请优化以下代码：metss_interp = ERA5['metss_interp'] ERA5_mu_Jan1 = metss_interp[:,:,0:120:12].mean(2).T #mean(2)的意思是把第三个维度的数据进行平均，原来是(144,96,120),取平均之后就是(144,96) ERA5_mu_July = metss_interp[:,:,6:120:12].mean(2).T mntss_interp = ERA5['mntss_interp'] ERA5_mv_Jan = mntss_interp[:,:,0:120:12].mean(2).T ERA5_mv_July = mntss_interp[:,:,6:120:12].mean(2).T mslhf_interp = ERA5['mslhf_interp'] msshf_interp = ERA5['msshf_interp'] # ERA5_mo = np.sqrt(pow(metss_interp, 2)+pow(mntss_interp,2)) # ERA5_mo_Jan = ERA5_mo[:,:,0:120:12].mean(2).T # ERA5_mo_July = ERA5_mo[:,:,6:120:12].mean(2).T ERA5_SH_Jan = msshf_interp[:,:,0:120:12].mean(2) ERA5_SH_Jan = -ERA5_SH_Jan.T ERA5_SH_July = msshf_interp[:,:,6:120:12].mean(2) ERA5_SH_July = -ERA5_SH_July.T ERA5_LH_Jan = mslhf_interp[:,:,0:120:12].mean(2) ERA5_LH_Jan = -ERA5_LH_Jan.T ERA5_LH_July = mslhf_interp[:,:,6:120:12].mean(2) ERA5_LH_July = -ERA5_LH_July.T

优化后的代码如下：

metss_interp = ERA5['metss_interp']
mntss_interp = ERA5['mntss_interp']
mslhf_interp = ERA5['mslhf_interp']
msshf_interp = ERA5['msshf_interp']

variables = {
    'ERA5_mu_Jan1': (metss_interp[:,:,0:120:12].mean(2).T),
    'ERA5_mu_July': (metss_interp[:,:,6:120:12].mean(2).T),
    'ERA5_mv_Jan': (mntss_interp[:,:,0:120:12].mean(2).T),
    'ERA5_mv_July': (mntss_interp[:,:,6:120:12].mean(2).T),
    'ERA5_SH_Jan': (-msshf_interp[:,:,0:120:12].mean(2).T),
    'ERA5_SH_July': (-msshf_interp[:,:,6:120:12].mean(2).T),
    'ERA5_LH_Jan': (-mslhf_interp[:,:,0:120:12].mean(2).T),
    'ERA5_LH_July': (-mslhf_interp[:,:,6:120:12].mean(2).T)
}

通过使用字典来存储变量名和对应的结果，避免了重复的代码。这样可以更清晰地组织代码，并使代码更易于维护和扩展。