| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Xing, Hang, et al.
(författare)
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Impacts of changes in climate extremes on wildfire occurrences in China
- 2023
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Ingår i: Ecological Indicators. - 1470-160X. ; 157
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Tidskriftsartikel (refereegranskat)abstract
- Climate change has caused more frequent instances of extreme climatic events around the world, being an influential factor on the occurrence of wildfires in China on large scale. However, the impact of changes in extreme climate on the occurrence of wildfires in different climate zones remains unclear. In the present study, 26 extreme climate indices were selected to analyze the thereof relationship with wildfire occurrences from 2005 to 2018 in different regions of China. Wildfires in China primarily occur in the south, with a measurable presence in the north. On an annual scale, the wildfire occurrences in southwestern China show stronger correlations with mean temperature than extreme temperature indices, but show stronger correlations with extreme precipitation indices than the total precipitation. On the contrary, the wildfire occurrences in southeastern China show stronger correlations with the total precipitation than extreme precipitation indices, but show stronger correlations with extreme temperature indices than the mean temperature. In Northeast China, wildfires show a more significant correlation with mean temperature than with any extreme climate indices, indicating a minimal impact from extreme climatic conditions. The fire-climate relationships in the main fire season (January-April) are similar to those in the annual scale. The wildfire occurrences in the southwestern, south-central, and southeastern China, which are located in the same latitudes, were affected by extreme climate indices of different types and on different time scales. Furthermore, we recommend that consecutive dry days (CDD) and diurnal temperature range (DTR) should be considered first when studying the relationship between wildfire occurrence and extreme climate in southwestern and southeastern China respectively.
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| 3. |
- Fang, Keyan, et al.
(författare)
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An interdecadal climate dipole between Northeast Asia and Antarctica over the past five centuries
- 2019
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 52:1/2, s. 765-775
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Springer-Verlag GmbH Germany, part of Springer Nature Climate models emphasize the need to investigate inter-hemispheric climatic interactions. However, these models often underestimate the inter-hemispheric differences in climate change. With the wide application of reanalysis data since 1948, we identified a dipole pattern between the geopotential heights (GPHs) in Northeast Asia and Antarctica on the interdecadal scale in boreal summer. This Northeast Asia/Antarctica (NAA) dipole pattern is not conspicuous on the interannual scale, probably in that the interannual inter-hemispheric climate interaction is masked by strong interannual signals in the tropics associated with the El Niño-Southern Oscillation (ENSO). Unfortunately, the instrumental records are not sufficiently long-lasting to detect the interdecadal variability of the NAA. We thus reconstructed GPHs since 1565, making using the proxy records mostly from tree rings in Northeast Asia and ice cores from Antarctica. The strength of the NAA is time-varying and it is most conspicuous in the eighteenth century and after the late twentieth century. The strength of the NAA matches well with the variations of the solar radiation and tends to increase in along with its enhancement. In boreal summer, enhanced heating associated with high solar radiation in the Northern Hemisphere drives more air masses from the South to the North. This inter-hemispheric interaction is particularly strong in East Asia as a result of the Asian summer monsoon. Northeast Asia and Antarctica appear to be the key regions responsible for inter-hemispheric interactions on the interdecadal scale in boreal summer since they are respectively located at the front and the end of this inter-hemispheric trajectory.
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| 4. |
- Fang, Keyan, et al.
(författare)
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Drought variation of western Chinese Loess Plateau since 1568 and its linkages with droughts in western North America
- 2017
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 49:11-12, s. 3839-3850
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Tidskriftsartikel (refereegranskat)abstract
- © 2017, Springer-Verlag Berlin Heidelberg. Understanding long-term drought variations in the past can help to evaluate ongoing and future hydroclimate change in the arid western Chinese Loess Plateau (WCLP), a region with increasing demand for water resources due to the increasing population and socioeconomic activities. Here we present a new tree-ring chronology inform the WCLP, which shows coherent interannual variations with tree-ring chronologies from 7 neighboring areas across the WCLP, suggesting a common regional climate control over tree growth. However, considerable differences are observed among their interdecadal variations, which are likely due to growth disturbances at interdecadal timescales. To deal with this issue, we use a frequency based method to develop a composite tree-ring chronology from 401 tree-ring series from these 8 sites, which shows more pronounced interdecadal variability than a chronology developed using traditional methods. The composite tree-ring chronology is used to reconstruct the annual precipitation from previous August to current July from 1568 to 2012, extending about 50 years longer than the previous longest tree-ring reconstruction from the region. The driest epoch of our reconstruction is found in the 1920s–1930s, which matches well with droughts recorded in historical documents. Over the past four centuries, a strong resemblance between drought variability in the WCLP and western North America (WNA) is evident on multidecadal timescales, but this relationship breaks down on timescales shorter than about 50 years.
