scholarly journals Characteristics of Monsoon inversions over Arabian Sea observed by satellite sounder and reanalysis data sets

2015 ◽  
Vol 15 (23) ◽  
pp. 35277-35312
Author(s):  
Sanjeev Dwivedi ◽  
M. S. Narayanan ◽  
M. Venkat Ratnam ◽  
D. Narayana Rao
Keyword(s):  
Arabian Sea ◽  
Monsoon Season ◽  
Southwest Monsoon ◽  
Reanalysis Data ◽  
Indian Region ◽  
Data Sets ◽  
Atmospheric Infrared Sounder ◽  
Huge Data ◽  
Strength Based ◽  
Atmospheric Sounding

Abstract. Monsoon inversions (MIs) over Arabian Sea (AS) are an important characteristic associated with the monsoon activity over Indian region during summer monsoon season. In the present study, we have used five years (2009–2013) data of temperature and water vapor profiles obtained from satellite sounder instrument, Infrared Atmospheric Sounding Interferometer (IASI) onboard MetOp satellite, besides ERA-Interim data, to study their characteristics. The lower atmospheric data over the AS have been examined first to identify the areas where monsoon inversions are predominant and occur with higher strength. Based on this information, a detailed study has been made to investigate their characteristics separately in eastern AS (EAS) and western AS (WAS) to examine their contrasting features. The initiation and dissipation times of MI, their percentage occurrence, strength etc., has been examined using the huge data base. The relation with monsoon activity (rainfall) over Indian region during normal and poor monsoon years is also studied. WAS ΔT values are ~ 2 K less than those over the EAS, ΔT being temperature difference between 950 and 850 hPa. A much larger contrast between WAS and EAS in Δ\\textit{T} is noticed in ERA-Interim dataset Vis a Vis those observed by satellites. The possibility of detecting MI from another parameter, Refractivity $N$, obtained directly from another satellite constellation of GPS RO (COSMIC), has also been examined. MI detected from IASI and Atmospheric InfraRed Sounder (AIRS) sounder onboard NOAA satellite have been compared to see how far the two data sets can be combined to study the MI characteristics. We suggest MI could also be included as one of the semi-permanent features of southwest monsoon along with the presently accepted six parameters.

scholarly journals Characteristics of monsoon inversions over the Arabian Sea observed by satellite sounder and reanalysis data sets

2016 ◽  
Vol 16 (7) ◽  
pp. 4497-4509 ◽  
Author(s):  
Sanjeev Dwivedi ◽  
M. S. Narayanan ◽  
M. Venkat Ratnam ◽  
D. Narayana Rao
Keyword(s):  
Arabian Sea ◽  
Monsoon Season ◽  
Measurement Data ◽  
Southwest Monsoon ◽  
Reanalysis Data ◽  
Indian Region ◽  
Data Sets ◽  
Atmospheric Infrared Sounder ◽  
Data Set ◽  
Strength Based

Abstract. Monsoon inversion (MI) over the Arabian Sea (AS) is one of the important characteristics associated with the monsoon activity over Indian region during summer monsoon season. In the present study, we have used 5 years (2009–2013) of temperature and water vapour measurement data obtained from satellite sounder instrument, an Infrared Atmospheric Sounding Interferometer (IASI) onboard MetOp satellite, in addition to ERA-Interim data, to study their characteristics. The lower atmospheric data over the AS have been examined first to identify the areas where MIs are predominant and occur with higher strength. Based on this information, a detailed study has been made to investigate their characteristics separately in the eastern AS (EAS) and western AS (WAS) to examine their contrasting features. The initiation and dissipation times of MIs, their percentage occurrence, strength, etc., has been examined using the huge database. The relation with monsoon activity (rainfall) over Indian region during normal and poor monsoon years is also studied. WAS ΔT values are  ∼  2 K less than those over the EAS, ΔT being the temperature difference between 950 and 850 hPa. A much larger contrast between the WAS and EAS in ΔT is noticed in ERA-Interim data set vis-à-vis those observed by satellites. The possibility of detecting MI from another parameter, refractivity N, obtained directly from another satellite constellation of GPS Radio Occultation (RO) (COSMIC), has also been examined. MI detected from IASI and Atmospheric Infrared Sounder (AIRS) onboard the NOAA satellite have been compared to see how far the two data sets can be combined to study the MI characteristics. We suggest MI could also be included as one of the semipermanent features of southwest monsoon along with the presently accepted six parameters.

scholarly journals Tropospheric ozone maxima observed over the Arabian Sea during the pre-monsoon

2017 ◽  
Vol 17 (8) ◽  
pp. 4915-4930 ◽  
Author(s):  
Jia Jia ◽  
Annette Ladstätter-Weißenmayer ◽  
Xuewei Hou ◽  
Alexei Rozanov ◽  
John P. Burrows
Keyword(s):  
Tropospheric Ozone ◽  
Arabian Sea ◽  
Monsoon Season ◽  
Lower Troposphere ◽  
Reanalysis Data ◽  
Data Sets ◽  
Hysplit Model ◽  
Height Range ◽  
Multiple Data ◽  
Multiple Data Sets

