The S5PVAL-IN-KOLKATA campaign is scheduled to start in 2020, in collaboration with BIRA-IASB, IISER Kolkata and IUP-UB. The campaign deployment in the campus of the India Institute of Science Education and Research Kolkata (IISER Kolkata; 22.9630° N, 88.5242° E, 22.390 m.a.s.l altitude interferometer - NDACC, 24.680 m.a.s.l altitude solar tracker - TCCON) in India focuses on multiple species under realistic conditions of cloud cover. The campaign site is located about 50 km north from the heart of the megacity Kolkata. It is well suited as a high-polluted site for S-5p carbon monoxide validation. The plumes from the urban areas as well as the long-range transport from surrounding regions can be observed. The location will serve as a humid site due to its proximity of the Bay of Bengal and the dominant monsoon season. The southern region of Bengal is known for its rice cultivation and the mangrove forest in the Sundarbans area. Both are sources of high methane emissions. The ground-based measurements will be crucial for the validation of S-5p methane product. The activities aim at performing measurements of column-averaged abundances of methane (CH4), carbon monoxide (CO) and carbon dioxide (CO2) with a ground-based low-resolution Fourier transform infrared (FTIR) spectrometer of the type Bruker Vertex70. The CH4 and CO measurements will be used to validate the corresponding S-5p level-2 products. The Vertex70 has been extensively tested during the ESA funded FRM4GHG campaign (2017 – 2019) by performing side-by-side measurements next to the Sodankylä TCCON spectrometer and an EM27/SUN (COCCON instrument). The Vertex70 has shown excellent results in terms of the measurement precision, very similar to that of TCCON and COCCON, and therefore the measurements complement the TCCON and COCCON networks perfectly (Sha et. al. 2019). In addition to the CO2, CH4 and CO measurements with an Indium Gallium Arsenide (InGaAs) detector, the Vertex70 is capable of measuring formaldehyde (HCHO) with a second liquid nitrogen cooled Indium Antimonide (InSb) detector. This has been tested during the FRM4GHG. However, the HCHO retrieval requires further optimization to improve the quality of the HCHO product. In addition, a number of ancillary parameters will be measured to record the atmospheric state. The measurements from this campaign will offer a unique dataset from a region from which no comparable data is available. BIRA-IASB will be coordinating the campaign together with the local support from IISER Kolkata. IUP-UB will act as an external consultant when needed.
Sha, M. K., De Mazière, M., Notholt, J., Blumenstock, T., Chen, H., Dehn, A., Griffith, D. W. T., Hase, F., Heikkinen, P., Hermans, C., Hoffmann, A., Huebner, M., Jones, N., Kivi, R., Langerock, B., Petri, C., Scolas, F., Tu, Q., and Weidmann, D.: Intercomparison of low- and high-resolution infrared spectrometers for ground-based solar remote sensing measurements of total column concentrations of CO2, CH4, and CO, Atmos. Meas. Tech., 13, 4791–4839, https://doi.org/10.5194/amt-13-4791-2020, 2020.