Greater temperature sensitivity of vegetation greenup onset date in areas with weaker temperature seasonality across the Northern Hemisphere

2022 ◽  
Vol 313 ◽  
pp. 108759
Author(s):  
Miaogen Shen ◽  
Xiaolin Zhu ◽  
Dailiang Peng ◽  
Nan Jiang ◽  
Yan Huang ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Temperature Sensitivity ◽  
Onset Date ◽  
Temperature Seasonality

scholarly journals Distribution and Attribution of Terrestrial Snow Cover Phenology Changes over the Northern Hemisphere during 2001–2020

2021 ◽  
Vol 13 (9) ◽  
pp. 1843
Author(s):  
Xiaona Chen ◽  
Yaping Yang ◽  
Yingzhao Ma ◽  
Huan Li
Keyword(s):  
Snow Cover ◽  
Northern Hemisphere ◽  
Onset Date ◽  
Driving Factor ◽  
Climate Variables ◽  
Significance Level ◽  
The Past ◽  
Attribution Analysis ◽  
Altitudinal Distributions ◽  
Melting Season

Snow cover phenology has exhibited dramatic changes in the past decades. However, the distribution and attribution of the hemispheric scale snow cover phenology anomalies remain unclear. Using satellite-retrieved snow cover products, ground observations, and reanalysis climate variables, this study explored the distribution and attribution of snow onset date, snow end date, and snow duration days over the Northern Hemisphere from 2001 to 2020. The latitudinal and altitudinal distributions of the 20-year averaged snow onset date, snow end date, and snow duration days are well represented by satellite-retrieved snow cover phenology matrixes. The validation results by using 850 ground snow stations demonstrated that satellite-retrieved snow cover phenology matrixes capture the spatial variability of the snow onset date, snow end date, and snow duration days at the 95% significance level during the overlapping period of 2001–2017. Moreover, a delayed snow onset date and an earlier snow end date (1.12 days decade−1, p < 0.05) are detected over the Northern Hemisphere during 2001–2020 based on the satellite-retrieved snow cover phenology matrixes. In addition, the attribution analysis indicated that snow end date dominates snow cover phenology changes and that an increased melting season temperature is the key driving factor of snow end date anomalies over the NH during 2001–2020. These results are helpful in understanding recent snow cover change and can contribute to climate projection studies.

Continental temperature seasonality from Eocene Warmhouse to Oligocene Coolhouse — A model-data comparison

2021 ◽  
Author(s):  
Agathe Toumoulin ◽  
Yannick Donnadieu ◽  
Delphine Tardif ◽  
Jean-Baptiste Ladant ◽  
Alexis Licht ◽  
...  
Keyword(s):  
Sea Level ◽  
Northern Hemisphere ◽  
Surface Albedo ◽  
Middle Eocene ◽  
Late Eocene ◽  
Strong Increase ◽  
High Latitudes ◽  
Sea Level Changes ◽  
Annual Range ◽  
Temperature Seasonality

&lt;p&gt;At the junction of warmhouse and coolhouse climate phases, the Eocene Oligocene Transition (EOT) is a key moment in the history of the Cenozoic climate. Yet, while it is accompanied by severe extinctions and biodiversity turnovers, terrestrial climate evolution remains poorly resolved. On lands, some fossil and geochemistry records suggest a particularly marked cooling in winter, which would have led to the development of more pronounced seasons (higher Mean Annual Range of Temperatures, MATR) in certain regions of the Northern Hemisphere. This type of climate change should have had consequences on biodiversity and an implication in some of the fauna and flora renewals described at the EOT. However, this season strengthening has been studied only superficially by model studies, and questions remain about the geographical extent of this phenomenon and the associated climatic processes. Although other components of the climate system vary seasonally (e.g., precipitation, wind), we therefore focus on the seasonality of temperatures only.&lt;/p&gt;&lt;p&gt;In order to better understand and describe temperature seasonality change patterns from the middle Eocene to the early Oligocene, we use the Earth System Model IPSL-CM5A2 and a set of simulations reconstructing the EOT through three major climate forcings: pCO2 decrease (1120/840 to 560 ppm), the Antarctic ice-sheet (AIS) formation, and the associated sea-level decrease (-70 m).&amp;#160;&lt;/p&gt;&lt;p&gt;Our results suggest that seasonality changes across the EOT rely on the combined effects of the different tested mechanisms which result in zonal to regional climate responses. Sea-level changes associated with the earliest stage of the AIS formation may have also contributed to middle to late Eocene MATR reinforcement. We reconstruct strong and heterogeneous patterns of seasonality changes across the EOT. Broad continental areas of increased MATR reflect a strengthening of seasonality (from 4&amp;#176;C to &gt; 10&amp;#176;C increase of the MATR) in agreement with MATR and Coldest Month Mean Temperatures (CMMT) changes indicated by a review of existing proxies. pCO2 decrease induces a zonal pattern with alternating increasing and decreasing seasonality bands. In the northern high-latitudes, it results in sea-ice and surface albedo feedback, driving a strong increase in seasonality (up to 8&amp;#176;C MATR increase). Conversely, the onset of the AIS is responsible for a more constant surface albedo, which leads to a strong decrease in seasonality in the southern mid- to high-latitudes (&gt; 40&amp;#176;S). Finally, continental areas emerged due to the sea level lowering cause the largest increase in seasonality and explain most of the global heterogeneity in MATR changes patterns. The seasonality change patterns we reconstruct are consistent with the variability of the EOT biotic crisis intensity across the Northern Hemisphere.&lt;/p&gt;