Abstract. An enhancement of the tropospheric ozone column (TOC) over Arabian Sea (AS) during the pre-monsoon season is reported in this study. The potential sources of the AS spring ozone pool are investigated by use of multiple data sets (e.g., SCIAMACHY Limb-Nadir-Matching TOC, OMI/MLS TOC, TES TOC, MACC reanalysis data, MOZART-4 model and HYSPLIT model). Three-quarters of the enhanced ozone concentrations are attributed to the 0–8 km height range. The main source of the ozone enhancement is considered to be caused by long-range transport of ozone pollutants from India (∼  50 % contributions to the lowest 4 km,  ∼  20 % contributions to the 4–8 km height range), the Middle East, Africa and Europe (∼  30 % in total). In addition, the vertical pollution accumulation in the lower troposphere, especially at 4–8 km, was found to be important for the AS spring ozone pool formation. Local photochemistry, on the other hand, plays a negligible role in producing ozone at the 4–8 km height range. In the 0–4 km height range, ozone is quickly removed by wet deposition. The AS spring TOC maxima are influenced by the dynamical variations caused by the sea surface temperature (SST) anomaly during the El Niño period in 2005 and 2010 with a  ∼  5 DU decrease.

scholarly journals Tropospheric ozone maxima observed over the Arabian Sea during the pre-monsoon

2016 ◽  
Author(s):  
Jia Jia ◽  
Annette Ladstätter-Weißenmayer ◽  
Xuewei Hou ◽  
Alexei Rozanov ◽  
John Burrows
Keyword(s):  
Tropospheric Ozone ◽  
Arabian Sea ◽  
Monsoon Season ◽  
Lower Troposphere ◽  
Reanalysis Data ◽  
Data Sets ◽  
Hysplit Model ◽  
Height Range ◽  
Multiple Data ◽  
Multiple Data Sets

Abstract. An enhancement of the tropospheric ozone column (TOC) over Arabian Sea (AS) during the pre-monsoon season is reported in this study. The potential sources of the AS spring ozone pool are investigated by use of multiple data sets (e.g., SCIAMACHY Limb-Nadir-Matching TOC, OMI/MLS TOC, TES TOC, MACC reanalysis data, MOZART-4 model and HYSPLIT model). 3/4 of the enhanced ozone concentrations are attributed to the 0–8 km height range. The main source of the ozone enhancement is considered to be caused by long range transport of ozone pollutants from India (~ 50 % contributions to the lowest 4 km, ~ 20 % contributions to the 4–8 km height range), the Middle East, Africa and Europe (~ 30 % in total). In addition, the vertical pollution accumulation in the lower troposphere, especially at 4–8 km, was found to be important for the AS spring ozone pool formation. Local photochemistry, on the other hand, plays a negligible role in producing ozone at the 4–8 km height range. In the 0–4 km height range, ozone is quickly removed by wet-deposition. The AS spring TOC maxima are influenced by the dynamical variations caused by the sea surface temperature (SST) anomaly during the El Niño period in 2005 and 2010 with a ~ 5 DU decrease.

Evaluation of evapotranspiration estimates from observed and reanalysis data sets over Indian region

2019 ◽  
Vol 39 (15) ◽  
pp. 5791-5800 ◽  
Author(s):  
G. Purnadurga ◽  
T.V. Lakshmi Kumar ◽  
K. Koteswara Rao ◽  
Humberto Barbosa ◽  
R.K. Mall
Keyword(s):  
Reanalysis Data ◽  
Indian Region ◽  
Data Sets

Atmospheric summer circulation and coastal upwelling in the Arabian Sea during the Holocene and the last glaciation

1991 ◽  
Vol 36 (1) ◽  
pp. 72-93 ◽  
Author(s):  
Frank Sirocko ◽  
Michael Sarnthein ◽  
Heinz Lange ◽  
Helmut Erlenkeuser
Keyword(s):  
Arabian Sea ◽  
Coastal Upwelling ◽  
Monsoon Season ◽  
Sediment Cores ◽  
Southwest Monsoon ◽  
Accumulation Rates ◽  
Summer Circulation ◽  
The Holocene ◽  
Dust Flux ◽  
Northern Arabian Sea

AbstractAccumulation rates of biogenic and lithogenic components were studied in 39 turbidite-free, well-dated sediment cores from the northern Indian Ocean to define the proportions of fluvial and eolian input and to reconstruct Quaternary patterns of coastal upwelling. The majority of dust deposited in the western Arabian Sea during the Holocene (about 100 × 106t yr−1) is advected from Arabia by northwesterly winds, which overlie the low-level southwest monsoon. The glacial increase in dust flux to 160 × 106t yr−1 culminated in the northern Arabian Sea, most probably due to (i) entrainment of dust, rich in chlorite, dolomite, and lithogenic carbonate in the then-dry Persian Gulf, and (ii) a southward shift of the mean position of the southwest monsoon during glacial summer. This shift is recorded in reduced accumulation rates of biogenic opal and increased rates of marine carbonate off Somalia and Oman. Both the terrigenous and biogenic sediment records show that the northwesterly winds and the southwest monsoon persisted over the last 27,000 yr, as well as the Asian continental summer heat low. However, the glacial seasonal time span of the southwest monsoon season was much reduced, most likely because of a delay in the seasonal onset of the southwest monsoon.

