# The Summertime Diurnal Cycle of Precipitation Derived from IMERG
## 5 Conclusions
The diurnal cycle of accumulation tends to maximise at similar times across all seasons over land, whilst more variations are found over the mid-latitude oceans. 8. The summertime diurnal cycle of precipitation was unaffected by the strong El Nino event of 2015/2016. This suggests that four years of IMRG data are sufficient for analysing the diurnal cycle of precipitation at 2\({}^{\circ}\)\(\times\) 2\({}^{\circ}\) resolution. Improvements in the random errors for the IMRG precipitation estimates are necessary, and are under investigation by the IMRG community [11]. The current constellation of passive microwave radiometers provides unprecedented revisit time (see Figure 4 in [10]); it is paramount to maintain (if not to improve) such microwave constellation in order to curb (reduce) uncertainties in the precipitation-feature morphing procedure between different sampling times. A future study could focus on identifying the optimum spatial resolution at which the diurnal cycle should be analysed, by statistically assessing the relative importance of the improvements in IMERG precipitation representation and errors with coarser spatio-temporal resolutions [21] against the capture of the localised features of the diurnal cycle at finer spatial resolutions. The results within this article could provide a variety of opportunities for improving understanding of the diurnal cycle of precipitation. One such opportunity is to use the results for validating models which simulate precipitation and its characteristics; note that the grid box size should be kept consistent for a comparison as the errors in the diurnal cycle may be sensitive to such parameter. Another opportunity is to use these results to identify regions for conducting further analyses of the diurnal cycle. Use of three-dimensional measurements from the GPM dual-frequency precipitation radar in localised studies can aid in better characterising the differences between the diurnal cycles of accumulation, occurrence and intensity. Finally, these results offer the opportunity to optimise the orbit selection for satellites with instruments that are detrimentally affected by precipitation [28]. Conceptualization, A.B. ; methodology, A.B. & D.W.; software, D.W.; validation, D.W. & A.B. ; formal analysis, D.W.; investigation, D.W.; resources, D.W. & A.B. ; data curation, D.W.; writing--original draft preparation, D.W.; writing--review and editing, A.B. & D.W.; visualization, D.W. & A.B. ; supervision, A.B., project administration, A.B. & D.W.; funding acquisition, D.W. & A.B. [PERSON] was funded by a Natural Environment Research Council studentship awarded through the Central England NERC Training Alliance (CENTA; grant reference NE/L002493/1) and by the University of Leicester. The work by [PERSON] was funded by ESA in the frame of the RAINCAST project (ESA Contract No. 4000125959/18/NL/NA). The version-5 level-3 IMERG data were provided by the NASA/Goddard Space Flight Center and PPS, which develop and compute the V05 level-3 IMERG data as a contribution to GPM, and archived at the NASA GES DISC. This research used the SPECTRE High Performance Computing Facility at the University of Leicester. The authors thank three anonymous reviewers for their helpful comments and recommendations which greatly helped to improve the manuscript. The authors thank [PERSON] for providing comments on the manuscript prior to submission. The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.