scholarly journals Characteristics of Spring Phenological Changes in China over the Past 50 Years

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Junhu Dai ◽  
Huanjiong Wang ◽  
Quansheng Ge
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Woody Plants ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Observation Data ◽  
Phenological Data ◽  
The Past ◽  
The North ◽  
Spatial Differences

In order to understand past plant phenological responses to climate change in China (1963–2009), we conducted trends analysis of spring phenophases based on observation data at 33 sites from the Chinese Phenological Observation Network (CPON). The phenological data on first leaf date (FLD) and first flowering date (FFD) for five broad-leaved woody plants from 1963 to 2009 were analyzed. Since most phenological time series are discontinuous because of observation interruptions at certain period, we first interpolated phenological time series by using the optimal model between the spring warming (SW) model and the UniChill model to form continuous time series. Subsequently, by using regression analysis, we found that the spring phenophases of woody plants in China advanced at a mean rate of 0.18 days/year over the past 50 years. Changes of spring phenophases exhibited strong regional difference. The linear trends in spring phenophases were −0.18, −0.28, −0.21, −0.04, and −0.14 days/year for the Northeast China Plain, the North China Plain, the Middle-Lower Yangtze Plain, the Yunnan-Guizhou Plateau, and South China, respectively. The spatial differences in phenological trends can be attributed to regional climate change patterns in China.

scholarly journals Climate change projections of the North American Regional Climate Change Assessment Program (NARCCAP)

2013 ◽  
Vol 120 (4) ◽  
pp. 965-975 ◽  
Author(s):  
L. O. Mearns ◽  
S. Sain ◽  
L. R. Leung ◽  
M. S. Bukovsky ◽  
S. McGinnis ◽  
...  
Keyword(s):  
Climate Change ◽  
North American ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Climate Change Projections ◽  
Change Assessment ◽  
Assessment Program ◽  
The North ◽  
Climate Change Assessment

CLIMATE CHANGE AND DEFORESTATION: Implications for the Maya collapse

2003 ◽  
Vol 14 (1) ◽  
pp. 157-167 ◽  
Author(s):  
Justine M. Shaw
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Ninth Century ◽  
Regional Climate Change ◽  
Climatic Data ◽  
Key Factors ◽  
Entire Region ◽  
The North ◽  
Maya Collapse ◽  
Systems Failure

During the ninth century, many sites in the Southern Maya Lowlands were abandoned as elite and commoners felt the effects of the Classic-period Maya collapse. At the same time, sites to the north and east continued to flourish. Recent climatic data indicate that, at this time, much of the Maya area experienced a significant drought. However, this drought does not appear to have uniformly affected the entire region; instead, climate appears to have acted as a mosaic, shifting through time and space. It is hypothesized that one of the key factors responsible for these variable cultural trajectories is localized and regional climate change brought about through irregular anthropogenic deforestation. These changes, when coupled with an out-of-balance cultural system, may have served as a catalyst that sent some parts of the Maya world down the path to systems failure, while other zones were able—at least, temporarily—to adjust and continue.

scholarly journals Potential Value of Expert Elicitation for Determining Differential Credibility of Regional Climate Change Simulations: An Exercise with the NARCCAP co-PIs for the Southwest Monsoon Region of North America

2017 ◽  
Vol 98 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Linda O. Mearns ◽  
Melissa S. Bukovsky ◽  
Vanessa J. Schweizer
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Expert Elicitation ◽  
Model Quality ◽  
Model Simulations ◽  
The North ◽  
Climate Model Simulations

Abstract In this brief article, we report the initial results of an expert elicitation with the co-PIs (regional climate modelers) of the North American Regional Climate Change Assessment Program regarding their evaluation of the relative quality of regional climate model simulations focusing on the subregion dominated by the North American monsoon (NAM). We assumed that an expert elicitation framework might reveal interesting beliefs and understanding that would be different from what would be obtained from calculating quantitative metrics associated with model quality. The simulations considered were of six regional climate models (RCMs) that used NCEP Reanalysis 2 as boundary conditions for the years 1980–2004. The domain covers most of North America and adjacent oceans. The seven participating regional modelers were asked to complete surveys on their background beliefs about model credibility and their judgments regarding the quality of the six models based on a series of plots of variables related to the NAM (e.g., temperature, winds, humidity, moisture flux, precipitation). The specific RCMs were not identified. We also compared the results of the expert elicitation with those obtained from using a series of metrics developed to evaluate a European collection of climate model simulations. The results proved to be quite different in the two cases. The results of this exercise proved very enlightening regarding regional modelers’ perceptions of model quality and their beliefs about how this information should or should not be used. Based on these pilot study results, we believe a more complete study is warranted.

scholarly journals Relative Importance of Northern Hemisphere Circulation Modes in Predicting Regional Climate Change

2004 ◽  
Vol 17 (21) ◽  
pp. 4180-4189 ◽  
Author(s):  
Monika Rauthe ◽  
Heiko Paeth
Keyword(s):  
Climate Change ◽  
Northern Hemisphere ◽  
North Atlantic ◽  
North Pacific ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Relative Importance ◽  
Near Surface ◽  
The North ◽  
The North Pacific

Abstract The Northern Hemisphere annular mode (NAM), North Atlantic Oscillation (NAO), and Aleutian low (AL) are known to be the most prominent components of Northern Hemisphere (NH) near-surface climate variability. In a tremendous number of studies, the impact of these circulation features on regional climate has been demonstrated. More recently, research has gone into the connection between the NAO and NAM and into the physical meaning of the latter. However, the relevance of those circulation modes for climatological issues may also be inferred from another nondynamical point of view: their statistical relationship to various climate parameters. This study comprises two steps: 1) qualifying and quantifying the relative importance of NH circulation modes with respect to twentieth-century near-surface temperature and precipitation, using stepwise multiple regression with cross validation; and 2) using predictor–predictand relationships to access the contributions of each circulation mode to regional climate change in the middle of the twenty-first century, given multimodel predictions of the circulation modes' responses to increasing greenhouse gas (GHG) and sulfate aerosol (SUL) concentrations. Altogether, the NAM, NAO, and AL account locally for up to 75% of the total interannual temperature and rainfall variability over NH continents. Over the major part of the NH, the NAM appears to be the most important predictor. In some parts of the North Atlantic, temperature and rainfall are more closely linked to the NAO, while the North Pacific is clearly dominated by the AL dynamics. In general, the NAO and AL have a more regionally confined influence. Climate change experiments mostly predict an intensification of the NAM and AL under GHG+SUL forcing, while the NAO response is much less consistent with different models and generally undergoes no long-term changes. This leads to substantial contributions to temperature and rainfall anomalies, especially over the NH landmasses. Temperature changes amount to ±1 K over large parts of Russia, North America, and the North Pacific. The major precipitation changes occur over the North Pacific, the North Atlantic, and Scandinavia. This circulation-induced contribution accounts for a considerable part of total expected change in these regions. Given its distinct trend, the NAM plays the main role, except over the Pacific Ocean and North America, where the AL is driving regional climate anomalies. Thus, whether physically relevant or not, the NAM is an appropriate statistical indicator of NH regional climate change.

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