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Quantifying the Intra-Regional Precipitation Variability in Northwestern China over the Past 1,400 Years.

Lee HF, Pei Q, Zhang DD, Choi KP - PLoS ONE (2015)

Bottom Line: Also, we offer statistical evidence of El Niño Southern Oscillation (Indo-Pacific warm pool sea surface temperature and China-wide land surface temperature) as the prominent multi-decadal to centennial (centennial to multi-centennial) determinant of the IRPV in NW China.The present study contributes to the quantitative validation of the long-term IRPV in NW China and its driving forces, covering the periods with and without instrumental records.It may help to comprehend the complex hydro-climatic regimes in the region.

View Article: PubMed Central - PubMed

Affiliation: Department of Geography, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China; International Centre of China Development Studies, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.

ABSTRACT
There has been a surge of paleo-climatic/environmental studies of Northwestern China (NW China), a region characterized by a diverse assortment of hydro-climatic systems. Their common approach, however, focuses on "deducing regional resemblance" rather than "exploring regional variance." To date, efforts to produce a quantitative assessment of long-term intra-regional precipitation variability (IRPV) in NW China has been inadequate. In the present study, we base on historical flood/drought records to compile a decadal IRPV index for NW China spanned AD580-1979 and to find its major determinants via wavelet analysis. Results show that our IRPV index captures the footprints of internal hydro-climatic disparity in NW China. In addition, we find distinct ~120-200 year periodicities in the IRPV index over the Little Ice Age, which are attributable to the change of hydro-climatic influence of ocean-atmospheric modes during the period. Also, we offer statistical evidence of El Niño Southern Oscillation (Indo-Pacific warm pool sea surface temperature and China-wide land surface temperature) as the prominent multi-decadal to centennial (centennial to multi-centennial) determinant of the IRPV in NW China. The present study contributes to the quantitative validation of the long-term IRPV in NW China and its driving forces, covering the periods with and without instrumental records. It may help to comprehend the complex hydro-climatic regimes in the region.

No MeSH data available.


Related in: MedlinePlus

Location and geographic configuration of our study area (modified from [32–34]).Our study area is delineated into two regions (Regions A and B) according to the present-day 400 mm isohyet. The hydro-climate in Regions A and B is dominated by the Westerlies and ASM, respectively. Arrows represent ASM (including East ASM and Indian Summer Monsoon), Westerlies, and Winter Monsoon. The checkered belt is the region between the 200–400 mm isohyets, which is the approximate present-day northern fringe of ASM.
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pone.0131693.g001: Location and geographic configuration of our study area (modified from [32–34]).Our study area is delineated into two regions (Regions A and B) according to the present-day 400 mm isohyet. The hydro-climate in Regions A and B is dominated by the Westerlies and ASM, respectively. Arrows represent ASM (including East ASM and Indian Summer Monsoon), Westerlies, and Winter Monsoon. The checkered belt is the region between the 200–400 mm isohyets, which is the approximate present-day northern fringe of ASM.

Mentions: Nevertheless, the availability of proxy data depends on the properties of the proxy media itself. For instance, trees for dendrochronology tend to concentrate in places favorable to plant growth. Also, the distribution of cave speleothems, ice cores, and lake sediments are confined to certain geographic regions. For the selection of study areas, those sites in which the proxies contain very strong climate signals are usually preferred. The resulting reconstructions may be ideal to reveal the condition at climate-sensitive/marginal areas. Yet, they may contain site-specific climatic signals [23]. It remains an issue how far the associated findings can be generalized to the other parts of NW China. It is worth mentioning that NW China sits at the present-day northern fringe of the Asian Summer Monsoon (ASM) (Fig 1). The hydrological balance and effective moisture of the region is controlled by the interactions of ASM, Winter Monsoon, and Westerlies [2, 24]. Subject to this unique geographic configuration, precipitation regimes in NW China are typified by salient intra-regional differences, especially between the zones north and south of the ASM fringe [25–27]. This inherent feature makes it impossible to apply generalizations about the precipitation regime of any single locality to other parts of NW China. Most importantly, a fine-grained picture of the intra-regional precipitation variability (IRPV) in NW China over extended periods is still nonexistent at the moment, as the common approach employed in most of the abovementioned paleo-climatic/environmental studies has focused on “deducing regional resemblance” rather than “exploring regional variance.” This limits the examination of the related phenomena.


