We examine the spatio‐temporal characteristics of aerosols in recent years (2000–2003) over Indian region with special emphasis on Indo‐Gangetic basin (northern India) using data from Moderate Resolution Imaging Spectroradiometer (MODIS), Aerosol Robotic Network (AERONET) and Total Ozone Mapping (TOMS). First, we have compared MODIS‐derived aerosol optical depth (AOD) fine‐mode fraction (FMAF ratio AOD to total mode AOD) those AERONET at Kanpur (26.45°N, 80.346°E). It has been found that...

Abstract We estimate the distribution of ice thickness for a Himalayan glacier using surface velocities, slope and flow law. Surface velocities over Gangotri Glacier were estimated sub-pixel correlation Landsat TM ETM+ imagery. Velocities range from ˜14–85 m –1 in accumulation region to ˜20–30 near snout. Depth profiles calculated equation laminar flow. Thickness varies ˜540 upper reaches ˜50–60 The volume is be 23.2 ± 4.2 km 3 .

Mineral dust is the single largest contributor of natural aerosols over land. Dust exhibit high variability in their radiative effects because composition varies locally. This arises regional distinctiveness soil characteristics as well accumulation other aerosol species, such black carbon, on while airborne. To accurately estimate climate impact dust, spatial and temporal distribution its properties are essential. However, this poorly understood many regions world, including Indian region....

Abstract To predict how monsoons will evolve in the 21st century, we need to understand they have changed past. In paleoclimate literature, major focus has been on role of solar forcing but not amplification by feedbacks internal climate system. Here used results from a transient simulation show that amplify effect change insolation Indian summer monsoon. We during deglacial (22 ka 10 ka) were predominantly influenced rising water vapor due increasing sea surface temperature, whereas...

Abstract. The changes in seasonal snow covered area the Hindu Kush-Himalayan (HKH) region have been examined using Moderate – resolution Imaging Spectroradiometer (MODIS) 8-day standard products. average of HKH based on satellite data from 2000 to 2010 is 0.76 million km2 which 18.23% total geographical region. linear trend annual cover −1.25±1.13%. This consistent with earlier reported decline decade 1990 2001. A similar for western, central and eastern 8.55±1.70%, +1.66% ± 2.26%...

Abstract During recent years, an increase in the intensity of pre‐monsoon tropical cyclones ( TCs ) is observed over Arabian Sea. This study suggests that this due to epochal variability and associated with storm‐ambient vertical wind shear cyclone heat potential TCHP ). There a significant (0.53 kJ cm −2 year −1 during years. The warmer upper ocean helps sustain or their by uninterrupted supply sensible latent fluxes from surface atmosphere.

Recent experiments conducted over the oceanic regions adjacent to Indian sub continent have revealed presence of anthropogenic aerosol haze during January March. It has been suggested that major source this is South and Southeast Asia. Here we show from long term, multi‐station ship borne observations aerosols transported northwest subcontinent especially Arabian Saharan (mostly natural dust) along with locally produced sea‐salt by sea‐surface winds constitute a more significant April–May...

Role of Asian and African orography in the Indian summer monsoon has been investigated using a general circulation model. Orography region west 80°E appears to have more impact on rainfall than east 80°E. It found that removal increases seasonal precipitation over sub‐continent by 28%, whereas entire globe reduces it 25%. Moreover, there was substantial delay all‐India onset experiment which mountains were removed globally, mainly due intrusion midlatitude dry air The increase Africa...

In order to understand the response of Earth‐atmosphere system anthropogenic aerosol forcing, it is essential know relative impact various species on radiative budget. Most models used for estimating direct forcing have assumed that are mixed externally or internally. However, possible one may be coated over another form core‐shell structure and resulting can significantly different than those externally‐mixed internally‐mixed aerosols. Our study suggests changes in state mixing black carbon...