scholarly journals Climatology of Energetics of cyclones over Indian Seas

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Somenath Dutta ◽  
Geena Sandhu ◽  
Sanjay G Narkhedkar ◽  
Sunitha Devi
Keyword(s):  
Tropical Cyclones ◽  
Bay Of Bengal ◽  
Arabian Sea ◽  
Monsoon Season ◽  
Recent Decade ◽  
Reanalysis Data ◽  
Monsoon Period ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Indian Seas

The study discusses the energetic aspects of tropical cyclones formed over Arabian Sea (AS) and Bay of Bengal (BOB) during the period from 1991 till 2013 and aims at bringing out climatology of the energetics of tropical cyclones over Indian Seas. Total 88 cyclones that developed over the Indian Seas during the recent decade of 1991-2013 have been studied. These intense systems are categorized on the basis of their formation region and season of formation. It is seen that during the study period, the frequency of formation of cyclones over BOB is twice that over AS which is consistent with the climatology of the regions. Further, it is noticed that over both the regions, they are more frequently formed in the post monsoon period compared to pre monsoon. The trend analysis of the frequency of cyclones forming over both basins, season wise shows that the overall trend for both basins is of just decreasing type. However, for Arabian Sea; the decreasing trend is more apparent in the post monsoon season, whereas in the case of the Bay of Bengal the decreasing trend is more evident in the pre monsoon season. Various energy terms, their generation and conversion terms have been computed using NCEP/NCAR reanalysis data. Day to day quantitative analysis of these parameters is studied critically during various stages of the cyclones. The composites of these categorized systems are formed and studied. The formative, intensification and dissipation stages showed variations in their energy terms.

scholarly journals Radiometric consistency assessment of hyperspectral infrared sounders

2015 ◽  
Vol 8 (11) ◽  
pp. 4831-4844 ◽  
Author(s):  
L. Wang ◽  
Y. Han ◽  
X. Jin ◽  
Y. Chen ◽  
D. A. Tremblay
Keyword(s):  
Infrared Imaging ◽  
Data Sets ◽  
Atmospheric Infrared Sounder ◽  
Benchmark Data ◽  
Long Wave ◽  
Atmospheric Sounding ◽  
Spectral Scale ◽  
Cross Track ◽  
Spectral Channels

Abstract. The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark data sets for both intercalibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and MetOp-B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through simultaneous nadir overpass (SNO) observations in 2013, to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the long-wave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1–0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both polar and tropical SNOs. The combined global SNO data sets indicate that the CrIS–AIRS BT differences are less than or around 0.1 K among 21 of 25 spectral regions and they range from 0.15 to 0.21 K in the remaining four spectral regions. CrIS–AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

scholarly journals A Climatology of Arabian Sea Cyclonic Storms

2011 ◽  
Vol 24 (1) ◽  
pp. 140-158 ◽  
Author(s):  
Amato T. Evan ◽  
Suzana J. Camargo
Keyword(s):  
Bay Of Bengal ◽  
Environmental Conditions ◽  
Arabian Sea ◽  
Large Scale ◽  
Late Onset ◽  
Southwest Monsoon ◽  
Reanalysis Data ◽  
Tropical Cyclogenesis ◽  
Storm Frequency ◽  
Cyclonic Storms

Abstract On average 1–2 tropical cyclones form over the Arabian Sea each year, and few of these storms are intense enough to be classified as very severe or super cyclonic storms. As such, few studies have explicitly identified the seasonal to interannual changes in environmental conditions that are associated with Arabian Sea tropical cyclogenesis. However, over the last 30 yr several intense Arabian storms did form and make landfall, with large impacts, which motivates this new study of the basin. The conclusions of earlier studies are visited by utilizing modern observational and reanalysis data to identify the large-scale features associated with Arabian tropical cyclone variability on seasonal time scales. Then year-to-year changes in environmental conditions that are related to interannual variability in Arabian storms during the pre- and postmonsoon periods are elucidated. The analysis of the relationship between large-scale environmental variables and seasonal storm frequency supports conclusions from work completed more than 40 yr prior. Investigation of the year-to-year changes in premonsoon storm frequency suggests that May (June) storms are associated with an early (late) onset of the southwest monsoon. The findings also demonstrate that November cyclones (the month when the majority of postmonsoon cyclogenesis occurs) primarily form during periods when the Bay of Bengal experiences a broad region of high sea level pressure, implying that November storms form in either the Arabian Sea or the Bay of Bengal but not in both during the same year. Finally, the analysis of changes in a genesis potential index suggests that long-term variability in the potential for a storm to form is dictated by changes in midlevel moisture.

Sign in / Sign up

Export Citation Format

Share Document