Influence of atmospheric heat sources over the Tibetan Plateau and the tropical western North Pacific on the inter-decadal variations of the stratosphere-troposphere exchange of water vapor

2008 ◽  
Vol 51 (8) ◽  
pp. 1179-1193 ◽  
Author(s):  
RuiFen Zhan ◽  
JianPing Li
Keyword(s):  
Water Vapor ◽  
Tibetan Plateau ◽  
North Pacific ◽  
Western North Pacific ◽  
The Tibetan Plateau ◽  
Heat Sources ◽  
Decadal Variations ◽  
Atmospheric Heat ◽  
Tropical Western North Pacific

Interannual variation in rainfall and atmospheric heat sources over the Tibetan Plateau

2008 ◽  
Author(s):  
Shanshan Zhong ◽  
Jinhai He ◽  
Zhaoyong Guan ◽  
Chunhua Shi
Keyword(s):  
Tibetan Plateau ◽  
Interannual Variation ◽  
The Tibetan Plateau ◽  
Heat Sources ◽  
Atmospheric Heat

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 Summer Atmospheric Heat Sources over the Western–Central Tibetan Plateau: An Integrated Analysis of Multiple Reanalysis and Satellite Datasets

2019 ◽  
Vol 32 (4) ◽  
pp. 1181-1202 ◽  
Author(s):  
Zhiling Xie ◽  
Bin Wang
Keyword(s):  
Tibetan Plateau ◽  
Integrated Analysis ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
Heat Sources ◽  
Central Tibetan Plateau ◽  
New Finding ◽  
Highly Correlated ◽  
Atmospheric Heat ◽  
Heat Released

Multiple bias-corrected top-quality reanalysis datasets, gauge-based observations, and selected satellite products are synthetically employed to revisit the climatology and variability of the summer atmospheric heat sources over the Tibetan Plateau (TP). Verification-based selection and ensemble-mean methods are utilized to combine various datasets. Different from previous works, this study pays special attention to estimating the total heat source (TH) and its components over the data-void western plateau (70°–85°E), including the surface sensible heat (SH), latent heat released by precipitation (LH), and net radiation flux (RD). Consistent with previous studies, the climatology of summer SH (LH) typically increases (decreases) from southeast to northwest. Generally, LH dominates TH over most of the TP. A notable new finding is a minimum TH area over the high-altitude region of the northwestern TP, where the Karakoram mountain range is located. We find that during the period of 1984–2006, TH shows insignificant trends over the eastern and central TP, whereas it exhibits an evident increasing trend over the western TP that is attributed to the rising tendency of LH before 1996 and to that of RD after 1996. The year-to-year variation of TH over the central–eastern TP is highly correlated with that of LH, but that is not the case over the western TP. It is also worth noting that the variations of TH in each summer month are not significantly correlated with each other, and hence study of the interannual variation of the TP heat sources should consider the remarkable subseasonal variations.

scholarly journals Interannual Variation of Summer Atmospheric Heat Source over the Tibetan Plateau and the Role of Convection around the Western Maritime Continent

2015 ◽  
Vol 29 (1) ◽  
pp. 121-138 ◽  
Author(s):  
Xingwen Jiang ◽  
Yueqing Li ◽  
Song Yang ◽  
Kun Yang ◽  
Junwen Chen
Keyword(s):  
Water Vapor ◽  
Tibetan Plateau ◽  
Heat Source ◽  
Interannual Variation ◽  
The Tibetan Plateau ◽  
The South ◽  
Maritime Continent ◽  
Southern Boundary ◽  
Atmospheric Heat Source ◽  
Atmospheric Heat

Abstract The impacts of summer atmospheric heat source over the Tibetan Plateau (TP) on regional climate variation have attracted extensive attention. However, few studies have focused on possible causes of the interannual variation of atmospheric heat source over the TP. Total heat (TH) is generally composed of three components: surface sensible heat, latent heat release of condensation (LH), and radiative convergence. In this study, it is found that interannual variation of summer TH is dominated by LH in the central and eastern TP. The atmospheric circulation patterns associated with the TH over the TP in June are different from those in July and August. Large TH is accompanied by a cyclone centered over the South China Sea in June, which is replaced by an anticyclone in July and August. The interannual variation of July–August TH over the central and eastern TP is significantly affected by convection around the western Maritime Continent (WMC) that modulates the LH over the southeastern TP. Enhanced WMC convection induces an anticyclone to the south of the TP, which favors water vapor transport to the southeastern TP and thus an increase in precipitation. Enhanced convection over the southeastern TP may exert a positive feedback on local precipitation through pumping more water vapor from the southern boundary. Both observations and model simulations indicate that the enhanced WMC convection can induce the anticyclone to the south of the TP and convection–circulation is important for maintenance of the anticyclone.

