Metr 415/715                                    Name __________________________

Quiz 2 Spring 2011

Part A.

Meteorologists Only. (114 points) Using correct color and symbol conventions, analyze the portion of following image (boxed portion only), indicating the following:

  1. Surface (50 points)
    • Surface Fronts (36 pts)
    • Surface Lows (14 pts)

      Triple point in indefensible position -10 or fraction

      Cold front not on back edge of cloud band, migrating to front edge near major trough axis -10 or fraction

      Warm front drawn at wrong angle to triple point -10 or fraction

      Occluded front not on back edge of could band, ¼ of way around cloud pattern -10 or fraction
      Surface low should be drawn connected to occlusion (-5)
      Surface low symbol should be colocated with upper low symbol (-5)


  2. Cloud Features
    • A large area of open cell cumulus (OC) (7 pts)
    • A large area of closed cell cumulus (CC) (7 pts)
  3. Middle/Upper Tropospheric (50 points)
    • Ridges and Troughs (20 pts),
    • Closed Lows (6 pts)
    • 500 mb jet stream (blue) (12 pts)
    • 300 mb jet stream (purple) (12 pts)

      Jets should be colocated over triple point and consistent with ridge and trough positions -5 or fraction each

      Western edge of map should have jets looping around upstream ridge, and then on boundary of closed and open cell cumulus -5 or fraction each

      Surface low symbol should be colocated with upper low symbol (-5)

Oceanographers Only. (64 points) Using correct color and symbol conventions, analyze the portion of following image (boxed portion only), indicating the following:

  1. Ocean Temperatures on Basis of Cloud Features
    • Area in which sea surface temperatures are warmer than overlying atmosphere (based upon cloud features) (W) (7 pts)
    • Area in which sea surface temperatures are colder than overlying atmopshere (based upon cloud features) (C) (7 pts)
  2. Middle/Upper Tropospheric (50 points)
    • Ridges and Troughs (20 pts),
    • Closed Lows (6 pts)
    • 500 mb jet stream (blue) (12 pts)
    • 300 mb jet stream (purple) (12 pts)
Quiz2

UpperSchematic

Sfc

 

 

 

 

 

 

 

Part B.

The charts below, from left to right, are the sea-surface temperatures (C) (Map 1), current speeds and streamlines (Map 2) and sea-surface altimetery (Map 3) for the Gulf of Mexico for April 18, 2011.

Meteorologists Only. (36 points) Using correct color and symbol conventions, analyze the portion of following image (boxed portion only), indicating the following:

  1. Ocean Current Features
    • Loop current (LC) (10 pts) (Map 2)
    • A warm ring associated with an eddy in the strongfest current (WR) (13 pts) (Map 1)
    • Explain why warm rings are associated (in the Northern Hemisphere) with anticyclonic eddies. (13 pts)

    Warm rings are associated with a closed anticyclonic (clockwise) circulation in the ocean. Normally, these occur for two reasons, either there is an oceanic circulation imposed by the atmosphere, or a anticyclonic eddy developing in place in the ocean. In either case, the increased speeds of water parcels moving in a clockwise fashion create an enhanced Coriolis acceleration acting to take the water parcels inward, relative to the center of circulation, and out of geostrophic balance. Thus, convergence at the sea surface takes place and downwelling. This has the effect of producing warmer temperatures sequested from the colder temperatures in the sea surface on all sides.

Oceanographers Only.. (86 points).

  1. Geostrophy (50 points)
    • Explain how, together, maps 2 and 3 illustrate that the Loop Current is in basic geostrophic balance.

      The current vectors are tangent to the altimetry contours, are flowing clockwise aroundthe altimetry high north of Cuba and with a speed in proportion to the altimetry gradient. This is consistent with a geostrophic current.



  2. Ocean Current Features
    • Loop current (LC) (10 pts) (Map 2)
    • A warm ring associated with an eddy in the strongfest current (WR) (13 pts) (Map 1)
    • Explain why warm rings are associated (in the Northern Hemisphere) with anticyclonic eddies. (13 pts)

SST

Map 1

Current

Map 2

Altimetry

Map 3