| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Jin, Y H, et al.
(författare)
-
Detection of ENSO-influence on the monthly precipitation in South Korea
- 2005
-
Ingår i: Hydrological Processes. - : Wiley. - 1099-1085 .- 0885-6087. ; 19:20, s. 4081-4092
-
Tidskriftsartikel (refereegranskat)abstract
- During the latest several decades, there has been considerable interest in revealing the relationship between El Nino-southern oscillation (ENSO) and hydro-meteorological variables. The oscillation is characterized by a simple index, the southern oscillation index (SOI). However, thus far, there is little evidence for the influence of ENSO in Korea and Japan. The influence of ENSO has also been studied in South Korea, but the estimated results are still qualitative and show an indirect relationship between ENSO and hydro-meteorological variables. In this study we use simple approaches to reveal the quantitative and direct correlation between SOI and the monthly precipitation at five stations distributed over South Korea. The monthly precipitation data are transformed into nonexceedance probability time series because the data cannot be normally distributed by applying the usual transformations. The SOI is classified into five categories according to their values. Additionally, to detect the nonlinear relationship between categorized SOI and nonexceedance probability of the monthly precipitation, we use Kendall's tau, a nonparametric test. Significant correlations between the categorized SOI and the transformed precipitation are detected. Generally, the monthly precipitation is influenced by a La Nina event with a lag time of 4 months for southern coastal areas and a lag time of 5 months for middle to high regions in South Korea.
|
|
| 5. |
- Jin, YH, et al.
(författare)
-
Nonlinear multivariable analysis of SOI and local precipitation and temperature
- 2005
-
Ingår i: Nonlinear Processes in Geophysics. - 1023-5809. ; 12:1, s. 67-74
-
Tidskriftsartikel (refereegranskat)abstract
- Global climate variability affects important local hydro-meteorological variables like precipitation and temperature. The Southern Oscillation (SO) is an easily quantifiable major driving force that gives impact on regional and local climate. The relationships between SO and local climate variation are, however, characterized by strongly nonlinear processes. Due to this, teleconnections between global-scale hydro-meteorological variables and local climate are not well understood. In this paper, we suggest to study these processes in terms of nonlinear dynamics. Consequently, the nonlinear dynamic relationship between the Southern Oscillation Index (SOI), precipitation, and temperature in Fukuoka, Japan, is investigated using a nonlinear multivariable approach. This approach is based on the joint variation of these variables in the phase space. The joint phasespace variation of SOI, precipitation, and temperature is studied with the primary objective to obtain a better understanding of the dynamical evolution of local hydro-meteorological variables affected by global atmospheric-oceanic phenomena. The results from the analyses display rather clear low-order phase space trajectories when treating the time series individually. However, when plotting phase space trajectories for several time series jointly, complicated higher-order nonlinear relationships emerge between the variables. Consequently, simple data-driven prediction techniques utilizing phase-space characteristics of individual time series may prove successful. On the other hand, since either the time series are too short and/or the phase-space properties are too complex when analysing several variables jointly, it may be difficult to use multivariable statistical prediction techniques for the present investigated variables. In any case, it is essential to further pursue studies regarding links between the SOI and observed local climatic and other geophysical variables even if these links are not fully understood in physical terms.
|
|
| 6. |
- Jin, YH, et al.
(författare)
-
Quantitative relationship between SOI and observed precipitation in southern Korea and Japan by nonparametric approaches
- 2005
-
Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 301:1-4, s. 54-65
-
Tidskriftsartikel (refereegranskat)abstract
- Several studies have tried to link southern oscillation index (Sol) and observed precipitation in Korea and Japan. However, so far no clear relationship between the Sol and the precipitation in the area has been found. In the present study, categorized Sol are used to reveal quantitative and statistically significant influence on monthly precipitation at Busan in Korea and at Fukuoka in Japan. Monthly precipitation data were transformed to cubic root and nonexceedance probability time series. Correlation between the categorized Sol and transformed precipitation was calculated by Kendall's tau and Pearson's r. The results show that significant correlation is at hand when using both approaches. Significant correlation at the 1% level was obtained with lag time of 4 months under the 'Strong La Nina' category (SOI>2) at both stations. The results show that southern Korea and southern parts of Japan are located in the same or very close influence range of Sol.
|
|
| 7. |
|
|
| 8. |
|
|
