Current Science

Manish Naja ¹, Piyush Bhardwaj ¹, Narendra Singh ¹, Phani Kumar ¹, Rajesh Kumar ², N. Ojha ¹, Ram Sagar ³, S. K. Satheesh ⁴, K. Krishna Moorthy ⁵, V. R. Kotamarthi ⁶

Affiliations
1 Aryabhatta Research Institute of Observational Sciences, Nainital 263 002, IN
2 National Center for Atmospheric Research, Boulder, Colorado, US
3 Indian Institute of Astrophysics, Bengaluru 560 034, IN
4 Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bengaluru 560 012, IN
5 Indian Space Research Organization, Head Quarters, Bengaluru 560 231, IN
6 Argonne National Laboratory, Argonne, IL, US

Abstract

An extensive field study, RAWEX-GVAX, was carried out during a 10-month (June 2011-March 2012) campaign at ARIES, Nainital and observations on a wide range of parameters like physical and optical properties of aerosols, meteorological parameters and boundary layer evolution were made. This work presents results obtained from high-frequency (four launches per day), balloon-borne observations of meteorological parameters (pressure, temperature, relative humidity, wind speed and wind direction). These observations show wind speed as high as 84 m/s near the subtropical jet. It is shown that reanalysis wind speeds are in better agreement at 250 hPa (altitude of subtropical jet) than those above or below this value (100 hPa or 500 hPa). These observations also demonstrate that AIRS-derived temperature profiles are negatively biased in the lower altitude region, whereas they are positively biased near the tropopause. WRF simulated results are able to capture variations in temperature, humidity and wind speed profile reasonable well. WRF and AIRS-derived tropopause height, tropopause pressure and tropopause temperature also show agreement with radiosonde estimates.

Keywords

Aerosols, Radiosonde, Subtropical Jet, Tropopause Folding, Vertical Profiling.

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Prajjwal Rawat ¹, Manish Naja ¹, Pradeep K. Thapliyal ², Shuchita Srivastava ³, Piyush Bhardwaj ⁴, Rajesh Kumar ⁴, Samaresh Bhatacharjee ¹, S. Venkatramani ⁵, S. N. Tiwari ⁶, Shyam Lal ⁵

Affiliations
1 Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263 002, IN
2 Space Applications Centre, Jodhpur Tekra, Ahmedabad 380 015, IN
3 Indian Institute of Remote Sensing, 4 Kalidas Road, Dehradun 248 001, IN
4 National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301, US
5 Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, IN
6 DDU Gorakhpur University, Gorakhpur 273 009, IN

Abstract

Vertical distribution of ozone has been obtained for the first time using INSAT-3D for the period 2013-2017 over the central Himalaya and validated utilizing balloon-borne observations from a high-altitude site in Nainital (29.4°N, 79.5°E, 1793 m amsl). The INSAT-3D retrieved ozone profiles captured ozone gradient and ozone peak altitude successfully, despite only one IR channel for ozone. This demonstrates the capability of the INSAT-3D Sounder in capturing the observed features, with a smaller bias in the stratosphere and somewhat larger bias in the troposphere. Total ozone column from INSAT-3D showed maximum difference of 8% with ozonesonde-derived total ozone column. Larger ozone bias in the lower troposphere could be attributed to lower reliability of regression coefficient and INSAT-3D channel constraints itself, whereas high variability near the tropopause is possibly due to low ozone, poor temperature retrieval near the tropo-pause and stratosphere–troposphere transport process in the Himalayan region.

Keywords

Ozone Profiles, Ozonesonde, Satellite Data, Vertical Distribution.

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