Keane, R, Williams, K, Stirling, A et al. (3 more authors) (2019) Fast biases in monsoon rainfall over southern and central India in the Met Office Unified Model. Journal of Climate, 32 (19). pp. 6385-6402. ISSN 0894-8755
Abstract
The Met Office Unified Model (MetUM) is known to produce too little total rainfall on average over India during the Monsoon period, when assessed for multi-year climate simulations. We investigate how quickly this dry bias appears by assessing the 5-day operational forecasts produced by the MetUM for six different years. It is found that the MetUM shows a drying tendency across the five days of the forecasts, for all of the six years (which correspond to two different model versions). We then calculate each term in the moisture budget, for a region covering southern and central India, where the dry bias is worst in both climate simulations and weather forecasts. By looking at how the terms vary with forecast lead time, we are able to identify biases in the weather forecasts that have been previously identified in climate simulations using the same model, and we attempt to quantify how these biases lead to a reduction in total rainfall. In particular, an anticyclonic bias develops to the east of India throughout the forecast, and has a complex effect on the moisture available over the peninsula, and a reduction in the wind speed into the west of the region appears after about 3 days, indicative of upstream effects. In addition we find a new bias that the air advected from the west is too dry from very early in the forecast, and this has an important effect on the rainfall.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 American Meteorological Society. This is an author produced version of a paper published in Journal of Climate. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number NERC No External Refererence Met Office Not Known Met Office L4161 |
Depositing User: | Symplectic Publications |
Date Deposited: | 10 Jul 2019 10:33 |
Last Modified: | 09 Jul 2020 00:38 |
Status: | Published |
Publisher: | American Meteorological Society |
Identification Number: | 10.1175/JCLI-D-18-0650.1 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:148345 |