scholarly journals Seasonal and interannual coastal wind variability off the central Maluku Islands revealed by satellite oceanography

2022 ◽  
Keyword(s):  
Extreme Events ◽  
Phytoplankton Bloom ◽  
Southern Oscillation ◽  
Surface Wind ◽  
Surface Characteristics ◽  
Research Area ◽  
Sea Surface ◽  
Climate Extreme ◽  
Wind Variability ◽  
Anomaly Analysis

<p>The Maluku Islands (henceforth MI) are situated in the northeastern Indonesia. Ocean region off the central MI is pivotal as it provides a course for the Indonesian Throughflow (ITF) through the Lifamatola passage. However, sea surface dynamics off the central MI is unknown until recently due to inadequate measurements. The current fact motivates the present study to decipher the coastal wind variability off the central MI and its effect on the sea surface by analysing long-term datasets (2007-2019) of satellite-derived sea surface wind, sea surface temperature (SST), and surface chlorophyll-a concentration. Possible influence of extreme climate events of the 2015 El Niño-Southern Oscillation (ENSO) and the 2019 Indian Ocean Dipole (IOD) on all oceanographic parameters was also examined. Results show that the prevailing southeasterly winds over the central MI induce SST cooling and phytoplankton bloom. Correlation analysis revealed that the ENSO and IOD play significant roles in defining spatial distribution of the coastal wind, SST, and phytoplankton bloom in the research area. In addition, the anomaly analysis exhibits distinct oceanographic features during the climate extreme events of 2015 and 2019. Collectively, results of the present research highlight the importance of coastal wind variability and extreme events in shaping the ocean surface characteristics and perhaps regional fisheries production.</p>

Detecting the Phytoplankton Bloom From Satellite Images

2011 ◽  
Author(s):  
Nan-Jung Kuo ◽  
Chung-Ru Ho ◽  
Shih-Jen Huang ◽  
Yao-Tsai Lo
Keyword(s):  
Cold Water ◽  
Phytoplankton Bloom ◽  
Surface Wind ◽  
Winter Monsoon ◽  
Luzon Strait ◽  
Sea Surface ◽  
Wind Stress Curl ◽  
Aquatic Life ◽  
Chl A ◽  
Sea Surface Wind

Phytoplankton is the base of the marine food web. However, the phytoplankton bloom may deplete the dissolved oxygen and shade aquatic life, and even damages the marine environment. In this study, the satellite-derived sea surface chlorophyll-a concentration (Chl-a) and sea surface temperature (SST) are considered to examine the behavior of the phytoplankton bloom in the sea around the western side of the Luzon Strait in the northeastern South China Sea (SCS). Meanwhile, the related sea surface wind (SSW) is also included to understand the possible mechanism to induce the high Chl-a plume around there. The results indicate that the clear high Chl-a water is mainly around the northeastern SCS in winter, and spreads out westward from the northern edge of the Luzon island, Philippines. The external force of this blooming is probably from monsoon wind driving, the strong and diverse winter monsoon in the Luzon Strait can develop a very clear positive wind stress curl in the northwestern side of Luzon island, and then induce the cold and high nutrient water upward. Meanwhile, the strong winter monsoon can also spread this cold water plume out to develop a very clear and large phytoplankton blooming around there.

scholarly journals Drivers and impacts of the most extreme marine heatwaves events

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alex Sen Gupta ◽  
Mads Thomsen ◽  
Jessica A. Benthuysen ◽  
Alistair J. Hobday ◽  
Eric Oliver ◽  
...  
Keyword(s):  
Extreme Events ◽  
Southern Oscillation ◽  
Ecological Impacts ◽  
Sea Surface ◽  
Wind Speeds ◽  
Ocean Productivity ◽  
Physical Attributes ◽  
Generation Mechanisms ◽  
Mixed Layers ◽  
Weak Wind

Abstract Prolonged high-temperature extreme events in the ocean, marine heatwaves, can have severe and long-lasting impacts on marine ecosystems, fisheries and associated services. This study applies a marine heatwave framework to analyse a global sea surface temperature product and identify the most extreme events, based on their intensity, duration and spatial extent. Many of these events have yet to be described in terms of their physical attributes, generation mechanisms, or ecological impacts. Our synthesis identifies commonalities between marine heatwave characteristics and seasonality, links to the El Niño-Southern Oscillation, triggering processes and impacts on ocean productivity. The most intense events preferentially occur in summer, when climatological oceanic mixed layers are shallow and winds are weak, but at a time preceding climatological maximum sea surface temperatures. Most subtropical extreme marine heatwaves were triggered by persistent atmospheric high-pressure systems and anomalously weak wind speeds, associated with increased insolation, and reduced ocean heat losses. Furthermore, the most extreme events tended to coincide with reduced chlorophyll-a concentration at low and mid-latitudes. Understanding the importance of the oceanic background state, local and remote drivers and the ocean productivity response from past events are critical steps toward improving predictions of future marine heatwaves and their impacts.

scholarly journals Wind-Forced Delayed Action Oscillator in Tropical Oceans with Satellite Multi-Sensor Observations

2020 ◽  
Vol 12 (6) ◽  
pp. 933
Author(s):  
Jiayi Pan ◽  
Adam T. Devlin ◽  
Hui Lin
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Surface Wind ◽  
European Space Agency ◽  
Sea Surface ◽  
Height Anomaly ◽  
Spatial And Temporal Variability ◽  
Enso Events ◽  
Delayed Action

