The Apparent Water Vapor Sinks and Heat Sources Associated with the Intraseasonal Oscillation of the Indian Summer Monsoon

2011 ◽  
Vol 24 (16) ◽  
pp. 4466-4479 ◽  
Author(s):  
Sun Wong ◽  
Eric J. Fetzer ◽  
Baijun Tian ◽  
Bjorn Lambrigtsen ◽  
Hengchun Ye
Keyword(s):  
Remote Sensing ◽  
Water Vapor ◽  
Heat Source ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Intraseasonal Oscillation ◽  
Precipitation Anomaly ◽  
Specific Humidity ◽  
Heat Sources ◽  
Test Bed

Abstract The possibility of using remote sensing retrievals to estimate apparent water vapor sinks and heat sources is explored. The apparent water vapor sinks and heat sources are estimated from a combination of remote sensing, specific humidity, and temperature from the Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit (AIRS) and wind fields from the National Aeronautics and Space Administration (NASA)’s Goddard Space Flight Center (GSFC)’s Modern Era Retrospective-Analysis for Research and Applications (MERRA). The intraseasonal oscillation (ISO) of the Indian summer monsoon is used as a test bed to evaluate the apparent water vapor sink and heat source. The ISO-related northward movement of the column-integrated apparent water vapor sink matches that of precipitation observed by the Tropical Rainfall Measuring Mission (TRMM) minus the MERRA surface evaporation, although the amplitude of the variation is underestimated by 50%. The diagnosed water vapor and heat budgets associated with convective events during various phases of the ISO agree with the moisture–convection feedback mechanism. The apparent heat source moves northward coherently with the apparent water vapor sink associated with the deep convective activity, which is consistent with the northward migration of the precipitation anomaly. The horizontal advection of water vapor and dynamical warming are strong north of the convective area, causing the northward movement of the convection by the destabilization of the atmosphere. The spatial distribution of the apparent heat source anomalies associated with different phases of the ISO is consistent with that of the diabatic heating anomalies from the trained heating (TRAIN Q1) dataset. Further diagnostics of the TRAIN Q1 heating anomalies indicate that the ISO in the apparent heat source is dominated by a variation in latent heating associated with the precipitation.

Modulation of coupled modes of Tibetan Plateau heating and Indian Summer Monsoon on summer rainfall over Central Asia

2021 ◽  
pp. 1-54
Keyword(s):  
Water Vapor ◽  
Tibetan Plateau ◽  
Central Asia ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Diabatic Heating ◽  
Summer Rainfall ◽  
Hadley Cell ◽  
Vapor Transport ◽  
Water Vapor Transport

Abstract It has been suggested that summer rainfall over Central Asia (CA) is significantly correlated with the summer thermal distribution of the Tibetan Plateau (TP) and the Indian summer monsoon (ISM). However, relatively few studies have investigated their synergistic effects of different distribution. This study documents the significant correlations between precipitation in CA and the diabatic heating of TP and the ISM based on the results of statistical analysis and numerical simulation. Precipitation in CA is is dominated by two water vapor transport branches from the south which are related to the two primary modes of anomalous diabatic heating distribution related to the TP and ISM precipitation, that is, the “+-” dipole mode in the southeastern TP and the Indian subcontinent (IS), and the “+-+” tripole mode in the southeastern TP, the IS, and southern India. Both modes exhibit obvious mid-latitude Silk Road pattern (SRP) wave trains with cyclone anomalies over CA, but with different transient and stationary eddies over south Asia. The different locations of anomalous anticyclones over India govern two water vapor transport branches to CA, which are from the Arabian Sea and the Bay of Bengal. The water vapor flux climbs while being transported northward and can be transported to CA with the cooperation of cyclonic circulation. The convergent water vapor and ascending motion caused by cyclonic anomalies favor the precipitation in CA. Further analysis corroborates the negative South Indian Ocean Dipole (NSIOD) in February could affect the tripole mode distribution of TP heating and ISM via the atmospheric circulation, water vapor transport and an anomalous Hadley cell circulation. The results indicate a reliable prediction reference for precipitation in CA.

scholarly journals A diagnostic study on heat sources and moisture sinks in the monsoon trough area during active-break phases of the Indian summer monsoon, 1979

1997 ◽  
Vol 49 (4) ◽  
pp. 455-473 ◽  
Author(s):  
U. V. BHIDE ◽  
V. R. MUJAMDAR ◽  
S. P. GHANEKAR ◽  
D. K. PAUL ◽  
TSING-CHANG CHEN ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Monsoon Trough ◽  
Diagnostic Study ◽  
Heat Sources

scholarly journals The Intraseasonal Fluctuation of Indian Summer Monsoon Rainfall and its Relation with Monsoon Intraseasonal Oscillation (MISO) and Madden Julian Oscillation (MJO)

2021 ◽  
Author(s):  
Avijit Dey ◽  
R. Chattopadhyay ◽  
S. Joseph ◽  
M. Kaur ◽  
R. Mandal ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Monsoon Rainfall ◽  
Indian Summer Monsoon Rainfall ◽  
Intraseasonal Oscillation ◽  
Summer Monsoon Rainfall ◽  
Madden Julian Oscillation ◽  
Phase 2 ◽  
Seasonal Fluctuations ◽  
Northward Propagation

