Selasa, 10 Februari 2009

Gelombang dan Optik

Merupakan Kumpulan Materi Kuliah Gelombang dan Optik

Gelombang Optik

4 SKS

Dosen:

1. Dr. Andhy Setiawan, S.Pd., M.Si.

2. Lina Aviyanti, S.Pd., M.Si.

Sumber Buku:

Drs. Taufik Ramlan Ramalis, M.Si.


Dinamika Gelombang

A. Pendahuluan

B. Gelombang Dalam Medium Elastis

1. Gelombang Pada Pegas

2. Gelombang Pada Tali

3. Gelombang Pada Batang Logam

4. Gelombang Pada Zat Cair

C. Gelombang Bunyi di Udara

1. Cepat Rambat Gelombang Bunyi

2. Energi dan Intensitas Gelombang Bunyi

D. Gelombang Permukaan Air

1. Penerapan Syarat Batas

2. Hubungan Dispersi Gelombang Permukaan Air

3. Gelombang Gravitasi dan Gelombang Riak

E. Soal Latihan




Wave Dynamics


Manfred Ern, Peter Preusse, Sebastian Schröder

Atmospheric waves are observed as wave-like variations of the atmosphere with respect to the mean atmospheric background state. Waves are found in meteorological parameters like e.g. atmospheric temperature, pressure, wind speed and wind direction. They cover a large range of scales from planetary scale (horizontal wavelengths of about 10000km or even more) over mesoscale (100-1000km) to small-scale with horizontal wavelengths of only several km (one example for meso- and small-scale waves are gravity waves).

Atmospheric waves are very important for many processes in both atmospheric chemistry and dynamics.

Waves are involved in the formation of clouds. For example temperature variations due to waves can modulate the shape of cloud bands. Very important is the formation of polar stratospheric clouds (PSCs) triggered by mountain waves at high latitudes since the main process responsible for ozone depletion in the Arctic winter are heterogeneous chemical reactions in those PSCs.

Atmospheric waves are also a main coupling process in the atmosphere. Wave sources are mostly located in the troposphere and tropopause region. Waves are excited, for example, by convection, weather systems, geostrophic adjustment, and orographic forcing. By conveying momentum from lower to high altitudes wave dynamics links the different altitude regimes in Earth's atmosphere (troposphere, stratosphere, mesosphere, thermosphere). Momentum is deposited where the waves break. This mechanism is responsible for many features of the global circulation patterns: breaking waves are the main driver of the atmospheric residual circulation (Brewer-Dobson circulation); they govern the vertical structure of the global zonal wind systems (for example, the quasi-biennial oscillation (QBO) of the zonal wind in the tropics or the reversal of the zonal wind jets in the mesosphere); and wave breaking also plays an important role for the vertical temperature structure of the atmosphere (for example, the cold summer mesopause, where the lowest temperatures in the Earth's atmosphere are observed, in spite that the sun never sets).

The interaction of waves with the mean flow is quantitatively not well understood. In particular, the forcing of waves by convection and the parameterization of gravity waves are major sources of uncertainty in atmospheric modeling and climate prediction.

The wave types that are most important for atmospheric dynamics are:

Research at ICG-1 focuses mainly on:

  1. Gravity Waves

  2. Equatorial Waves

The effects of wave propagation and wave breaking are shown in in the following diagram for the example of gravity waves.

Di Susun Oleh:

Arip Nurahman
&
Kawan-kawan

Pendidikan Fisika, FPMIPA. Universitas Pendidikan Indonesia
and
Follower Open Course Ware at MIT-Harvard University, Cambridge. USA

Tidak ada komentar: