scholarly journals Assessing the Tropical South Atlantic atmosphere thermodynamics under distinct Sea Surface Temperature patterns

2021 ◽  
Author(s):  
Thiago L. V. Silva ◽  
Doris Veleda ◽  
Alexandre Costa ◽  
Claudia Parise ◽  
Rita Alves ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Lower Layer ◽  
Weather Conditions ◽  
South Atlantic ◽  
Sea Surface ◽  
Eastern Coast ◽  
Atmospheric Conditions ◽  
Atmospheric Instability ◽  
Meteorological Systems

Abstract Northeast Brazil (NEB) is a susceptible region to the occurrence of extreme rainfall events. Sea surface temperature (SST) is used as an indicator for predicting intense weather events in this region. The westernmost Tropical South Atlantic region, also called Southern Atlantic Warm Pool (SAWP), is characterized by a source of heat and humidity which creates atmospheric instability for the NEB. In June 2010 the eastern coast of NEB (ENEB)was influenced by heavy rainfall, causing flash floods and landslides. On the other hand, 2012 marked the beginning of a period of droughts that affected the whole NEB area. The SAWP temperature in turn recorded anomalous values ​​of + 1ºC (-0.5ºC) in 2010 (2012), respectively, although in June 2012 intense rainfall was recorded in ENEB, even with intense negative SST anomalies. With the Coupled-Ocean-Atmosphere-Wave and Sediment Transport (COAWST) model, simulations were made to characterize 2010 and 2012 atmospheric conditions, modifying the SST input data in both situations. The goal of this work is to assess the meteorological systems that occurred in 2010 and 2012 using observational, reanalysis, and simulated data, as well as to identify changes in atmospheric instability patterns, which are under influences of different SST conditions. We performed four cases, including: a) SST measured in 2010 with 2010 atmospheric conditions; b) SST measured in 2012 with weather conditions of 2010; c) SST measured in 2012 with 2012 weather conditions; d) measured in2010 with atmospheric conditions from 2012. The results showed that SAWP temperature significantly influenced the instability of meteorological systems. The impacts were more significant in the lower layer of the atmosphere, especially in the variables that lead to low-level instabilities. Also, it was observed that warmer atmospheric conditions favor the ocean environment to remain warmer, maintaining the unstable conditions over SAWP.

scholarly journals Sea surface temperature variations in the south-eastern BalticSea in 1960–2015

Baltica ◽  
2018 ◽  
Vol 30 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Viktorija Rukšėnienė ◽  
Inga Dailidienė ◽  
Loreta Kelpšaitė-Rimkienė ◽  
Tarmo Soomere
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Air Temperature ◽  
Weather Conditions ◽  
Sea Surface ◽  
South Eastern ◽  
Air Temperatures ◽  
Joint Application ◽  
Open Sea ◽  
And Cluster Analysis

This study focuses on time scales and spatial variations of interrelations between average weather conditions and sea surface temperature (SST), and long-term changes in the SST in south-eastern Baltic Sea. The analysis relies on SST samples measured in situ four times a year in up to 17 open sea monitoring stations in Lithuanian waters in 1960–2015. A joint application of non-metric multi-dimensional scaling and cluster analysis reveals four distinct SST regimes and associated sub-regions in the study area. The increase in SST has occurred during both winter and summer seasons in 1960–2015 whereas the switch from relatively warm summer to colder autumn temperatures has been shifted by 4–6 weeks over this time in all sub-regions. The annual average air temperature and SST have increased by 0.03°C yr–1 and 0.02°C yr–1, respectively, from 1960 till 2015. These data are compared with air temperatures measured in coastal meteorological stations and averaged over time intervals from 1 to 9 weeks. Statistically significant positive correlation exists between the SST and the average air temperature. This correlation is strongest for the averaging interval of 35 days.

scholarly journals SST Indexes in the Tropical South Atlantic for Forecasting Rainy Seasons in Northeast Brazil

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 335 ◽  
Author(s):  
Gbèkpo Aubains Hounsou-Gbo ◽  
Jacques Servain ◽  
Moacyr Araujo ◽  
Guy Caniaux ◽  
Bernard Bourlès ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Positive Relationship ◽  
South Atlantic ◽  
Sea Surface ◽  
Boreal Summer ◽  
Northeast Brazil ◽  
Tropical Atlantic ◽  
Rainfall Anomalies ◽  
Atlantic Niño

