scholarly journals Ocean surface wind prediction in the north Indian Ocean from in situ and satellite observations using genetic algorithm

2005 ◽  
Vol 32 (24) ◽  
Author(s):  
Sujit Basu ◽  
K. Satheesan ◽  
Abhijit Sarkar ◽  
C. M. Kishtawal
Keyword(s):  
Genetic Algorithm ◽  
Indian Ocean ◽  
Surface Wind ◽  
Ocean Surface ◽  
North Indian Ocean ◽  
Satellite Observations ◽  
The North ◽  
Ocean Surface Wind

scholarly journals Use of scatterometer based surface vorticity fields in forecasting genesis of tropical cyclones over the north Indian Ocean

MAUSAM ◽  
2021 ◽  
Vol 62 (1) ◽  
pp. 61-72
Author(s):  
O. P. SINGH ◽  
HARVIR SINGH
Keyword(s):  
Indian Ocean ◽  
Tropical Cyclones ◽  
Lead Time ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
North Indian Ocean ◽  
The North ◽  
Peak Intensity ◽  
Ocean Surface Wind ◽  
Vorticity Anomaly

. Utilizing surface vorticity fields computed with the ocean surface wind speed and direction dataobtained from QuikSCAT, a study has been undertaken to investigate the increase in surface vorticity during the genesisphase of tropical cyclones over the north Indian Ocean. Six named tropical cyclones; Agni, Hibaru, Mala, Akash, Nargisand Phyan which formed over the region during 2004-2009 have been selected for this purpose. It has been found thatthere was a steep rise in scatterometer based surface vorticity before the formation of a cyclone in the cyclogenesisregion. The peak surface vorticity in the genesis region was observed on the day of intensification of the vortex to thedepression stage or a day earlier. However, the rising trend in the genesis region begins a few days before the formationof the system. Thus, the surface vorticity fields derived on the basis of scatterometer data can provide predictiveindication of the genesis of tropical cyclones over the Bay of Bengal and Arabian Sea with a lead time of 2-3 days. Usingthis technique it is possible to increase the lead time of pre-cyclone watch period over the north Indian Ocean. No relationship was found between the peak surface vorticity anomaly during the genesis phase and the surfacevorticity anomaly at the time of peak intensity of the system during its life cycle. In other words, the peak surfacevorticity anomaly during genesis phase does not provide any indication of future maximum intensity of the cyclone.

scholarly journals Effect of tropical cyclones on the Stratosphere-Troposphere Exchange observed using satellite observations over north Indian Ocean

2016 ◽  
Author(s):  
M. Venkat Ratnam ◽  
S. Ravindra Babu ◽  
S. S. Das ◽  
Ghouse Basha ◽  
B. V. Krishnamurthy ◽  
...  
Keyword(s):  
Water Vapor ◽  
Indian Ocean ◽  
Tropical Cyclones ◽  
Lower Stratosphere ◽  
North Indian Ocean ◽  
Satellite Observations ◽  
Upper Troposphere ◽  
North West ◽  
The North ◽  
The Impact

Abstract. Tropical cyclones play an important role in modifying the tropopause structure and dynamics as well as stratosphere-troposphere exchange (STE) process in the Upper Troposphere and Lower Stratosphere (UTLS) region. In the present study, the impact of cyclones that occurred over the North Indian Ocean during 2007–2013 on the STE process is quantified using satellite observations. Tropopause characteristics during cyclones are obtained from the Global Positioning System (GPS) Radio Occultation (RO) measurements and ozone and water vapor concentrations in UTLS region are obtained from Aura-Microwave Limb Sounder (MLS) satellite observations. The effect of cyclones on the tropopause parameters is observed to be more prominent within 500 km from the centre of cyclone. In our earlier study we have observed decrease (increase) in the tropopause altitude (temperature) up to 0.6 km (3 K) and the convective outflow level increased up to 2 km. This change leads to a total increase in the tropical tropopause layer (TTL) thickness of 3 km within the 500 km from the centre of cyclone. Interestingly, an enhancement in the ozone mixing ratio in the upper troposphere is clearly noticed within 500 km from cyclone centre whereas the enhancement in the water vapor in the lower stratosphere is more significant on south-east side extending from 500–1000 km away from the cyclone centre. We estimated the cross-tropopause mass flux for different intensities of cyclones and found that the mean flux from stratosphere to troposphere for cyclonic stroms is 0.05 ± 0.29 × 10−3 kg m−2 and for very severe cyclonic stroms it is 0.5 ± 1.07 × 10−3 kg m−2. More downward flux is noticed in the north-west and south-west side of the cyclone centre. These results indicate that the cyclones have significant impact in effecting the tropopause structure, ozone and water vapour budget and consequentially the STE in the UTLS region.

Validation of satellite-derived tropical cyclone heat potential with in situ observations in the North Indian Ocean

2012 ◽  
Vol 3 (7) ◽  
pp. 615-620 ◽  
Author(s):  
Pullaiahgari V. Nagamani ◽  
Meer M. Ali ◽  
Gustavo J. Goni ◽  
DiNezio N. Pedro ◽  
John C. Pezzullo ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Indian Ocean ◽  
North Indian Ocean ◽  
The North ◽  
Tropical Cyclone Heat Potential ◽  
Heat Potential ◽  
In Situ Observations

scholarly journals The Relationship between the Interannual Variation of the North Indian Ocean SST Induced by Surface Wind and ENSO during Boreal Summer

2005 ◽  
Vol 18 (12) ◽  
pp. 1942-1956 ◽  
Author(s):  
Motoki Nagura ◽  
Masanori Konda
Keyword(s):  
Indian Ocean ◽  
Interannual Variation ◽  
Temporal Change ◽  
Surface Wind ◽  
North Indian Ocean ◽  
Boreal Summer ◽  
The North ◽  
Second Mode ◽  
Sst Anomaly ◽  
The Relationship

Abstract The relationship between the interannual variation of the surface wind in the north Indian Ocean (0°–30°N, 30°–100°E) and El Niño–Southern Oscillation (ENSO) during boreal summer is investigated. The association of the surface wind with the sea surface temperature (SST) in the north Indian Ocean is evaluated. The NCEP–NCAR reanalysis, NOAA outgoing longwave radiation (OLR), and Reynolds SST data are used. The June–August mean of the surface wind anomaly over the north Indian Ocean is decomposed by EOF analysis, and two dominant modes are extracted. The first (second) mode shows the corresponding variation with the ENSO events maturing in the subsequent (previous) winter. The first mode has a large amplitude during the 1990s, while the amplitude of the second mode is large mainly during the 1980s. Such contrast of the amplitude of the two modes results in the temporal change of the surface wind–ENSO relationships between the two decades. The temporal characteristics of the first and second modes are consistent with those of convective variability in the eastern Indian Ocean and the Philippine Sea, respectively. The local thermal forcings associated with these two contrastive modes are compared with the time change of the SST anomaly. The thermal forcings are evaluated in terms of the latent heat flux and the Ekman heat transport. The thermal forcing of the first mode is consistent with a meridionally antisymmetric pattern of the SST anomaly during the 1990s, while that of the second mode is correlated with the basinwide SST anomaly during the 1980s. This result suggests that the temporal change is also found in the north Indian Ocean SST anomaly.

scholarly journals Comparison of Multiple Surface Ocean Wind Products with Buoy Data over Blue Amazon (Brazilian Continental Margin)

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Vitor Paiva ◽  
Milton Kampel ◽  
Rosio Camayo
Keyword(s):  
Wind Speed ◽  
Continental Margin ◽  
Surface Wind ◽  
Remote Sensing Data ◽  
Ocean Surface ◽  
Surface Wind Speed ◽  
Global Scale ◽  
In Situ Data ◽  
Ocean Surface Wind

Remote sensing data for space-time characterization of wind fields in extensive oceanic areas have been shown to be increasingly useful. Orbital sensors, such as radar scatterometers, provide data on ocean surface wind speed and direction with spatial and temporal resolutions suitable for multiple applications and air-sea studies. Even considering the relevant role of orbital scatterometers to estimate ocean surface wind vectors on a regional and global scale, the products must be validated regionally. Six different ocean surface wind datasets, including advanced scatterometer (ASCAT-A and ASCAT-B products) estimates, numerical modelling simulations (BRAMS), reanalysis (ERA5), and a blended product (CCMP), were compared statistically with in situ measurements obtained by anemometers installed in fifteen moored buoys in the Brazilian margin (8 buoys in oceanic and 7 in shelf waters) to analyze which dataset best represents the wind field in this region. The operational ASCAT wind products presented the lowest differences in wind speed and direction from the in situ data (0.77 ms−1 < RMSEspd < 1.59 ms−1, 0.75 < Rspd < 0.96, −0.68 ms−1 < biasspd < 0.38 ms−1, and 12.7° < RMSEdir < 46.8°). CCMP and ERA5 products also performed well in the statistical comparison with the in situ data (0.81 ms−1 < RMSEspd < 1.87 ms−1, 0.76 < Rspd < 0.91, −1.21 ms−1 < biasspd < 0.19 ms−1, and 13.7° < RMSEdir < 46.3°). The BRAMS model was the one with the worst performance (RMSEspd > 1.04 m·s−1, Rspd < 0.87). For regions with a higher wind variability, as in the southern Brazilian continental margin, wind direction estimation by the wind products is more susceptible to errors (RMSEdir > 42.4°). The results here presented can be used for climatological studies and for the estimation of the potential wind power generation in the Brazilian margin, especially considering the lack of availability or representativeness of regional data for this type of application.

Inter-comparison of model, satellite and in situ tropical cyclone heat potential in the North Indian Ocean

2019 ◽  
Vol 102 (2) ◽  
pp. 557-574 ◽  
Author(s):  
Babita Jangir ◽  
D. Swain ◽  
Samar Kumar Ghose ◽  
Rishav Goyal ◽  
T. V. S. Udaya Bhaskar
Keyword(s):  
Tropical Cyclone ◽  
Indian Ocean ◽  
North Indian Ocean ◽  
The North ◽  
Tropical Cyclone Heat Potential ◽  
Heat Potential
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