Wind
trajectories Related to Diamondback Moth (DBM) and Aster Leafhopper
Introductions to the Canadian Prairies in 2015
BACKGROUND: Potential wind events capable of carrying insect pests from source areas in the USA can be identified by following trajectories for air parcels through time. High altitude air masses, originating from southern locations, frequently move northerly to Canadian destinations. Insect pest species such as Diamondback moth and Aster leafhoppers, traditionally unable to overwinter above the 49th parallel, can utilize these air masses in the spring to move north from Mexico and the United States (southern or Pacific northwest).
Wind trajectory
data processing by AAFC-Saskatoon Staff (Weiss & Olfert) began in April.
Reverse Trajectories track air masses arriving across the
prairies back to their point of origin. Forward Trajectories predict favorable winds
expected to arrive across the Canadian Prairies.
Updated: June 1,
2015
1. Reverse
trajectories (RT)
Pacific Northwest (PNW) – Relative to the previous week,
there has been an increase in the number of
reverse trajectories that were predicted to cross the prairies over the
last few days (May 30 – 1; May 31 – 10; June 1 – 17).
2. Forward
trajectories (FT)
For the last couple of
weeks the winds originating over southwest USA were generally tracking
eastward, to the Atlantic Ocean. Over the last few days, forward trajectories
are predicted to move north of 49oN before moving in an eastward
direction (e.g. Brownsville TX). Over the next few days these trajectories may
carry insects north to the prairies.
3. Trajectory
summary for April 1-May 28, 2015
Based trajectory data from
April 1 – May 28, 2015, a greater number of trajectories were
predicted to arrive across the prairies originating from the Pacific northwest (Figure 1) compared to southwest USA
(Figure 2).
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| Figure 1 |
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| Figure 2 |
