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Innovate with Science, Serve with Heart (Hong Kong Observatory)

The Hong Kong Observatory keeps pace with the times to provide people-oriented quality services in meteorology and related fields, and to enhance the society's capability in natural disaster prevention and response through science, innovation and partnership.MULTI-CHANNEL INFORMATION DISSEMINATION TO RAISE PUBLIC AWARENESS ON DISASTER PREVENTION With increasing demand for weather-related information, the Observatory's online information service recorded more than 146 billion page views in 2018. The total number of downloads of the "My Observatory" mobile application exceeded 7.8 million. The Observatory also provided timely weather reminders and warnings through the social media platforms such as Facebook and Instagram. Several days before Super Typhoon Mangkhut hit Hong Kong, the Observatory began to issue daily Facebook posts to alert the public to take preventive measures. Frequent updates on wind strengths and storm surges were provided on the day when the typhoon hit Hong Kong, enhancing public awareness and resilience to natural disasters.INNOVATIVE SERVICES WITH INTERDISCIPLINARY COLLABORATIONS In line with the "paperless aircraft cabin" measure, the Observatory partnered with the aviation industry to launch the "MyFlightWx" electronic flight bag mobile application, the world’s first-of-its-kind developed by an official meteorological authority. On the subject of big data analysis and smart city development, the Observatory developed “microclimate monitoring stations” to collect high-density meteorological data for studying urban climate and supporting personalised weather information services. The "SWIRLS" nowcasting system developed by the Observatory supports rainstorms forecasting and warning services operations. Such forecasts are also provided to other government departments to mitigate landslips, enhance ecology and preserve freshwater. The system has also won various information technology awards. The Observatory was designated by the World Meteorological Organisation as a Regional Specialised Meteorological Centre (RSMC) for Nowcasting in 2018. It is a recognition of the significant international role that the Observatory plays in applying nowcasting techniques.INCORPORATING OPINIONS, INNOVATING CONTINUOUSLY, KEEPING PACE WITH THE TIMES The Observatory has established sharing platforms such as Yammer and WhatsApp Group to enhance interactions and collaborations among colleagues. There are also very diverse modes of external communications, including regular liaison group meetings with the maritime, aviation and media communities to understand the needs of users and the effectiveness of service applications. The "Strategic Advisory Committee", which is composed of scholars and experts from different sectors, examines the Observatory's services from various perspectives. Members of the "Community Weather Observing Scheme" and "Friends of the Observatory" are also invited to participate in testing new products and services. Through incorporating opinions from different stakeholders, long-term development strategies and objectives are formulated so that the Observatory can continue to innovate and keep pace with the times. (The video is broadcasted in Cantonese) (For more details, please visit Sevice Excellence Website)

Why are spectacles or camera lens so difficult to clean?

Why are spectacles or camera lens so difficult to clean? It seems to get worse when an ordinary cloth is used, which tends to produce mult-coloured marks.When an ordinary cloth is used to rub grease off the glass, the grease becomes an additional coating with varying thickness. This produces multi-coloured reflections, because light is made up of different colours (i.e. different wavelengths). The 'rainbow' effect is similar to what we see when looking at a wet road with an oil film on it.What is the proper way to clean the glasses?Use the special cloth that comes with spectacles or camera lens. It is made of thin fibres that are good at picking up grease, rather than spreading it.A wet method involves washing with soap or a little liquid detergent. Then rinse, and leave it to dry or dry with a clean linen. You can also go to an optical shop for such a service. (For more details, please click here to read the article written by Hong Kong Observatory) (Information provided by Hong Kong Observatory)

Why does wet sand look darker than dry sand?

