Effect of dust storm on ocean color and snow parameters

Kayetha, Vinay; Kumar, Jitendra; Prasad, Anup K.; Cervone, Guido; Singh, Ramesh P.

doi:10.1007/bf02991828

Cited by 37 publications

(22 citation statements)

References 13 publications

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“…The longest available record of tropospheric (lower and middle) temperature data from satellite sensors (MSU-AMSU) from have been used to analyze the trends of lower and middle tropospheric temperatures over the Himalayan region, Tibetan Plateau, adjacent IG plains and major dust source regions in the northern mid-latitudes that are known to affect the western Himalayas and IG plains (Prasad and Singh, 2007a, b;Kayetha et al, 2007). The annual and month-to-month MSU-derived warming trend of the troposphere and their connection with other major factors that control atmospheric temperature (such as CO 2 , aerosols, water vapor, sunlight) is largely unknown over the region.…”

Section: Objectives Of the Present Studymentioning

confidence: 99%

Melting of major Glaciers in the western Himalayas: evidence of climatic changes from long term MSU derived tropospheric temperature trend (1979–2008)

et al. 2009

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Abstract. Global warming or the increase of the surface and atmospheric temperatures of the Earth, is increasingly discernible in the polar, sub-polar and major land glacial areas. The Himalayan and Tibetan Plateau Glaciers, which are the largest glaciers outside of the Polar Regions, are showing a large-scale decrease of snow cover and an extensive glacial retreat. These glaciers such as Siachen and Gangotri are a major water resource for Asia as they feed major rivers such as the Indus, Ganga and Brahmaputra. Due to scarcity of ground measuring stations, the long-term observations of atmospheric temperatures acquired from the Microwave Sounding Unit (MSU) since 1979-2008 is highly useful. The lower and middle tropospheric temperature trend based on 30 years of MSU data shows warming of the Northern Hemisphere's midlatitude regions. The mean month-to-month warming (up to 0.048±0.026 • K/year or 1.44 • K over 30 years) of the mid troposphere (near surface over the high altitude Himalayas and Tibetan Plateau) is prominent and statistically significant at a 95% confidence interval. Though the mean annual warming trend over the Himalayas (0.016±0.005 • K/year), and Tibetan Plateau (0.008±0.006 • K/year) is positive, the month to month warming trend is higher (by 2-3 times, positive and significant) only over a period of six months (December to May). The factors responsible for the reversal of this trend from June to November are discussed here. The inequality in the magnitude of the warming trends of the troposphere between the western and easternCorrespondence to: A. K. Prasad (aprasad@chapman.edu) Himalayas and the IG (Indo-Gangetic) plains is attributed to the differences in increased aerosol loading (due to dust storms) over these regions. The monthly mean lowertropospheric MSU-derived temperature trend over the IG plains (dust sink region; up to 0.032±0.027 • K/year) and dust source regions (Sahara desert, Middle East, Arabian region, Afghanistan-Iran-Pakistan and Thar Desert regions; up to 0.068±0.033 • K/year) also shows a similar pattern of month-to-month oscillation and six months of enhanced and a statistically significant warming trend. The enhanced warming trend during the winter and pre-monsoon months (December-May) may accelerate glacial melt. The unequal distribution of the warming trend over the year is discussed in this study and is partially attributed to a number of controlling factors such as sunlight duration, CO 2 trends over the region (2003)(2004)(2005)(2006)(2007)(2008), water vapor and aerosol distribution.

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Section: Objectives Of the Present Studymentioning

confidence: 99%

Melting of major Glaciers in the western Himalayas: evidence of climatic changes from long term MSU derived tropospheric temperature trend (1979–2008)

et al. 2009

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“…The second objective is to present an assessment of the boundary layer sources for the 2007-2010 pre-monsoon seasons based on Lagrangian numerical simulations. It is in fact necessary to investigate the role of distant desert areas since some studies evidenced the role of westerly winds during the pre-monsoon season (Bonasoni et al, 2010;Kayetha et al, 2007;Prasad et al, 2006). Also Liu et al (2008), using Hysplit (Hybrid Single Particle Lagrangian Integrated Trajectory Model) back trajectories, showed that dust can be advected to the region from the Tarim Basin and the major deserts of northeastern India, Pakistan and Afghanistan.…”

