRC-RAM, but the AR-WRF underestimates cloud height to the south of the SST front for the event on 3 July (Fig. 17). And the amount of cloud liquid water in the AR-WRF is much larger than in the IPRC-RAM. These tendencies are also seen on the other days. Although our conclusion that the SST front significantly affected cloud height is consistent, there have still been problems in evaluating the effect quantitatively.
We point out that the simulation results can also be affected by the initial and lateral boundary condition entered into the regional models. Figure 18 shows time-mean cloud liquid water simulated in the AR-WRF with lateral boundary and initial conditions taken from three global atmospheric reanalysis data sets: the NCEP-FNL, the European Center for Medium-Range Weather Forecast (ECMWF) Re-Analysis Interim (ERA-Interim) (Dee et al. 2011), and the JMA Climate Data Assimilation System (JCDAS) analysis (Onogi et al. 2007 ). The elevated cloud deck to the south of the SST front relative to its north is reproduced as an impact of the lower boundary condition regardless of the lateral boundary and initial conditions, but the amount of cloud liquid water itself does depend on those conditions. The use of the JCDAS yields the greatest amount of cloud liquid water below 400 m height and least amount above 500 m height to the south of the front. These differences in model-simulated cloud liquid water can be caused by differences in humidity, temperature, and trajectories of air mass that comes into the model domain through the lateral boundaries. We need to pay attention to the effect of the lateral boundary in the investigation of air–sea interaction around the SST front area.
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Kawai, Y., Miyama, T., Iizuka, S. et al. Marine atmospheric boundary layer and low-level cloud responses to the Kuroshio Extension front in the early summer of 2012: three-vessel simultaneous observations and numerical simulations. J Oceanogr 71, 511–526 (2015). https://doi.org/10.1007/s10872-014-0266-0
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DOI: https://doi.org/10.1007/s10872-014-0266-0