Dry spell characteristics over India based on IMD and APHRODITE datasets

• Published in: Climate dynamics Vol. 43; no. 12; pp. 3419 - 3437
• Main Authors: Sushama, L, Ben Said, S, Khaliq, M. N, Nagesh Kumar, D, Laprise, R
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Climatology; Climatology. Bioclimatology. Climate change; Data analysis; data collection; Drought; Droughts; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Environmental aspects; Exact sciences and technology; External geophysics; Geophysics/Geodesy; Meteorological research; Meteorology; monsoon season; Monsoons; Oceanography; Precipitation; Precipitation (Meteorology); summer; Water in the atmosphere (humidity, clouds, evaporation, precipitation); Water resources; India; Asia; India, Karnataka; India, Punjab; Dry spells; Gridded precipitation data; Trends; India; time series analysis; trend-surface analysis; atmospheric precipitation; 1950-2000; sustainable development; 2000-2010; water resource management; Dry spell; monsoons
• ISSN: 0930-7575; 1432-0894
• DOI: 10.1007/s00382-014-2113-9

Selected characteristics of dry spells and associated trends over India during the 1951–2007 period is studied using two gridded datasets: the Indian Meteorological Department (IMD) and the Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of the water resources (APHRODITE) datasets. Two precipitation thresholds, 1 and 3 mm, are used to define a dry day (and therefore dry spells) in this study. Comparison of the spatial patterns of the dry spell characteristics (mean number of dry days, mean number of dry spells, mean and maximum duration of dry spells) for the annual and summer monsoon period obtained with both datasets agree overall, except for the northernmost part of India. The number of dry days obtained with APHRODITE is larger for this region compared to IMD, which is consistent with the smaller precipitation for the region in APHRODITE. These differences are also visible in the spatial patterns of mean and maximum dry spell durations. Analysis of field significance associated with trends, at the level of 34 predefined meteorological subdivisions over the mainland, suggests better agreement between the two datasets in positive trends associated with number of dry days for the annual and summer monsoon period, for both thresholds. Important differences between the two datasets are noted in the field significance associated with the negative trends. While negative trends in annual maximum duration of dry spells appear field significant for the desert regions according to both datasets, they are found field significant for two regions (Punjab and South Interior Karnataka) for the monsoon period for both datasets. This study, in addition to providing information on the spatial and temporal patterns associated with dry spell characteristics, also allows identification of regions and characteristics where the two datasets agree/disagree.