May-to-July and February-to-April represent peak rainy seasons in two sub-regions of Northeast Brazil (NEB): Eastern NEB and Northern NEB respectively. In this paper, we identify key oceanic indexes in the tropical South Atlantic for driving these two rainy seasons. In Eastern NEB, the May-to-July rainfall anomalies present a positive relationship with the previous boreal winter sea surface temperature anomalies (SSTA) in the southeast tropical Atlantic (20°–10° S; 10° W–5° E). This positive relationship, which spread westward along the southern branch of the South Equatorial Current, is associated with northwesterly surface wind anomalies. A warmer sea surface temperature in the southwestern Atlantic warm pool increases the moisture flux convergence, as well as its ascending motion and, hence, the rainfall along the adjacent coastal region. For the Northern NEB, another positive relationship is observed between the February-to-April rainfall anomalies and the SSTA of the previous boreal summer in the Atlantic Niño region (3° S–3° N; 20° W–0°). The negative remote relationship noticeable between the Northern NEB rainfall and the concomitant Pacific Niño/Niña follows cold/warm events occurring during the previous boreal summer in the eastern equatorial Atlantic. The southeastern tropical Atlantic and Atlantic Niño SSTA indexes may, then, be useful to predict seasonal rainfall over the Eastern and Northern NEB, respectively, for about a 6 month leading period. The ability of both southeastern tropical Atlantic and Atlantic Niño SSTA indexes to forecast the Eastern and Northern NEB rainfall, with about a 6 month lead time, is improved when these indexes are respectively combined with the Niño3 (5° S–5° N; 150°–90° W) and the northeast subtropical Atlantic (20° N–35° N, 45° W–20° W), mainly from the 1970’s climate shift.

South Atlantic sea surface temperature anomalies and air-sea interactions: stochastic models

1994 ◽  
Vol 12 (9) ◽  
pp. 903-909
Author(s):  
S. G. Dobrovolski
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Climate Models ◽  
South Atlantic ◽  
Entropy Method ◽  
Sea Surface ◽  
Temperature Anomalies ◽  
Leading Role ◽  
Sea Surface Temperature Anomalies ◽  
Dynamic Stochastic

Abstract. Data on the South Atlantic monthly sea surface temperature anomalies (SSTA) are analysed using the maximum-entropy method. It is shown that the Markov first-order process can describe, to a first approximation, SSTA series. The region of maximum SSTA values coincides with the zone of maximum residual white noise values (sub-Antarctic hydrological front). The theory of dynamic-stochastic climate models is applied to estimate the variability of South Atlantic SSTA and air-sea interactions. The Adem model is used as a deterministic block of the dynamic-stochastic model. Experiments show satisfactorily the SSTA intensification in the sub-Antarctic front zone, with appropriate standard deviations, and demonstrate the leading role of the abnormal drift currents in these processes.

scholarly journals ANALISIS HUJAN ES DI KOTA LUBUKLINGGAU DENGAN MEMANFAATKAN DATA CITRA SATELIT HIMAWARI-8 DAN RADIOSONDE

2019 ◽  
Vol 3 ◽  
pp. 130
Author(s):  
Heriyanto Wicaksono ◽  
Fazrul Rafsanjani Sadarang ◽  
Ahmad Fadlan
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Satellite Imagery ◽  
Air Temperature ◽  
Air Pressure ◽  
Peak Temperature ◽  
Sea Surface ◽  
Atmospheric Conditions ◽  
Air Humidity ◽  
Sumatra Island

