Himawari-8 6.2 µm infrared water vapor channel images (click to play animation)

Full-resolution animations of Himawari-8 6.2 µm water vapor imagery suggest what a gamechanger Himawari-8 data is, and what a gamechanger GOES-R data will be. Full-disk imagery at every 10 minutes, and at 2-km resolution, means atmospheric motion vectors computed from water vapor imagery (or other channels, such as the 10.35 µm) will cover a larger area and be far more accurate than with present GOES (or MTSAT).

In addition, because there are multiple water vapor channels on Himawari-8 (as will be on GOES-R), water vapor at different levels in the atmosphere can be tracked easily. In the animation below, low-level cloud streets between Japan and the large storm over the northern Pacific are clearly evident, whereas they are shielded from view in the animation above by high-level cirrus — although their presence is evident once they emerge from under the cirrus. Weighting Functions for two similar channels on the GOES Sounder (from here) show that the shorter-wavelength 6.2µm channel will have a larger response to upper level moisture; the longer-wavelength 7.3 µm channel will have a larger response to lower level moisture. Interactions with land features that are evident in the 7.3 µm imagery below do not show up in the 6.2 µm imagery above because most of the signal at 6.2µm is emitted from the upper troposphere. Combining the three water vapor channels (there is also a 6.9 µm channel, not shown here) gives an excellent three-dimensional representation of water vapor in the atmosphere at high temporal resolution.

Himawari-8 7.3 µm infrared water vapor channel images (click to play animation)

View only this post Read Less

Suomi NPP VIIRS 11.45 µm infrared channel images (click to enlarge)

The ongoing change in seasons was accompanied last night by a round of convection over the Missouri River Valley. Suomi NPP 11.45 µm imagery from overnight shows scattered convection over Kansas, Missouri and Iowa at 0728 and 0909 UTC. Coldest cloud tops are around -65 C. The Day-Night band showed lightning streaks at both times as well, over east-central Kansas at 0728 and north-central Kansas 0909 UTC.

Suomi NPP VIIRS 0.70 µm Day-Night band visible channel images (click to enlarge)

GOES Sounder DPI Lifted Index, times as indicated (click to enlarge)

The GOES Sounder showed the unstable air that was feeding into this convection. Imagery at three-hourly intervals, above, shows values between 0 and -4 persisting over the central Plains. Plots of 850-mb data on top of the GOES Sounder DPI Lifted index, below, shows the development of strong warm advection over the central Plains that helped feed moisture into the developing convection.

GOES Sounder DPI Lifted Index and Radiosonde data at 850 hPa (click to enlarge)

NUCAPS soundings, created from both CrIS and ATMS data on board Suomi NPP, below, showed steepening mid-level lapse rates over/near Kansas. This convection likely was not surface-based.

Suomi/NPP NUCAPS Soundings near Kansas City (07z) and over Eastern Kansas (09z) with an individual sounding from the starred point plotted (click to enlarge)

View only this post Read Less

GOES-13 0.63 µm visible channel images (click to play animation)

GOES-13 (GOES-East) 0.63 µm visible channel images (above; click to play animation) showed a patch of sea fog just off the coast of northeastern Florida on 21 March 2015. As daytime inland heating increased, a sea breeze circulation began to draw some of the offshore sea fog toward the coast.

A closer view is provided by a Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image at 18:08 UTC (below), visualized using the SSEC RealEarth web map server site. The surface visibility at New Smyrna Beach was reduced to 1 mile at the time.

Suomi NPP VIIRS true-color image

A web camera image at 18:17 UTC or 2:17 PM local time (below) showed the dramatic reduction in visibility as the dense sea fog moved inland at Dunlawton Beach (near Daytona Beach).

Dunlawton Beach webcam image

A comparison of Suomi NPP VIIRS 0.64 µm visible channel, 3.74 µm shortwave IR channel, and 11.45 µm longwave IR images (below) showed that the patch of sea fog exhibited a strong signal on the shortwave IR image (due to the efficient reflection of incoming solar radiation by the spherical water droplets), but no signal at all on the longwave IR image (since the temperature of the sea fog feature was nearly identical to that of the surrounding ocean waters).

Suomi NPP VIIRS 0.64 µm visible channel, 3.74 µm shortwave IR channel, and 11.45 µm longwaveIR channel images

The easterly to northeasterly onshore flow along the coast (enhanced by the sea breeze circulation) was well-depicted by the 18 UTC Real-Time Mesoscale Analysis (RTMA) surface winds (below).

Suomi NPP VIIRS 0.64 µm visible channel image, with RTMA surface winds

View only this post Read Less

GOES-13 0.65 µm visible channel images (click to enlarge)

A total solar eclipse occurred on 20 March before sunrise over the USA. Its appearance on visible imagery from Meteosat-10 was documented here and here. Did GOES-13 also view this event? The imagery above, half-hourly from 0845 through 0945 UTC, shows evidence of darkening (the lunar shadow) initially near 40 N, then a very dark slice in the atmosphere at 0915 UTC and a hint of darkness at 0945 UTC at the extreme limb of the satellite, beyond Iceland. Note also how the terminator in the image, the boundary between day and night, is parallel to longitudinal lines. Happy Equinox!

The shadow of totality was also captured on a NOAA-18 AVHRR 0.86 µm visible channel image at 0907 UTC (below). The shadow extends out over the Atlantic Ocean well to the northeast of Newfoundland.

NOAA-18 AVHRR 0.86 µm visible channel image

View only this post Read Less