A Numerical Study of a Dynamically Induced Foehn Observed in the Abashiri-Ohmu Area

Ikawa, Motohki; Nagasawa, Yoshitsugu

doi:10.2151/jmsj1965.67.3_429

Cited by 19 publications

(22 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ikawa and Nagasawa (1989) conducted a numerical experiment for a dynamically induced foehn event Water vapor data retirieved from radar reflectivity Table 1. Modifications for operational mesoscale NWP at JMA.…”

Section: Mountain Flowmentioning

confidence: 99%

The JMA Nonhydrostatic Model and Its Applications to Operation and Research

Saitō¹

2012

Atmospheric Model Applications

View full text Add to dashboard Cite

Section: Mountain Flowmentioning

confidence: 99%

The JMA Nonhydrostatic Model and Its Applications to Operation and Research

Saitō¹

2012

Atmospheric Model Applications

View full text Add to dashboard Cite

“…Figures 6 and 7 display the daily total precipitation pattern on July 31 and August 2, respectively. On July 31, weak precipitation, with values of about 10-20 mm, is observed in the Shikoku and Kinki districts, but there is no significant precipitation around the Hida Mountains, which may imply that the foehn prevailing in the Hokuriku district is identified with a dynamically-induced foehn accompanied by no precipitation on the windward side of a mountain range (e.g., Scorer and Klieforth 1959;Ikawa and Nagasawa 1989). In contrast, on August 2 heavy precipitation H. INABA, R. KAWAMURA, T. KAYAHARA and H. UEDAexceeding 100 mm occurs, especially in the Shikoku and part of Kyusyu districts, and we also see somewhat weak precipitation less than 50 mm on the Pacific Ocean side of Tokai district to the south of the Hida Mountains.…”

Section: Regional Featuresmentioning

confidence: 99%

“…The bora also is a downward wind on the leeward side of a mountain range, but when it commences, the air temperature on the leeward slope falls. Such local winds depend strongly on the configuration of the land, the pressure field at the level of the mountain peaks, and the atmospheric stability (e.g., Ikawa and Nagasawa 1989;Saito and Ikawa 1991;Saito 1993). The occurrence of extremely strong foehns in midsummer brings about the outstanding increase in daily maximum temperature and the decrease in daily minimum humidity, eventually damaging a variety of crops including grains, vegetables, and fruits.…”

Section: Introductionmentioning

confidence: 99%

Extraordinary Persistence of Foehn Observed in the Hokuriku District of Japan in the 1999 Summer.

Inaba¹,

Kawamura²,

Kayahara

et al. 2002

Journal of the Meteorological Society of Japan

View full text Add to dashboard Cite

An unusually prolonged foehn was observed at Toyama in the Hokuriku district, located on the coast of the Sea of Japan of central Japan, from 30 July to 3 August 1999. A 5-day foehn is extraordinarily persistent and was not observed during the 24-year period 1975-1998, which makes the 1999 summer quite exceptional. While an anticyclone east of Japan is intensified over the 5-day period, a combination of the anticyclone with a rapidly developing cyclone over southeastern Siberia and a typhoon migrating northward into the East China Sea induces a definite intensification of southerly geostrophic winds over central Japan, a favorable condition for the occurrence of unusually prolonged foehn.Observational and model results show that on a monthly mean basis, a noticeable east-west pressure gradient around Japan is present due to the prominence of the Pacific and Japan (PJ) teleconnection pattern in response to tropical convective heating, resulting in reinforcing southerly geostrophic winds across central Japan. Once large-scale circulation anomalies are initiated and sustained as a result of such an extratropical response, the development and movement of adjacent synoptic-scale disturbances are largely regulated by those anomalies. A combined effect of the excitation of the PJ pattern and associated synoptic-scale disturbances is crucial for the extraordinary persistence of foehn along the coast of the Sea of Japan. The PJ pattern that appeared in July 1999 has an unusual geographical location and configuration because enhanced cumulus convection over the warm pool region of the western North Pacific is significantly displaced about 20 westward and 2-3 northward, compared to the typical hot summer that Japan experiences. This displacement is presumably attributed to a similar shift of distinctive warm SST anomalies over the warm pool region.

show abstract

“…The foehn phenomenon can appear when Fr is greater than unity, because flow impinging a mountain is expected to rise over the mountain ridge. In addition, so-called dry (dynamic) foehn can occur when Fr has a value between 0.5 and 1, according to Ikawa and Nagasawa (1989). In that case, air having higher potential temperature descends to the surface on the lee side.…”

Section: Introductionmentioning

confidence: 99%

Summertime Temperature Extremes over Japan in the Late 21st Century Projected by a High-Resolution Regional Climate Model

Murata¹,

Nakano

Kanada

et al. 2012

Journal of the Meteorological Society of Japan

View full text Add to dashboard Cite

Future changes in summertime temperature extremes over Japan are projected by a well-developed regional climate model (RCM) with a spatial resolution of 5 km. The performance of the RCM with respect to temperature in the present climate is evaluated first based on observations. Although the di¤erences in the biases (from observations) of daily temperatures between the RCM and the driving atmospheric general circulation model (AGCM) simulations are not statistically significant, root-mean-square errors (from observations) in daily mean and minimum temperatures reproduced by the RCM are smaller than those by the AGCM with a coarser spatial resolution. These results indicate that RCM with a higher spatial resolution has better performance than the driving AGCM in simulating temperature variability. A test of whether the RCM can capture temperature extremes reveals a good quantitative agreement between simulated and observed values in appearance frequency of extreme high temperature for the daily minimum temperature during July and August. The spatial pattern of the upper tail of the frequency distribution for the daily maximum temperature is also in good agreement with observations, although the model values are underestimated.Projected changes for extremely high daily minimum temperature are relatively large in July on the lee side of the Hidaka Mountains, southeast of Hokkaido. This finding can be explained by the foehn phenomenon: changes in the windward Froude number indicate that atmospheric conditions in the future climate are more favorable for the intensification of foehn. In terms of extremely high daily maximum temperature, the di¤erence between the present-day and future climates during August is relatively large over the Tama area, west of Tokyo. Although the foehn phenomenon is not solely responsible for the projected changes, the phenomenon can explain the projected changes when westerly winds prevail over the Tama area, located on the lee side of the Kanto Mountains.

show abstract

A Numerical Study of a Dynamically Induced Foehn Observed in the Abashiri-Ohmu Area

Cited by 19 publications

References 36 publications

The JMA Nonhydrostatic Model and Its Applications to Operation and Research

The JMA Nonhydrostatic Model and Its Applications to Operation and Research

Extraordinary Persistence of Foehn Observed in the Hokuriku District of Japan in the 1999 Summer.

Summertime Temperature Extremes over Japan in the Late 21st Century Projected by a High-Resolution Regional Climate Model

Contact Info

Product

Resources

About