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| 5. |
- Fang, Keyan, et al.
(författare)
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Interdecadal modulation of the Atlantic Multi-decadal Oscillation (AMO) on southwest China’s temperature over the past 250 years
- 2019
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 52:3/4, s. 2055-2065
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Springer-Verlag GmbH Germany, part of Springer Nature The temperature gradient between southwestern China and Indian Ocean is one key driver of the Indian Summer Monsoon, suggesting the necessity to understand temperature variability in southwestern China. Contrary to the general warming experienced in most of China, a few regions in southwestern China have undergone a cooling trend since the 1950s. To place this cooling trend in a historical context, this study develops an Abies fabri tree-ring width chronology in the Sichuan Basin, the most populated region in southwest China. The chronology spans from 1590 to 2012, with its reliable portion from 1758 to 2012, by far the longest in the Sichuan Basin. To better extract regional climate signals encoded in tree rings with strong local disturbances, we incorporate climate signals of nearby tree-ring chronologies to generate a large-scale tree-ring chronology (LSC). The LSC shows higher correlations with temperature near the sampling site on Mount Emei and sea surface temperatures of the northern Atlantic Ocean than chronologies developed using traditional methods. The highest correlations between the LSC and temperature are found from current February to July in the Sichuan Basin for the period 1901–1950 (r = 0.70), with a sharp decrease afterwards. Interdecadal variations of the LSC match well with Atlantic Multi-decadal Oscillation reconstructions, except for the late nineteenth century and after ~ 1980s. This study provides evidence that southwest China is a transitional region both affected by the interdecadal temperature variations of the northern Atlantic and Asian areas, although their influences weakened in recent possible due to enhanced human activities.
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| 6. |
- Guo, Guoyang, et al.
(författare)
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Increasing intrinsic water-use efficiency over the past 160 years does not stimulate tree growth in southeastern China
- 2018
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Ingår i: Climate Research. - : Inter-Research Science Center. - 0936-577X .- 1616-1572. ; 76:2, s. 115-130
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Inter-Research. Understanding the responses of tree growth and intrinsic water-use efficiency (iWUE) to anthropogenic CO2 increase and climate warming provides important benchmarks for evaluating future forest dynamics under different scenarios of warming and CO2 changes. Relative to the short period of instrumental data of the past few decades, long-term tree-ring width and stable carbon isotopic (δ13C) data are invaluable in fully comprehending their interactions during the entire industrial era, since ~1850. Here, we present a tree-ring width chronology (1856 to 2015) and Δ13C series (1876-2015) of Pinus massoniana for Yongtai county of Fujian province, in humid subtropical China, a 'green island' relative to other dry subtropical areas of the world. Tree growth was limited by precipitation of the hydrological year (previous November to current October) (r = 0.568, p < 0.001), and the stable carbon isotope discrimination (Δ13C) was strongly correlated with relative humidity in September-October (r =-0.677, p < 0.001) of the current growing season. We found that the iWUE increased by 40.9% since 1876. Specifically, we found that the ci:ca ratio decreased during the study period whereas intercellular CO2 concentration (ci) increased. The negative relationship between basal area increment (BAI) and iWUE indicated that increasing iWUE may not lead to long-term enhancement of tree growth. Our results indicated a drought-induced limitation to tree growth in response to rising CO2, and that trees may mitigate the negative effects of a decrease in water availability through a reduction in stomatal conductance.
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| 7. |
- Tang, Wanru, et al.
