 weather.gov |
 |
 |
 |
 |
Home | News | Organization |  |
|
|
Station List Observations Mobile Access Obs via Google Maps Classic Maps Recent Historical DART® Oil & Gas ADCP Obs Search Ship Obs Report Gliders APEX TAO DODS HF Radar OSMC Dial-A-Buoy RSS Feeds  Obs Web Widget Email Access Station Status NDBC Maintenance NDBC Platforms Partner Platforms Program Info  NDBC on Facebook About NDBC Met/Ocean Moored Buoy C-MAN TAO DART® VOS CSP IOOS® Program IOOS® DAC Publications NDBC DQC Handbook Hurricane Data Plots Mariners Weather Log Observing Handbook No. 1 Science Education NDBC Director FAQ Media Inquiries Contact Us Visitor Information Links  |
 |
See recent photos from NDBC weather buoy 42039 in the Gulf of Mexico. See recent photos from the following TAO stations: 2N 95W, 0 95W, 2S 95W, 8N 110W, 5N 110W, 2N 110W, 0 110W NDBC Science Education PagesDoes air pressure vary with respect to air temperature?
Lets examine some air pressure data from the Gulf of Mexico. The following data was measured at Station 42001 in the central Gulf. In January, when air temperatures average 20.7 C (69F), the average pressure is 1019.1 mb. In June, when the average air temperature is 27.6C (81.7F), the average air pressure is 1015.0 mb. As you can see, air pressure does vary according to temperature. Cold air is more dense than warm air, i.e., it weighs more. As a result, it tends to sink. Warm air, on the other hand, is less dense. Therefore, it weighs less and tends to rise. Meteorologists say that warm air is buoyant.
Look at the above image. Imagine that the little circles in the beakers are air molecules. The image on the left shows the beaker of molecules when the air is cool. However, the image on the right shows the same beaker when it is warmed. As you can see, some of the molecules leave the beaker when heat is applied. The same situation occurs when the atmosphere is heated: some of the air molecules "leave" or float away, thus causing decreased air pressure. |
