Vertical motion and diabatic heating over the Indian monsoon region during the Bay of Bengal depression of 5?8 July, 1979

1992 ◽  
Vol 138 (1) ◽  
pp. 115-133 ◽  
Author(s):  
U. S. Singh ◽  
R. K. Singh
Keyword(s):  
Bay Of Bengal ◽  
Diabatic Heating ◽  
Indian Monsoon ◽  
Vertical Motion ◽  
Monsoon Region ◽  
Indian Monsoon Region

scholarly journals Diurnal variability of the atmospheric boundary layer height over a tropical station in the Indian monsoon region

2017 ◽  
Vol 17 (1) ◽  
pp. 531-549 ◽  
Author(s):  
Sanjay Kumar Mehta ◽  
Madineni Venkat Ratnam ◽  
Sukumarapillai V. Sunilkumar ◽  
Daggumati Narayana Rao ◽  
Boddapaty V. Krishna Murthy
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Diurnal Variation ◽  
Indian Monsoon ◽  
Winter Season ◽  
Monsoon Region ◽  
Diurnal Variability ◽  
The Mean ◽  
Indian Monsoon Region ◽  
Tropical Station

Abstract. The diurnal variation of atmospheric boundary layer (ABL) height is studied using high-resolution radiosonde observations available at 3 h intervals for 3 days continuously from 34 intensive campaigns conducted during the period December 2010–March 2014 over a tropical station Gadanki (13.5° N, 79.2° E; 375 m), in the Indian monsoon region. The heights of the ABL during the different stages of its diurnal evolution, namely, the convective boundary layer (CBL), the stable boundary layer (SBL), and the residual layer (RL) are obtained to study the diurnal variabilities. A clear diurnal variation is observed in 9 campaigns out of the 34 campaigns. In 7 campaigns the SBL did not form in the entire day and in the remaining 18 campaigns the SBL formed intermittently. The SBL forms for 33–55 % of the time during nighttime and 9 and 25 % during the evening and morning hours, respectively. The mean SBL height is within 0.3 km above the surface which increases slightly just after midnight (02:00 IST) and remains almost constant until the morning. The mean CBL height is within 3.0 km above the surface, which generally increases from morning to evening. The mean RL height is within 2 km above the surface which generally decreases slowly as the night progresses. The diurnal variation of the ABL height over the Indian region is stronger during the pre-monsoon and weaker during winter season. The CBL is higher during the summer monsoon and lower during the winter season while the RL is higher during the winter season and lower during the summer season. During all the seasons, the ABL height peaks during the afternoon (∼ 14:00 IST) and remains elevated until evening (∼ 17:00 IST). The ABL suddenly collapses at 20:00 IST and increases slightly in the night. Interestingly, it is found that the low level clouds have an effect on the ABL height variability, but the deep convective clouds do not. The lifting condensation level (LCL) is generally found to occur below the ABL for the majority of the database and they are randomly related.

scholarly journals High-resolution gridded soil moisture and soil temperature datasets for the Indian monsoon region

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
H. P. Nayak ◽  
K. K. Osuri ◽  
Palash Sinha ◽  
Raghu Nadimpalli ◽  
U. C. Mohanty ◽  
...  
Keyword(s):  
Soil Moisture ◽  
High Resolution ◽  
Soil Temperature ◽  
Indian Monsoon ◽  
Monsoon Region ◽  
Indian Monsoon Region

Performance Optimization of Operational WRF Model Configured for Indian Monsoon Region

2019 ◽  
Vol 3 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Pavani Andraju ◽  
A Lakshmi Kanth ◽  
K Vijaya Kumari ◽  
S. Vijaya Bhaskara Rao
Keyword(s):  
Performance Optimization ◽  
Indian Monsoon ◽  
Wrf Model ◽  
Monsoon Region ◽  
Indian Monsoon Region

scholarly journals Comparison of the Long-Range Climate Memory in Outgoing Longwave Radiation over the Tibetan Plateau and the Indian Monsoon Region

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongping Shen ◽  
Jun Shi ◽  
Yadong Lei
Keyword(s):  
Time Series ◽  
Outgoing Longwave Radiation ◽  
Cloud Cover ◽  
Indian Monsoon ◽  
Longwave Radiation ◽  
The Tibetan Plateau ◽  
Monsoon Region ◽  
Scaling Exponents ◽  
High Cloud ◽  
Indian Monsoon Region

Based on the detrended fluctuation analysis (DFA) method, scaling behaviors of the daily outgoing longwave radiation (OLR) from 1979 to 2015 over the Tibetan Plateau (TP) and the Indian Monsoon Region (IMR) are analyzed. The results show that there is long-term memory for the OLR time series over the TP and IMR. The long-range memory behaviors of OLR over TP are stronger than those over IMR. The averaged values of the scaling exponents over TP and IMR are 0.71 and 0.64; the maximum values in the two regions are 0.81 and 0.75; the minimum values are 0.59 and 0.58. The maximum frequency counts for scaling exponents occur in the range of 0.625 and 0.675 both in TP and in IMR. The spatial distribution of the scaling exponents of the OLR sequence is closely related to the conditions of climatic high cloud cover in the two areas. The high cloud cover over TP is obviously less than that of IMR. In addition, the scaling behaviors of OLR over TP and IMR are caused by the fractal characteristics of time series, which is further proved by randomly disrupting the time series to remove trends and correlation.

