Influence of Intraseasonal Variability on the Development of Monsoon Depressions
Abstract Previous studies showed that the activity of monsoon low‐pressure systems (LPS), which produce a large fraction of the South Asian monsoon's total rainfall, is modulated by intraseasonal variability. Using satellite‐derived products and atmospheric reanalyzes, this study examines how t...
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| Format: | Article |
| Language: | English |
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Wiley
2021-01-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2020GL090425 |
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| author | Nirupam Karmakar William R. Boos Vasubandhu Misra |
| author_facet | Nirupam Karmakar William R. Boos Vasubandhu Misra |
| author_sort | Nirupam Karmakar |
| collection | DOAJ |
| description | Abstract Previous studies showed that the activity of monsoon low‐pressure systems (LPS), which produce a large fraction of the South Asian monsoon's total rainfall, is modulated by intraseasonal variability. Using satellite‐derived products and atmospheric reanalyzes, this study examines how the boreal summer intraseasonal oscillation (ISO) separately modulates the occurrence of weaker LPS (lows) and stronger LPS (depressions). It is found that the genesis of lows is insensitive to ISO phase, while depressions exhibit a strong preference for genesis during the phase that is convectively active over the northern Indian Ocean. Essentially, development of LPS into depressions depends upon the timing of genesis of the initial disturbance. Evidence is presented supporting the hypothesis that the development of lows into depressions is fostered by large‐scale atmospheric conditions governed by the ISO. Results also suggest that while lows have no preference for forming over ocean compared to land, depressions mostly form over ocean. |
| format | Article |
| id | doaj-art-bfbee356cf3d4b7190ac171504ebeedf |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2021-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-bfbee356cf3d4b7190ac171504ebeedf2025-08-20T03:04:21ZengWileyGeophysical Research Letters0094-82761944-80072021-01-01482n/an/a10.1029/2020GL090425Influence of Intraseasonal Variability on the Development of Monsoon DepressionsNirupam Karmakar0William R. Boos1Vasubandhu Misra2Earth, Ocean and Atmospheric Science Department Florida State University Tallahassee FL USADepartment of Earth and Planetary Science University of California Berkeley CA USAEarth, Ocean and Atmospheric Science Department Florida State University Tallahassee FL USAAbstract Previous studies showed that the activity of monsoon low‐pressure systems (LPS), which produce a large fraction of the South Asian monsoon's total rainfall, is modulated by intraseasonal variability. Using satellite‐derived products and atmospheric reanalyzes, this study examines how the boreal summer intraseasonal oscillation (ISO) separately modulates the occurrence of weaker LPS (lows) and stronger LPS (depressions). It is found that the genesis of lows is insensitive to ISO phase, while depressions exhibit a strong preference for genesis during the phase that is convectively active over the northern Indian Ocean. Essentially, development of LPS into depressions depends upon the timing of genesis of the initial disturbance. Evidence is presented supporting the hypothesis that the development of lows into depressions is fostered by large‐scale atmospheric conditions governed by the ISO. Results also suggest that while lows have no preference for forming over ocean compared to land, depressions mostly form over ocean.https://doi.org/10.1029/2020GL090425intraseasonal variabilitylarge‐scale dynamicslow‐pressure systemsmonsoon rainfallSouth Asian monsoon |
| spellingShingle | Nirupam Karmakar William R. Boos Vasubandhu Misra Influence of Intraseasonal Variability on the Development of Monsoon Depressions Geophysical Research Letters intraseasonal variability large‐scale dynamics low‐pressure systems monsoon rainfall South Asian monsoon |
| title | Influence of Intraseasonal Variability on the Development of Monsoon Depressions |
| title_full | Influence of Intraseasonal Variability on the Development of Monsoon Depressions |
| title_fullStr | Influence of Intraseasonal Variability on the Development of Monsoon Depressions |
| title_full_unstemmed | Influence of Intraseasonal Variability on the Development of Monsoon Depressions |
| title_short | Influence of Intraseasonal Variability on the Development of Monsoon Depressions |
| title_sort | influence of intraseasonal variability on the development of monsoon depressions |
| topic | intraseasonal variability large‐scale dynamics low‐pressure systems monsoon rainfall South Asian monsoon |
| url | https://doi.org/10.1029/2020GL090425 |
| work_keys_str_mv | AT nirupamkarmakar influenceofintraseasonalvariabilityonthedevelopmentofmonsoondepressions AT williamrboos influenceofintraseasonalvariabilityonthedevelopmentofmonsoondepressions AT vasubandhumisra influenceofintraseasonalvariabilityonthedevelopmentofmonsoondepressions |