This study investigates correlations among interannual variabilities of sea surface wind, sea surface temperature (SST), and sea surface height anomaly (SSHA) in the tropical region from latitude 15°S to 15°N. Sea surface winds were derived from the European Space Agency (ESA)’s European Remote-Sensing Satellite (ERS)-1/2 scatterometer and the National Aeronautics and Space Administration (NASA)’s QuickSCAT observations; SST data were obtained from the National Oceanic and Atmospheric Administration (NOAA)’s Advanced Very-High-Resolution Radiometer (AVHRR) missions; and the SSHA data were acquired from the NASA TOPEX/Poseidon and Jason-1 altimeter measurements. All these datasets were resampled into 1° × 1° grids between 15°S and 15°N. The annual cycles were removed from all datasets and an empirical orthogonal function (EOF) analysis was applied to extract the major modes of spatial and temporal variability. The first EOF modes of the wind, SST, and SSHA revealed the interannual variability of each data source, reflecting spatio-temporal signatures related to El Nino Southern Oscillation (ENSO) events. The correlation results suggested that, during the strong El Nino period of 1997–1998, the wind variability led the variability of SST. A wind-forced delayed action oscillator (WDAO) system was proposed and analyzed using the ENSO modes of wind and SST data, covering the period from October 1995 to June 2002. The results show that the delayed SST mechanism is the strongest forcing factor in the WDAO system, and the wind forcing is the second strongest forcing factor. The correlations among SST change rate, the wind, and delayed/un-delayed SST also confirm the WDAO analysis’ results.

scholarly journals Interannual Variability and Trends in Sea Surface Temperature, Lower and Middle Atmosphere Temperature at Different Latitudes for 1980–2019

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 454
Author(s):  
Andrew R. Jakovlev ◽  
Sergei P. Smyshlyaev ◽  
Vener Y. Galin
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
Southern Oscillation ◽  
Lower Troposphere ◽  
Reanalysis Data ◽  
Sea Surface ◽  
The Arctic ◽  
The Impact

The influence of sea-surface temperature (SST) on the lower troposphere and lower stratosphere temperature in the tropical, middle, and polar latitudes is studied for 1980–2019 based on the MERRA2, ERA5, and Met Office reanalysis data, and numerical modeling with a chemistry-climate model (CCM) of the lower and middle atmosphere. The variability of SST is analyzed according to Met Office and ERA5 data, while the variability of atmospheric temperature is investigated according to MERRA2 and ERA5 data. Analysis of sea surface temperature trends based on reanalysis data revealed that a significant positive SST trend of about 0.1 degrees per decade is observed over the globe. In the middle latitudes of the Northern Hemisphere, the trend (about 0.2 degrees per decade) is 2 times higher than the global average, and 5 times higher than in the Southern Hemisphere (about 0.04 degrees per decade). At polar latitudes, opposite SST trends are observed in the Arctic (positive) and Antarctic (negative). The impact of the El Niño Southern Oscillation phenomenon on the temperature of the lower and middle atmosphere in the middle and polar latitudes of the Northern and Southern Hemispheres is discussed. To assess the relative influence of SST, CO2, and other greenhouse gases’ variability on the temperature of the lower troposphere and lower stratosphere, numerical calculations with a CCM were performed for several scenarios of accounting for the SST and carbon dioxide variability. The results of numerical experiments with a CCM demonstrated that the influence of SST prevails in the troposphere, while for the stratosphere, an increase in the CO2 content plays the most important role.

scholarly journals On the Use of Doppler Shift for Sea Surface Wind Retrieval From SAR

2012 ◽  
Vol 50 (7) ◽  
pp. 2901-2909 ◽  
Author(s):  
Alexis A. Mouche ◽  
Fabrice Collard ◽  
Bertrand Chapron ◽  
Knut-Frode Dagestad ◽  
Gilles Guitton ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Surface Wind ◽  
Sea Surface ◽  
Wind Retrieval ◽  
Sea Surface Wind ◽  
Sea Surface Wind Retrieval

scholarly journals SST Anomalies in the Mozambique Channel Using Remote Sensing and Numerical Modeling Data

2019 ◽  
Vol 11 (9) ◽  
pp. 1112
Author(s):  
Guoqing Han ◽  
Changming Dong ◽  
Junde Li ◽  
Jingsong Yang ◽  
Qingyue Wang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mixed Layer Depth ◽  
Surface Wind ◽  
Radiant Heat ◽  
Heat Fluxes ◽  
Sea Surface ◽  
Surface Mixed Layer ◽  
Mozambique Channel ◽  
Sea Surface Wind ◽  
Sst Anomalies

Based on both satellite remote sensing sea surface temperature (SST) data and numerical model results, SST warming differences in the Mozambique Channel (MC) west of the Madagascar Island (MI) were found with respect to the SST east of the MI along the same latitude. The mean SST west of the MI is up to about 3.0 °C warmer than that east of the MI. The SST differences exist all year round and the maximum value appears in October. The area of the highest SST is located in the northern part of the MC. Potential factors causing the SST anomalies could be sea surface wind, heat flux and oceanic flow advection. The presence of the MI results in weakening wind in the MC and in turn causes weakening of the mixing in the upper oceans, thus the surface mixed layer depth becomes shallower. There is more precipitation on the east of the MI than that inside the MC because of the orographic effects. Different precipitation patterns and types of clouds result in different solar radiant heat fluxes across both sides of the MI. Warm water advected from the equatorial area also contribute to the SST warm anomalies.

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