<p class="AbstractEnglish"><strong>Abstract:</strong> The phenomenon of hail again hit Indonesia. The hail occurred in Lubuklinggau City, South Sumatra on October 15 2018, at around 16.20 WIB. Based on AWS Tugu Mulyo observation data, the rainfall on 15 October 2018 was recorded at 26.8 mm which included the medium rainfall category according to BMKG. This research aims to analyze the state of the atmosphere, satellite imagery, sea surface temperature anomalies, and air lability during the hailstorm in Lubuklinggau. Analysis of atmospheric conditions using air temperature data (T), air humidity (RH), and air pressure (P) results of observations of the surface before, during, and after the event. The Himawari satellite image with a resolution of 0.02º x 0.02º is processed with the SATAID application and is used to view the cloud growth phase. Air lability was analyzed by processing radiosonde data from Weather Wyoming Web using the RAOB application 5.7. The results of the analysis show that in the event of hail, the surface air temperature has decreased significantly, the surface air humidity has a significant increase, and the lowest surface air pressure is lower than the day before the hail. The air lability index shows that before the occurrence of hail, atmospheric conditions are unstable causing massive growth of convective clouds. The anomaly of sea surface temperature around Sumatra Island is quite warm, which is 0.5ºC. 1,8ºC which results in the possibility of cloud formation around Sumatra Island getting bigger. Based on satellite imagery, the peak temperature of the cloud at 16.00 WIB is -10.3ºC and at 16.10 WIB the cloud peak temperature reaches -67.8ºC. The significant decrease in cloud peak temperature in the 10-minute period indicates the presence of cloud growth due to a very strong updraft so that the peak temperature of the cloud becomes very cold. The temperature of the cloud peak reaching -67.8ºC shows that there is a convective cloud that is strong enough when there is hail in Lubuklinggau.</p><p class="KeywordsEngish"><strong>Abstrak:</strong> Fenomena hujan es kembali melanda Indonesia. Hujan es tersebut terjadi di Kota Lubuklinggau, Sumatra Selatan pada tanggal 15 Oktober 2018 sekitar pukul 16.20 WIB. Berdasarkan data pengamatan AWS Tugu Mulyo, curah hujan pada tanggal 15 Oktober 2018 tercatat sebesar 26,8 mm yang termasuk kategori hujan sedang menurut BMKG. Penelitian kali ini bertujuan untuk menganalisis keadaan atmosfer, citra satelit, anomali suhu permukaan laut, dan labilitas udara pada saat terjadi hujan es di Lubuklinggau<em>. </em>Analisis keadaan atmosfer menggunakan data suhu udara (T), kelembapan udara (RH), dan tekanan udara (P) hasil pengamatan permukaan sebelum, saat, dan sesudah kejadian. Citra satelit Himawari dengan resolusi 0.02º x 0.02º diolah dengan aplikasi SATAID dan digunakan untuk melihat fase pertumbuhan awan. Labilitas udara dianalisis dengan mengolah data radiosonde dari <em>Weather Wyoming Web</em> menggunakan aplikasi RAOB 5.7. Hasil analisis menunjukkan bahwa pada saat terjadi hujan es, suhu udara permukaan mengalami penurunan yang signifikan, kelembapan udara permukaan mengalami kenaikan yang signifikan, serta tekanan udara permukaan terendah lebih rendah daripada hari sebelum terjadinya hujan es. Indeks labilitas udara menunjukkan bahwa sebelum terjadinya hujan es, kondisi atmosfer dalam keadaan labil sehingga menyebabkan pertumbuhan awan konvektif yang masif. Anomali suhu permukaan laut di sekitar Pulau Sumatera cukup hangat, yaitu 0,5ºC s.d. 1,8ºC yang mengakibatkan peluang terbentuknya awan di sekitar Pulau Sumatera semakin besar. Berdasarkan citra satelit, suhu puncak awan pada jam 16.00 WIB sebesar -10,3ºC dan pada jam 16.10 WIB suhu puncak awan mencapai -67,8ºC. Penurunan suhu puncak awan yang signifikan dalam kurun waktu 10 menit tersebut mengindikasikan adanya pertumbuhan awan akibat <em>updraft </em>yang sangat kuat sehingga suhu puncak awan menjadi sangat dingin. Suhu puncak awan yang mencapai -67,8ºC menunjukkan bahwa terdapat awan konvektif yang cukup kuat saat teradi hujan es di Lubuklinggau.</p>

The Decadal Reduction of Southeastern Australian Autumn Rainfall since the Early 1990s: A Response to Sea Surface Temperature Warming in the Subtropical South Pacific

2020 ◽  
Vol 33 (6) ◽  
pp. 2249-2261 ◽  
Author(s):  
ZhongDa Lin ◽  
Yun Li ◽  
Yong Liu ◽  
AiXue Hu
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
General Circulation ◽  
Circulation Model ◽  
South Pacific ◽  
Sea Surface ◽  
South Pacific Convergence Zone ◽  
Eastern Coast ◽  
Sst Warming ◽  
Rainfall Reduction

