This report contains a summary of information on the Cryo-TEMPO (Baseline-C v001) Land Ice TDP (thematic data products) for May 2020. For detailed information and statistics on all parameters, please use the product viewer.
This section shows the availability of Cryo-TEMPO Land Ice products during May 2020.
As each orbit may be split in to several Cryo-TEMPO files, the number of files and orbits may be different.
| Product Area | Number of Orbits | Number of Files |
|---|---|---|
| Antarctica | 449 | 2108 |
| Greenland | 153 | 323 |
The primary parameter measured for land ice is ice surface elevation. This section shows the statistics of the number of elevation measurements that passed or failed the Cryo-TEMPO processor quality tests for May 2020.
Over land ice, measurement failure is primarily due to high surface slope or complex terrain, which makes it difficult to accurately identify the surface from the returned radar waveform.| Area | Number Valid | Number Invalid | %Valid | %Invalid |
|---|---|---|---|---|
| Antarctica | 4719193 | 527824 | 89.94 | 10.06 |
| Greenland | 451979 | 38213 | 92.20 | 7.80 |
A map of valid elevation measurements and also failure locations (shown in red in the smaller map) over Antarctica and Greenland for May 2020. is displayed below.
The estimated uncertainty of each elevation measurement is provided in the uncertainty parameter. Uncertainty for land ice is estimated by calculating the mean precision (through repeat elevation differences at orbit crossover points) per 0.1 degrees of slope. Maps of uncertainty for Antarctica and Greenland for May 2020 are provided below. As expected uncertainty is highest in areas of high slope (> 0.3 degrees).
The accuracy of CryoSat Cryo-TEMPO elevation measurements is calculated by comparison with external ground truth data collected during Operation IceBridge validation campaigns over specific test sites in Antarctica and Greenland. The statistics below show how closely the Cryo-TEMPO elevation measurements from each CryoSat instrument mode (LRM or SIN) match the ground truth data over the different surface types available in the test sites:
| Site | Ice sheet | Topography and Climatology | Mode | Bias (m) | Dispersion (m) |
|---|---|---|---|---|---|
| Vostok | Antarctica | Smooth, low slope, dry snowpack | LRM | 0.10 | 0.08 |
| Greenland Summit | Greenland | Low slope, predominantly dry snowpack | LRM | 0.03 | 0.08 |
| Amundsen Sea | Antarctica | Moderate slope, predominantly dry snow pack | SIN | -0.47 | 0.45 |
| Russell Glacier | Greenland | High slope, complex snowpack | SIN | -1.13 | 1.39 |
The following list of known issues applies to the land ice products in this Cryo-TEMPO baseline (C):
| Issue | Description |
|---|---|
| LRM Backscatter drift and step | The Cryo-TEMPO backscatter parameter (in LRM mode only) is affected by an anomaly in CS2 Baseline-D L1b products from which these Cryo-TEMPO products are derived (until Aug 2021, after which Baseline-E is used). The anomaly is a calibration error which introduces a gradual 1.5dB linear decline in mean backscatter between the start of the mission and Jan 2016. Between Jan 2016 and Aug 2021 backscatter is correctly calibrated. From Aug 2021 there is a step in mean backscatter due to a recalibration in CS2 L1b from Baseline-E. This drift and step anomaly is expected to be corrected in the next version of Cryo-TEMPO products. Although individual monthly maps of backscatter appear normal, users should be aware of this anomaly if using the backscatter parameter to calculate a backscatter correction to elevation during studies of surface elevation change. |
The Cryo-TEMPO products for May 2020 are processed from original lower level ESA CS2 L1b Baseline-D products.
Report by the Cryo-TEMPO science team, created by MSSL (UCL) on 10/11/2024