Presenting Author: Dr. Semyon Grodsky
Weekly average satellite based estimates of latent heat flux (LHTFL) are used to characterize spatial patterns and temporal variability in the intraseasonal band (periods shorter than 3 months). The strongest intraseasonal LHTFL is observed at middle latitudes in the regions of major SST fronts where the standard deviation of intraseasonal LHTFL is up to 50 Wm-2. Amplitude of intraseasonal LHTFL decreases at high latitudes and in the regions of equatorial upwelling reflecting the effect of decreased SST. In middle latitudes the intraseasonal variability of LHTFL is forced by passing storms and is locally amplified by unstable air stratification over warm SSTs. Although weaker in amplitude but still significant intraseasonal variability is observed in the tropical Indian and Pacific Oceans due to the eastward propagation of Madden-Julian Oscillations. In this tropical region the intraseasonal LHTFL and incoming solar radiation vary out-of-phase, i.e. evaporation enhances just below convective clusters. Over much of the global Ocean anomalous LHTFL provides a negative feedback on the underlying intraseasonal SST anomaly, although there are considerable geographical variations. The feedback exceeds 20 Wm-2/oC in the regions around 20oS and 20oN, but decreases at high latitudes and in the eastern tropical Pacific and Atlantic where the time average LHTFL is weak.
2019 International OVWST Meeting
May 29-31 in Portland, Maine, USA