Typhoon Hagibis south of Japan

October 11th, 2019 |

Himawari-8 Clean Window Infrared (10.41 µm) imagery every 2.5 minutes, from 1429 UTC to 1932 UTC on 11 October 2019. Imagery courtesy JMA (Click to animate)

Himawari-8 Advanced Himawari Imagery (AHI) from the ‘Target’ sector, above, show a strong albeit asymmetric storm south of Ise Bay and southwest of Tokyo Bay. Clean window infrared (10.41 µm) imagery, above, shows a compact eye that is cooling with time, suggesting weakening (and/or becoming more cloud-filled). Most of the cold clouds in the storm are north of the center, a distribution that suggests shear.  However, the storm is still producing strong convection that is wrapping around the eye. By the end of the animation, at 1929 UTC, the eye is no longer distinct.  This toggle compares the 1432 and 1929 UTC images.  A decrease in storm cloud-top organization near the eye is apparent.

Data from the CIMSS Tropical Page at 1530 UTC on 11 October, shown below in a stepped animation, show southerly shear that will increase with time over the storm as it moves towards Japan. Microwave imagery (85 GHz) also suggest a sheared storm, as does the infrared imagery.  Low-level water vapor imagery (7.3 µm), here), shows dry air (yellows in the color enhancement chosen) prevalent over the southern half of the storm.  These data suggest that a slow extratropical transition is underway.

Past and Predicted path of Hagibis, Observed Shear at 1500 UTC, the latest 85 GHz image over the storm, and Infrared window imagery at 1530 UTC. (Click to enlarge) All imagery from the CIMSS Tropical Page.

The Airmass RGB image over the Pacific Basin, (animation), (from this site at CIRA) also shows dry air consistent with a transition from tropical to extratropical. The zoomed-in image of the Airmass RGB, below, from Real Earth, shows the dry air as shades or orange/copper southwest of the storm, in contrast to the deep tropical moisture, feeding into the storm from the south, that is greener.

Airmass RGB from Himawari-8 Data, 1630 UTC on 11 October 2019

The Joint Typhoon Warning Center has the latest on Hagibis. A projected path valid at 1500 UTC 11 October is here.

Suomi NPP overflew Hagibis at 1639 UTC on 11 October. The toggle below shows the Day Night Band (0.7 µm Visible imagery) and the 11.45 µm infrared imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS) Instrument.  A larger-scale view of the Day Night Band is here.  (Imagery courtesy William Straka, CIMSS)

Suomi NPP Day Night Band Visible Imagery (0.7 µm) and Window Infrared (11.45 µm) from VIIRS, 1638 UTC on 11 October 2019 (Click to enlarge)

ACSPO SSTs from VIIRS in AWIPS

October 10th, 2019 |

ACSPO SSTs (range from 41 F to 68 F or 5 C to 20 C) at 0818 UTC on 10 October 2019 (Click to enlarge)

SSEC/CIMSS is producing Advanced Clear Sky Processor for Ocean ACSPO Sea Surface Temperatures (SSTs) from Direct Broadcast data received in Madison. (Here is a blog post on ACSPO SSTs in Guam) The example above shows Great Lakes water temperatures around 0800 UTC on 10 October 2019. The example below shows SSTs computed from the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi-NPP and NOAA-20 around Vancouver Island from 8 through 10 October (a period when the Pacific Northwest was enjoying a spate of clear skies that are necessary for ACSPO SST computation).  These data are available via LDM feed.

ACSPO SSTs (range from 41 F to 68 F or 5 C to 20 C) from 8 October through 10 October 2019 (Click to enlarge)

Satellite views of a Spacecraft Freighter Launch from Tanegashima Island in Japan

September 24th, 2019 |

NOAA-20 Day Night Band visible (0.7 µm) imagery at 1602 UTC on 24 September 2019 (Click to enlarge) (Image courtesy Mike Ziobro and Brandon Aydlett, WFO Guam)

NOAA-20 has viewed the launch from Tanegashima Island of a Japanese Spacecraft (NASA Blog Coverage; YouTube video, launch is at minute 35 in the video). Brandon Aydlett, NWS Guam, noted the appearance of a very bright spot in the Day Night Band imagery from NOAA-20 at 1602 UTC on 24 September (and a hot spot as well in the infrared imagery shown below). (NOAA-20 and Suomi-NPP data in this blog post were downloaded at the Direct Broadcast Antenna at the Forecast Office in Guam). NOAA-20 Orbital passes (from this site) show an overpass near the island at 1605 UTC; Suomi NPP had a more direct overpass over the island around 1657 UTC. Compare the NOAA-20 image, above, timestamped 1602 UTC, to the Suomi NPP image, below, timestamped at 1654 UTC. The bright signal over Tanegashima at 1602 UTC is missing from the 1654 UTC Suomi NPP imagery.

Suomi-NPP Day Night Band visible imagery (0.7 µm) at 1654 UTC on 24 September 2019 (Click to enlarge) (Image courtesy Mike Ziobro and Brandon Aydlett, WFO Guam)

Infrared Imagery captured the thermal signature of this launch as well. The hot spots in VIIRS imagery are obvious at 1602 UTC from NOAA-20, but not at 1654 UTC from Suomi NPP, at both 3.74 and 11.45, as shown below.

VIIRS shortwave infrared (3.74 µm) imagery at 1654 UTC (left) and at 1602 UTC (center, right, with two different color enhancements). Blown-up versions of the warm pixels are shown (Click to enlarge) (Image courtesy Mike Ziobro and Brandon Aydlett, WFO Guam)

VIIRS infrared (11.45 µm) imagery at 1654 UTC (left) and at 1602 UTC (right, same color enhancements). Blown-up versions of the warm pixels are shown (Click to enlarge) (Image courtesy Mike Ziobro and Brandon Aydlett, WFO Guam)

 

Himawari-8 shortwave infrared imagery also captured the launch, with a hot spot in a Japan Sector image at 1605 UTC on 24 September 2019, below.

Himawari-8 shortwave infrared (3.9 µm) imagery from 1600-1610 UTC on 24 September 2019 (Click to enlarge). Himawari data courtesy of JMA.

There is a considerable parallax shift in the NOAA-20 imagery, as the VIIRS instrument is scanning at the limb in the image, and the rocket at the time was very high in the atmosphere. The parallax shift in the Himawari-8 imagery is less noticeable.

GOES-17 Loop Heat Pipe data outages reach seasonal peak

August 30th, 2019 |

All 16 GOES-17 Bands, 0750 – 1640 UTC on 30 August 2019 (Click to animate)

The periodic deleterious heating of the GOES-17 Advanced Baseline Imager (ABI) will reach a peak on 30 or 31 August 2019. The effects (in ABI bands 8-16) of the heating are manifest because the Loop Heat Pipe on the GOES-17 satellite does not operate at peak efficiency and cannot dissipate the heat that accumulates as the sun shines directly on the ABI instrument at night. The animation above shows full-disk imagery for all 16 bands on GOES-17 from 0750 UTC through 1640 UTC. Band 12 (9.6 µm) imagery is affected the most by the heating: data are unuseable from 1040 UTC to 1630 UTC; Band 10, the low-level water vapor channel at 7.3 µm is unuseable from 1050 UTC to 1620 UTC. Other infrared bands show different outages. Only Band 14 (11.2 µm) is mostly unaffected, although some striping is apparent between 1210 and 1330 UTC.

Other well-known artifacts are present in the animation. For example, a keep-out zone (or solar avoidance zone, sometimes also called the “Cookie Monster Effect”) is apparent moving across the northern 1/5th of the Globe; this image from 0910 UTC shows the feature. Satellite-Earth-Geometry means the Sun is near the limb of the Earth and the satellite sensors do not scan near the Sun. Stray Light is also present in the imagery. This shows up most distinctly in visible/near-infrared imagery, but its effects are also present in the 3.9 µm imagery.

The figure below, from this blog post, shows predicted maximum focal plane temperatures for each day.  In early September, a rapid cool-down in the peak temperature occurs as the GOES-17 satellite starts entering the shadow of the Earth during night times when it would otherwise be illuminated by the Sun.

Predicted warmest Focal Plane Temperature as a function of Year. Also included: the threshold temperatures when the ABI Detection is affected by the warmer Focal Plane. The step in values near both Equinoxes occurs when a Yaw Flip is performed on the satellite (Click to enlarge)

This website shows comparisons between GOES-16 and GOES-17 for different bands, and includes observations of the focal plane temperature.  The animation below shows the steady increase in the maximum focal plane module (FPM) temperature in August and that warmth’s impact on the Band 12 observations:  there are longer and longer periods of time with no GOES-17 Band 12 data as you move through August (indicated by difference values that are off the chart).

Mean Band 12 (9.6 µm) brightness temperature difference (between GOES-16 and GOES-17, plotted in blue) over a region on 27 July, 2 August, 10 August, 16 August, 22 August and 29 August 2019. The black line shows the Focal Plane Temperature (Click to enlarge)

A similar chart for Band 8 (6.19 µm) is shown below. Band 8 is not affected so severely by the Loop Heat Pipe. (Click here here for a similar chart for Band 14 (11.2 µm)).

Mean Band 8 (6.19 µm) brightness temperature difference (between GOES-16 and GOES-17, plotted in blue) over a region on 27 July, 2 August, 10 August, 16 August, 22 August and 29 August 2019. The black line shows the Focal Plane Temperature (Click to animate)

The intra-band differences on the effects of the excess heat are shown here for values on 29 August for Bands 8 (6.19 µm), 12 (9.6 µm) and 14 (11.2 µm).