Strong jet stream over the North Pacific Ocean

January 2nd, 2019 |
GOES-17 Mid-level Water Vapor (6.9 µm) images, with 250 hPa wind isotachs [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images, with 250 hPa wind isotachs [click to play animation | MP4]

* GOES-17 images shown here are preliminary and non-operational *

GOES-17 Mid-level Water Vapor (6.9 µm) images with an overlay of 250 hPa wind isotachs from the GFS90 model (above) showed a string of disturbances (surface analysis) along the axis of a 180-knot “Japan Jet” across the North Pacific Ocean on 02 January 2019.

GOES-17 Split Ozone (9.6 µm10.3 µm) Brightness Temperature Difference images (below) include an overlay of PV1.5 pressure (an indicator of the height of the “dynamic tropopause”) — they showed the difference between cold polar air having a low tropopause (shades of cyan to blue) north of the jet stream and warm tropical air having a much higher tropopause (shades of yellow). The Split Ozone BTD is the Green component of the Air Mass Red-Green-Blue (RGB) product.

GOES-17 Split Ozone (9.6 - 10.3 µm) images, with contours of PV1.5 pressure [click to play animation | MP4]

GOES-17 Split Ozone (9.6 – 10.3 µm) images, with contours of PV1.5 pressure [click to play animation | MP4]

Rawinsonde data also showed the significant difference in tropopause height between St. Paul Island, Alaska (pressure=314 hPa, height=8.1 km) in the polar air of the Bering Sea and Lihue, Hawai’i (pressure=82 hPa, height=17.9 km) in the tropical air of the central Pacific (below).

Plots of rawinsonde data from St. Paul Island, Alaska [click to enlarge]

Plots of rawinsonde data from St. Paul Island, Alaska [click to enlarge]

Plots of rawinsonde data from Lihue, Hawai'i [click to enlarge]

Plots of rawinsonde data from Lihue, Hawai’i [click to enlarge]

GOES-17 Air Mass RGB images from the UW-AOS site (below) further illustrated the sharp contrast between the cold/dry polar air to the north and warm/moist tropical air to the south of the strong jet stream. The purple hues along the northwestern edge of the scan are a result of the “limb cooling” effect, as the satellite’s infrared detectors sense radiation from colder upper levels of the atmosphere at large viewing angles.

GOES-17 Air Mass RGB images [click to play animation | MP4]

GOES-17 Air Mass RGB images [click to play animation | MP4]

In addition to the series of larger disturbances along the jet stream axis, there were also some smaller-scale storms apparent in the Bering Sea (surface analyses). Better detail of these high-latitude features could be seen using Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images separated by 10 hours (below).

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1427 UTC and 0022 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1427 UTC and 0022 UTC [click to enlarge]

Regarding the strong Japan Jet, GOES-15 (GOES-West) Derived Motion Winds (source) tracked targets having velocities as high as 200 knots at 03 UTC (below).

GOES-15 Water Vapor (6.5 µm) Derived Motion Winds [click to enlarge]

GOES-15 Water Vapor (6.5 µm) Derived Motion Winds [click to enlarge]