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: May 20, 2015
1.
Reverse trajectories (RT)
During the early part of May, reverse
trajectories (RTs) were originating over the Arctic, but have recently shifted
southward. This week a number of RTs, originating from California, Texas
and Mexico have passed over a number of prairie locations. The following table provides
an overview of were RTs originating across southwest USA and Mexico have
crossed the prairies.
|
Number
of Dates Reverse Trajectories Were Tracked to these Prairie Sites (between
May 13-20, 2015)
|
|||
|
Location
|
Latitude
|
Longitude
|
Number
of Dates
|
|
BRANDON_MB
|
49.8
|
-99.9
|
3
|
|
SELKIRK_MB
|
50.1
|
-96.9
|
3
|
|
YORKTON_SK
|
51.2
|
-102.4
|
2
|
|
RUSSELL_MB
|
50.8
|
-101.3
|
2
|
|
CARMAN_MB
|
49.5
|
-98
|
2
|
|
GRENFELL_SK
|
50.4
|
-102.9
|
2
|
|
PORTAGE_MB
|
50
|
-98.3
|
2
|
|
LETHBRIDGE_AB
|
49.7
|
-112.8
|
1
|
|
KINDERSLEY_SK
|
51.5
|
-109.1
|
1
|
|
DAUPHIN_MB
|
51.1
|
-100
|
1
|
|
GAINSBOROUGH_SK
|
49.2
|
-101.4
|
1
|
|
PROVOST_AB
|
52.4
|
-110.3
|
1
|
2. Forward trajectories (FT)
Environment Canada models indicate that
most of the forward trajectories crossing the prairies are expected to
originate over northwestern USA (Pacific).