(författare)
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Drought variations in the southeastern Tibetan Plateau region since 1704 and their link to the Atlantic Multidecadal Oscillation
- 2023
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - 0031-0182. ; 630
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the long-term history of drought in the Tibetan Plateau region is important to improve understanding of drought frequency in response to future global warming. Although the Tibetan Plateau has become generally wetter recently, the southeastern part of the Tibetan Plateau has become drier since the 2000s. To place this drying trend in a historical context, we conducted tree-ring studies for Abies spectabilis and Tsuga dumosa at three sites in the southeastern Tibetan Plateau, and developed tree-ring width (TRW), earlywood width (EWW), and latewood width (LWW) chronologies to permit local drought reconstruction. Based on correlation between these tree-ring parameters and instrumental meteorological data, the EWW chronologies were identified as suitable variables for reconstructing the average April–July self-calibrating Palmer Drought Index (scPDSI). The reconstruction accounted for 45.86% of the variance in the instrumental record and allowed us to extend the drought record back to 1704 CE. Based on this new dataset, the driest interval was from 1907 to 1919 CE during which time agricultural production fell by about 70% according to written historical records, leading to severe famine. Our findings suggest that this early twentieth century drought was in phase with the previously known drought over the northern Daxing'an Mountains. However, the southeastern Tibetan Plateau drought occurred one decade earlier than the known widespread drought event in North China during the 1920s–1930s. We show that this spatial drought pattern may have been modulated by the Atlantic Multidecadal Oscillation.
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| 8. |
- Tobias, Deirdre K, et al.
(författare)
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Second international consensus report on gaps and opportunities for the clinical translation of precision diabetes medicine
- 2023
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Ingår i: Nature Medicine. - 1546-170X. ; 29:10, s. 2438-2457
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Forskningsöversikt (refereegranskat)abstract
- Precision medicine is part of the logical evolution of contemporary evidence-based medicine that seeks to reduce errors and optimize outcomes when making medical decisions and health recommendations. Diabetes affects hundreds of millions of people worldwide, many of whom will develop life-threatening complications and die prematurely. Precision medicine can potentially address this enormous problem by accounting for heterogeneity in the etiology, clinical presentation and pathogenesis of common forms of diabetes and risks of complications. This second international consensus report on precision diabetes medicine summarizes the findings from a systematic evidence review across the key pillars of precision medicine (prevention, diagnosis, treatment, prognosis) in four recognized forms of diabetes (monogenic, gestational, type 1, type 2). These reviews address key questions about the translation of precision medicine research into practice. Although not complete, owing to the vast literature on this topic, they revealed opportunities for the immediate or near-term clinical implementation of precision diabetes medicine; furthermore, we expose important gaps in knowledge, focusing on the need to obtain new clinically relevant evidence. Gaps include the need for common standards for clinical readiness, including consideration of cost-effectiveness, health equity, predictive accuracy, liability and accessibility. Key milestones are outlined for the broad clinical implementation of precision diabetes medicine.
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| 9. |
- Wang, Lei, et al.
(författare)
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Intensified variability of the El Niño–Southern Oscillation enhances its modulations on tree growths in southeastern China over the past 218 years
- 2018
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Ingår i: International Journal of Climatology. - : Wiley. - 0899-8418 .- 1097-0088. ; 38:14, s. 5293-5304
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Royal Meteorological Society Lack of long-term tree-ring records in the core regions of the Asian summer monsoon in southeastern China limits our ability of evaluating the current climate change in a historical context. In this study, we developed the first 218-year tree-ring chronology (1798–2015) of Pinus massoniana in Zhangping area, Fujian Province, humid subtropical China. This chronology is positively correlated with winter–spring (January–March) temperature (r = 0.359, p <.01) and summer (July–September) precipitation (r = 0.351, p <.01). Although the correlations between our tree rings with sea surface temperatures (SSTs) are not very high, the correlation pattern is very close to the correlation pattern with the El Niño–Southern Oscillation variability (ENSO). These suggest that the ENSO could be the major large-scale regulator on the growth of our tree rings. The strength of the correlations between our tree rings and the ENSO (r = 0.30, N = 66) matches closely with the ENSO variability during 1950–2015. The modulations of the ENSO on regional tree growth have been the most conspicuous since the 1950s, which corresponds to its enhanced inter-annual variability. The extreme growth anomalies match quite well with the extreme years of the moisture-sensitive chronologies. The dry epoch from 1935 to 1958 is the most severe long-lasting drought in our tree rings, which is a widely distributed pattern in southeastern China and is likely modulated by the La Niña-like modes in that period.
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