Water is colourless and transparent, but why is wet sand darker than dry sand? Is it because water absorbs more light than air? Not entirely correct. All else being equal, wet sand looks darker because not much light is coming out. For sand grains in water, the change in the direction of light is smaller than in air. On average, it takes a much longer path for light in wet sand to come out (left) than in dry sand (right). The longer the path, the greater the chance that light gets absorbed. Hence, wet sand looks darker than dry sand. (For more details, please click here to read the article written by Hong Kong Observatory) (Information provided by Hong Kong Observatory)

Myths about protection against UV radiation

Although most people are aware of the need to take protective actions against sunburn, there are some common misconceptions about UV radiation and the ways of protection: Myth 1: Darker sunglasses offer more protection from UV radiationThe most important thing to look for in sunglasses is how much UV radiation they filter out.  It should be noted that there is no relationship between the colour of sunglasses and their UV filtering action.  When one wears sunglasses the pupil widens as there is less light reaching the eye.  If the sunglasses have poor UV protection, the amount of UV radiation getting into the eyes may even be greater than not wearing sunglasses at all.  For adequate protection, one should wear sunglasses that are able to block at least 98% of the UV radiation. Myth 2: You can't get sunburn on a cloudy dayYou do get sunburned on a cloudy day, that is of course, if you are engaged in outdoor activities but not properly protected against ultraviolet radiation (UV).  It is true that on a cloudy day, you won't get as much exposed to UV from direct sunlight as when it is a clear sunny day.  However, sunlight, including UV, are scattered by gases in the atmosphere, as well as by clouds, dust, haze and even fog. Up to 80% of solar UV radiation can penetrate thin cloud cover.  There are also occasions when broken clouds enhance UV radiation by reflection from their sides.Therefore, in case of doubt, it is advisable to check the latest UV index through radio, television, the Observatory's website and Dial-a-Weather system (1878200). Myth 3: You can't get sunburn while in the waterWater offers only minimal protection from UV radiation.  At half a metre under water, the UV radiation level is still 40% as intense as at the surface.  Also, the part of body above water is additionally exposed to ultraviolet rays reflected from the water surface. Myth 4: Sunscreen lotion protects me so I can sunbathe much longerSunscreen lotion should not be used to increase sun exposure time but to increase protection during unavoidable exposure. The protection provided by sunscreen lotion depends critically on their correct application.  For more about sunscreen lotion and sunburn protection, please check out "Sunburn and SPF". Myth 5: If you take regular breaks during sunbathing you won't get sunburnUV radiation exposure is cumulative.  The total health damage you get will be the sum of the effect of individual exposure.  Therefore, to protect yourself the objective is to reduce exposure to UV radiation as far as practicable. This could decrease the chance of skin cancer. Myth 6: If you don't feel the hot rays of the sun you won't get sunburnSunburn is caused by UV radiation which cannot be felt.  The heating effect is caused by the sun's infrared radiation and not by UV radiation.  Therefore, even if you don't feel the warmth, you may also get sunburn. Human exposure to UV radiation may result in acute and chronic health effects on the skin, eye and immune system. So please be aware to take protective actions against sunburn. (For more details, please click here to read the article written by Hong Kong Observatory) (Information provided by Hong Kong Observatory)

The physics of gurgling

What causes the bubbling sound when drinking from a bottle?When drinking from an inverted bottle, a vacuum starts to appear at the top as water flows out of the bottle. Because of the air pressure outside, air forces its way through the neck of the bottle and bubbles up. This is followed by more water escaping, and more air bubbles moving up. So on and so forth. The glug-glug is caused by these two alternating processes.Does water flow faster at the beginning or near the end?Water flows faster at the beginning because this is when the pressure is highest.Does water flow faster when the bottle is in an inverted position (i.e. upside down) or when it is tilted?(The experiment can be carried out quite easily in a kitchen or bathroom. The result accords with our experience.)Water flows faster when the bottle is tilted, i.e. at an angle. This avoids the gurgling, i.e. air bubbles coming up through the liquid, which obstructs the passage of water.What is the fastest way to pour out water?The fastest way is to pour water at an angle and with a swirl. To create a swirl, move the bottle in small circles before pouring. This way, water moves to the side of the bottle and no gurgling occurs, allowing air to freely enter through the centre (For more details, please click here to read the article written by Hong Kong Observatory) (Information provided by Hong Kong Observatory)

Experimental Officer

Mr Ken Wong, an Experimental Officer of the Hong Kong Observatory, talks about his career as an Experimental Officer.An Experimental Officer is mainly deployed on weather forecasting, data processing, radioactivity, hydrometeorological, physical oceanographic, seismological, and time services duties.An Experimental Officer may be required to attend a professional training course in meteorology during his/her probationary period. He/She may be required to work outdoors, shifts or outside normal office hours. Organisation chartOfficial recruitment page