Satellite Down! No Sea Ice Measurements, says NSIDC

[elektra]

Slow Sensor Degradation, resulting in anomalously low readings, has occurred for how long? Normally it takes months for them to correct the daily reading which is full of inaccuracies. Given all these factors, it seems extremely premature and poltical to report sea ice extent on a daily basis. It also seems extremely expensive, a huge waste of resources. Is there not more important things for the "scientists" do? We actually pay scientists to color grids on a map, daily? Well, I guess our energy needs are solved and there is no more cancer or heart disease so what else are they to do, than color?

 

[elektra]

Seems there are tons of problems yet people post as if the record is complete, settled, science.

| National Snow and Ice Data Center

• 
  
  

Data Set ID:
NSIDC-0081
Near-Real-Time DMSP SSMIS Daily Polar Gridded Sea Ice Concentrations, Version 1

Notice (04/05/2016): Notice (04/19/2016): Daily sea ice concentration updates have improved. On 04/05/2016 a change in the solar panel position to shade the nitrogen tank on board the Defense Meteorological Satellite Program (DMSP) F-17 satellite was made. In doing so, the integrity of the vertically polarized 37 GHz channel (37V) of the Special Sensor Microwave Imager and Sounder (SSMIS) was compromised. This is a primary channel used in the sea ice processing. On 04/13/16 an additional change in the solar panel position was made.This change has improved the problems we were seeing in the 37V GHz channel. The affected daily files from 04/05 – 04/13 have been removed from distribution.

 

[mamooth]

Knowing they are degrading, I wonder how the "scientists" may be biased when they physically hand color in the grids to indicate where they believe there is ice or no ice.

You actually think scientists color grids by hand each day? That's hilarious. Scientists have better things to do than color graphs each day.

The process is very subjective, and given how a small difference in the details can amplify the results, all is suspect.

No, the process is totally automated. That's why the sea ice levels apparently suddenly spiked up when the one sensor started failing and reporting ice that wasn't there, because there weren't any human eyeballs looking at the results before they were published.

Oh, AMSR2 maps, from U Bremen, continue to be published as usual.

Daily AMSR2 sea ice maps

 

[jc456]

Knowing they are degrading, I wonder how the "scientists" may be biased when they physically hand color in the grids to indicate where they believe there is ice or no ice.

You actually think scientists color grids by hand each day? That's hilarious. Scientists have better things to do than color graphs each day.

The process is very subjective, and given how a small difference in the details can amplify the results, all is suspect.

No, the process is totally automated. That's why the sea ice levels apparently suddenly spiked up when the one sensor started failing and reporting ice that wasn't there, because there weren't any human eyeballs looking at the results before they were published.

Oh, AMSR2 maps, from U Bremen, continue to be published as usual.

Daily AMSR2 sea ice maps

no, it was reporting loss of ice if I recall the scenario. hmmmm you should re look that up there bubba/bubbiest!

Satellite sensor errors cause data outage | Arctic Sea Ice News and Analysis

excerpt:
"As some of our readers have already noticed, there was a significant problem with the daily sea ice data images on February 16. The problem arose from a malfunction of the satellite sensor we use for our daily sea ice products. Upon further investigation, we discovered that starting around early January, an error known as sensor drift caused a slowly growing underestimation of Arctic sea ice extent. The underestimation reached approximately 500,000 square kilometers (193,000 square miles) by mid-February. Sensor drift, although infrequent, does occasionally occur and it is one of the things that we account for during quality control measures prior to archiving the data. See below for more details."

 

[elektra]

Knowing they are degrading, I wonder how the "scientists" may be biased when they physically hand color in the grids to indicate where they believe there is ice or no ice.

You actually think scientists color grids by hand each day? That's hilarious. Scientists have better things to do than color graphs each day.

The process is very subjective, and given how a small difference in the details can amplify the results, all is suspect.

No, the process is totally automated. That's why the sea ice levels apparently suddenly spiked up when the one sensor started failing and reporting ice that wasn't there, because there weren't any human eyeballs looking at the results before they were published.

Oh, AMSR2 maps, from U Bremen, continue to be published as usual.

Daily AMSR2 sea ice maps

Your link does not work? I think they do color in the maps, by hand with a computer? Or maybe on a big map? I guess it would have to be computer generated based on algorithms.

From what I understand, the sensors reported no ice, it was failing, not detecting.

Sea Ice emits more microwave radiation, hence a sensor would have a tendency to not detect, not to detect more. The older the sensor gets, the less it will detect? Or will it detect more? I guess it could go either way or both?

 

[elektra]

How did the sensor fail and for how long, how long was the performance degraded. Over the course of months I am sure the sensor provided false information, did not detect the energy level of the microwaves which is quite low.

Remote Sensing | Remote Sensing: Passive Microwave | National Snow and Ice Data Center

A major drawback to measuring passive microwave radiation is that the energy level is quite low. As a result, the radiation must be collected over a larger region. Details of the sea ice, such as leads, are not easily detected.

 

[elektra]

And there is a large amount of error, how much more so when the sensor is degraded, not sensing.

http://ioc-goos-oopc.org/meetings/oopc-9/presentations/monPM/Rayner_OOPC9_pr.pdf

 

[elektra]

5 satellites, with 5 different sensors, different components, different tolerances of discrete components, different margin of errors

Sea Ice Utilities

Since 1979, there have been 5 satellites: n07, f08, f11, f13 and f15. During most periods, only one satellite is operating,

 

[elektra]

I am just kind of saving some files/webpages, quotes that show the uncertainties of measuring sea ice, in relation to failing sensors I think it is proper to know the limitations the "scientists" were dealing with to begin with.

https://nsidc.org/data/docs/daac/nsidc0079_bootstrap_seaice/docs/Bootstrap_Algorithm_Revised07.pdf

The binary characterization of the surface is valid only if the observations allow this to be possible and the discrimination of sea ice and open water can be done unambiguously. This assumes that within the footprint of the sensor, the radiances from 100% ice and 100% liquid water are distinct enough to make it possible to estimate or infer from the data the concentration on a measurement by measurement basis. This is generally true for microwave data (and also for visible, infrared which are usually used for validation studies) but it is not always the case and there are at least two situations in which there is a special concern, namely: (a) new ice/thin ice regions as in polynyas and marginal ice zones during autumn and winter and (b) melt/meltponding regions as in Arctic basin during the spring and summer. In new/thin ice regions, the emissivity of sea ice is not well defined since it changes constantly from close to that of liquid water to that of thick sea ice. Other physical processes associated with the growth of sea ice that may affect the radiative signature are described in detail in Weeks and Ackley (1986), Tucker et al. (1992), and Eicken et al. (1991). Also, when the surface temperature goes above freezing in spring and summer, the brightness temperature of the surface goes up as the emissivity increases to almost that of a blackbody as liquid starts to form around the ice crystals, but as the snow continues to melt and forms slush and then melt ponds, the brightness temperature goes down to that of an ice free water (Eppler et al., 1992).