scholarly journals Towards an improved representation of carbonaceous aerosols over the Indian monsoon region in a regional climate model RegCM4.6

2021 ◽  
Author(s):  
Sudipta Ghosh ◽  
Sagnik Dey ◽  
Sushant Das ◽  
Nicole Riemer ◽  
Graziano Giuliani ◽  
...  
Keyword(s):  
Life Cycle ◽  
Regional Climate Model ◽  
Climate Model ◽  
Indian Monsoon ◽  
Regional Climate ◽  
Carbonaceous Aerosols ◽  
Monsoon Region ◽  
Gangetic Plain ◽  
Emission Fluxes ◽  
Indian Monsoon Region

Abstract. Mitigation of carbonaceous aerosol emissions is expected to provide climate and health co-benefits. The accurate representation of carbonaceous aerosols in climate models is critical for reducing uncertainties in their climate feedbacks. In this regard, emission fluxes and aerosol life-cycle processes are the two primary sources of uncertainties. Here we demonstrate that incorporating a dynamic ageing scheme and emission estimates that are updated for the local sources improve the representation of carbonaceous aerosols over the Indian monsoon region in a regional climate model, RegCM, compared to its default configuration. The mean BC and OC surface concentrations in 2010 are estimated to be 4.25 and 10.35 μg m−3, respectively, over the Indo-Gangetic Plain (IGP), in the augmented model. The BC column burden over the polluted IGP is found to be 2.47 mg m−2, 69.95 % higher than in the default model configuration and much closer to available observations. The anthropogenic AOD increases by more than 19 % over the IGP due to the model enhancement, also leading to a better agreement with observed AOD. The top-of-the-atmosphere, surface, and atmospheric anthropogenic aerosol shortwave radiative forcing are estimated at −0.3, −9.3, and 9.0 W m−2, respectively, over the IGP and −0.89, −5.33, and 4.44 W m−2, respectively, over Peninsular India. Our results suggest that both the accurate estimates of emission fluxes and a better representation of aerosol processes are required to improve the aerosol life cycle representation in the climate model.

scholarly journals Investigation of negative cloud radiative forcing over the Indian subcontinent and adjacent oceans during the summer monsoon season

2014 ◽  
Vol 14 (13) ◽  
pp. 6739-6758 ◽  
Author(s):  
B. V. Thampi ◽  
R. Roca
Keyword(s):  
Summer Monsoon ◽  
Radiative Forcing ◽  
Indian Monsoon ◽  
Indian Subcontinent ◽  
Monsoon Season ◽  
Radiative Properties ◽  
Monsoon Region ◽  
Summer Monsoon Season ◽  
Cloud Radiative Forcing ◽  
Indian Monsoon Region

Abstract. Radiative properties of clouds over the Indian subcontinent and nearby oceanic regions (0–25° N, 60–100° E) during the Asian summer monsoon season (June–September) are investigated using the Clouds and Earth's Radiant Energy System (CERES) top-of-the-atmosphere (TOA) flux data. Using multiyear satellite data, the net cloud radiative forcing (NETCRF) at the TOA over the Indian region during the Asian monsoon season is examined. The seasonal mean NETCRF is found to be negative (with its magnitude exceeding ~30 Wm−2) over (1) the northern Bay of Bengal (close to the Myanmar–Thailand coast), (2) the Western Ghats and (3) the coastal regions of Myanmar. Such strong negative NETCRF values observed over the Indian monsoon region contradict the assumption that near cancellation between LWCRF and SWCRF is a generic property of all tropical convective regions. The seasonal mean cloud amount (high and upper middle) and corresponding cloud optical depth observed over the three regions show relatively large values compared to the rest of the Indian monsoon region. Using satellite-derived cloud data, a statistical cloud vertical model delineating the cloud cover and single-scattering albedo was developed for the three negative NETCRF regions. The shortwave (SW), longwave (LW) and net cloud radiative forcing over the three negative NETCRF regions are calculated using the rapid radiative transfer model (RRTM) with the cloud vertical model as input. The NETCRF estimated from CERES observations show good comparison with that computed using RRTM (within the uncertainty limit of CERES observations). Sensitivity tests are conducted using RRTM to identify the parameters that control the negative NETCRF observed over these regions during the summer monsoon season. Increase in atmospheric water vapor content during the summer monsoon season is found to influence the negative NETCRF values observed over the region.

Sign in / Sign up

Export Citation Format

Share Document