{"id":591,"date":"2006-10-16T05:00:00","date_gmt":"2006-10-15T21:00:00","guid":{"rendered":"http:\/\/www.weather.org.hk\/blog\/?p=591"},"modified":"2010-11-11T18:23:33","modified_gmt":"2010-11-11T10:23:33","slug":"%e7%82%ba%e7%94%9a%e9%ba%bc%e6%9c%83%e4%b8%8b%e9%9b%a8%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.weather.org.hk\/news\/%e7%82%ba%e7%94%9a%e9%ba%bc%e6%9c%83%e4%b8%8b%e9%9b%a8%ef%bc%9f\/","title":{"rendered":"\u70ba\u751a\u9ebc\u6703\u4e0b\u96e8\uff1f"},"content":{"rendered":"

\t\t\t\t\t\t\t\t\t\u9019\u500b\u770b\u4f3c\u7c21\u55ae\u7684\u554f\u984c\uff0c\u5176\u5be6\u80cc\u5f8c\u6709\u5f88\u591a\u7406\u8ad6\u3002<\/p>\n\n

\u4e0b\u96e8\u7684\u7b2c\u4e00\u500b\u689d\u4ef6\u662f\u8981\u6709\u6c34\u3002\u7a7a\u6c23\u4e2d\u7684\u6c34\u6c7d\uff08water vapour\uff09\u51b7\u537b\u51dd\u7d50\u5c31\u6703\u8b8a\u6210\u6c34\u3002\u5f9e\u96ea\u6ac3\u53d6\u51fa\u6c7d\u6c34\u4e26\u653e\u7f6e\u5728\u5ba4\u6eab\u4e0b\uff0c\u5e7e\u5206\u9418\u5f8c\u6c7d\u6c34\u8868\u9762\u4fbf\u51fa\u73fe\u6c34\u9ede\uff0c\u9019\u5c31\u662f\u6c34\u6c7d\u51b7\u537b\u51dd\u7d50\u7684\u7d50\u679c\u3002<\/p>\n

\u90a3\u9ebc\u5927\u81ea\u7136\u5982\u4f55\u63d0\u4f9b\u51b7\u537b\u7684\u689d\u4ef6\uff1f\u7b54\u6848\u662f\u7a7a\u6c23\u4e0a\u5347\u3002\u7a7a\u6c23\u5728\u5730\u9762\u7684\u5bc6\u5ea6\u6700\u9ad8\uff0c\u6c23\u58d3\u6700\u5927\u3002\u9ad8\u5ea6\u589e\u52a0\u6642\uff0c\u7a7a\u6c23\u7684\u5bc6\u5ea6\u6e1b\u5c0f\uff0c\u6c23\u58d3\u964d\u4f4e\u3002\u5047\u8a2d\u4e00\u5718\u7a7a\u6c23\uff08\u6216\u7a31\u6c23\u584a air parcel\uff09\u4e0a\u5347\uff0c\u7531\u65bc\u5468\u570d\u7684\u6c23\u58d3\u964d\u4f4e\uff0c\u6c23\u584a\u7684\u9ad4\u7a4d\u589e\u5927\uff0c\u6eab\u5ea6\u56e0\u6b64\u4e0b\u964d\u3002\u9019\u500b\u539f\u7406\u5c31\u50cf\u628a\u6c23\u7403\u653e\u6c23\uff0c\u5439\u51fa\u4f86\u7684\u7a7a\u6c23\u662f\u6dbc\u7684\u3002\u7531\u65bc\u9019\u500b\u73fe\u8c61\u4e26\u4e0d\u6d89\u53ca\u71b1\u91cf\u4ea4\u63db\uff0c\u7a31\u70ba\u7d55\u71b1\u51b7\u537b\uff08adiabatic cooling\uff09\u3002<\/p>\n

