Cloud formation 夠竟係吸定放latent heat?
September 14, 2024
https://www.weather.gov/source/zhu/ZHU_Training_Page/clouds/cloud_development/clouds.htm Formation of cloud requires a continuation of the lifting process. It is assisted by the property of water of giving off heat when changing from vapor to liquid and solid states, the latent heats of condensation and of deposition, respectively. (If the vapor first changes to a liquid before freezing, then we also have
Clouds 雲
September 8, 2024
Ref: https://cloudatlas.wmo.int/en/clouds.html 雲係一種同水有關既大氣現象 A cloud is a hydrometeor consisting of minute particles of liquid water or ice, or of both, suspended in the atmosphere and usually not touching the ground. It may also include larger particles of liquid water or ice, as well as non-aqueous liquid or solid particles such as those present in fumes, smoke or
Types of meteors (WMO)
September 8, 2024
Ref : https://cloudatlas.wmo.int/en/general-classification-of-meteors.html (4) Four types of meteors (WMO): 水 moisture related 光 light related 電 electrical related 塵 dust and particle related Meteors present a great diversity of character. However, by considering their constituent particles or the physical processes surrounding their occurrence, meteors can be classified into four groups: hydrometeors, lithometeors, photometeors and electrometeors. 大氣現象呈現出多種多樣的特徵。但是，根據它們的組成粒子或它們發生期間的物理過程，大氣現象可以分為四組：水凝物、大氣塵粒現象、大氣光學現象 和 大氣電學現象。
meteor (流星) ; meteor (大氣現象)
September 8, 2024
Today, let us do some revision on basic. Ref : https://cloudatlas.wmo.int/en/meteorological-definition-of-a-meteor.html Meteorological definition of a meteor – according to the World Meteorological Organization (WMO) In meteorology, a phenomenon observed in the atmosphere or on the surface of the Earth is known as a meteor. 在氣象學中，在大氣層或地球表面觀測到的現象稱為大氣現象。 It may be a form of precipitation, a suspension
Manual on the Observation of Clouds and Other Meteors (WMO)
September 7, 2024
What’s Anabatic wind , Katabatic wind?
September 7, 2024
Ref Anabatic Wind | SKYbrary Aviation Safety, Katabatic Wind | SKYbrary Aviation Safety Air flow travelling up a facing slope of an orographic surface (eg. hill, mountain). A cold flow of air travelling down an orographic slope (eg. hill or mountain). Please be reminded that Katabatic wind does not heat up adiabatically! 而Anabatic
Gust front v.s Microburst?
August 24, 2024
Microburst affect smaller area (say around 2.5 miles), and short-lived (last for 5-10 minutes) Gust front affect wider area (say up to 20 miles) A microburst is a small concentrated downburst that produces an outward burst of strong winds at or near the surface. Microbursts are small — less than 4 km across — and short-lived, lasting
Typical causes of windshear and turbulence at VHHH?
August 24, 2024
Ref: https://www.hko.gov.hk/en/aviat/articles/files/booklet_4th_edition.pdf (6) Six typical causes of windshear and turbulence in Hong Kong: Terrain induced strong winds blowing across the hills over Lantau Island to the south of the airport (account for 75% of reported windshear) Sea breeze account for 15% of reported windshear Gust front (thunderstorm related) Microburst (thunderstorm related) Building induced Low level
Turbulence v.s Wind Shear
August 24, 2024
With reference to HKO publication: Windshear – sustained change (i.e lasting more than a few seconds as experienced by the aircraft) in the wind direction and/or speed, resulting in a change in the headwind or tailwind encountered by an aircraft change in lift (usually decrease lift), and cause the aircraft to go below the intended
Thunderstorm, CB?
August 23, 2024
(4) four main types of thunderstorm Single-cell small, and isolated storm Multi-cell a cluster of single-cell Squall line a line of thunderstorm Super cell very strong thunderstorm, and capable of producting tornadoes Criteria of forming thunderstorm (CB) unstable atmoshpere (warm air) moisture (larage amount) lifting mechanism (trigger action) (5) five types of lifting
到底HKO 幾耐UPDATE 一次METAR/TAF?
June 16, 2024
Ref AIP VHHH Part 1 GEN – GEN 3.5 METEOROLOGICAL SERVICES 3 Meteorological Observations and Reports 3.1 Weather Observers are on duty H24 at the AMO and I-AMO to make routine meteorological observations and to issue reports at half-hourly intervals. Reports of routine observations are issued as local routine report for dissemination at the aerodrome and as METAR for dissemination
一次搞懂香港,澳洲, 美國的Cloud base / Cloud ceiling
June 16, 2024
話說上堂老師教Cloud Base 同 Cloud Ceiling 既分別 METAR / TAF 報既cloud 都係AGL? 同埋提我地一個好重要既Concept: METAR 同 TAF 報既Cloud information 都是AGL! 到底邊到有講…都真係搵左幾耐! Hong Kong AIP HONG KONG – GEN 1.7 DIFFERENCES FROM ICAO STANDARDS, RECOMMENDED PRACTICES AND PROCEDURES “Cloud ceiling” in relation to an aerodrome means the vertical distance from the elevation of the aerodrome to the
What is global circulation?
June 9, 2024
Knowledge from this clip: Global Circullation is one of the drivers for climate and phenomenon: Jet Steam Previling wind Engergy (heat) from sun reachs the earth by radiation Earth itself is an irregularly shaped ellipsoid Energy is much more concentrated near the equator Earth is tilted, sun light cannot reach the poles at all time In
Monsoon 合集: 一次了解多個地方既季候風
June 9, 2024
Monsoon: a seasonal prevailing wind in the region. Monsoons are large-scale wind systems caused by differences in the temperatures of land and sea over the seasons. HONG KONG 香港 Also Reference:Strong Monsoon Signal｜Hong Kong Observatory(HKO)｜Details of Warnings Key knowledge from this clip: Winter in Hong Kong : North to East (North-East) monsoon Summer in Hong
What’s El Niño and La Niña? 厄爾尼諾? 拉尼娜? 聖嬰?
June 9, 2024
生字 learn from these videos: Extreme natural events Bush fire 山火 Heat waves Drought 乾旱 Floods Cyclones coral bleaching (珊瑚白化) Reference:El Niño Southern Oscillation (ENSO) Swing (shifts/ changes) between phases El Nino Neutral La Nina Notes: can divided into more phases, but in general, there are three “status”. Knowledge from this clip: Effect
What’s Tropical Cyclone (Typhoon)?
May 26, 2024
Tropical cyclones is one of the natural hazard for aviation. How do we call them depending on the region. According to WMO (World Meteorological Organization): [Ref Tropical cyclone (wmo.int)] A tropical cyclone is a rapidly rotating storm that begins over tropical oceans, and they can vary in speed, size, and intensity. Tropical cyclones are the
What’s Foehn effect 焚風效應?
May 26, 2024
Ref Foehn effect – Met Office The foehn effect describes the change from wet and cold conditions one side of a mountain, to warmer and drier conditions on the other (leeward) side. Note: Latent heating (LH) arises predominantly from the release of heat associated with the condensation of water vapor into cloud droplets in clouds
