12.29.10: ARGO-like time series of nitrate and potential density in the 1/10th OFES simulation¶
We produce here a time series from the 1/10th OFES simulation that has the same spatial and temporal characteristics as the ARGO time series of the float Hawaii5145. Two types of interpolation are used: either a 4D interpolation in time and space (Figs. 2 and 5) or the cloest location and time (Figs. 3 and 6). Nitrate is compared in Figs. 1 to 3, potential density σ in Figs. 4 to 6.
Both interpolations give the same temporal structure, although the interpolation using the closest location and time has a little more high-frequency noise but nothing that has the scale of the nitrate events. In both cases, one obtain events in nitrate that resemble those in the observations. However, there are less events in the model time series than in the observations and none is as short as the observed ones.
The possible reasons for this difference is:
- lack of resolution (highly likely): the model underestimates the number of filaments and submesoscale vorticies as well as frontal processes (unfortunately, both processes produce tracer filamentation so that it is not possible to isolate them from observations of tracer alone)
- the contours of nitrate are less parallel in reality than in the model (least likely)
- the model underestimates the mesoscale field responsible for the stirring.
Figure 1: Nitrate measured by ARGO float Hawaii5145.
Figure 2: Nitrate in the 1/10th OFES simulation following the trajectory of ARGO float Hawaii5145 using 4D interpolation.
Figure 3: Nitrate in the 1/10th OFES simulation following the trajectory of ARGO float Hawaii5145 using closest location and time.
Figure 4: σ measured by ARGO float Hawaii5145.
Figure 5: σ in the 1/10th OFES simulation following the trajectory of ARGO float Hawaii5145 using 4D interpolation.
Figure 6: σ in the 1/10th OFES simulation following the trajectory of ARGO float Hawaii5145 using closest location and time.
See sampling_ntr_as_ARGO_float.m in RESEARCH/PROJECTS/MARINE_BIOLOGY/SUBMESOSCALE_PROCESSES/OFES/sampling_ntr_as_ARGO_float.