scholarly journals Higher temperature variability reduces temperature sensitivity of vegetation growth in Northern Hemisphere

2017 ◽  
Vol 44 (12) ◽  
pp. 6173-6181 ◽  
Author(s):  
Xiuchen Wu ◽  
Hongyan Liu ◽  
Xiaoyan Li ◽  
Shilong Piao ◽  
Philippe Ciais ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Temperature Sensitivity ◽  
Temperature Variability ◽  
Vegetation Growth ◽  
Higher Temperature

scholarly journals Earlier-Season Vegetation Has Greater Temperature Sensitivity of Spring Phenology in Northern Hemisphere

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e88178 ◽  
Author(s):  
Miaogen Shen ◽  
Yanhong Tang ◽  
Jin Chen ◽  
Xi Yang ◽  
Cong Wang ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Temperature Sensitivity ◽  
Spring Phenology

scholarly journals Northern Hemisphere Modes of Variability and the Timing of Spring in Western North America

2011 ◽  
Vol 24 (15) ◽  
pp. 4003-4014 ◽  
Author(s):  
Toby R. Ault ◽  
Alison K. Macalady ◽  
Gregory T. Pederson ◽  
Julio L. Betancourt ◽  
Mark D. Schwartz
Keyword(s):  
North America ◽  
Northern Hemisphere ◽  
Principal Component ◽  
Reanalysis Data ◽  
Onset Date ◽  
Western North America ◽  
Spatial And Temporal Patterns ◽  
Modes Of Variability ◽  
Index Model ◽  
Maximum Temperatures

Abstract Spatial and temporal patterns of variability in spring onset are identified across western North America using a spring index (SI) model based on weather station minimum and maximum temperatures (Tmin and Tmax, respectively). Principal component analysis shows that two significant and independent patterns explain roughly half of the total variance in the timing of spring onset from 1920 to 2005. However, these patterns of spring onset do not appear to be linear responses to the primary modes of variability in the Northern Hemisphere: the Pacific–North American pattern (PNA) and the northern annular mode (NAM). Instead, over the period when reanalysis data and the spring index model overlap (1950–2005), the patterns of spring onset are local responses to the state of both the PNA and NAM, which together modulate the onset date of spring by 10–20 days on interannual time scales. They do so by controlling the number and intensity of warm days. There is also a regionwide trend in spring advancement of about −1.5 days decade−1 from 1950 to 2005. Trends in the NAM and PNA can only explain about one-third (−0.5 day decade−1) of this trend.

Mongolian tree-rings, temperature sensitivity and reconstructions of Northern Hemisphere temperature

The Holocene ◽  
2000 ◽  
Vol 10 (6) ◽  
pp. 669-672 ◽  
Author(s):  
Rosanne D'Arrigo ◽  
Gordon Jacoby ◽  
Neil Pederson ◽  
David Frank ◽  
Brendan Buckley ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Tree Rings ◽  
Temperature Sensitivity ◽  
Northern Hemisphere Temperature ◽  
Hemisphere Temperature

scholarly journals Northern Hemisphere spring snow cover variability and change over 1922–2010 including an assessment of uncertainty

2010 ◽  
Vol 4 (4) ◽  
pp. 2483-2512
Author(s):  
R. D. Brown ◽  
D. A. Robinson
Keyword(s):  
Snow Cover ◽  
Northern Hemisphere ◽  
Temperature Sensitivity ◽  
Northern China ◽  
The Tibetan Plateau ◽  
Climate Data ◽  
The Past ◽  
The North ◽  
Snow Cover Extent ◽  
The North Atlantic Oscillation

