scholarly journals Kajian Kondisi Atmosfer dan Rekonstruksi Hujan Pada Kejadian Banjir di Lamandau Menggunakan Radar Cuaca Doppler C-Band

Jurnal Fisika ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 50-61
Author(s):  
Deffi Putri
Keyword(s):  
Sea Level ◽  
Moisture Transport ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Level Pressure

Gangguan cuaca merupakan kondisi dinamika udara yang secara cepat akan mengubah kondisi cuaca yang berbeda dari sebelumnya. Gangguan cuaca yang menyebabkan terjadinya hujan dapat berpotensi menimbulkan bencana hidrometeorologi yang mengakibatkan berbagai kerugian. Hujan yang terjadi di Kabupaten Lamandau, Kalimantan Tengah pada 20 Juni 2020 telah mengakibatkan bencana banjir di sejumlah wilayah salah satunya kecamatan Lamandau. Penelitian ini bertujuan untuk mengkaji kondisi atmosfer melalui data anomali suhu permukaan laut, mean sea level pressure, streamline dan moisture transport sedangkan kajian terhadap awan hujan dan curah hujan yang terjadi di wilayah penelitian memanfaatkan data radar cuaca Doppler C-Band. Gangguan cuaca yang memicu terjadinya cuaca buruk adalah peningkatan suhu permukaan laut yang didukung oleh adanya belokan angin disekitar wilayah kejadian. Awan penyebab hujan tumbuh mulai pukul 09.00 hingga 10.30 UTC dengan reflectivity maksimum mencapai 55 – 60 dBz yang terklasifikasi sebagai awan konvektif. Rekonstruksi QPE di wilayah penelitian menunjukan bahwa hujan terjadi dalam durasi 40 menit dengan intensitas puncak sebesar 55.2 mm/jam pukul 10.00 UTC.

scholarly journals Tropical cyclone simulations over Bangladesh at convection permitting 4.4 km & 1.5 km resolution

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hamish Steptoe ◽  
Nicholas Henry Savage ◽  
Saeed Sadri ◽  
Kate Salmon ◽  
Zubair Maalick ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Sea Level ◽  
Tropical Cyclones ◽  
Weather Forecasting ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Level Pressure ◽  
Medium Range ◽  
Gust Speed

AbstractHigh resolution simulations at 4.4 km and 1.5 km resolution have been performed for 12 historical tropical cyclones impacting Bangladesh. We use the European Centre for Medium-Range Weather Forecasting 5th generation Re-Analysis (ERA5) to provide a 9-member ensemble of initial and boundary conditions for the regional configuration of the Met Office Unified Model. The simulations are compared to the original ERA5 data and the International Best Track Archive for Climate Stewardship (IBTrACS) tropical cyclone database for wind speed, gust speed and mean sea-level pressure. The 4.4 km simulations show a typical increase in peak gust speed of 41 to 118 knots relative to ERA5, and a deepening of minimum mean sea-level pressure of up to −27 hPa, relative to ERA5 and IBTrACS data. The downscaled simulations compare more favourably with IBTrACS data than the ERA5 data suggesting tropical cyclone hazards in the ERA5 deterministic output may be underestimated. The dataset is freely available from 10.5281/zenodo.3600201.

Glacial-interglacial mean sea level pressure change due to sea level, ice sheet and atmospheric mass changes

1991 ◽  
Vol 3 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Marie-Antoinette Mélières ◽  
Patricia Martinerie ◽  
Dominique Raynaud ◽  
Louis Lliboutry
Keyword(s):  
Sea Level ◽  
Ice Sheet ◽  
Pressure Change ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Level Pressure ◽  
Level Ice ◽  
Atmospheric Mass

scholarly journals Diagnosing Santa Ana Winds in Southern California with Synoptic-Scale Analysis

2013 ◽  
Vol 28 (3) ◽  
pp. 704-710 ◽  
Author(s):  
John T. Abatzoglou ◽  
Renaud Barbero ◽  
Nicholas J. Nauslar
Keyword(s):  
Sea Level ◽  
Southern California ◽  
The United States ◽  
Fire Weather ◽  
Synoptic Scale ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Santa Ana ◽  
Level Pressure ◽  
Santa Ana Winds

Abstract Santa Ana winds (SAW) are among the most notorious fire-weather conditions in the United States and are implicated in wildfire and wind hazards in Southern California. This study employs large-scale reanalysis data to diagnose SAW through synoptic-scale dynamic and thermodynamic factors using mean sea level pressure gradient and lower-tropospheric temperature advection, respectively. A two-parameter threshold model of these factors exhibits skill in identifying surface-based characteristics of SAW featuring strong offshore winds and extreme fire weather as viewed through the Fosberg fire weather index across Remote Automated Weather Stations in southwestern California. These results suggest that a strong northeastward gradient in mean sea level pressure aligned with strong cold-air advection in the lower troposphere provide a simple, yet effective, means of diagnosing SAW from synoptic-scale reanalysis. This objective method may be useful for medium- to extended-range forecasting when mesoscale model output may not be available, as well as being readily applied retrospectively to better understand connections between SAW and wildfires in Southern California.

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