Name:________________________________
Synoptic Meteorology I
Project#5
Due: Thursday, 1 October 2015
Part I (Group Portion), teammate initials: ___________ ___________ ___________
{by initialing above you are acknowledging that you participated in research, discussion,
and analysis that went into the responses to Part I}
Teleconnections
[1] Go to the web site http://www.esrl.noaa.gov/psd/gcos_wgsp/Timeseries/NAO/ to determine the highest
magnitude positive and negative monthly wintertime (Dec, Jan, or Feb) NAO phase indices over the period
January 1970-December 1979 and write the month/year/NAO index value below. Describe the expected
differences in the winter storm track across the North Atlantic Ocean near Europe in a positive phase NAO
period compared to a negative phase NAO period. Go to the web site http://data.giss.nasa.gov/stormtracks/
and plot the appropriate monthly storm tracks that correspond to the two NAO index extrema. Are your
expectations confirmed in the two plots? What monthly temperature and precipitation accumulation
departures from normal would accompany these track differences in Europe, if any?
[2] An extreme negative (cool) phase PDO occurred in 1950, while an extreme positive (warm) phase PDO
occurred in 1987. Note your expectations with regards to mean monthly air temperature for each phase of
the PDO over the southeastern U.S. and verify these expectations by finding and writing below the mean
January temperature for Asheville for the two years noted above. [Be sure to cite the data source that you
used in this exercise.]
[3] Find the heaviest rain event for Seattle-Tacoma airport in December 1996 using the NCDC web page
https://www.ncdc.noaa.gov/cdo-web/datatools/findstation. Note the date of the heaviest rain event below.
Determine if the [MJO] or [other] atmospheric oscillation is a likely candidate to have contributed to this
heavy precipitation event. In order to answer “yes” to the MJO, you must {a} determine if the phase of
ENSO was favorable for MJO activity and {b} confirm that the MJO phasing and timing is favorable for
contributing to the event by examining the web page at (
http://www.cpc.noaa.gov/products/precip/CWlink/daily_mjo_index/mjo_index.html ). If you find the
answer to parts {a} and {b} are “yes”, you can conclude that the MJO is a likely candidate. Include a plot
of low-level atmospheric moisture over the Pacific Ocean for this event and note if the moisture in Seattle
is linked to the tropics (“Pineapple Express”). [Be sure to cite the ENSO and moisture data sources that you
used in this exercise.]
[4] Find the number of hurricanes occurring in the Atlantic basin during the 2005 and 2006 seasons. Were
these seasons above- or below-normal years in terms of hurricane activity? Which phase (30 hPa wind
direction west or east) of the QBO do you expect to find in an above-normal year in terms of the Atlantic
basin hurricane activity? Examine QBO index data for the peak hurricane season months (Aug, Sep, Oct)
during 2005 and 2006 and note the anomaly types for each year below. Do you find the expected
correlation between QBO phase and level of Atlantic basin hurricane activity? What might be reasons for a
poor correlation between the two parameters? [Be sure to cite the data sources that you used in this
exercise.]
Name:________________________________
Synoptic Meteorology I
Project#5
Due: Thursday, 1 October 2015
Part II (Individual Portion):
[1] The moisture flux of a moisture plume can be estimated by
where Fh is the horizontal water vapor flux (kg s-1), z is the depth of the moisture plume
(= 1.5 km), L is the horizontal width of the moisture plume, and , U, and q are the
mean values of air density (=1.1 kg m-3), wind speed, and water vapor specific humidity
within the moisture plume. The pre-cold frontal low-level jet (LLJ) is a narrow feature
found to coincide with an “atmospheric river” of moisture typical of a mid-latitude
cyclone. Recall the observation that four to five atmospheric “rivers (at a given latitude in
the mid-latitudes) accomplish 90% of the total instantaneous meridional water vapor
transport.” If the only other significant moisture transport is accomplished by midlatitude anticyclones, what must you conclude about the U, q, and L properties of the
anticyclones given the above observation? In order to receive full credit, your explanation
must include a discussion of how the parameters U, q, and L in the vicinity of the precold frontal LLJ differ from locations of mid-latitude anticyclones. Focus on the
poleward transport of moisture.