Abstract The intra-seasonal fluctuations of Indian summer monsoon rainfall (ISMR) are mainly controlled by northward propagating Monsoon Intra-seasonal Oscillation (MISO) and eastward propagating Madden Julian Oscillation (MJO). In the current study, we examine the relationship between the intra-seasonal fluctuations (active and break spells) of ISMR with the phase propagation and amplitude of MISO and MJO. We notice that active spells generally occur during MISO phase 2–5 (MJO phase 3–6), and break spells mainly occur during MISO phase 6–8 (MJO phase 6–8 and 1). The association of active/break spells with MISO phases is more prominent than with MJO phases. We show the phase composite of unfiltered and regression based reconstructed rainfall for eight MISO and MJO phases, and the same is consistent with the earlier findings. We notice that the reconstructed field shows a systematic and well-organised northward propagation compared to the unfiltered field. Phase composite also indicates that there is a lead-lag relationship between MISO and MJO phases. MISO phase composite shows more robust northward propagation than the MJO phase composite. MISO reconstructed rainfall explained more percentage variance than MJO reconstructed rainfall with reference to 20–90 days filtered rainfall. It is found that long active (> 7 days) predominantly occurs when either MISO or MJO, or both of them are active, and the associated signal is somewhere in between phase 2–5. A long break occurs when either one or both of them are feeble, or even though associated signals are strong, they are primarily located in phases 1, 6, 7 and 8.

The role of water vapor and cloud feedback on the evolution of the Indian summer monsoon over the last 22,000 years

2020 ◽  
Author(s):  
Chetankumar Jalihal ◽  
Jayaraman Srinivasan ◽  
Arindam Chakraborty
Keyword(s):  
Water Vapor ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Climate Simulation ◽  
Net Energy ◽  
Effect Of Water ◽  
Radiative Feedbacks ◽  
The Impact ◽  
The Last Glacial

<p>In the paleo literature, the emphasis has been on the role of insolation in driving monsoons on orbital timescales, but not on the role of feedbacks internal to the climate system. Here, using the energetics framework, we have underscored the effect of water vapor on the Indian summer monsoon over the last 22,000 years in transient climate simulation, called the TraCE-21K. We show that water vapor amplifies the impact of variations in insolation during cold climates like the Last Glacial Maximum. Insolation affects water vapor through its impact on sea surface temperature. During warmer periods like the Holocene, insolation drives monsoon through its influence on the net energy at the top of the atmosphere. Cloud radiative feedbacks are prominent during these periods. Thus, there are two pathways through which insolation drives monsoons. These pathways can be delineated quantitatively using the energetics. We show further that simultaneous variations in greenhouse gases and ice sheets enhance the effect of water vapor on monsoons. Hence, the sensitivity of monsoon to local summer insolation is different during different periods. Our results suggest that feedbacks play a crucial role in the evolution of Indian monsoon on orbital timescales.</p>

scholarly journals A diagnostic study on heat sources and moisture sinks in the monsoon trough area during active-break phases of the Indian summer monsoon, 1979

1997 ◽  
Vol 49 (4) ◽  
pp. 455-473
Author(s):  
U.V. Bhide ◽  
V.R. Mujamdar ◽  
S.P. Ghanekar ◽  
D.K. Paul ◽  
Tsing-Chang Chen ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Monsoon Trough ◽  
Diagnostic Study ◽  
Heat Sources

scholarly journals Tropical and mid-latitude teleconnections interacting with the Indian summer monsoon rainfall: a theory-guided causal effect network approach

2020 ◽  
Vol 11 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Giorgia Di Capua ◽  
Marlene Kretschmer ◽  
Reik V. Donner ◽  
Bart van den Hurk ◽  
Ramesh Vellore ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Causal Effect ◽  
Intraseasonal Variability ◽  
Intraseasonal Oscillation ◽  
Causal Link ◽  
Teleconnection Pattern ◽  
Boreal Summer ◽  
Circumglobal Teleconnection

Abstract. The alternation of active and break phases in Indian summer monsoon (ISM) rainfall at intraseasonal timescales characterizes each ISM season. Both tropical and mid-latitude drivers influence this intraseasonal ISM variability. The circumglobal teleconnection observed in boreal summer drives intraseasonal variability across the mid-latitudes, and a two-way interaction between the ISM and the circumglobal teleconnection pattern has been hypothesized. We use causal discovery algorithms to test the ISM circumglobal teleconnection hypothesis in a causal framework. A robust causal link from the circumglobal teleconnection pattern and the North Atlantic region to ISM rainfall is identified, and we estimate the normalized causal effect (CE) of this link to be about 0.2 (a 1 standard deviation shift in the circumglobal teleconnection causes a 0.2 standard deviation shift in the ISM rainfall 1 week later). The ISM rainfall feeds back on the circumglobal teleconnection pattern, however weakly. Moreover, we identify a negative feedback between strong updraft located over India and the Bay of Bengal and the ISM rainfall acting at a biweekly timescale, with enhanced ISM rainfall following strong updraft by 1 week. This mechanism is possibly related to the boreal summer intraseasonal oscillation. The updraft has the strongest CE of 0.5, while the Madden–Julian oscillation variability has a CE of 0.2–0.3. Our results show that most of the ISM variability on weekly timescales comes from these tropical drivers, though the mid-latitude teleconnection also exerts a substantial influence. Identifying these local and remote drivers paves the way for improved subseasonal forecasts.

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