\u7a7a\u6c23\u4e0a\u5347\u63d0\u4f9b\u51b7\u537b\u7684\u689d\u4ef6\uff0c\u90a3\u9ebc\u7a7a\u6c23\u5982\u4f55\u624d\u80fd\u4e0a\u5347\uff1f\u6709\u5e7e\u500b\u60c5\u6cc1\uff1a<\/p>\n

1. \u7a7a\u6c23\u53d7\u71b1\u81a8\u8139\uff0c\u5bc6\u5ea6\u6e1b\u5c0f\u4e0a\u5347
2. \u7a7a\u6c23\u6d41\u904e\u5c71\u7684\u8fce\u98a8\u5761\uff0c\u53d7\u5730\u5f62\u5f71\u97ff\u4e0a\u5347
3. \u7a7a\u6c23\u5f9e\u56db\u5468\u6d41\u5411\u4e2d\u5fc3\uff0c\u7a7a\u6c23\u5728\u4e2d\u5fc3\u4e0a\u5347
4. \u9ad8\u7a7a\u7a7a\u6c23\u6d41\u8d70\uff0c\u5730\u9762\u7a7a\u6c23\u4e0a\u5347\u88dc\u5145
5. \u4e0d\u540c\u6027\u8cea\u7684\u7a7a\u6c23\uff08\u6216\u6c23\u5718 air mass\uff09\u76f8\u9047\uff0c\u8f03\u6696\u7684\u7a7a\u6c23\u4e0a\u5347<\/p>\n

\u6709\u4e86\u6c34\u6c7d\uff0c\u6709\u4e86\u4e0a\u5347\u7684\u689d\u4ef6\uff0c\u6c34\u6c7d\u4e0a\u5347\u6642\u4fbf\u51dd\u7d50\u6210\u4e0d\u540c\u7684\u96f2\uff0c\u4f46\u4e0d\u662f\u6240\u6709\u96f2\u90fd\u6703\u4e0b\u96e8\u3002\u751a\u9ebc\u96f2\u4e0b\u751a\u9ebc\u96e8\uff0c\u4e0b\u6b21\u518d\u8ac7\u3002<\/p>\n

<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"

這個看似簡單的問題，其實背後有很多理論。 下雨的第一個條件是要有水。空氣中的水汽（water vapour）冷卻凝結就會變成水。從雪櫃取出汽水並放置在室溫下，幾分鐘後汽水表面便出現水點，這就是水汽冷卻凝結的結果。 那麼大自然如何提供冷卻的條件？答案是空氣上升。空氣在地面的密度最高，氣壓最大。高度增加時，空氣的密度減小，氣壓降低。假設一團空氣（或稱氣塊 air parcel）上升，由於周圍的氣壓降低，氣塊的體積增大，溫度因此下降。這個原理就像把氣球放氣，吹出來的空氣是涼的。由於這個現象並不涉及熱量交換，稱為絕熱冷卻（adiabatic cooling）。 空氣上升提供冷卻的條件，那麼空氣如何才能上升？有幾個情況： 1. 空氣受熱膨脹，密度減小上升2. 空氣流過山的迎風坡，受地形影響上升3. 空氣從四周流向中心，空氣在中心上升4. 高空空氣流走，地面空氣上升補充5. 不同性質的空氣（或氣團 air mass）相遇，較暖的空氣上升 有了水汽，有了上升的條件，水汽上升時便凝結成不同的雲，但不是所有雲都會下雨。甚麼雲下甚麼雨，下次再談。<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[4],"tags":[],"class_list":["post-591","post","type-post","status-publish","format-standard","hentry","category-4"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/posts\/591","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/comments?post=591"}],"version-history":[{"count":1,"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/posts\/591\/revisions"}],"predecessor-version":[{"id":728,"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/posts\/591\/revisions\/728"}],"wp:attachment":[{"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/media?parent=591"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/categories?post=591"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.weather.org.hk\/news\/wp-json\/wp\/v2\/tags?post=591"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}