ERRATA

In Volume 27, Issue 1–2 of Marine Geodesy, in the article “Sea State and Rain: A Second Take on Dual-Frequency Altimetry,” by Graham D. Quartly, Figures 1–7 appeared in poor quality. Enhanced figures are published below.

FIG. 1 Location of nominal “1 second” averages along track 123, for cycle 10 for Jason and corresponding cycle 353 for TOPEX. Circle (8 km in diameter) indicates size of instantaneous AGC footprint for TOPEX.

FIG. 2 Comparison of various parameters for near-simultaneous TOPEX and Jason data along pass 225 (cycle 6 for Jason, cycle 349 for TOPEX). Right-hand column shows in finer detail the variation within the marked boxes in the left hand column. (a) Sigma0 (with bulk adjustment of Jason as discussed in text and 3.55 dB subsequently removed from C-band values to overlie K_u-band values); (b) Wave height; (c) Pseudo-SSH (which is orbit minus range with only dry tropospheric correction applied); and (d) 37 GHz brightness temperature from the TMR.

FIG. 3 Histograms of Jason's H_s and σ⁰ values for TOPEX-paired observations in cycles 10 and 11. Lines give number of points per bin for full matchup dataset; shaded region is for those also passing the data editing tests listed in Table 1. (a) K_u-band value of H_s in 0.1 m bins; (b) K_u- and C-band values of σ⁰ in 0.1 dB bins. (Jason values not adjusted to match TOPEX.)

FIG. 4 Intercomparison of K_u- and C-band wave height data from TOPEX and Jason. (a) Scatter plot of difference between Jason and TOPEX K_u records against TOPEX K_u-band values. (b) Mean difference as a function of wave height. (c) Standard deviation of difference of 1 Hz values. (d) Standard deviation of running 11-point median. Data are from Jason cycles 10 and 11, with top plot only showing a subset of the points used in the analysis. Interpretation of lines in (b), (c), and (d) is given by key in (b), where solid black line represent Jason-K_u minus TOPEX-K_u plotted as a function of TOPEX-K_u etc.

FIG. 5 Intercomparison of K_u- and C-band σ⁰ data from TOPEX and Jason. (a) Mean difference. (b) Standard deviation of difference. Cycles of data and labeling are as for Figure 4, except all Jason data have been adjusted by mean σ⁰ difference between Jason and TOPEX.

FIG. 6 Definition of a dual-frequency rain flag for Jason. (The σ⁰ values from the Jason GDRs have had their atmospheric correction removed and a bulk adjustment applied to agree in the mean with TOPEX.) (a) Scatter plot of difference between σ⁰ _Ku and σ⁰ _C against σ⁰ _C. Crosses indicate 5000 points sampled from cycles 10 and 11; added lines are calculated from all available data from these two cycles. The circles show 75 points believed to be strongly affected by rain (according to BT and σ_h values). (b) No. of observations in each 0.05 dB bin.

FIG. 7 Comparison of the σ⁰-σ⁰ relationships for Jason and TOPEX (after Jason values adjusted to agree in the mean with TOPEX). (a) Mean relationships (including curve for early in TOPEX-A mission). (b) Standard deviation about mean. (c) Rms variation of the mean profiles calculated independently from seventy 2-day subsets. (d) Wave height dependency of σ⁰-σ⁰ relationship for Jason.