scholarly journals DEVISING OF THE EVALUATION METHOD FOR SNOW DEPTH OVER THE TIBETAN PLATEAU BASED ON AVNIR-2 AND MODIS

2013 ◽  
Vol 69 (4) ◽  
pp. I_433-I_438
Author(s):  
Hiroyuki TSUTSUI ◽  
Toshio KOIKE
Keyword(s):  
Tibetan Plateau ◽  
Snow Depth ◽  
Evaluation Method ◽  
The Tibetan Plateau

scholarly journals Spatio-Temporal Variation Characteristics of Snow Depth and Snow Cover Days over the Tibetan Plateau

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 307
Author(s):  
Chi Zhang ◽  
Naixia Mou ◽  
Jiqiang Niu ◽  
Lingxian Zhang ◽  
Feng Liu
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Snow Depth ◽  
Feedback Effect ◽  
Effect Of Temperature ◽  
The Tibetan Plateau ◽  
Reanalysis Dataset ◽  
Spatio Temporal ◽  
The Impact ◽  
Main Factor

Changes in snow cover over the Tibetan Plateau (TP) have a significant impact on agriculture, hydrology, and ecological environment of surrounding areas. This study investigates the spatio-temporal pattern of snow depth (SD) and snow cover days (SCD), as well as the impact of temperature and precipitation on snow cover over TP from 1979 to 2018 by using the ERA5 reanalysis dataset, and uses the Mann–Kendall test for significance. The results indicate that (1) the average annual SD and SCD in the southern and western edge areas of TP are relatively high, reaching 10 cm and 120 d or more, respectively. (2) In the past 40 years, SD (s = 0.04 cm decade−1, p = 0.81) and SCD (s = −2.3 d decade−1, p = 0.10) over TP did not change significantly. (3) The positive feedback effect of precipitation is the main factor affecting SD, while the negative feedback effect of temperature is the main factor affecting SCD. This study improves the understanding of snow cover change and is conducive to the further study of climate change on TP.

Impacts of ENSO and IOD on Snow Depth Over the Tibetan Plateau: Roles of Convections Over the Western North Pacific and Indian Ocean

2019 ◽  
Vol 124 (22) ◽  
pp. 11961-11975 ◽  
Author(s):  
Xingwen Jiang ◽  
Tuantuan Zhang ◽  
Chi‐Yung Tam ◽  
Junwen Chen ◽  
Ngar‐Cheung Lau ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Tibetan Plateau ◽  
North Pacific ◽  
Snow Depth ◽  
Western North Pacific ◽  
The Tibetan Plateau

scholarly journals The Effect of ENSO on Tibetan Plateau Snow Depth: A Stationary Wave Teleconnection Mechanism and Implications for the South Asian Monsoons

2005 ◽  
Vol 18 (12) ◽  
pp. 2067-2079 ◽  
Author(s):  
Jeffrey Shaman ◽  
Eli Tziperman
Keyword(s):  
Tibetan Plateau ◽  
South Asian ◽  
Snow Depth ◽  
Rossby Waves ◽  
Stationary Wave ◽  
The Tibetan Plateau ◽  
The South ◽  
Central Pacific ◽  
The North ◽  
Asian Monsoons

Abstract An atmospheric stationary wave teleconnection mechanism is proposed to explain how ENSO may affect the Tibetan Plateau snow depth and thereby the south Asian monsoons. Using statistical analysis, the short available record of satellite estimates of snow depth, and ray tracing, it is shown that wintertime ENSO conditions in the central Pacific may produce stationary barotropic Rossby waves in the troposphere with a northeastward group velocity. These waves reflect off the North American jet, turning equatorward, and enter the North African–Asian jet over the eastern Atlantic Ocean. Once there, the waves move with the jet across North Africa, South Asia, the Himalayas, and China. Anomalous increases in upper-tropospheric potential vorticity and increased wintertime snowfall over the Tibetan Plateau are speculated to be associated with these Rossby waves. The increased snowfall produces a larger Tibetan Plateau snowpack, which persists through the spring and summer, and weakens the intensity of the south Asian summer monsoons.

scholarly journals Observed Relationship of Spring and Summer East Asian Rainfall with Winter and Spring Eurasian Snow

2007 ◽  
Vol 20 (7) ◽  
pp. 1285-1304 ◽  
Author(s):  
Renguang Wu ◽  
Ben P. Kirtman
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Snow Depth ◽  
Snow Water Equivalent ◽  
Southern Oscillation ◽  
Southern China ◽  
Summer Rainfall ◽  
Wave Pattern ◽  
Summer Monsoon Rainfall ◽  
The Tibetan Plateau