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

2020 ◽  
Author(s):  
Tuantuan Zhang ◽  
Xingwen Jiang ◽  
Chi-Yung Tam ◽  
Junwen Chen ◽  
Ngar-Cheung Lau ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Tibetan Plateau ◽  
North Pacific ◽  
Snow Depth ◽  
Western North Pacific ◽  
Cyclonic Circulation ◽  
Cold Temperature ◽  
The Tibetan Plateau ◽  
The Tropics ◽  
Anomalous Cyclonic Circulation

<p>This is a consensus that snow over the Tibetan Plateau (TP) modulates the regional climate significantly. Possible causes for the interannual variability of snow over the TP, however, are under debate, especially regarding the independent roles of El Niño-Southern (ENSO) and Indian Ocean dipole (IOD). Based on in-situ observational data analyses and model simulations, our study shows that impacts of ENSO and IOD on snow depth (SD) over the TP are different during early winter. In particular, ENSO mostly affects SD over the eastern TP, while IOD affects SD over the central-western TP. Both above-normal snowfall and cold temperature anomaly contribute to deeper-than-normal SD, with the former playing a more important role. Diabatic cooling of the suppressed convection over the western North Pacific that related to the positive phase of ENSO could excite an anomalous cyclonic circulation and strong cold temperature anomalies over the eastern TP. There is an enhanced moisture transported over the eastern TP from the tropics due to the anomalous cyclonic circulation; along with strong cold temperature anomalies, resulting in above-normal snowfall in the eastern TP. On the other hand, anomalous convection over the western Indian Ocean related to the positive IOD could generate a wave-train propagating northeastward and induce an anomalous cyclonic circulation over the central-western TP. The associated anomalous circulation transports extra moisture from the tropics to the central-western TP, providing conditions favorable for more snowfall over the central-western TP. Opposite conditions tend to occur during negative phases of ENSO and IOD.</p>

scholarly journals Factors of boreal summer latent heat flux variations over the tropical western North Pacific

2021 ◽  
Author(s):  
Yuqi Wang ◽  
Renguang Wu
Keyword(s):  
Heat Flux ◽  
Wind Speed ◽  
North Pacific ◽  
High Frequency ◽  
Western North Pacific ◽  
Surface Wind ◽  
Low Frequency ◽  
Boreal Summer ◽  
Wind Intensity ◽  
Tropical Western North Pacific

AbstractSurface latent heat flux (LHF) is an important component in the heat exchange between the ocean and atmosphere over the tropical western North Pacific (WNP). The present study investigates the factors of seasonal mean LHF variations in boreal summer over the tropical WNP. Seasonal mean LHF is separated into two parts that are associated with low-frequency (> 90-day) and high-frequency (≤ 90-day) atmospheric variability, respectively. It is shown that low-frequency LHF variations are attributed to low-frequency surface wind and sea-air humidity difference, whereas high-frequency LHF variations are associated with both low-frequency surface wind speed and high-frequency wind intensity. A series of conceptual cases are constructed using different combinations of low- and high-frequency winds to inspect the respective effects of low-frequency wind and high-frequency wind amplitude to seasonal mean LHF variations. It is illustrated that high-frequency wind fluctuations contribute to seasonal high-frequency LHF only when their intensity exceeds the low-frequency wind speed under which there is seasonal accumulation of high-frequency LHF. When high-frequency wind intensity is smaller than the low-frequency wind speed, seasonal mean high-frequency LHF is negligible. Total seasonal mean LHF anomalies depend on relative contributions of low- and high-frequency atmospheric variations and have weak interannual variance over the tropical WNP due to cancellation of low- and high-frequency LHF anomalies.

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