Section: Introductionmentioning

confidence: 99%

Aerosol variability and atmospheric transport in the Himalayan region from CALIOP 2007–2010 observations

et al. 2014

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Abstract. This work quantifies the spatial distribution of different aerosol types, their seasonal variability and sources.The analysis of four years of CALIOP (CloudAerosol LIdar with Orthogonal Polarization) vertically resolved aerosol data allows the identification of spatial patterns of desert dust and carbonaceous particles in different atmospheric layers. Clusters of Lagrangian back trajectories highlight the transport pathways from source regions during the dusty spring season. The analysis shows a prevalence of dust; at low heights it occurs frequently (up to 70 % of available observations) and is distributed north of the Tibetan Plateau with a main contribution from the Gobi and Taklamakan deserts, and west of the Tibetan Plateau, originating from the deserts of southwest Asia and advected by the Westerlies. Above the Himalayas the dust amount is minor but still not negligible (occurrence around 20 %) and mainly affected by the transport from more distant deserts sources (Sahara and Arabian Peninsula). Carbonaceous aerosol, produced mainly in northern India and eastern China, is subject to shorter-range transport and is indeed observed closer to the sources, while there is a limited amount reaching the top of the plateau. Data analysis reveals a clear seasonal variability in the frequencies of occurrence for the main aerosol types; dust is regulated principally by the monsoon dynamics, with maximal occurrence in spring. We also highlight relevant interannual differences, showing a larger presence of aerosol in the region during 2007 and 2008. The characterization of the aerosol spatial and temporal distribution in terms of observational frequency is a key piece of information that can be directly used for the evaluation of global aerosol models.

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“…The region off Somalia shows high positive correlation between Chl-a and NASA-AOT and it is located along the path of winds carrying dust aerosols emanating from South Asia, South-West Asia, North Africa (Sahara) and the eastern Horn of Africa (Pease et al, 1998;Ginoux et al, 2001;Goudie and Middleton, 2001;Prospero et al, 2002;Léon and Legrand, 2003). Although there are several studies (Banzon et al, 2004;Kayetha et al, 2007;Patra et al, 2007;Singh et al, 2008;Nezlin et al, 2010;Banerjee and Prasanna Kumar, 2014) that have examined the relationship between Chl-a and AOT in various parts of the Arabian Sea, the region off Somalia has not yet been explored in detail, and it is the region selected for our investigation.…”

Section: Relationship Between Chl-a and Aot In The Arabian Seamentioning

confidence: 99%

Comparison of Seasonal Cycles of Phytoplankton Chlorophyll, Aerosols, Winds and Sea-Surface Temperature off Somalia

et al. 2017

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In climate research, an important task is to characterize the relationships between Essential Climate Variables (ECVs). Here, satellite-derived data sets have been used to examine the seasonal cycle of phytoplankton (chlorophyll concentration) in the waters off Somalia, and its relationship to aerosols, winds and Sea Surface Temperature (SST). Chlorophyll-a (Chl-a) concentration, Aerosol Optical Thickness (AOT), Ångström Exponent (AE), Dust Optical Thickness (DOT), SST and sea-surface wind data for a 16-year period were assembled from various sources. The data were used to explore whether there is evidence to show that dust aerosols enhance Chl-a concentration in the study area. The Cross Correlation Function (CCF) showed highest positive correlation (r 2 = 0.3) in the western Arabian Sea when AOT led Chl-a by 1-2 time steps (here, 1 time step is 8 days). A 2 × 2 • box off Somalia was selected for further investigations. The correlations of alongshore wind speed, Ekman Mass Transport (EMT) and SST with Chl-a were higher than that of AOT, for a lag of 8 days. When all four variables were considered together in a multiple linear regression, the increase in r 2 associated with the AOT is only about 0.02, a consequence of covariance among AOT, SST, EMT and alongshore wind speed. The AOT data show presence of dust aerosols most frequently during the summer monsoon season (June-September). When the analyses were repeated for the dust aerosol events, the correlations were generally lower, but still significant. Again, the inclusion of DOT in the multiple linear regression increased the correlation coefficient by only 2%, indicating minor enhancement in Chl-a concentration. Interestingly, during summer monsoon season, there is a higher probability of finding more instances of positive changes in Chl-a after one time step, regardless of whether there is dust aerosol or not. On the other hand, during the winter monsoon season (November-December) and rest of the year, the probability of Chl-a enhancement is higher when dust aerosol is present than when it is absent. The phase relationship in the 8-day climatologies of Chl-a and AOT (derived from NASA's SeaWiFS and MODIS-A ocean colour processing chain) showed that AOT Shafeeque et al.Seasonal Cycle of Phytoplankton Chlorophyll off Somalia led Chl-a for most of the summer monsoon season, except when Chl-a was very high, during which time, Chl-a led AOT. The phase shift in the Chl-a and AOT climatological relationship at the Chl-a peak was not observed when AOT from Aerosol Climate Change Initiative (Aerosol-CCI) was used.

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Effect of dust storm on ocean color and snow parameters

Cited by 37 publications

References 13 publications

Melting of major Glaciers in the western Himalayas: evidence of climatic changes from long term MSU derived tropospheric temperature trend (1979–2008)

Melting of major Glaciers in the western Himalayas: evidence of climatic changes from long term MSU derived tropospheric temperature trend (1979–2008)

Aerosol variability and atmospheric transport in the Himalayan region from CALIOP 2007–2010 observations

Comparison of Seasonal Cycles of Phytoplankton Chlorophyll, Aerosols, Winds and Sea-Surface Temperature off Somalia

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