Abstract This study investigates the relationship between spring and summer rainfall in East Asia and the preceding winter and spring snow cover/depth over Eurasia, using station rainfall observations, satellite-observed snow cover, satellite-derived snow water equivalent, and station observations of the number of days of snow cover and snow depth. Correlation analysis shows that snow-depth anomalies can persist from winter to spring whereas snow cover anomalies cannot in most regions of Eurasia. Locally, snow cover and snow-depth anomalies in February are not related in most regions to the north of 50°N, but those anomalies in April display consistent year-to-year variations. The results suggest that the winter snow cover cannot properly represent all the effects of snow and it is necessary to separate the winter and spring snow cover in addressing the snow–monsoon relationship. Spring snow cover in western Siberia is positively correlated with spring rainfall in southern China. The circulation anomalies associated with the western Siberian spring snow cover variations show an apparent wave pattern over the eastern Atlantic through Europe and midlatitude Asia. Spring snow cover over the Tibetan Plateau shows a moderate positive correlation with spring rainfall in southern China. Analysis shows that this correlation includes El Niño–Southern Oscillation (ENSO) effects. In contrast to the Indian summer monsoon rainfall for which the ENSO interferes with the snow effects, the Tibetan Plateau snow cover and ENSO work cooperatively to enhance spring rainfall anomalies in southern China. In comparison, ENSO has larger impacts than the snow on spring rainfall in southern China.

Trends in Summer Rainfall over China Associated with the Tibetan Plateau Sensible Heat Source during 1980–2008

2013 ◽  
Vol 26 (1) ◽  
pp. 261-275 ◽  
Author(s):  
Anmin Duan ◽  
Meirong Wang ◽  
Yonghui Lei ◽  
Yangfan Cui
Keyword(s):  
Tibetan Plateau ◽  
Heat Source ◽  
Snow Depth ◽  
Southern China ◽  
Summer Rainfall ◽  
Monsoon Circulation ◽  
The Tibetan Plateau ◽  
Sensible Heat ◽  
Local Circulation ◽  
Precipitation Events

Abstract The impacts of the thermal forcing over the Tibetan Plateau (TP) in spring on changes in summer rainfall in China are investigated using historical records from the period between 1980 and 2008. The spring sensible heat (SH) flux and snow depth over the TP both decreased over this time period, although the trend in SH was more significant than that in snow depth. The similarity between patterns of precipitation trends over China and corresponding patterns of regression coefficients on the leading mode of spring SH change over the TP demonstrates the distinct contribution of changes in TP SH during spring. Enhanced precipitation in southern China was accompanied by increases in heavy rainfall, precipitation intensity, and the frequency of precipitation events, while reduced precipitation in northern China and northeastern China was primarily associated with decreases in the frequency of precipitation events. Further analysis using observational data and numerical simulations reveals that the reductions in SH over the TP have weakened the monsoon circulation and postponed the seasonal reversal of the land–sea thermal contrast in East Asia. In addition, the positive spring SH anomaly may generate a stronger summer atmospheric heat source over the TP due to the positive feedback between diabatic heating and local circulation.

scholarly journals Combining Snow Depth From FY-3C and In Situ Data Over the Tibetan Plateau Using a Nonlinear Analysis Method

2021 ◽  
Vol 9 ◽  
Author(s):  
Aixia Feng ◽  
Feng Gao ◽  
Qiguang Wang ◽  
Aiqing Feng ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Time Series ◽  
Time Delay ◽  
Phase Space ◽  
Tibetan Plateau ◽  
Satellite Data ◽  
Snow Depth ◽  
Hydrological Cycle ◽  
The Tibetan Plateau ◽  
Analysis Method

Snow cover over the Tibetan Plateau plays a vital role in the regional and global climate system because it affects not only the climate but also the hydrological cycle and ecosystem. However, high-quality snow data are hindered due to the sparsity of observation networks and complex terrain in the region. In this study, a nonlinear time series analysis method called phase space reconstruction was used to obtain the Tibetan Plateau snow depth by combining the FY-3C satellite data and in situ data for the period 2014–2017. This method features making a time delay reconstruction of a phase space to view the dynamics. Both of the grids and their nearby in situ snow depth time series were reconstructed with two appropriate parameters called time delay and embedding dimension. The values of the snow depth for grids were averaged over the in situ observations and retrieval of the satellite if their two parameters were the same. That implies that the two trajectories of the time series had the same evolution trend. Otherwise, the snow depth values for grids were averaged over the in situ observation. If there were no in situ sites within the grids, the retrieval of the satellite remained. The results show that the integrated Tibetan Plateau snow depth (ITPSD) had an average bias of –1.35 cm and 1.14 cm, standard deviation of the bias of 3.96 cm and 5.67 cm, and root mean square error of 4.18 cm and 5.79 cm compared with the in situ data and FY-3C satellite data, respectively. ITPSD expressed the issue that snow depth is usually overestimated in mountain regions by satellites. This is due to the introduction of more station observations using a dynamical statistical method to correct the biases in the satellite data.

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