Abstract. A theory is proposed to determine the onset of Indian Summer Monsoon (ISM) in an Atmospheric General Circulation Model (AGCM). The ISM delayed substantially absence global orography. impact orography over different parts Earth on has also been investigated using five additional perturbed simulations. large difference date these simulations explained by a new based Surface Moist Static Energy (SMSE) and vertical velocity at mid-troposphere. It found that occurs only after SMSE...

The Bay of Bengal (BoB) region is a small oceanic surrounded by landmasses with distinct natural and anthropogenic aerosol sources. Despite this the significant influence BoB on Indian monsoon weather, information aerosols its spatial temporal heterogeneity sparse. observations onboard several cruises an island location have been used in paper along satellite (MODIS TERRA satellite) data (2000–2004) to study properties. Our studies show that seasonal variation optical depths over northern...

Abstract The low‐level jet (LLJ) over the Indian region, which is most prominent during monsoon (June–September) season, has been studied with a general circulation model (GCM). role of African orography in modulating this focus article. presence intensifies cross‐equatorial flow. Contrary to previous modelling studies we find that flow occurs even absence orography, though much weaker when rainfall high. However, location meridional near equator Somali region linked rather than land–sea...

The second‐generation MODIS aerosol retrieval (Collection 005) from EOS‐ Aqua (2002–2005) was evaluated using ground‐based AERONET measurements at Kanpur (26.45°N, 80.35°E) northern India. We found that the optical depth (AOD) retrievals are more accurate compared to of previous 004). About 70% total 0.47 μ m and 0.55 60% 0.66 wavelength in new version fall within pre‐launch uncertainty (Δ τ = ±0.05 ± 0.15 , where is AOD) with better correlation (R 2 ∼ 0.83) all three wavelengths. However,...

Abstract. It has been observed that a majority of glaciers in the Himalayas have retreating. In this paper, we show there are two major factors which control advance/retreat Himalayan glaciers. They slope glacier and changes equilibrium line altitude. While it is well known, these important, propose new way combining them use to predict retreat. The functional form model derived from numerical simulations using an ice-flow code. successfully applied movement eight during past 25 years....

Abstract. The changes in Earth's precession have an impact on the tropical precipitation. This has been attributed to seasonal solar radiation at top of atmosphere. primary mechanism that proposed is change thermal gradient between two hemispheres. may be adequate understand zonal mean changes, but cannot explain variations land and oceans. We used a simple model intertropical convergence zone (ITCZ) unravel how precipitation with precession. Our attributes energy fluxes vertical stability....

Abstract The South Asian summer monsoon has been suggested to be influenced by atmospheric aerosols, and this influence can the result of either local or remote emissions. We have used Hadley Centre Global Environment Model Version 3 (HadGEM3) coupled atmosphere‐ocean climate model investigate for first time centennial‐scale precipitation response emissions sulfur dioxide (SO 2 ), dominant anthropogenic precursor sulfate aerosol, from different midlatitude regions. Despite localized nature...

Abstract Rain gauges are considered the most accurate method to estimate rainfall and used as “ground truth” for a wide variety of applications. The spatial density rain varies substantially hence influences accuracy gridded gauge-based products. temporal changes in gauge over region introduce considerable biases historical trends mean its extremes. An uncertainty estimates associated with nonuniform layout placement pattern network is vital national decisions policy planning India, which...

Abstract. Single scattering albedo (SSA) represents a unique identification of aerosol type and can be determinant factor in the estimation radiative forcing. However, SSA retrievals are highly uncertain due to cloud contamination composition. The recent improvement retrieval algorithm has combined superior cloud-masking technique Moderate Resolution Imaging Spectroradiometer (MODIS) higher sensitivity Ozone Monitoring Instrument (OMI) absorption. OMI–MODIS only been validated over small...

Based on the data from Earth Radiation Budget Experiment (ERBE), many investigators have concluded that net cloud radiative forcing at top of atmosphere is small in deep convective region Tropics. This conclusion has been shown to be invalid for Asian monsoon during period June–September. The ERBE used show negative and its magnitude exceeds 30 W m−2 25% grids this region. large June–September account presence amount high clouds optical depth these clouds. combination occurs only. In other...