Jetstreams And Rossby Waves

Question 1

Properties of convection

Answer 1

• Causes vertical mixing in the atmosphere (important when looking at buoyancy and thermal eddies)
• Position of convection cells link to the ground surface heating or cooling
• Formation of quasi-stationary HP and Alpes you developed Overland (blocking highs)
• Quasi-stationary Front equals a front which is nearly stationary or moves very little since the last synoptic position
• Convection cells are affected by the Coriolis force which therefore causes horizontal mixing (advection) when air is drawn in or pushed out in different directions (enhances vertical movement)

Question 2

Global circulation

Answer 2

• HP over subtopics
• LP over equator heating up of near service air
• LP over mid latitudes
• ITCZ Forms along the equator due to the very strong bands of heat formation
• Cells are linked by poleward heat and mass transport.
• Due to the fact that we have a flow of air circulation on the global system we have a cell that with form
• Where we have A polar front we will have the formation of a polar jetstream due to the fact that we have a very intense cold and warm weather coming together
• Jet stream information between the Farrel and Hadley cell has a lot to do with the flow and direction of air or an ai parcel.
• Main jet streams are located in the tropopause and are associated with westerly winds (move from east to west)
• their paths are meandering in shape and have very distinct pathways
• change in formation of cells at different temperatures
• polar and Ferrel cells in very cold regions are very distinct cell formations ( has big effects on the jet streams near the tropopause)

Question 3

Jet-streams

Answer 3

• a narrow variable band of very strong predominantly westerly air currents in the upper levels atmosphere
• subtropical (more distinct in Jan)
• typically located at 250hPa about 7-12km above sea level
• weaker subtropical jets are generally much higher in the atmosphere at about 10-16km above sea level - they wonder laterally and form the breaks in the tropopause (transition points of the circulation cells)
• jet streams are very easily formed due to changes in pressure, temperature and density.
• Subpolar ( more distinct during July).

Question 4

Rossby waves

Answer 4

• meander waves within jet streams
• large meandering stream or air flow
• geostrophic winds located near the tropopause between pressure cells.
• wavelength can determine the size of the jet stream and how many Rossby waves may be present within the jet stream.