Atmospheric Moisture during Monsoon 2002 ARMEX Phase I Anu Simon, K. Mohankumar, Aype Thomas and C.K. Rajan Department of Atmospheric Sciences Cochin University of Science and Technology Cochin-682 016
16 14 12 10 All India Rainfall (mm) for June to September 2002 (Climatology is plotted) 8 6 4 2 0 03-Oct There was a long dry spell from end June to beginning of August 30-M ay 06-Jun 13-Jun 20-Jun 27-Jun 04-Jul 11-Jul 18-Jul 25-Jul 01-Aug 08-Aug 15-Aug 22-Aug 29-Aug 05-Sep 12-Sep 19-Sep 26-Sep
Evolution Of OLR field NOAA(10 dayaverages) JUNE to AUGUST 2002
In the present study The moisture field of NCMRWF analysis of the 2002 monsoon (ARMEX Phase I) at levels 1000, 850, 700, 600 and 500 hpa is studied and compared with the and ERA reanalysis data sets.
A comparison is also made with the moisture field of monsoon 1998, during which the break monsoon spells were short, using the available and ERA reanalysis data sets.
18 16 14 12 10 8 6 4 2 0 All India Rainfall (mm) for June to September 1998 (Climatology is plotted)
Average Specific Humidity(g/kg) -NCMWRF for Arabian sea box (10-20N,55-75 E) 01 June to 31 August 2002 18 16 1000hPa 700hPa 14 ALL INDIA DAILY RAINFALL (mm) -JUNE TO SEPTE 12 10 8 6 4 2 0 30-May 06-Jun 13-Jun 20-Jun 27-Jun 04-Jul 11-Jul 18-Jul 25-Jul 01-Aug 08-Aug 15-Aug 22-Aug 29-Aug 05-Sep 600hPa 500hPa
Average Specific Humidity(g/kg) NCMWRF for Bay Of Bengal (10-20N,80-100 E) 01 June to 31 August 2002 1000hPa 700hPa 600hPa 500hPa
Average Specific Humidity(g/kg) for Arabian sea (10-20N,55-75 E) 01 June 31 August 1998 1000hPa 700hPa 600hPa 500hPa
7.5 7 6.5 6 5.5 5 4.5 4 3.5 3 2.5 2 1.5 1 Specfic Humdity (g/kg) 600hPa -2002 7.5 7 6.5 6 5.5 5 4.5 4 3.5 3 2.5 2 1.5 1 Specfic Humdity (g/kg) 500hPa -2002 1-Jun 8-Jun 15-Jun 22-Jun 29-Jun 6-Jul 13-Jul 20-Jul 27-Jul 3-Aug 10-Aug 17-Aug 24-Aug 1-Jun 8-Jun 15-Jun 22-Jun 29-Jun 6-Jul 13-Jul 20-Jul 27-Jul 3-Aug 10-Aug 17-Aug 24-Aug 7.5 7 6.5 6 5.5 5 4.5 4 3.5 3 2.5 2 1.5 1 Specfic Humdity (g/kg) 600hPa -1998 7.5 7 6.5 6 5.5 5 4.5 4 3.5 3 2.5 2 1.5 1 Specfic Humdity (g/kg) 500hPa -1998 1-Jun 8-Jun 15-Jun 22-Jun 29-Jun 6-Jul 13-Jul 20-Jul 27-Jul 3-Aug 10-Aug 17-Aug 24-Aug 1-Jun 8-Jun 15-Jun 22-Jun 29-Jun 6-Jul 13-Jul 20-Jul 27-Jul 3-Aug 10-Aug 17-Aug 24-Aug
Evolution Of OLR field NOAA(10 dayaverages) JUNE to AUGUST 1998
10 day average of Specific Humidity July 2002 1-10 JUL 1000 hpa NCMRWF NCMRW 11-20 JUL1000 hpa NCMRW 21-31 JUL 1000 hpa F F NCMRWF
10 day average of Specific Humidity July 2002 NCMRWF 1-10 JUL 700 hpa 11-20 JUL 700 hpa NCMRWF 21-31 JUL 700 hpa NCMRWF
1-10 JUL 500 hpa 10 day average of Specific Humidity July 2002 NCMRWF 11-20 JUL 500 hpa NCMRWF 21-31 JUL 500 hpa NCMRWF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 July at 1000hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 July at 700hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 July at 600hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 July at 500hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 August at 1000hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 August at 700hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 August at 600hPa NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 2002 August at 500hPa NCMWRF NCMWRF
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 July at 1000hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 July at 700hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 July at 600hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 July at 500hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 August at 1000hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 August at 700hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 August at 600hPa
Wind in m/s (vectors) and Specific Humidity in g/kg (shaded) for 1998 August at 500hPa
INTEGRATED MOISTURE FLUX (Kgm -1 s -1 ) (1000-500) for July 2002 NCMRWF Integrated Flux = 1 g P t P 0 Vq dp
INTEGRATED MOISTURE FLUX (Kgm -1 s -1 ) (1000-500) for July 1998
DAILY MOISTURE TRANSPORT ACROSS 75 E FROM 10 20N (kg/day) 2002 -NCMRWF 1000-700hPa 700-500hPa
DAILY MOISTURE TRANSPORT ACROSS 75 E FROM 10 20N (kg/day) 1000-700hPa - 2002 1998
DAILY MOISTURE TRANSPORT ACROSS 75 E FROM 10 20N (kg/day) 700-500hPa - 2002 1998
Conclusions During the dry July of 2002 (long break) Arabian Sea had very low moisture at levels above 700hPa Dry air over Arabian sea above 700hPa in July 2002 appears to have come from both the south Indian ocean across the equator and also from the dry continental areas to the north In August, the Arabian sea was more moist with the relatively dry air from the south Indian ocean spreading to south of the Indian peninsula.
The moisture field of Bay of Bengal doesn't show much variation during July unlike that of the Arabian Sea. A comparison with the moisture at 600 and 500 hpa levels of 1998 (year with short breaks) show that moisture at these levels in July was more than that of 2002. It also remained high throughout the season with very little variations The vertically integrated moisture (1000-500hPa) during July 2002 was relatively less than that during 1998
Moisture transport at 700-500 hpa across the west coast of India (10-20N) during July 2002 was very low compared to August 2002 and also of July & August 1998. In general at all levels 1000hPa to 500hPa / has less/more moisture than NCMWRF
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