AbstractRainfall in southeastern Australia (SEA) decreased substantially in the austral autumn (March–May) of the 1990s and 2000s. The observed autumn rainfall reduction has been linked to the climate change–induced poleward shift of the subtropical dry zone across SEA and natural multidecadal variations. However, the underlying physical processes responsible for the SEA drought are still not fully understood. This study highlights the role of sea surface temperature (SST) warming in the subtropical South Pacific (SSP) in the autumn rainfall reduction in SEA since the early 1990s. The warmer SSP SST enhances rainfall to the northwest in the southern South Pacific convergence zone (SPCZ); the latter triggers a divergent overturning circulation with the subsidence branch over the eastern coast of Australia. As such, the subsidence increases the surface pressure over Australia, intensifies the subtropical ridge, and reduces the rainfall in SEA. This mechanism is further confirmed by the result of a sensitivity experiment using an atmospheric general circulation model. Moreover, this study further indicates that global warming and natural multidecadal variability contribute approximately 44% and 56%, respectively, of the SST warming in the SSP since the early 1990s.

scholarly journals KAJIAN SEA SURFACE TEMPERATURE (SST), SOUTHERN OSCILLATION INDEX (SOI) DAN DIPOLE MODE PADA KEGIATAN PENERAPAN TEKNOLOGI MODIFIKASI CUACA DI PROPINSI RIAU DAN SUMATERA BARAT JULI – AGUSTUS 2009

2010 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
M Djazim Syaifullah
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Temperature Anomaly ◽  
Southern Oscillation ◽  
Sea Surface ◽  
Dipole Mode ◽  
Atmospheric Conditions ◽  
Cloud Seeding ◽  
Sea Temperature ◽  
Global Condition

Kajian suhu muka laut, SOI dan Dipole Mode Index (DMI) telah dilakukan untuk melihatpengaruh global terhadap kondisi pertumbuhan awan di daerah DAS Kotapanjang danSingkarak pada pelaksanaan Teknologi Modifikasi Cuaca (TMC) Juli – Agustus 2009.Data yang dipakai dalam penelitian ini adalah data Sea Surface Temperature (SST)yang diambil dari University Corporation for Athmospheric Research (UCAR). suhumuka laut yang dianalisis adalah daerah Nino dan daerah Sumatera bagian barat. Darihasil analisis terlihat bahwa selama kegiatan TMC nilai anomali SST untuk keempatdaerah Nino (Nino12, Nino3, Nino34 dan Nino4) adalah positif, hal ini menunjukkanbahwa selama kegiatan TMC kondisi global sudah memasuki fase ElNino meskipunbelum begitu kuat. Sedangkan di wilayah Sumatera bagian barat secara umum sejakawal bulan April 2009 nilai suhu muka laut berada di atas rerata dari normalnya (anomali positif). Dilihat dari nilai SOI secara umum berada pada kisaran normal. Hasil analisis menunjukkan bahwa selama kegiatan TMC kondisi atmosfer kedua DAS cukup kering dan sangat sulit untuk mendapatkan awan-awan yang potensial untuk disemai. Study of sea surface temperature, SOI and dipole mode indices (DMI), was held to seeglobal influence conditions of cloud growth in Kotapanjang and Singkarak catchment on the cloud seeding project from July to August 2009. The data used in this study was sea surface temperature (SST), taken from University Corporation Athmospheric research(UCAR). The sea surface temperature was analysed in Nino12 regions and Westernregion of Sumatra. Based on the analysis shows that during cloud seeding period thesea surface temperature anomaly for the four regions of Niño (Niño2 Niño3, Niño34and Niño4) is positive, while in the western of Sumatra in general since the beginning ofApril 2009 the sea temperature was higher than normal. This indicates that during cloudseeding period global condition has entered a stage of Elnino, although not so strong.The soi is generally in the range of normal. The analysis showed that during the cloudseeding period either watershed atmospheric conditions dry enough and very difficult toget a potential cloud for sowing.

Sign in / Sign up

Export Citation Format

Share Document