A phytoplankton bloom caused by the super cyclonic storm Amphan in the central Bay of Bengal
<p>The super cyclonic storm Amphan originated in the central Bay of Bengal (BoB) in May 2020, and a phytoplankton bloom occurred in the upper ocean that was devoid of background nutrients. The dynamic mechanism of the chlorophyll <span class="inline-formula"><i>a</i>...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-08-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://nhess.copernicus.org/articles/23/2807/2023/nhess-23-2807-2023.pdf |
| Summary: | <p>The super cyclonic storm Amphan originated in the central Bay of Bengal (BoB) in May 2020, and a phytoplankton bloom occurred in the upper ocean that was devoid of background nutrients. The dynamic mechanism of the chlorophyll <span class="inline-formula"><i>a</i></span> (Chl <span class="inline-formula"><i>a</i></span>) bloom was researched based on reanalysis data,
remote sensing and Argo float data. During the passage of Amphan, an inertial oscillation with a 2 d period appeared in the thermocline and
lasted for approximately 2 weeks. After the passage of Amphan, a cyclonic
eddy with a maximum vorticity of approximately 0.36 s<span class="inline-formula"><sup>−1</sup></span> formed in the
study area (Box A). Additionally, horizontal transport of Chl <span class="inline-formula"><i>a</i></span> also
occurred when the maximum inlet fluxes through the western and northern
sides of Box A were 0.304 and <span class="inline-formula">−0.199</span> mg m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span>, respectively. With the weakened thermocline and thinner barrier layer thickness (BLT), nitrate and Chl <span class="inline-formula"><i>a</i></span> were uplifted to the upper ocean by upwelling. Then, with the high photosynthetically available radiation (PAR) in the upper ocean, a phytoplankton bloom occurred. This study provides new insights into the biological responses in the BoB during the passage of tropical cyclones (TCs).</p> |
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| ISSN: | 1561-8633 1684-9981 |