Quantifying the Intra-Regional Precipitation Variability in Northwestern China over the Past 1,400 Years.

Lee HF, Pei Q, Zhang DD, Choi KP - PLoS ONE (2015)

Location and geographic configuration of our study area (modified from [32–34]).Our study area is delineated into two regions (Regions A and B) according to the present-day 400 mm isohyet. The hydro-climate in Regions A and B is dominated by the Westerlies and ASM, respectively. Arrows represent ASM (including East ASM and Indian Summer Monsoon), Westerlies, and Winter Monsoon. The checkered belt is the region between the 200–400 mm isohyets, which is the approximate present-day northern fringe of ASM.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495927&req=5

pone.0131693.g001: Location and geographic configuration of our study area (modified from [32–34]).Our study area is delineated into two regions (Regions A and B) according to the present-day 400 mm isohyet. The hydro-climate in Regions A and B is dominated by the Westerlies and ASM, respectively. Arrows represent ASM (including East ASM and Indian Summer Monsoon), Westerlies, and Winter Monsoon. The checkered belt is the region between the 200–400 mm isohyets, which is the approximate present-day northern fringe of ASM.
Mentions: Nevertheless, the availability of proxy data depends on the properties of the proxy media itself. For instance, trees for dendrochronology tend to concentrate in places favorable to plant growth. Also, the distribution of cave speleothems, ice cores, and lake sediments are confined to certain geographic regions. For the selection of study areas, those sites in which the proxies contain very strong climate signals are usually preferred. The resulting reconstructions may be ideal to reveal the condition at climate-sensitive/marginal areas. Yet, they may contain site-specific climatic signals [23]. It remains an issue how far the associated findings can be generalized to the other parts of NW China. It is worth mentioning that NW China sits at the present-day northern fringe of the Asian Summer Monsoon (ASM) (Fig 1). The hydrological balance and effective moisture of the region is controlled by the interactions of ASM, Winter Monsoon, and Westerlies [2, 24]. Subject to this unique geographic configuration, precipitation regimes in NW China are typified by salient intra-regional differences, especially between the zones north and south of the ASM fringe [25–27]. This inherent feature makes it impossible to apply generalizations about the precipitation regime of any single locality to other parts of NW China. Most importantly, a fine-grained picture of the intra-regional precipitation variability (IRPV) in NW China over extended periods is still nonexistent at the moment, as the common approach employed in most of the abovementioned paleo-climatic/environmental studies has focused on “deducing regional resemblance” rather than “exploring regional variance.” This limits the examination of the related phenomena.

Bottom Line: Also, we offer statistical evidence of El Niño Southern Oscillation (Indo-Pacific warm pool sea surface temperature and China-wide land surface temperature) as the prominent multi-decadal to centennial (centennial to multi-centennial) determinant of the IRPV in NW China.The present study contributes to the quantitative validation of the long-term IRPV in NW China and its driving forces, covering the periods with and without instrumental records.It may help to comprehend the complex hydro-climatic regimes in the region.

View Article: PubMed Central - PubMed

Affiliation: Department of Geography, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China; International Centre of China Development Studies, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.

ABSTRACT
There has been a surge of paleo-climatic/environmental studies of Northwestern China (NW China), a region characterized by a diverse assortment of hydro-climatic systems. Their common approach, however, focuses on "deducing regional resemblance" rather than "exploring regional variance." To date, efforts to produce a quantitative assessment of long-term intra-regional precipitation variability (IRPV) in NW China has been inadequate. In the present study, we base on historical flood/drought records to compile a decadal IRPV index for NW China spanned AD580-1979 and to find its major determinants via wavelet analysis. Results show that our IRPV index captures the footprints of internal hydro-climatic disparity in NW China. In addition, we find distinct ~120-200 year periodicities in the IRPV index over the Little Ice Age, which are attributable to the change of hydro-climatic influence of ocean-atmospheric modes during the period. Also, we offer statistical evidence of El Niño Southern Oscillation (Indo-Pacific warm pool sea surface temperature and China-wide land surface temperature) as the prominent multi-decadal to centennial (centennial to multi-centennial) determinant of the IRPV in NW China. The present study contributes to the quantitative validation of the long-term IRPV in NW China and its driving forces, covering the periods with and without instrumental records. It may help to comprehend the complex hydro-climatic regimes in the region.

No MeSH data available.


Related in: MedlinePlus