Abstract. An update is provided of Northern Hemisphere (NH) spring (March, April) snow cover extent (SCE) over the 1922–2010 period incorporating the new climate data record (CDR) version of the NOAA weekly SCE dataset, with annual 95% confidence intervals estimates from regression analysis and intercomparison of multiple datasets. The uncertainty analysis indicated a 95% confidence interval in NH spring SCE of ±5–10% over the pre-satellite period and ±3–5% over the satellite era. The multi-dataset analysis showed there are larger uncertainties monitoring spring SCE over Eurasia (EUR) than North America (NA) due to the more complex regional character of the snow cover variability with the largest dataset uncertainty located over eastern Eurasia in a large region extending from the Tibetan Plateau across northern China. Trend analysis of the updated SCE series provided evidence that NH spring snow cover extent has undergone significant reductions over the past ~90 years and that the rate of decrease has accelerated over the past 40 years. The rate of decrease in March and April NH SCE over the 1970–2010 period is ~7–8 million km2 per 100 years which corresponds to an 8–11% decrease in NH March and April SCE respectively from pre-1970 values. In March, most of the change is being driven by Eurasia (NA trends are not significant) but both continents exhibit significant SCE reductions in April. The observed trends in SCE are consistent with recent warming trends over northern mid-latitude land areas with NH SCE exhibiting significant negative correlations to air temperature anomalies in March and April. The NH spring SCE-temperature sensitivity has remained relatively stable over the period of record although there is some evidence of contrasting changes in temperature sensitivity over both continents in April. There is evidence that changes in atmospheric circulation around 1980 involving the North Atlantic Oscillation and Scandinavian Pattern have contributed to reductions in March SCE over Eurasia.

scholarly journals Evolution of continental temperature seasonality from the Eocene greenhouse to the Oligocene icehouse - A model-data comparison

2021 ◽  
Author(s):  
Agathe Toumoulin ◽  
Delphine Tardif ◽  
Yannick Donnadieu ◽  
Alexis Licht ◽  
Jean-Baptiste Ladant ◽  
...  
Keyword(s):  
Sea Level ◽  
Northern Hemisphere ◽  
Surface Albedo ◽  
Climate Models ◽  
Middle Eocene ◽  
Regional Climate ◽  
Strong Increase ◽  
High Latitudes ◽  
Annual Range ◽  
Temperature Seasonality

Abstract. At the junction of greenhouse and icehouse climate phases, the Eocene-Oligocene Transition (EOT) is a key moment in the history of the Cenozoic climate. Yet, while it is associated with severe extinctions and biodiversity turnovers, terrestrial climate evolution remains poorly resolved. Paleobotanical and geochemical continental records suggest a marked cooling in winter, leading to the development of more pronounced seasons (i.e., increase of the Mean Annual Range of Temperature, MATR) in parts of the Northern Hemisphere. However, this increase of the annual temperature range has been poorly studied by climate models; uncertainties remain about the geographical extent of this phenomenon and the associated climatic processes. Although other components of the climate system vary seasonally (e.g., precipitation, wind), we therefore focus on the seasonality of temperatures only. In order to better understand and describe temperature seasonality patterns from the middle Eocene to the early Oligocene, we use the Earth System Model IPSL-CM5A2 and a set of simulations reconstructing the EOT through three major climate forcings: pCO2 decrease (1120/840 to 560 ppm), the Antarctic ice-sheet (AIS) formation, and the associated sea-level decrease (-70 m). Our simulations suggest that seasonality changes across the EOT rely on the combined effects of the different tested mechanisms which result in zonal to regional climate responses. Broad continental areas of increased MATR reflect a strengthening of seasonality (from 4°C to > 10°C increase of the MATR) across the EOT in agreement with MATR and Coldest Month Mean Temperatures (CMMT) changes indicated by a review of existing proxies. pCO2 decrease induces a zonal pattern with alternating increasing and decreasing seasonality bands. In the northern high-latitudes, it results in sea-ice and surface albedo feedback, driving a strong increase in seasonality (up to 8°C MATR increase). Conversely, the onset of the AIS is responsible for a more constant surface albedo, which leads to a strong decrease in seasonality in the southern mid- to high-latitudes (> 40°S). Finally, continental areas emerged due to the sea level lowering cause the largest increase in seasonality and explain most of the global heterogeneity in MATR changes (∆MATR) patterns. ∆MATR patterns we reconstruct are consistent with the variability of the EOT biotic crisis intensity across the Northern Hemisphere.

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